Search

Ethnopharmacological Relevance. Development of resistance to antimalarial drugs by Plasmodium falciparum is still rampant, and there is an urgent need for novel drugs to either standalone or to partner artemisinin for treatment of malaria. Traditionally, plants have, over the years, been a good source of antimalarial drugs. Efficacy and safety of such plants need to be scientifically authenticated. Aims, Materials, and Method. This study investigated the in vitro antiplasmodial activity, cytotoxicity, and genotoxicity of aqueous extracts of Acanthospermum hispidum DC, Alstonia boone (De Wild), Cocos nucifera L, Cymbopogon citratus (DC.) Stapf, Morinda lucida Benth, Psidium guajava, Phyllanthus niruri L, and Senna siamea Lam. Results. Five out of the eight plants, A. boonei stem bark, S; siamea Lam root, M. lucida Benth leaves, P. niruri, and A. hispidum DC whole plants, showed varying degrees of antiplasmodial activity against the asexual stage of the parasite. The most active extract against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) P. falciparum strains is the A. hispidum extract which yielded a mean inhibitory concentration at 50% (IC50) of 3.66 µg/ml and 3.71 µg/ml for 3D7 and Dd2, respectively. This was followed by S. siamea Lam with 3.95 µg/ml for 3D7 and 4.47 µg/ml for Dd2. The IC50 values of the A. boonei extract against 3D7 and Dd2 P. falciparum parasites were 5.13 µg/ml and 3.62 µg/ml, respectively. For the M. lucida Benth extract, the least IC50 value was 6.46 µg/ml. All five extracts exhibited dose-dependent antiplasmodial activity. Assessment of the genotoxic effects the A. hispidum extract by the comet assay revealed substantial damage to P. falciparum DNA. Conclusion. This study demonstrates that the crude extract of A. hispidum DC, one of the plants used traditionally to treat malaria, inhibits the growth of P. falciparum in vitro and could be a potential source of antimalarial drug. The report has highlighted genotoxic and cytotoxic effects of the selected plant extracts on human leukocytes as well.

Trypanosomiasis, leishmaniasis, and malaria are protozoan infections of public health importance with thousands of new cases recorded annually. Control of these infection(s) with existing chemotherapy is limited by drug toxicity, lengthy parenteral treatment, affordability, and/or the emergence of resistant strains. Medicinal plants on the other hand are used in the treatment of various infectious diseases although their chemical properties are not fully evaluated. In this study, we screened 112 crude extracts from 72 selected Ghanaian medicinal plants for anti-Trypanosoma, anti-Leishmania, and anti-Plasmodium activities in vitro and investigated their mechanisms of action. Twenty-three extracts from 20 plants showed significant antiprotozoan activity against at least 1 of 3 protozoan parasites screened with IC50 values less than 20 μg/ml. Eleven extracts showed high anti-Trypanosoma activity with Bidens pilosa whole plant and Morinda lucida leaf extracts recording the highest activities. Their IC50 (selectivity index [SI]) values were 5.51 μg/ml (35.00) and 5.96 μg/ml (13.09), respectively. Nine extracts had high anti-Leishmania activity with Annona senegalensis and Cassia alata leaf extracts as the most active. Their IC50 (SI) values were 10.8 μg/ml (1.50) and 10.1 μg/ml (0.37), respectively. Six extracts had high anti-Plasmodium activity with the leaf and stem-bark extracts of Terminalia ivorensis recording the highest activity. Their IC50 (SI) values were 7.26 μg/ml (129.36) and 17.45 μg/ml (17.17), respectively. Only M. lucida at 25 μg/ml induced significant apoptosis-like cell death in Trypanosoma parasites. Anti-Leishmania active extracts induced varying morphological changes in Leishmania parasites such as multiple nuclei and/or kinetoplast, incomplete flagella division, or nuclear fragmentation. Active extracts may be potential sources for developing new chemotherapy against these infections.

