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Background: Ethnopharmacological research aims at gathering information on local and traditional uses of plants and other natural substances. However, the approaches used and the methods employed vary, and while such a variability is desirable in terms of scientific diversity, research must adhere to well defined quality standards and reproducible methods. Objectives: With ConSEFS (the Consensus Statement on Ethnopharmacological Field Studies) we want to define best-practice in developing, conducting and reporting field studies focusing on local and traditional uses of medicinal and food plants, including studies using a historical approach. Methods: After first developing an initial draft the core group invited community-wide feedback from researchers both through a web-based consultation and a series of workshops at conferences during 2017. Outcomes:The consultation resulted in a large number of responses. Feedback was received via a weblink on the Journal of Ethnopharmacology´s website (ca. 100 responses), other oral and written responses (ca. 50) and discussions with stakeholders at four conferences. The main outcome is a checklist, covering best practice for designing, implementing and recording ethnopharmacological field studies and historical studies. Conclusions: Prior to starting ethnopharmacological field research, it is essential that the authors are fully aware of the best practice in the field. For the first time in the field of ethnopharmacology a community-wide document defines guidelines for best practice on how to conduct and report such studies. It will need to be updated and further developed. While the feedback has been based on responses by many experienced researchers, there is a need to test it in practice by using it both in implementing and reporting field studies (or historical studies), and peer-review. Fil: Heinrich, Michael. University of London; Reino Unido Fil: Lardos, Andreas. No especifíca; Fil: Leonti, Marco. Università Degli Studi Di Cagliari.; Italia Fil: Weckerle, Caroline. Universitat Zurich; Suiza Fil: Willcox, Merlin. University of Southampton; Reino Unido Fil: Applequist, Wendy. Missouri Botanical Garden; Estados Unidos Fil: Ladio, Ana Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Lin Long, Chun. Minzu University Of China; China Fil: Mukherjee, Pulok. Jadavpur University; India Fil: Stafford, Gary. Stellenbosch University; Sudáfrica

Southern Africa has three indigenous genera in the Amaryllidaceae subfamily Allioideae. Prototulbaghia is monospecific and Allium is represented by a single species, whereas Tulbaghia has > 20 described species. Tulbaghia spp. are popular in horticulture and used extensively as medicinal plants in southern Africa. Despite their popularity and economic importance, species delimitation is problematic and the infrageneric classification uncertain. The objective of this study was to test the monophyly of Tulbaghia and the relationships of Prototulbaghia and to produce the first molecular phylogenetic hypothesis for Tulbaghia as a basis for a revised infrageneric classification and species concepts. Fifty-four Tulbaghia samples covering 17 of the c. 23 accepted species were included in this study. In total, 160 new sequences of nuclear ribosomal internal transcribed spacers (ITS) and plastid encoded trnL-F and ndhF were produced for this study and were analysed using maximum parsimony and Bayesian inference. Tulbaghia including Prototulbaghia is strongly supported as monophyletic (BP = 100%, PP = 1.00) and in general clades that are well supported in either or both of the ITS and the combined plastid analysis are also well supported in the total combined analysis. Several major clades within Tulbaghia are resolved and ITS and plastid data indicated that Prototulbaghia and some Tulbaghia spp. are in need of taxonomic recircumscription.

Ethnopharmacological relevance Persian shallot (Allium stipitatum) is a bulbous plant native to Turkey, Iran and Central Asia. It is frequently used in folk medicine for the treatment of a variety of disorders, including inflammation and stress. Antiinflammatory and neurological activities of pyrithione and four related sulfur-containing pyridine N-oxides which are prominent constituents of Allium stipitatum were tested. Methods The antiinflammatory activity was tested by the ability of the compounds to inhibit cyclooxygenase (COX-1 and COX-2), whereas the neurological activities were evaluated by assessing the compounds ability to inhibit monoamine oxidase-A (MAO-A) and acetylcholinesterase (AChE). The compounds׳ affinity for the serotonin transport protein (SERT) and the GABAA–benzodiazepine receptor were also investigated. Results 2-[(Methylthio)methyldithio]pyridine N-oxide showed very high antiinflammatory effects which are comparable with those of common pharmaceuticals (IC50 of 7.8 and 15.4 µM for COX-1 and COX-2, respectively). On the other hand, neurological activities of the compounds were rather modest. Some compounds moderately inhibited AChE (IC50 of 104–1041 µM) and MAO-A (IC50 of 98–241 µM) and exhibited an affinity for the SERT and GABAA–benzodiazepine receptor. Conclusions Our findings may help to rationalize the wide use of Persian shallot for the treatment of inflammatory disorders.

