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This study aimed to determine in vitro anthelmintic activity of plant extracts of eleven plant species used traditionally in South Africa to treat various disorders including symptoms related to nematode infections, and to isolate bioactive compounds from the most active plant extract. Crude plant extracts were tested on different life-cycle stages of Haemonchus contortus. The cytotoxicity of the most active extracts, fractions and compounds was evaluated on Vero cells and the most potent extract, fractions and compounds were tested for their ability to kill the parasitic H. contortus and the free-living nematode Caenorhabditis elegans. Typha capensis acetone extract had the strongest egg hatching inhibitory effect with an EC50 of 184.94 μg/mL, and this extract also halted larval development of H. contortus with an EC50 of 83.30 μg/mL compared to the positive control (albendazole) with an EC50 of 2.66 μg/mL. Typha capensis crude extract and its butanol fraction had promising anthelmintic activity against both parasitic H. contortus and free-living C. elegans. Two compounds isolated from T. capensis, namely, isorhamnetin-3-O-β-d-glucoside and isorhamnetin 3-O-rutinoside, had antioxidant activity with IC50 values of 3.16 μg/mL and 0.96 μg/mL respectively, and good anthelmintic activity against H. contortus with IC50 values of 55.61 μg/mL and 145.17 μg/mL respectively. Identification of bioactive compounds from the T. capensis crude extract supports development of this extract as a complementary or alternative treatment against haemonchosis. However, further research is necessary to confirm the anthelmintic efficacy of the plant, including in vivo studies. [ABSTRACT FROM AUTHOR]

• The use of South African plants in sunscreen formulations as multifunctional ingredients. • Stabilizing and photostabilizing effect of South African plant extracts. • Characterisation of plant extracts through GC-MS analysis. • Cosmetically safe extracts as observed through in vivo irritancy and mutagenic testing. • Significant antioxidant activity. 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 (IC 50) 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 IC 50 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 IC 50 value of 31.80 ± 0.35 µg/mL (human malignant melanoma, UCT-MEL-1) for B. saligna and IC 50 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. [ABSTRACT FROM AUTHOR]

• Six species of endophytic fungi were identified from six South African medicinal plants. • Endophytes extracts had low levels of antibacterial and antifungal activity. • Some endophytes produced useful extracellular enzymes and ability to solubilize phosphate. • Three isolates had polyketide synthase 1 gene, with potential to produce interesting polyketides. Endophytes are bacteria or fungi which live inside the host plant and participate in many biological processes without causing disease or other adverse effects. Endophytes are recognised as a rich source of secondary metabolites with potentially useful pharmacological properties. Many South African medicinal plants are highly under-investigated sources of potentially useful endophytic microbes. In this report six endophytic fungi were obtained from the leaves, stems and roots of South African medicinal plants which are known for their traditional uses and pharmacological properties. The endophytic fungi were isolated from Cotyledon orbiculata L., Psychotria zombamontana (Kuntze) Petit, Tecomaria capensis (Thunb.) Lindl., Catha edulis (Vahl) Endl. and Melianthus comosus Vahl. The crude extracts of the isolated endophytic fungi were investigated for their antimicrobial potential, extracellular enzymatic activity and phosphate solubilization. Additionally, the present study used genetic screening to assess the ability of the endophytic fungi to synthesize bioactive compounds, indicated by the presence of the polyketide synthase type 1 (PKS 1) gene. In preliminary microbial inhibition screening the fungal extracts had promising antifungal activity against Cryptococcus neoformans and Candida albicans. Furthermore, the endophytic fungus Talaromyces funiculosus displayed extracellular enzymatic activity, namely xylanase and cellulase. Five fungal strains demonstrated ability to solubilize phosphate and three strains demonstrated the presence of polyketide synthase type 1 (PKS 1) gene. It is worth considering further investigation of their bioactive secondary metabolites. [ABSTRACT FROM AUTHOR]