Background: The leaves of Pergularia daemia Forsk (family Asclepidaceae) provide alternative plant-based treatments for the management of diabetes mellitus and diarrhoea in both humans and indigenous poultry species like the Guinea fowls (Numida meleagris). However, no scientific investigations to validate its usefulness in Ghana have been established. This study therefore sought to investigate the anti-hyperglycaemic activity of the 70 % ethanolic extract of P. daemia using streptozotocin (STZ)-induced diabetic male Sprague–Dawley rats. Additionally, the antioxidant and antimicrobial properties of the extract were investigated. Methods: The total phenolic content, total flavonoids content, radical scavenging activity and reducing power assays were estimated using Folin–Ciocalteu method, aluminium chloride colorimetric assay, Fe3+ reduction assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, respectively. Results: The results showed that P. daemia extract caused anti-hyperglycaemic activity in the STZ-induced rats at doses of 30, 60 and 90 mg/kg body weight with significant reduction in blood glucose levels. The phytosterols, saponins, phenols, alkaloids, tannins and triterpenes found in the extract may be responsible for the observed anti-hyperglycaemia and antioxidant activities. The extract also showed antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. Conclusions: These findings justify the folkloric use of P. daemia as an anti-diabetic and antibacterial agents for susceptible species.

A prospective randomised double blind parallel controlled trial was conducted to evaluate the safety and clinical effectiveness of a standardised Ghanaian polyherbal product EAF-2011 comprising: Alchornea cordifolia, Eugenia caryophyllata, Psidium guajava, Tridax procumbens and Zanthoxylum zanthoxyloides, used in the management of skin diseases. A total number of 84 participants aged between 8 and 45 years who were clinically diagnosed with superficial mycoses were recruited into the study and followed up for 4 months. Participants were randomised to receive 2%, 5% or 10% (w/w) concentrations of the finished herbal product or the control treatment of Whitfield ointment. Primary efficacy outcome (complete cure): defined as total signs and symptoms score (TSSS) of zero and where applicable mycological cure also defined as a negative mycological culture and microscopic examination was achieved by 30.0%, 34.78%, 75.0% and 91.30% of the control, 2%, 5% and 10% (w/w) EAF-2011 treatments respectively. Safety analyses using urine, biochemical and haematological parameters were normal at the end of the study. Also, no adverse reactions were recorded during the study. The study thus showed all the treatments to be safe and effective for the management of dermatophytes with 10% (w/w) finished herbal product being the most effective treatment.

Benign prostatic hyperplasia (BPH) is an enlargement of the prostate. The study aimed at validating the use of freeze-dried Croton membranaceus ethanolic root extract for BPH management. Thirty-three patients were observed before and after 3-month administration of 20 mg t.i.d orally. The International Prostate Symptom Score (IPSS), and the International Index of Erectile Function (IIEF) questionnaires were used. Total/free PSA (tPSA, fPSA), renal, liver function, lipid tests, and ultrasonographic imaging were performed. Thirty (30) patients (66 ± 11 years) completed the study. IPSS results showed 37% had severe, 40% moderate, and 23% mild symptoms before; 57% and 43% had moderate and mild symptoms, respectively, after treatment. IIED of patients’ results showed 30% with severe, 40% moderate, 24% mild-moderate, 3% mild, and 3% no erectile dysfunction before treatment and 20% severe, 43% moderate, and 37% mild-moderate dysfunction, after treatment. Quality of life (QoL) improved (P=0.001). Significant but non-pathological increases in total and indirect bilirubin as well as apolipoprotein A occurred. Mean tPSA reduced from 27.9 ± 19.0 to 16.2 ± 11.8 ng/mL (P=0.002); fPSA from 6.1 ± 4.8 to 3.9 ± 2.9 ng/mL (P=0.045); and prostate volume from 101.8 ± 41.3 to 54.5 ± 24.8 cm3 (P=0.023). C. membranaceus shrinks the prostate and improves QoL.