Ethnopharmacology relevance Hypoxis species are used extensively in traditional medicine in southern Africa for several ailments including tuberculosis, chest infections, and nervous and urinary disorders. Several other claims have been made for extracts emanating from Hypoxis species and have led to the production of several commercial products used as immunostimulants mostly for people living with HIV/AIDS and cancer. This study was aimed at investigating the biological activity of four Hypoxis species and a commercial herbal product, ‘African potato extract’ (APE). Materials and methods Antibacterial, antifungal, cyclooxygenase (COX) and acetylcholineasterase (AChE) inhibitory activities of four Hypoxis species (H. acuminata, H. colchicifolia, H. hemerocallidea and H. rigidula) and a popular Hypoxis-based herbal preparation, APE were tested. The phytoconstituents of the mixture were also profiled using TLC methods. Several combinations of the Hypoxis species were prepared and their synergism, additive, autonomic and antagonism effects investigated. As a quality control measure, batch to batch comparison in the phytoconstituents and biological activity of APE was carried out. Results The results confirmed H. colchicifolia and H. hemerocallidea as the phytoconstituents of APE. The extracts showed a broad spectrum of activities against the bacterial and fungal strains used. Of particular interest were the activities exhibited by the APE and combinations of H. colchicifolia and H. hemerocallidea. The APE mixture exhibited good antibacterial activity (MIC values of 0.78 mg/ml each) in all the tested batches against the bacterial strains used. The water extracts of all four Hypoxis species, three batches of APE and the combination (water extracts) of H. colchicifolia and H. hemerocallidea exhibited high COX-1 and moderate COX-2 inhibitory activity except for H. acuminata which showed low activity against COX-2. All the extract, batches of APE and combinations showed low to moderate AChE inhibitory activity. These results provided some evidence of phytosynergy in some extracts of H. hemerocallidea and H. colchicifolia except for a few extracts which act as additive, autonomous and antagonistic when used to inhibit some bacterial and fungal strains. However, this was not the case for COX and AChE inhibition, as only acetone extracts acted in a synergistic way to reduce the activity of the enzyme. Conclusion Even though the results give an indication of a positive interaction between some extracts of H. hemerocallidea and H. colchicifolia, the study was carried out on 1:1 v/v combinations only. It is therefore important to carry out isobologram studies, which considers more than one ratio of the combinations.

The alkaloid rich extracts from an acid/base extraction of bulb material of Haemanthus coccineus L., H. montanus Baker and H. sanguineus Jacq. revealed that two montanine type Amaryllidaceae alkaloids, montanine (1) and coccinine (2) were the major alkaloid constituents. Together these two alkaloids constituted 88, 91 and 98% of the total alkaloid extract from each species respectively. GC–MS analysis revealed that H. coccineus and H. sanguineus had a relative abundance of coccinine (74 and 91% respectively) to montanine (14 and 7% respectively); whereas H. montanus had 20% coccinine and 71% montanine. The three extracts and two isolated alkaloids were evaluated for binding to the serotonin transporter protein (SERT) in vitro. Affinity to SERT was highest in H. coccineus (IC50 = 2.0 ± 1.1 μg/ml) followed by H. montanus (IC50 = 6.8 ± 1.0 μg/ml) and H. sanguineus (IC50 = 28.7 ± 1.1 μg/ml). Montanine (IC50 = 121.3 ± 3.6 μM or 36.56 ± 1.14 μg/ml; Ki = 66.01 μM) was more active than coccinine (IC50 = 196.3 ± 3.8 μM or 59.15 ± 1.08 μg/ml; Ki = 106.8 μM), both of which were less active than the total alkaloid extracts of each species investigated. The possible synergistic effects of two coccinine/montanine mixtures (80:20 and 20:80) were investigated, however the mixtures gave similar activities as the pure compounds and did not show any increase in activity or activity similar to the total alkaloid extracts. Thus the considerably higher activity observed in the total alkaloid extracts is not correlated to the relative proportions of coccinine and montanine in the extracts and thus are likely to be due to more potent unidentified minor constituents. Both alkaloids exhibited low binding affinity to P-glycoprotein (P-gp) as demonstrated by low inhibition of calcein-AM efflux in the MDCK-MDR1 cell line. This indicates that P-gp efflux will not be limiting for blood–brain-barrier passage of the alkaloids.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological investigations of traditional medicines have made significant contributions to plant-derived drugs, as well as the advancement of pharmacology. Drug discovery from medicinal flora is more complex than generally acknowledged because plants are applied for different therapeutic indications within and across cultures. Therefore we propose the concept of “reverse ethnopharmacology” and compare biomedical uses of plant taxa with their ethnomedicinal and popular uses and test the effect of these on the probability of finding biomedical and specifically anticancer drugs. MATERIALS AND METHODS: For this analysis we use data on taxonomy and medical indications of plant derived biomedical drugs, clinical trial, and preclinical trial drug candidates published by Zhu et al. (2011) and compare their therapeutic indications with their ethnomedicinal and popular uses as reported in the NAPRALERT® database. Specifically, we test for increase or decrease of the probability of finding anticancer drugs based on ethnomedicinal and popular reports with Bayesian logistic regression analyses. RESULTS: Anticancer therapy resulted as the most frequent biomedicinal indication of the therapeutics derived from the 225 drug producing higher plant taxa and showed an association with ethnomedicinal and popular uses in women's medicine, which was also the most important popular use-category. Popular remedies for dysmenorrhoea, and uses as emmenagogues, abortifacients and contraceptives showed a positive effect on the probability of finding anticancer drugs. Another positive effect on the probability of discovering anticancer therapeutics was estimated for popular herbal drugs associated with the therapy of viral and bacterial infections, while the highest effect was found for popular remedies used to treat cancer symptoms. However, this latter effect seems to be influenced by the feedback loop and divulgence of biomedical knowledge on the popular level. CONCLUSION: We introduce the concept of reverse ethnopharmacology and show that it is possible to estimate the probability of finding biomedical drugs based on ethnomedicinal uses. The detected associations confirm the classical ethnopharmacological approach where a popular remedy for disease category X results in a biomedical drug for disease category X but does also point out the existence of cross-over relationships where popular remedies for disease category X result in biomedical therapeutics for disease category Y (Zhu et al., 2011). This paper is based on an oral presentation held at the 16th ISE Congress in Yulin, China (May 16-18th, 2016) and we would like to thank the organizers for the excellent congress and their hospitality. We are thankful also to Rich Spjut for the valuable comments on a draft version of this paper. GIS was a recipient of The Swiss Government Excellence Postdoctoral Scholarship awarded by the Federal Commission for Scholarships for Foreign Students (FCS). ML and CW acknowledge funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 606895. SC gratefully acknowledges funding from the RYC-2012-11455 and ECO2015-66593-P. MEC and SC acknowledge funding of the MINECO-Spain project (MTM2013-42323-P and MTM2016-77501-P).