Background: Diarrhoea, a global economically important disease burden affecting swine and, especially piglets, is commonly caused by infection with entero-toxigenic E. coli (ETEC). Adherence of ETEC to porcine intestinal epithelial cells following infection, is necessary for its pathogenesis. While antimicrobials are commonly given as therapy or as feed additives for prophylaxis against microbial infections, the concern over increased levels of antimicrobial resistance necessitate the search for safe and effective alternatives in livestock feed. Attention is shifting to natural products including plants as suitable alternatives to antimicrobials. The activity of acetone crude leaf extracts of nine under-explored South African endemic plants from the Myrtaceae family with good antimicrobial activity were tested against pathogenic E. coli of porcine origin using a microplate serial dilution method. Bioautography, also with p-iodonitrotetrazolium violet as growth indicator was used to view the number of bioactive compounds in each extract. In vitro toxicity of extracts was determined against Caco-2 cells using the 3-(4,5-dimethythiazolyl-2)-2,5-diphenyltetrazolium bromide reduction assay. The antimicrobial susceptibility of E. coli isolates was tested on a panel of antimicrobials using the Kirby-Bauer agar diffusion method while the anti-adherence mechanism was evaluated using a Caco-2 cell enterocyte anti-adhesion model. Results: The MIC of the extracts ranged from 0.07–0.14 mg/mL with S. legatii having the best mean MIC (0.05 mg/mL). Bioautography revealed at least two active bands in each plant extract. The 50% lethal concentration (LC50) values ranged between 0.03–0.66 mg/mL. Eugenia zeyheri least cytotoxic (LC50 = 0.66 mg/ml) while E. natalitia had the highest cytotoxicity (LC50 = 0.03 mg/mL). All the bacteria were completely resistant to doxycycline and colistin sulphate and many of the plant extracts significantly reduced adhesion of E. coli to Caco-2 cells. Conclusions: The extracts of the plants had good antibacterial activity as well as a protective role on intestinal epithelial cells against enterotoxigenic E. coli bacterial adhesion. This supports the potential use of these species in limiting infection causes by E. coli. Some of these plants or extracts may be useful as phytogenic feed additives but it has to be investigated by animal feed trials. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) production and resultant oxidative stress (OS) has been implicated as a pathway of toxicity in animal species exposed to pollutants. The gills of aquatic animals and the liver and kidneys of mammalian species are specific cellular sites of toxicity. Oxidative effects of acid mine drainage effluent (following passive and active treatment) impacting a natural stream were assessed using selected cell lines. Levels of pollutants such as heavy metals in acid mine drainage (AMD) effluent can be quantified following treatment, but it is unknown whether this is associated with equivalent reduction in toxicity. ROS production by AMD untreated (U) and after treatment (T) was quantified in a fish gill cell line (RTgill-W1) and in two mammalian cell lines (C3A human liver and Vero monkey kidney). ROS production was determined using the oxidant sensitive fluorogenic probe, 2', 7'-dichlorofluorescein diacetate (DCFH-DA) following exposure to U and T, AMD water. Treatment of AMD water caused reduction in levels of Al, Zn, Fe, Si and Mn while levels of Cr, Cu, Ar and Hg remained unchanged. A dose-dependent increase in ROS production was observed for U and T. ROS formation decreased from 14% to 4.5%, 16.4% to 7.2% and 25.3% to 17.7% in the RTgill-W1, C3A, and Vero cell lines exposed to 100% AMD water, U and T. The presence of Mn and/or other ions in treated water and subsequent ROS formation indicates that water could still be toxic to cells and requires further processing. The DCFH-DA assay in several cell lines can be used to rapidly bio-monitor quality of AMD water related to formation of ROS and subsequent cellular effects. However, cut-off levels for cellular toxicity must be established to ensure safety of this water for aquatic animals and for animal and human consumption. [ABSTRACT FROM AUTHOR]

