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Exposure to solar ultraviolet (UV) radiation is a major contributing factor to the increasing number of skin cancer cases. Interest has grown to use plant extracts as natural ingredients in cosmetic formulations due to their photoprotective effect, antioxidant and anti-inflammatory activity, as well as other biological activities. The aim of this study was to evaluate the biological activity of two South African plant extracts, Helichrysum odoratissimum (L.) Sweet. and Buddleja saligna Willd., and to successfully incorporate these extracts into sunscreen formulations (o/w emulsions) due to their reported biological activity. Ethanolic extracts were prepared from the leaves and stems of H. odoratissimum and B. saligna and evaluated for their antioxidant activity, mutagenic potential and antiproliferative activity against human dermal fibroblasts (MRHF). The extracts were further characterized using gas chromatography-mass spectrometry (GC-MS). Thereafter, the extracts were incorporated into separate sunscreen formulations to evaluate the in vivo dermal irritancy potential, in vivo sun protection factor, in vitro UVA protection, photostability and long term stability of the formulation, to confirm that by incorporating the extracts, the stability or photoprotective effect of the sunscreen formulation was not reduced and that these formulation were considered safe for topical application. Three separate sunscreen formulations were prepared; the base sunscreen formulation (formulation A), the base sunscreen formulation containing B. saligna (formulation B) and H. odoratissimum (formulation C) respectively. Both extracts showed significant radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with a fifty percent inhibitory concentration (IC50) of 5.13 ± 0.07 and 8.16 ± 0.34 µg/mL for H. odoratissimum and B. saligna respectively. No mutagenic activity was observed when the extracts were tested in the Ames assay using Salmonella typhimurium (TA98 and TA100). The PrestoBlue® cell viability assay was used to determine the antiproliferative activity of the extracts against MRHF cells, both extracts showed an IC50 value >90 µg/mL. Photoprotective activity was measured using in vivo sun protection factor (SPF) test method according to South African (SANS 1557) and International (ISO 24444) standards as well as the in vitro UVA SPF testing procedure (ISO 24443). The SPF results showed that the formulations had broad-spectrum UV protection with SPF values of 15.8±0.41, 16.1±0.66 and 16.0±0.49 and UVAPF values of 6.47±0.06, 6.45±0.06 and 6.47±0.07 for formulation A, B and C respectively. Furthermore, the formulations remained stable under normal and extreme conditions and the plant extracts did not affect the photoprotective effect of the sunscreen formulations and contributed towards the formulations stability. Additionally, each of the formulations were photostable, whereas the formulations with the addition of the extracts showed an incremental increase in photostability when compared to the base formulation. Both these extracts have been previously reported to display antiproliferative activity against skin cancer cell lines (previously published data), with an IC50 value of 31.80 ± 0.35 µg/mL (human malignant melanoma, UCT-MEL-1) for B. saligna and IC50 values of 15.50 ± 0.20 (human epidermoid carcinoma, A431) and 55.50 ± 6.60 µg/mL (human malignant melanoma, A375) for H. odoratissimum, contributing towards the medicinal benefit of using these extracts as ingredients into sunscreen formulations. Therefore, Helichrysum odoratissimum and Buddleja saligna could be considered as useful and viable additives to sunscreen formulations due to their reported biological activity.