Tulbaghia species are used in traditional medicine in southern Africa. They contain sulphur compounds, which have anti-Candida activity. The sulphur compounds are unstable, so different extraction methods were investigated. Grinding the rhizome material in liquid nitrogen and extraction with ethanol yielded the best results. Eight Tulbaghia species were tested and found to contain the same pattern of sulphur compounds on the TLC plate, though in varying concentrations, except T. simmleri, for which sulphur compounds could not be detected. This means that more species can potentially be utilised for the drug Tulbaghiae rhizoma. A simple quantitative TLC dilution method was developed, which can be used to ascertain whether the rhizome material contains a sufficient level of sulphur compounds. The effect of storage was investigated. The content of sulphur compounds in the rhizomes decreased fast upon storage, half of the main compound was lost four weeks after harvest. Possible adulterants for Tulbaghiae rhizoma are Allium sativum and Agapanthus campanulatus. It was not possible to detect adulteration with A. sativum, but a simple TLC test could detect adulteration with 10 % A. campanulatus material.

The modern trend in traditional medicines reflects an increase in the sale of complex herbal mixtures rather than those prepared from single plants. This trend is well documented in Traditional Chinese Medicine (TCM) and can be seen in recent developments in African traditional medicine. An increase in the prevalence of locally produced herbal preparations, especially those containing complex mixtures of several medicinal plants, sold in numerous retail outlets, including supermarkets and pharmacies has been observed. The appearance of these preparations is not surprising in rapidly urbanizing societies where traditional products are still desired but the users have neither the time nor resources to produce them. The production of these herbal mixtures has resulted in a growing herbal industry with about 50 to 100 private entrepreneurs in the informal market and has also contributed to creation of numerous jobs. The products are extensively advertised in newspapers, on the internet, television and radio programmes as well as through pamphlets and posters. This review examines and documents the prevalence of commercial herbal mixtures and preparations common in Pietermaritzburg, KwaZulu-Natal. Different types of herbal mixtures, claims, ethical and legal implications are discussed. Methods of preparation and marketing strategies as well as the way forward in ensuring economic impact, safety and efficacy of this new aspect of South African traditional medicine are also highlighted.

Mondia whitei (Apocynaceae) is used in traditional medicine to treat nervous disorders. Previous studies have shown in vivo antidepressant-like activity in the forced swimming test and affinity to the serotonin transporter of an ethanolic leaf extract of M. whitei. The aim of this study was to isolate the compound(s) responsible for in-vitro serotonin transporter affinity in M. whitei. Bioassay guided isolation lead to the identification of the monoterpene lactone (−)-loliolide. An ethanol extract was prepared from dry leaves. The residue was dissolved in ethyl acetate, extracted with water by liquid–liquid partitioning. This was followed by VLC fractionation. Through HPLC-UV separation the active compound was isolated and characterized by GC-MS, LC-MS and 1H-NMR. The activity of (−)-loliolide was tested in a serotonin transporter binding assay using [3H]-citalopram as ligand, giving an IC50-value of 997 µM, corresponding to a Ki-value of 409 µM. Loliolide is a non-nitrogenous compound and might bind to the transporter in a different way to nitrogen-containing inhibitors. The results provide a rationale for the use of M. whitei in the treatment of depression and other central nervous system diseases in traditional medicine.