Trypanosoma brucei parasites are kinetoplastid protozoa that devastate the health and economic well-being of millions of people in Africa through the disease human African trypanosomiasis (HAT). New chemotherapy has been eagerly awaited due to severe side effects and the drug resistance issues plaguing current drugs. Recently, there has been an emphasis on the use of medicinal plants worldwide. Morinda lucida Benth. is a popular medicinal plant widely distributed in Africa, and several research groups have reported on the antiprotozoal activities of this plant. In this study, we identified three novel tetracyclic iridoids, molucidin, ML-2-3, and ML-F52, from the CHCl 3 fraction of M. lucida leaves, which possess activity against the GUTat 3.1 strain of T. brucei brucei . The 50% inhibitory concentrations (IC 50 ) of molucidin, ML-2-3, and ML-F52 were 1.27 μM, 3.75 μM, and 0.43 μM, respectively. ML-2-3 and ML-F52 suppressed the expression of paraflagellum rod protein subunit 2, PFR-2, and caused cell cycle alteration, which preceded apoptosis induction in the bloodstream form of Trypanosoma parasites. Novel tetracyclic iridoids may be promising lead compounds for the development of new chemotherapies for African trypanosomal infections in humans and animals.

Human African trypanosomiasis (HAT), commonly known as sleeping sickness has remained a serious health problem in many African countries with thousands of new infected cases annually. Chemotherapy, which is the main form of control against HAT has been characterized lately by the viewpoints of toxicity and drug resistance issues. Recently, there have been a lot of emphases on the use of medicinal plants world-wide. Morinda lucida Benth. is one of the most popular medicinal plants widely distributed in Africa and several groups have reported on its anti-protozoa activities. In this study, we have isolated one novel tetracyclic iridoid, named as molucidin, from the CHCl3 fraction of the M. lucida leaves by bioassay-guided fractionation and purification. Molucidin was structurally elucidated by (1)H and (13)C NMR including HMQC, HMBC, H-H COSY and NOESY resulting in tetracyclic iridoid skeleton, and its absolute configuration was determined. We have further demonstrated that molucidin presented a strong anti-trypanosomal activity, indicating an IC50 value of 1.27 μM. The cytotoxicity study using human normal and cancer cell lines indicated that molucidin exhibited selectivity index (SI) against two normal fibroblasts greater than 4.73. Furthermore, structure-activity relationship (SAR) study was undertaken with molucidin and oregonin, which is identical to anti-trypanosomal active components of Alnus japonica. Overlapping analysis of the lowest energy conformation of molucidin with oregonin suggested a certain similarities of aromatic rings of both oregonin and molucidin. These results contribute to the future drug design studies for HAT.

Background: Borassus aethiopum Mart (Family Arecaceae), commonly known as the African Fan Palm, is a tropical plant species found widely across Africa, and used globally for both medicinal and non-medicinal purposes. In this study, the anti-oxidant, anti-microbial and anti-inflammatory activities of an ethanolic extract of the fruit of Borassus aethiopum was investigated. Methods: The Carrageenan induced foot edema model in chicks was used to investigate the anti-inflammatory activity of an ethanolic extract of the seed endocarp cotyledon. For the anti-oxidant activity determination, three assays were employed; namely, the total anti-oxidant capacity assay, the 2, 2-diphenyl- 1-picrylhydrazyl (DPPH) scavenging assay and the Folin-Ciocalteau’s assay for total phenols. For the anti-microbial activity, the agar diffusion method was used. Phytochemical analysis to determine the types of secondary metabolites present was also conducted on the plant extract. Results: The phytochemical screening showed the presence of alkaloid, tannins, saponins, steroids, carbohydrates triterpenoids and phenols. A dose dependent reduction in edema was observed when the extract was compared with Diclofenac and Dexamethasone. The extract had an EC50 of 13.49 µg/ml DPPH scavenging activity, which is excellent when compared to the reference ascorbic acid of 140.00 µg/ml. Thus the extract was about 10 times more potent than the ascorbic acid. Conclusion: The anti-microbial assay revealed activity against the gram positive bacteria Staphylococcus aureus and Bacillus subtilis. The results obtained showed that Borassus aethiopum has anti-inflammatory and significant anti-oxidant properties, which are dose and concentration dependent respectively.