This research was funded by the University of Pretoria, the National Research Foundation-DAAD (SFD13080220333), the Department of Science and Innovation (DST/CON 0059/2019), the Innovation Hub, L’Oréal-UNESCO. Publisher Copyright: © 2022 by the authors. Melanoma cells secrete pro-angiogenic factors, which stimulates growth, proliferation and metastasis, and therefore are key therapeutic targets. Buddleja saligna (BS), and an isolated triterpenoid mixture (DT-BS-01) showed a fifty percent inhibitory concentration (IC50) of 33.80 ± 1.02 and 5.45 ± 0.19 µg/mL, respectively, against melanoma cells (UCT-MEL-1) with selectivity index (SI) values of 1.64 and 5.06 compared to keratinocytes (HaCat). Cyclooxygenase-2 (COX-2) inhibition was observed with IC50 values of 35.06 ± 2.96 (BS) and 26.40 ± 4.19 µg/mL (DT-BS-01). BS (30 µg/mL) significantly inhibited interleukin (IL)-6 (83.26 ± 17.60%) and IL-8 (100 ± 0.2%) production, whereas DT-BS-01 (5 µg/mL) showed 51.07 ± 2.83 (IL-6) and 0 ± 6.7% (IL-8) inhibition. Significant vascular endothelial growth factor (VEGF) inhibition, by 15.84 ± 4.54 and 12.21 ± 3.48%, respectively, was observed. In the ex ovo chick embryo yolk sac membrane assay (YSM), BS (15 µg/egg) significantly reduced new blood vessel formation, with 53.34 ± 11.64% newly formed vessels. Silver and palladium BS nanoparticles displayed noteworthy SI values. This is the first report on the significant anti-angiogenic activity of BS and DT-BS-01 and should be considered for preclinical trials as there are currently no US Food and Drug Administration (FDA) approved drugs to inhibit angiogenesis in melanoma. publishersversion published

Buddleja saligna Willd (Loganiaceae), mostly indigenous to South Africa is traditionally used in the treatment cardio-dysfunctional related ailments amongst other diseases.The cardio-protective effect of B. saligna was investigated in ferric-induced oxidative cardiopathy.Hearts harvested from healthy male SD rats were incubated with 0.1 mM FeSOInduction of oxidative damage significantly (p 0.05) depleted the levels of GSH, SOD, catalase, and ENTPDase activities, while concomitantly elevating the levels of MDA, NO, ACE, acetylcholinesterase, lipase and ATPase activities. These levels and activities were significantly reversed on treatment with B. saligna. Treatment with B. saligna also led to depletion of cardiac cholesterol and LDL-c levels, while elevating triglyceride and HDL-c level. It also depleted oxidative-induced lipid metabolites with concomitant generation of thirteen other metabolites. B. saligna also inactivated oxidative-induced pathways for beta oxidation of very long chain fatty acids, glycerolipid metabolism, and fatty acid elongation in mitochondria.These results suggest that B. saligna protects against ferric-induced oxidative cardiopathy by mitigating oxidative stress, while concomitantly inhibiting ACE, acetylcholinesterase and lipase activities, and modulating lipid spectrum and dysregulated metabolic pathways.

There is a growing interest in herbal teas due to their health promoting properties. In this study, chemical composition, antioxidant activity and consumer acceptance of Buddleja saligna herbal teas were determined. Protein (14 g/ 100 g) and carbohydrate (85 g/ 100 g) were the major nutrients in fresh leaves and processed green, oolong and black teas. Ash, crude fiber and lipids were very low in all samples. Fe contents of oolong and black (28 mg/100 g) were almost twice that of fresh leaves. Green tea infusions showed the highest total phenolic contents (5 GAE g/ml), which were twice those of oolong and black teas. By DDPH (2,2-diphenyl-1-picrylhydrazyl) assay, black tea infusion exhibited a slightly high radical scavenging activity (81.5 % ± 3.8) compared to green tea (78.6 ± 3.7) and oolong (78.4 ± 2.8). Oolong tea and black teas were the most liked for their taste and mouth feel compared to green tea.