The genus Podocarpus sensu latissimo (s.l.) was initially subdivided into eight sections. However, based on new information from different morphological and anatomical studies, these sections were recognised as new genera. This change in nomenclature sometimes is problematic when consulting ethnobotanical data especially when selecting plants for pharmacological screening, thus there is a need to clear any ambiguity with the nomenclature. Species of Podocarpus s.l. are important timber trees in their native areas. They have been used by many communities in traditional medicine and as a source of income. Podocarpus s.l. is used in the treatment of fevers, asthma, coughs, cholera, distemper, chest complaints and venereal diseases. Other uses include timber, food, wax, tannin and as ornamental trees. Although extensive research has been carried out on species of Podocarpus s.l over the last decade, relatively little is known about the African species compared to those of New Zealand, Australia, China and Japan. Phytochemical studies have led to the isolation and elucidation of various terpenoids and nor- and bis-norditerpenoid dilactones. Biflavonoids of the amentoflavone and hinokiflavone types have also been isolated. Nor- and bis-norditerpenes are said to be taxonomic markers for this genus. Recent in vitro and in vivo studies have shown antitumor, antimicrobial, anti-inflammatory, antioxidant, larvicidal, plant and insect growth regulation activities. Various studies have yielded important natural bioactive products and two of them are worth mentioning. Taxol, a significant anticancer agent has been isolated from Podocarpus gracilior and totarol, a diterpenoid isolated from various species and now commercially produced as a potent antibacterial and antioxidant agent. Findings from this review supports the use of an ethnobotanical and chemotaxonomical approach in selecting plants for pharmacological screening since most of the species in the different morphological groups have similar uses. Also the isolated compounds have chemotaxonomic value amongst the groups. Some of the biological activities identified from extracts and compounds isolated from Podocarpus s.l. support the rationale behind the medicinal uses of these species.

Cytotoxic and mutagenic effects of thirteen commercial herbal mixtures sold in KwaZulu-Natal, South Africa were evaluated using the neutral red uptake (NRU) assay and the Ames test. The herbal mixtures tested included Umzimba omubi , Umuthi wekukhwehlela ne zilonda , Mvusa ukunzi , Umpatisa inkosi , Imbiza ephuzwato , Vusa umzimba , Ingwe ® muthi mixture , Ibhubezi ™, Supreme one hundred ™, Sejeso herbal mixture Ingwe ®, Lion izifozonke Ingwe ®, Stameta ™ BODicare ® and Ingwe ® special muti . The relative cytotoxicity of the herbal mixtures was established by determining their NI 50 values (50% inhibition of neutral red uptake). The test revealed that the most toxic herbal mixture was Umpatisa inkosi with an NI 50 value of 0.016 mg/mL and the least toxic mixture was Stameta™ BODicare® with an NI 50 value of 28.00 mg/mL. The herbal mixtures showed no mutagenic effects against Salmonella typhimurium tester strains TA98, TA100, TA102, TA1535 and TA1537 when the assay was done without S9 metabolic activation. However, four herbal mixtures, Umpatisa inkosi , Imbiza ephuzwato , Vusa umzimba and Stameta ™ BODicare ® showed mutagenic effects against TA98 but not the rest of the tester strains after using S9 metabolic activation. Umpatisa inkosi also exhibited weak mutagenic activity against TA1535 after metabolic activation. The remaining mixtures did not show mutagenic effects against all the tester strains after S9 metabolic activation. The cytotoxic and mutagenic results reported here offer a step toward determining the safety of commercial herbal mixtures in South Africa. Herbal mixtures showing higher cytotoxic and mutagenic effects need to be further investigated for their possible effects on humans.

Searsia species are used in South Africa to treat epilepsy. Previous studies have demonstrated an in vitro N-methyl-D-aspartic acid (NMDA) receptor antagonistic effect of the ethanolic leaf extract. The aim of this study was to evaluate the potential anticonvulsant properties of the ethanolic extract of S. dentata in various animal models of epilepsy. The extract was submitted to a screening in anticonvulsant assays including NMDA-, kainic acid (KA)-, pentylenetetrazol (PTZ)- and bicuculline (BIC)-induced seizures in rats. The extract protected 47% of the PN 18 Wistar pups (postnatal day 18, date of birth PN 0) (p 10) against NMDA-induced seizures and significantly delayed the onset of PTZ-induced seizures (p 8) at a dose of 250 mg/kg. A dose optimum was detected at 500 mg/kg for protection against KA-(63% protection, p 8) and BIC-induced seizures (50% protection, p 8) in young adult and PN 18 rats, respectively. The ethanolic extract of S. dentata showed anticonvulsive properties in several models of epilepsy. These results are compatible with previous findings of NMDA receptor antagonism. Due to the complex composition of the extract, the effect might be caused by more than one compound. Copyright © 2009 John Wiley & Sons, Ltd.