The crude extract of Alnus japonica bark exhibited a strong effect on the growth of Trypanosoma brucei. Subsequent chromatographic separation resulted in the isolation of two novel diarylheptanoids, known as alnuside C (2) and alnuside D (3), and three known compounds, 1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptan-3(R)-O-β-D-glucopyranoside (1), oregonin (4) and hirsutanone (5). The structures of the isolates were elucidated based on the use of extensive spectroscopic and chemical methods. Among the isolated diarylheptanoids, oregonin (4) (a major component of plant bark) and hirsutanone (5) exhibited potent in vitro inhibitory activity against T. brucei growth in the bloodstream with IC50values of 1.14 and 1.78 μM, respectively. We confirmed that oregonin (4) and hirsutanone (5) were not toxic to human normal skin fibroblast cells (NB1RGB) and colon cancer cells (HCT-15) at a concentration of 50 μM; however, lower levels of toxicity were observed for leukemia cells. To determine the structure activity relationships of the isolated components, we performed Conformation Search and found that the 3-oxo function of the heptane chain in the diarylheptanoid molecule is required for their trypanocidal activity.

A mutation-specific polymerase chain reaction method was used to estimate the proportion of pyrimethamine-resistant parasites in 101 children reporting with malaria at the hospital in Ifakara, a town in southern Tanzania. The method is based on the observation that a point mutation (Asn-108) in the dihydroifolate reductase gene confers resistance to pyrimethamine. Twenty-eight percent of the examined 101 children had pyrimethamine-resistant parasites, 65% had pyrimethamine-sensitive parasites with the wild-type Ser-108 codon, and 9% had both alleles, suggesting a mixed infection. None of the 21 children with clinical malaria had pyrimethamine-resistant parasites. Currently, sulfadoxine-pyrimethamine is considered a potential first-line drug for malaria treatment in most African countries. We suggest that although sulfadoxine-pyrimethamine could still be effective against chloroquine-resistant malaria in this area, its judicious use is important so as to minimize the spread of resistance.

BackgroundCerebral malaria (CM) is responsible for most of the malaria-related deaths in children in sub-Saharan Africa. Although, not well understood, the pathogenesis of CM involves parasite and host factors which contribute to parasite sequestration through cytoadherence to the vascular endothelium. Cytoadherence to brain microvasculature is believed to involve host endothelial receptor, CD54 or intercellular adhesion molecule (ICAM)-1, while other receptors such as CD36 are generally involved in cytoadherence of parasites in other organs. We therefore investigated the contributions of host ICAM-1 expression and levels of antibodies against ICAM-1 binding variant surface antigen (VSA) on parasites to the development of CM.Methodology/principal findingsPaediatric malaria patients, 0.5 to 13 years were recruited and grouped into CM and uncomplicated malaria (UM) patients, based on well defined criteria. Standardized ELISA protocol was used to measure soluble ICAM-1 (sICAM-1) levels from acute plasma samples. Levels of IgG to CD36- or ICAM-1-binding VSA were measured by flow cytometry during acute and convalescent states. Wilcoxon sign rank-test analysis to compare groups revealed association between sICAM-1 levels and CM (p0.05). Median levels of antibodies to CD36-binding VSAs were also comparable between acute and convalescent samples within any patient group. Median levels of antibodies to ICAM-1-binding VSAs were however significantly lower at admission time than during recovery in both groups.Conclusions/significanceHigh levels of sICAM-1 were associated with CM, and the sICAM-1 levels may reflect expression levels of the membrane bound form. Anti-VSA antibody levels to ICAM-binding parasites was more strongly associated with both UM and CM than antibodies to CD36 binding parasites. Thus, increasing host sICAM-1 levels were associated with CM whilst antibodies to parasite expressing non-ICAM-1-binding VSAs were not.