Buddleja saligna (family Buddlejaceae) is a medicinal plant endemic to South Africa. Two isomeric pentacyclic triterpenes, oleanolic acid and ursolic acid, were isolated from the leaves of B. saligna using silica gel column chromatography. Compounds oleanolic acid and ursolic acid were subjected to derivatization with acetic anhydride in the presence of pyridine to obtain oleanolic acid-3-acetate and ursolic acid-3-acetate, respectively. The structures of these compounds were fully characterized by detailed nuclear magnetic resonance (NMR) investigations, which included

Vachellia sieberiana , Albizia adianthifolia , Buddleja saligna , Combretum kraussii , Halleria lucida and Rapanea melanophloeos are fast-growing, indigenous tree species in South Africa. They are usually found growing alongside other plants in agricultural systems. In this study, the comparative phytotoxic activity of aqueous leaf extracts of these tree species at different concentrations was investigated using lettuce seeds ( Lactuca sativa L.) in a laboratory bioassay. To simulate natural situations, seeds were germinated under 16 h light/8 h darkness in a growth chamber using distilled water as control. The results showed that germination, chlorophyll accumulation and growth indices (plumule and radicle lengths) were significantly inhibited with increasing concentration of plant extracts. The treated lettuce seedlings experienced lipid peroxidation at high extract concentrations (1.0% and 2.0%) as evidenced by increased concentration of malondialdehyde (MDA). In response to this, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) increased at low extract concentration but significantly dropped as concentration increased. These results suggest that aqueous extracts of the studied tree species may produce growth inhibitory substances. Thus, our study revealed that these trees possess phytotoxic activity which could be exploited in the management of weeds in agroforestry systems.

Ethnopharmacological relevance Five plants used in traditional medicine in the Western Cape Province of South Africa, have been investigated for anti-mycobacterial activity: Olea capensis, Tulbaghia alliacea, Dittrichia graveolens, Leysera gnaphalodes and Buddleja saligna . Aim of the Study The aim was to assess antimycobacterial activity in plants used in treatment of symptoms of TB, and through activity-guided fractionation of extracts to isolate compounds or mixtures with potential as anti-TB drug leads. Materials and Methods Extracts and derived fractions were assayed against strains of Escherichia coli , Staphylococcus aureus , and Mycobacterium aurum A+. Isolated pure compounds were further tested against Mycobacterium species M. avium ATCC 25291, M. scrofulaceum ATCC 19981, M. microti ATCC 19422 and Mtb H37Rv, and for cytotoxicity against Chinese hamster ovarian cells. Results Extracts of B. saligna and L. gnaphaloides exhibited significant anti-mycobacterial activity, primarily associated with the presence of non-cytotoxic triterpenoids oleanolic acid in B. saligna and both oleanolic and ursolic acids in L. gnaphaloides . Conclusions Anti-mycobacterial activity of extracts of selected plants is consistent with their traditional use. The identification of oleanolic and ursolic acids in these plants, and verification of their activity, underlines the potential for exploring structure-activity relationships of derivatives of these ubiquitous triterpenoids.

Extracts from 26 plant species representing 16 families, collected in the Free State Province of South Africa, were tested in vitro for their potential to inhibit the growth of eight plant pathogenic fungi and five plant pathogenic bacteria. None of the crude extracts showed any mycelial growth inhibition of the eight test fungi. All of the extracts inhibited the growth of one or more of the five plant pathogenic test bacteria, but to varying degrees. Crude extracts from Acacia karroo and Elephantorrhiza elephantina inhibited the growth of four bacteria, while that of Euclea crispa, Acacia erioloba, Senna italica and Buddleja saligna inhibited the growth of all five plant pathogenic bacteria. Of these, the crude extract of Euclea crispa was clearly superior to the rest as it compared more favourably to that of a commercial bactericide, Dimethyl Dodecyl Ammonium Chloride (DDAC). Subsequently, the Euclea crispa crude extract was fractionated by means of liquid-liquid extraction using four organic solvents, hexane, diethyl ether, chloroform and ethyl acetate, in order of increasing polarity. This was done in an attempt to assess the antimicrobial potential of the more concentrated fractions. Once again, none of the semi-purified fractions showed any antifungal activity. However, antibacterial activity was located in the more polar ethyl acetate fraction indicating that the substances involved were very similar in polarity and/or structure. From this it seems justified to further purify the ethyl acetate fraction of the Euclea crispa extract and attempt to identify the active substance(s) involved.