Plants with hermaphrodite flowers risk conflict between male and female sexual function due to close proximity of sexual organs. Heterostyly, a genetic floral polymorphism characterized mainly by reciprocal herkogamy, may reduce this sexual conflict by increasing the precision of pollen transfer between morphs. This sexual organ reciprocity is often associated with various ancillary characters and a heteromorphic incompatibility system. Here we describe the morphometrics associated with heterostyly and ancillary characters in Plumbago auriculata. Using controlled pollination experiments, we show that this species has a heteromorphic incompatibility system. We also document the fauna of long-proboscid fly and butterfly pollinators in a P. auriculata population in KwaZulu-Natal, South Africa. © 2009 SAAB. Published by Elsevier B.V. All rights reserved.

The majority of the population in South Africa use traditional health care to treat various mental conditions. In this review, we present ethnobotanical information on plants used by the traditional healers in South Africa to treat mental illnesses, specifically epilepsy, depression, age-related dementia and debilitative mental disorders. Details of the recent scientific studies conducted on some of these plants are reviewed. Extracts of Searsia chirindensis, Cotelydon orbiculata and Leonotis leonurus have shown in vivo anticonvulsant activity. Extracts from Searsia dentata and Searsia pyroides showed spontaneous epileptiform discharge in mouse cortical slices, and acted as NMDA-receptor antagonists. Apigenin, amentoflavone and agathisflavone with affinity to the benzodiazepine site on the GABA(A)-receptor were isolated from Searsia pyroides. Naringenin with affinity to the GABA(A)-benzodiazepine receptor was isolated from Mentha aquatica. Agapanthus campanulatus, Boophone disticha, Mondia whitei and Xysmalobium undulatum exhibited antidepressant-like activity in three in vivo models for depression. Amaryllidaceae alkaloids with activity to the serotonin transporter were isolated from Boophone disticha. The alkaloid mesembrine, which act as a serotonin reuptake inhibitor, was isolated from Sceletium tortuosum. Investigations of plants used to treat age-related dementia and debilitative mental disorders lead to the isolation of a number of Amaryllidaceae alkaloids with acetylcholinesterase inhibitory activity from Boophone disticha and Crinum species. Extracts of Mentha aquatica, Gasteria croucheri, Ruta graveolens and Scotia brachypetala inhibited MAO-B. Naringenin was isolated from Mentha aquatica as a MAO inhibitor. Only a small number of the more than 300 southern African plant species reported to treat or affect the CNS have been scientifically evaluated. Very few of the active compounds have been isolated and identified.

South Africa has an amazing floral diversity—a ‘Botanical Gold Mine’. This perspective paper on the botanical wealth of South Africa deals with some aspects of botanical research over recent years and changes in research focus. It highlights some of the successful avenues of our research and draws attention to the threats and prospects that, depending on their management, will either lead to the demise or sustain-able exploration of South Africa's natural heritage.

Mentha aquatica L. is used in Zulu traditional medicine for spiritual purposes and an ethanolic leaf extract has previously shown strong affinity to the GABA-benzodiazepine receptor. Viridiflorol from the essential oil and ( S )-naringenin from an ethanolic extract was isolated by bioassay-guided fractionation using binding to the GABA-benzodiazepine site. Viridiflorol had an IC 50 of 0.19 M and ( S )-naringenin of 0.0026 M.

Traditional health care is utilized by a large majority of the population in southern Africa. This is particularly true of treatment for mental health problems. A large part of the treatment regimes used by traditional healers involve numerous herbal preparations. Twenty plants used traditionally were screened for MAO inhibition and specific MAO-B inhibition activity. MAO-B inhibitors are currently employed in the treatment of neurodegenerative related illnesses such as Parkinson's and Alzheimer's disease. A photometric peroxidase linked assay was used to determine the inhibition of the oxidative deamination of tyramine by MAO isolated from rat liver. Ruta graveolens exhibited the best MAO inhibitory activity (ethyl acetate leaf extract=IC50 5±1μg/ml, petroleum ether extract=3±1 μg/ml) and specific MAO-B inhibition (ethyl acetate leaf extract=IC50 7±6μg/ml petroleum ether extract=3±1 μg/ml). Schotia brachypetala, Mentha aquatica and Gasteria croucheri also exhibited good MAO-B inhibition activity. These findings support these plants traditional use and may lead to the discovery of novel MAO inhibitors. © 2007 SAAB. Published by Elsevier B.V. All rights reserved.

Quantitative structure–activity relationship (QSAR) studies on 24 Amaryllidaceae alkaloids, belonging to five ring types, as acetylcholinesterase inhibitors were carried out using physicochemical properties as descriptors. Multiple linear regression analysis of the data has shown that strain energy, heat of formation and substituents at both the aromatic ring and ring C play important roles in the development of the QSAR model. The contribution of substituents at ring C to the model was further supported when strain energy was omitted from the model and ring-type based QSAR analysis for crinine- and lycorine-type alkaloids were performed.