The in vivo anti-inflammatory and analgesic activities of the crude ethanol extract and chemical constituents of Clausena anisata roots were investigated. The crude extract, which was devoid of any visible acute toxicity, displayed significant anti-inflammatory effect at the dose of 1000 mg/kg (p.o.) when assessed using the carrageenan-induced oedema model. In the acetic acid-induced writhing and hot plate tests, it produced a very significant ( p < 0.001), dose-dependent analgesic effect, with maximum analgesic activity of 72.1% at 1000 mg/kg (p.o.). Phytochemical analysis of the crude extract resulted in the isolation of four coumarins (anisocoumarin B, osthol, imperatorin and xanthotoxol) and a carbazole alkaloid, heptaphylline. Among the isolated compounds, osthol and anisocoumarin B produced the highest anti-inflammatory activity at 9 mg/kg (p.o.): slightly better than the positive control, indomethacin. Except for xanthotoxol, all the isolated compounds administered at 6 mg/kg (p.o.) produced significant analgesic activity and higher than diclofenac; with heptaphylline being the most potent (48.7%). The analgesic activity of anisocoumarin B (50.4%) was the highest among the isolates tested and the standard, tramadol, in the hot plate test. The nonselective opioid receptor antagonist, naloxone, abolished the analgesic effect of the crude extract and the tested isolates (anisocoumarin B and xanthotoxol) in the hot plate test suggesting an effect via the central opioidergic system. These findings provide the scientific basis for the use of C. anisata roots in traditional medicine as anti-inflammatory and analgesic agents.

A cross-sectional pilot study of hookworm infection was carried out among 292 subjects from 62 households in Kintampo North, Ghana. The overall prevalence of hookworm infection was 45%, peaking in those 11–20 years old (58.5%). In children, risk factors for hookworm infection included coinfection with malaria and increased serum immunoglobulin G reactivity to hookworm secretory antigens. Risk factors for infection in adults included poor nutritional status, not using a latrine, not wearing shoes, and occupation (farming). Although albendazole therapy was associated with an overall egg reduction rate of 82%, 37 subjects (39%) remained infected. Among those who failed therapy, treatment was not associated with a significant reduction in egg excretion, and nearly one-third had higher counts on repeat examination. These data confirm a high prevalence of low-intensity hookworm infection in central Ghana and its association with poor nutritional status. The high rate of albendazole failure raises concern about emerging resistance.

Schistosomiasis has been a major public health problem especially in developing countries, where access to potable water is generally limited. Its control calls for a search for various interventions that would not only target the causative agent and human behavior, but also the snail intermediate host. This study explored the possibility of using bioactive factors from naturally occurring crude or semi-processed products including some plant parts and vegetables to control the Bulinus globosus intermediate host. In all, five (25%) of the test materials in decreasing order (pawpaw > cabbage > short banana > sugarcane > sweet orange) acted as statistically significant arrestants for the adults, but four (20%) of them in decreasing order (cabbage > unripe pawpaw > sugarcane > ripe tomato) were arrestants for the juveniles at (p short banana > sugarcane > cabbage and cabbage > palm > sugarcane > unripe pawpaw). However, mango tree bark, neem tree bark, unripe mango, onion and cassava stem acted as significant repellents to both adult and juvenile snails. The identified attractants and arrestants for Bulinus globosus, pawpaw and cabbage, may be useful in its chemical manipulations especially as molluscicides in controlling the intermediate host snails. Keywords : Schistosomiasis, snail, Bulinus globosus, chemoresponses, natural products

Takanori Hori a, , Jacob Barnor b, , Tung Nguyen Huu c, , Osamu Morinaga , Akiko Hamano , Jerry Ndzinu a, , Angela Frimpong , Keren Minta-Asare , Mildred Amoa-Bosompem , James Brandful , John Odoom , Joseph Bonney , Isaac Tuffour , Baffour-Awuah Owusu , Mark Ofosuhene , Philip Atchoglo , Maxwell Sakyiamah , Richard Adegle , Regina Appiah-Opong , William Ampofo , Kwadwo Koram , Alexander Nyarko , Laud Okine , Dominic Edoh , Alfred Appiah , Takuhiro Uto , Yoshiyuki Yoshinaka , Shin Uota a, , Yukihiro Shoyama , Shoji Yamaoka a, * a Tokyo Medical and Dental University, Japan b Noguchi Memorial Institute for Medical Research, Ghana c Nagasaki International University, Japan d Centre for Plant Medicine Research, Ghana