In our continuing search for biologically active natural product(s) of plant origin, Buddleja saligna, a South African medicinal plant, was screened in line with its traditional use for antidiabetic (yeast alpha glucosidase inhibitory) and antiplasmodial (against a chloroquine sensitive strain of Plasmodium falciparum (NF54)) activities. The hexane fraction showed the most promising activity with regards to its antidiabetic (IC50 = 260 ± 0.112 µg/ml) and antiplasmodial (IC50 = 8.5 ± 1.6 µg/ml) activities. Using activity guided fractionation three known terpenoids (betulonic acid, betulone and spinasterol) were isolated from this species for the first time. The compounds displayed varying levels of biological activities (antidiabetic: 27.31 µg/ml ≥ IC50 ≥ 5.6 µg/ml; antiplasmodial: 14 µg/ml ≥ IC50 ≥ 2 µg/ml) with very minimal toxicity.

Background Buddleja saligna Willd (Loganiaceae) is a small to medium-sized evergreen tree; trunk short, often gnarled and crooked; crown dense, rounded or domed-shaped; foliage greyish green. The wild olives are traditionally used to lower blood pressures in many parts of the world. In southern Africa, bark and leaf decoctions are used to treat colic, coughs, colds, sore eyes, urinary problems and as purgatives. Methods The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Buddleja saligna were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the leaves and stem extracts of Buddleja saligna were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant. Results The antioxidant activities of the leaves as determined by the ABTS and DPPH were similar to that of the stem. The flavonoids and the flavonols contents of the leaves were higher than that of the stem but the total phenols, proanthocyanidins and FRAP activities were higher in the methanol extracts of the stem. The extracts did show activity against both Gram-positive and Gram-negative bacteria. For instance, while the methanol extract of the leaves showed good activities on all the organisms except Serratia marcescens and Pseudomonas aeruginosa at MICs of between 2.5 and 5.0 mg/ml, the extract of the stem only showed activities on Bacillus cereus, Streptococcus pyrogens and Pseudomonas aeruginosa at the same concentration. Conclusion The results from this study indicate that the leaves and stem extracts of Buddleja saligna possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of Buddleja saligna are not as effective as the standard drugs-Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. Buddleja saligna may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products.

Dichloromethane and 90% methanol extracts of 42 South African plants were screened for mutagenicity and antimutagenicity using the Salmonella/microsome mutagenicity assay (Ames) against Salmonella typhimurium TA98 and TA100 bacterial strains in the presence and absence of metabolic activator S9. The methanol extracts from whole plants of Helichrysum simillimum, Helichrysum herbaceum and Helichrysum rugulosum indicated mutagenicity. These are the first reported tests on the mutagenicity of Helichrysum species. Six species indicated antimutagenic properties, all in the presence of S9: methanol leaf extract of Bauhinia galpinii, and dichloromethane leaf extracts of Bauhinia galpinii, Clerodendrum myricoides, Datura stramonium, Buddleja saligna, Millettia sutherlandii and Sutherlandia frutescens.

The crude ethanolic extract, hexane, dichloromethane, ethyl acetate and aqueous fractions of Buddleja saligna leaves were investigated for antiplasmodial, alpha-glucosidase and acetylcholinesterase inhibitory and cytotoxicity properties. Although the crude extract displayed some level of activity, the hexane fraction demonstrated the best antiplasmodial (IC 50 = 8.5 μg/ml), alpha-glucosidase inhibitory (IC 50 = 260 μg/ml) and anticholinesterase (IC 50 = 124.8 μg/ml) activities. The safety index values of the hexane fraction [antiplasmodial (0.2), alpha-glucosidase inhibition (0.007) and anticholinesterase (0.01)] revealed that the fraction is cytotoxic. These findings highlight the importance of reporting the SI values of biologically active samples together with their biological activities. It remains to be determined whether the toxicity observed is caused by the compounds responsible for the biological activities investigated or not.