Twenty-one Amaryllidaceae alkaloids isolated from different Amaryllidaceae species were investigated for their affinity to the serotonin reuptake transport protein and for GABA(A)-benzodiazepine receptor binding. Cherylline (21), crinamine (7), crinine (1), epibuphanisine (2), epivittatine (6), maritidine (11), O-methylmaritidine (12), powelline (3), 1-O-acetyllycorine (18) and tazettine ( 13) showed affinity to the serotonin reuptake transport protein. Cherylline (21) and epivittatine (6) yielded the highest activity among the group. No GABA(A)-benzodiazepine receptor binding activity was exhibited by the alkaloids tested.

South Africa is a country with both rich floral biodiversity and cultural diversity. Traditional herbal medicines form an important part of the healthcare of most South Africans, and relies heavily on the use of indigenous plants. This article briefly describes the role South Africa has played in recent years, in contributing to the worldwide increase in research in the field of ethnopharmacology.

A number of plants are traditionally used to treat mental diseases in South Africa. Aqueous and ethanol extracts of 43 plants that are traditionally used to treat against epilepsy and convulsions, were tested in the GABAA-benzodiazepine receptor binding assay, where the binding of 3H-Ro 15-1788 (flumazenil) to the benzodiazepine site is measured. The GABAA-benzodiazepine receptor complex is involved in epilepsy and convulsions. Out of the 118 extracts tested, one aqueous and 18 ethanol extracts showed activity. The most active extracts were the ethanolic leaf extracts of Rhus tridentata, Rhus rehmanniana and Hoslundia opposita and the ethanolic corm extract of Hypoxis colchicifolia, which all showed good dose-dependent activity.

Aims of the study To isolate the compound(s) responsible for the MAO-inhibitory activity. Materials and Methods Six extracts of varying polarity of Mentha aquatica L. were tested in a photometric peroxidase linked MAO bioassay. The 70% ethanol extract had highest inhibitory activity. (S)-Naringenin was isolated from the extract by bioassay guided fractionation on VLC and preparative TLC. The structure of the compound was determined by 1H, 13C and 13C-DEPT NMR and optical rotation. Results The IC50 values for MAO inhibition by naringenin were 342 ± 33 μM for the rat liver mitochondrial fraction, 955 ± 129 μM for MAO-A and 288 ± 18 μM for MAO-B. Conclusions The content of naringenin in Mentha aquatica might explain its use in traditional medicine for depression-like conditions.

Heteromorpha arborescens (syn. H. trifoliata) is used in traditional medicine for treatment of headache, pain and fevers. Aqueous and organic extracts of roots, bark and leaves were assayed for inhibition of COX-1. The organic extracts of roots had good activity, the stems/bark some activity and the leaves little activity. The water extracts were inactive. HPLC analysis revealed that falcarindiol, a known COX-1 inhibitor previously isolated from leaves of H. arborescens, was not responsible for the activity.

Bioassay-guided fractionation of dichloromethane extracts of Cyrtanthus suaveolens using the Salmonella/microsome assay (strain TA98) led to the isolation of captan [ N -(trichloromethylthio)cyclohex-4-ene-1,2-diccarboximide] at a concentration of 100mg kg − 1 of dry plant material. Captan is a pesticide used on a large scale on agricultural and horticultural crops. It is known for its mutagenic, genotoxic and teratogenic effects. Issues of quality and safety of traditional medicinal plants grown commercially in South Africa and the need for the establishment of good agricultural practices are discussed.

Ethnopharmacological relevance Several Searsia species (Anacardiaceae), including Searsia dentata and Searsia pyroides, are used in South Africa traditional medicine to treat epilepsy. Ethanol leaf extracts of these plants have been shown to act as possible antagonists of N-methyl- d -aspartate (NMDA)-type glutamate receptors. Materials and methods Leaf material of three Searsia species were collected from the Botanical Garden at the University of KwaZulu-Natal, Pietermaritzburg; dried and extracted with ethanol in an ultrasound bath. Filtered and dried extracts were resuspended in DMSO (100 mg/ml) and diluted in the recording solution. The effect of Searsia dentata, Searsia pyroides and Searsia glauca extracts was investigated in dissociated cerebellar granule cells (CGCs) from 8-day-old rats and in transiently transfected HEK (human embryonic kidney) 293 cells (HEK), expressing either NR1a/NR2A or NR1a/NR2B receptors. In both systems we measured whole-cell currents elicited by 0.5 mM NMDA (CGCs) or 50 μM glutamic acid (HEK) at −60 mV in 0 Mg and 30 μM glycine and NMDA driven Ca influx in Fura2-loaded CGC. Results Searsia dentata and Searsia pyroides ethanol extracts caused a dose-dependent decrease of NR current with ED50 close to 0.03 mg/ml in CGC and a similar inhibition (80% with 1 mg/ml) in HEK cells, while Searsia glauca was much less effective. The inhibition was dependent on time of incubation and slightly favored by opening of the NR channel. It was hardly reversible during the recording time, but was not caused by accelerated run-down or by interaction with the modulatory redox site. Searsia pyroides ethanol extract also depressed the NMDA stimulated increase in intracellular Ca. Conclusions The data confirm the specificity of Searsia dentata and Searsia pyroides and justify their use in traditional medicine. These plants may combine one or more γ-aminobutyric acid (GABA)A agonists with one or more NMDA antagonists, thus representing an efficient treatment for epilepsy.