The association between the clinical outcome of chloroquine treatment and mutations in the putative Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene at codon 76 and multidrug resistance gene 1 (Pf mdr1) at codon 86 were investigated among 406 children with uncomplicated malaria presenting at five sentinel health centres in Ghana. Presence of mutations in isolates taken at pre-treatment and on day of recurrence of parasites was detected using PCR followed by RFLP techniques. The prevalence of Pfcrt T76 mutants was 80% at Hohoe, 46% at Navrongo, 98% at Tarkwa, 61% at Sunyani and 46% at Yendi. The prevalence of the mutant Pfmdr1 at Hohoe, Navrongo, Tarkwa, Sunyani and Yendi were 78, 58, 95, 53 and 42%, respectively. Significant association between the Pfcrt mutation and treatment outcome was observed at Hohoe and Sunyani (p0.05), but not at Navrongo, Tarkwa or Yendi (p0.05). Similarly, a statistical significant association between Pfmdr1 86 and treatment failures was observed at Hohoe and Sunyani (p0.05) but not at the other three sites. A positive correlation was found between mutant Pfcrt prevalence only and treatment failures with a Spearman's rho-value of 0.872 and a p-value = 0.027. All parasite isolates from samples taken at recrudescence from patients with chloroquine treatment failures were found to have both Pfcrt and Pfmdr mutations.

Under some circumstances, polymerase chain reaction (PCR) amplification of deoxyribonucleic acid (DNA) from Plasmodium may become necessary from infections for which only blood slides are available. Established methods used for DNA preparation do not work in that case. We have developed a reliable and controlled method for DNA preparation from malaria parasites on fixed and stained blood films. 162 slides from 2 different locations, some stored for at least one year, have been analysed by PCR amplification of the polymorphic loci for MSA1 and MSA2. In 92% of microscopically positive slides, a PCR product could be detected using material derived from thick blood films. When thin blood films with scanty parasitaemia were used, a PCR product could be obtained with only 71% of samples. In all unsuccessful cases, DNA preparation was the limiting factor, which was controlled for by amplification of a control human template.

The concurrent use of herbal medicines and orthodox drugs, especially in the treatment and management of chronic ailments, may result in clinically significant herb-drug interactions. Bridelia ferruginea Benth (Euphorbiaceae) is a common medicinal plant with known anti-diabetic properties and has been reported to be taken alongside the orthodox medicine, metformin. The aim of this study was to investigate the effect of aqueous extract of B. ferruginea leaves on the pharmacokinetics of metformin in female Sprague-Dawley rats. Reconstituted freeze dried extract of B. ferruginea leaves (30 mg/kg), and metformin (7 mg/kg) were administered concurrently as a single dose to female Sprague-Dawley rats. Whole blood samples (1 ml) were aseptically withdrawn by tail bleeding at 1, 2, 4, 8, and 24 h after administration of the single dose for pharmacokinetics analyses. Concurrent administration of metformin and B. ferruginea significantly affected (P < 0.05) all the pharmacokinetics parameters of metformin except for the time to attain the maximum concentration (Tmax), which increased but insignificantly. Whereas the area under the curve, maximum whole blood concentration (Cmax) and half-life (T½) of metformin decreased significantly in the presence of B. ferruginea, the elimination rate constant (Kel), clearance (Cl), absorption rate constant (Ka), and volume of distribution (Vd) of metformin increased significantly in the presence of B. ferruginea. Therefore, in clinical practice, patients should be advised on the implication of concurrent administration of metformin and B. ferrruginea.

We have previously characterized the U2 small nuclear (sn) RNA gene family of Arabidopsis thaliana. To find out the structural features of upstream and downstream non-coding regions that are shared by different U-RNA genes in higher plants we have isolated the gene encoding a 125 nt-long U5 snRNA of Arabidopsis. Activity of the cloned gene was demonstrated in stably transformed tobacco calli and by transient expression in transfected protoplasts of Nicotiana plumbaginifolia. Southern analysis indicated that the Arabidopsis genome contains 8-9 copies of the U5 gene. Alignment of upstream non-coding regions revealed two elements conserved between all plant U-RNA genes characterized so far: the sequence RTCCCACATCG (-70/-80 region, 100% conservation) and the TATA homology around position -30. The coding regions in all genes are followed by the sequence CAN4-9AGTN (A/T)AA which may correspond to a termination and/or processing signal.