Searsia species are used in South Africa to treat epilepsy. Previous studies have demonstrated an in vitro N-methyl-D-aspartic acid (NMDA) receptor antagonistic effect of the ethanolic leaf extract. The aim of this study was to evaluate the potential anticonvulsant properties of the ethanolic extract of S. dentata in various animal models of epilepsy. The extract was submitted to a screening in anticonvulsant assays including NMDA-, kainic acid (KA)-, pentylenetetrazol (PTZ)- and bicuculline (BIC)-induced seizures in rats. The extract protected 47% of the PN 18 Wistar pups (postnatal day 18, date of birth PN 0) (p0.05, n10) against NMDA-induced seizures and significantly delayed the onset of PTZ-induced seizures (p0.05, n8) at a dose of 250 mg/kg. A dose optimum was detected at 500 mg/kg for protection against KA-(63% protection, p0.05, n8) and BIC-induced seizures (50% protection, p0.05, n8) in young adult and PN 18 rats, respectively. The ethanolic extract of S. dentata showed anticonvulsive properties in several models of epilepsy. These results are compatible with previous findings of NMDA receptor antagonism. Due to the complex composition of the extract, the effect might be caused by more than one compound.

Ethnopharmacology relevance In recent times, many products ranging from aloe drinks to aloe gels, powders, capsules, and creams have appeared on the commercial market prepared from different aloe species including Aloe barberae. These products are used in ethnomedicine to treat various conditions including gastrointestinal disorders, insect bites, skin burns and other skin injuries by traditional communities. Aim of the study This study was aimed at evaluating the antibacterial, antifungal and anti-inflammatory activities as well as genotoxic effects of different extracts of Aloe barberae. Materials and methods Organic and water extracts of the upper stem, young bark, mature bark, leaves and roots of the South African tree aloe (Aloe barberae) were evaluated for their antimicrobial [Gram-positive (Bacillus subtilis and Staphylococcus aureus), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria as well as the fungus Candida albicans], anti-inflammatory (COX-1 and COX-2) and mutagenic properties (Ames test). Thin layer chromatography (TLC) was used to compare the phytochemical profiles of different extracts of Aloe barberae. Results The petroleum ether (PE) and dichloromethane (DCM) extracts of the mature bark, leaves and roots exhibited good activity against all the bacteria and fungus Candida albicans with minimum inhibitory concentrations (MIC) ranging from 0.195 to 1.56 mg/ml. All the PE extracts evaluated showed a high activity (>70%) in both COX-1 and COX-2 assays. Apart from the organic extracts of the root with consistently good activity (>70%), all the remaining extracts showed moderate activity (40–69%) in COX-1 assay. The PE extracts also showed a dose dependent increase in activity. Ultraviolet (UV) spectrum of the leaves and root EtOH extracts indicated the presence of compounds that could absorb UV light (wavelength: 190–820 nm). None of the extracts had a mutagenic effect in the Salmonella/microsome assay against a tester strain, TA98. Conclusion Activity observed in the bark, leaves and roots of Aloe barberae validates its use in commercial herbal products, ethnobotany and ethnoveterinary medicine by South African communities and small scale farmers to treat various conditions.

Epilepsy is among the most prevalent of the serious neurological disorders, affecting from 0.5–1.0% of the world's population and the prevalence of epilepsy in developing countries is generally higher than in developed countries [1]. Recently, plants used in South African traditional medicine for treatment of epilepsy and convulsion were examined for their pharmacological properties in the search for new and better anti-epileptic drugs [2, 3, 4]. The root of Piper capense L.f. (Piperaceae) is used in traditional South African medicine. A bioassay guided fractionation of an ethanolic extract using VLC, HPLC-UV, GC-MS and 1H-NMR led to the isolation and identification of cinnamamides with affinity to the benzodiazepine site on the GABAA receptor in the [3H]flumazenil receptor binding assay. The isolated cinnamides piperine and 4,5 dihydropiperine binded to the receptor with IC50 values of 0.9 and 1.7±mM respectively. . References: 1. Sander and Shorvon (1996)J Neurol Neurosurg Psych 65:433–443. 2. Svenningsen et al. (2006)J Ethnopharmacol. 103: 276–280. 3. Stafford, et al. (2005)J Ethnopharmacol 100: 210–215. 4. Risa, et al. (2004)J Ethnopharmacol 93:177–182

Ethnopharmacological relevance The four South African medicinal plants Agapanthus campanulatus (AC), Boophone distica (BD), Mondia whitei (MW) and Xysmalobium undulatum (XU) are used in traditional medicine to treat depression. Aim To evaluate the effect of ethanolic extracts of the plants in models for depression. Materials and methods The extracts were screened for affinity for the serotonin transporter (SERT) in the [3H]-citalopram-binding assay. The inhibitory potency of the extracts towards the SERT, the noradrenalin transporter (NAT) and the dopamine transporter (DAT) were determined in a functional uptake inhibition assay. Antidepressant-like effects of the extracts were investigated using the tail suspension test (TST) and the forced swim test in both rats (rFST) and mice (mFST). Results All four plants showed affinity for SERT in the binding assay. AC and BD showed functional inhibition of SERT, NAT and DAT, MW affected SERT while XU showed no effect. BD showed significant effect in the TST and in the mFST/rFST, AC showed significant effect in mFST, MW showed significant effect in the rFST and XU showed significant effect in the mFST. Conclusion In this study we have demonstrated the antidepressant activity of four South African medicinal plants in vitro and in vivo, supporting their rational use in traditional medicine.

Ethnopharmacology relevance Manufactured and packaged herbal mixtures, known locally as muthi concoctions, have become a new feature of traditional medicine in South Africa. These herbal concoctions are often claimed to cure several diseases ranging from minor illness to life threatening conditions. Aim of the study To document the prevalence, variety and evaluate the efficacy of selected herbal concoctions sold in KwaZulu-Natal. Materials and methods Nine herbal concoctions were evaluated for their effects as antibacterial and antifungal agents as well as their ability to inhibit the cyclooxygenase (COX-1 and COX-2) enzymes using standard in vitro methods. Results Imbiza ephuzwato and Ibhubezi ™, both multipurpose mixtures showed high abilities to inhibit bacterial and fungal growth as well as inhibit the COX-1 and COX-2 enzymes. Umzimba omubi and Umuthi wekukhwehlela ne zilonda , both remedies for wounds, boils and chest infections were not active against the two Gram-positive and two Gram-negative bacterial strains tested. Vusa umzimba and Supreme one hundred were active against Candida albicans . Conclusions Four of the herbal concoctions showed no activity in all of the assays tested while only two showed good activity. Activity cannot be ruled out as there are many mechanisms upon which natural products can act.

Ethnopharmacological relevance Searsia dentata and Searsia pyroides are used in traditional South African medicine to treat convulsions and epilepsy. Previous studies have demonstrated that extracts of these plants comprise compounds that bind to the flumazenil-sensitive site on the GABAA receptor. However, their use as anticonvulsant medicinal plants cannot be adequately explained by these findings. Aims The aim of this study was to examine the possible involvement of the glutamatergic system of extracts from the plants. Materials and methods The mouse cortical wedge preparation was used for functional characterization of the extracts. The affinity towards the NMDA and the AMPA receptor was investigated using classical [3H]-GP39653 and [3H]-AMPA binding assays, respectively. Results The extracts of Searsia dentata and Searsia pyroides inhibited the spontaneous epileptiform discharges in mouse cerebral cortical slices with ED50 of 0.62 and 1.67 mg dry extract/mL, respectively. Both extracts displaced [3H]-GP39653 binding and significantly inhibited the NMDA-induced response during co-administration in cortical slices. Conclusion In this study, the NMDA receptor antagonistic effect of the crude ethanolic extracts of these two South African medicinal plants was demonstrated.

Ethnopharmacological relevance Several species of Podocarpus (Podocarpaceae) are utilized in treating ailments across the world. In Africa, four species are used traditionally in both animal and human health. Aim of the study To investigate the antimicrobial activity of Podocarpus species against Bacillus subtilis , Staphylococcus aureus , Escherichia coli , Klebsiella pneumoniae and Candida albicans . Materials and methods Six solvents of varying polarity were used for extraction. Antibacterial activity was assessed using the microdilution bioassay and for antifungal activity, the microdilution bioassay and (M27-P) broth dilution were used. Results All species exhibited antimicrobial activity with MIC values of less than 1 mg/ml. Inhibition against Gram-positive bacteria was stronger with an MIC value of 98 μg/ml while for Gram-negative bacteria, the highest inhibition was against Klebsiella pneumoniae with an MIC value of 0.33 mg/ml. All species exhibited strong antifungal activity with the best MIC being 30 μg/ml after 48 h. Conclusions All four species exhibited strong inhibition against all tested microbials, based on Aligiannis et al. [Aligiannis, N., Kalpotzakis, E., Mitaku, S., Chinou, I.B., 2001. Composition and antimicrobial activity of the essential oils of two Origanum species. Journal of Agricultural and Food Chemistry 40, 4168–4170] classification they can be classified as strong inhibitors.