Background: Antibiotics are commonly added to livestock feeds in sub-therapeutic doses as growth promoters and for prophylaxis against pathogenic microbes, especially those implicated in diarrhoea. While this practice has improved livestock production, it is a major cause of antimicrobial resistance in microbes affecting livestock and humans. This has led to the banning of prophylactic antibiotic use in animals in many countries. To compensate for this, alternatives have been sought from natural sources such as plants. While many studies have reported the antimicrobial activity of medicinal plants with potential for use as phytogenic/botanical feed additives, little information exists on their mode of action. This study is based on our earlier work and describes ultrastructural damage induced by acetone crude leaf extracts of Syzygium legatii and Eugenia zeyheri (Myrtaceae) active against diarrhoeagenic E. coli of swine origin using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescent microscopy (FM). Gas chromatography/mass spectrometry (GC-MS) was used to investigate the chemical composition of plant extracts. Results: The extracts damaged the internal and external anatomy of the cytoplasmic membrane and inner structure at a concentration of 0.04 mg/mL. Extracts also led to an increased influx of propidium iodide into treated bacterial cells suggesting compromised cellular integrity and cellular damage. Non-polar compounds such as α-amyrin, friedelan-3-one, lupeol, and β-sitosterol were abundant in the extracts. Conclusions: The extracts of S. legatii and E. zeyheri caused ultrastructural damage to E. coli cells characterized by altered external and internal morphology. These observations may assist in elucidating the mode of action of the extracts. [ABSTRACT FROM AUTHOR]

Ethnopharmacological Relevance: Zimbabwe is a key biodiversity domain in sub-Saharan Africa and ethnoveterinary medicines play an integral role in livestock health. However, knowledge on whether plants are used by only a small proportion of people or whether similar uses exist in different communities and in a more regional context is incompletely documented., Aim of the Study: Firstly, the study documented plant-based complementary medicines used for managing goat ailments. Secondly, culturally important medicinal plant species with highest use-reports (UR) as well as botanical and therapeutic consistency were computed. Thirdly, details on whether similar ethnobotanical practices exist in different communities as an indicator of information exchange were explored., Materials and Methods: A total of 200 informants from Gutu, Chikomba, Murewa and Mwenezi districts of Zimbabwe were interviewed. Plant identification was done at the National Herbarium and Botanic Gardens of Zimbabwe. Use-reports were generated and subjected to analysis using Analysis of Variance (ANOVA) in IBM SPSS statistical software., Results: The impact of parasites and diseases was ranked as the major goat production constraint. A total of 160 homemade remedies were documented, 151 of which comprised a single plant species (Homemade Single Species Herbal Remedy Reports, HSHR). The 151 HSHR prepared using 75 plant species belonging to 34 families referred to 401 UR. The foremost used medicinal plant species were from the Fabaceae family (28 HSHR, 19%). Cassia abbreviata was the most cited plant species (6 HSHR, 4%). The category of ecto- and endoparasites had the highest number of UR out of a total of 9 categories (136 UR, 34%). The most frequently used plant species for this category were Solanum campylacanthum (8 UR, 6%) and Strychnos spinosa (6 UR, 4%). Almost similar numbers of UR were computed across communities for 6 disease categories. Nine different combinations (9 HR, 9 UR) comprising mostly of three plant species were reported for various ailments. Baccharoides adoensis and Terminalia sericea were often reported in these combinations for January disease. Highest levels of therapeutic consistency were computed for Aloe vera and Lippia javanica against ectoparasites (10 out of 24 local studies). Interestingly, 28 new medicinal plant species were documented for the first time in Zimbabwe. Again, these were mostly used for ecto-and endoparasites (8 plant species, 29%)., Conclusions: Ethnoveterinary medicines play a pivotal role in management of livestock ailments in rural communities of Zimbabwe. However, attention is warranted to ensure transparency in use practices, as well as to conserve and scientifically validate culturally important medicinal plant species such as Aloe vera and Lippia javanica., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

Climate change and human activities severely impact the viability of plants and ecosystems, threatening the environment, biodiversity, and the sustainable development of plant-based products. Biotic and abiotic (ecosystem) determinants affect species distribution and long-term survival, which in turn influence the quality of plants used as herbal medicines and other high-value products. In recent decades, diverse anthropogenic impacts have significantly affected these quality aspects. Climate change, excessive plant exploitation, habitat loss, species vulnerability, and other factors have adversely affected the growth, reproduction, and adaptation of species populations, as well as the quality and volume of primary plant materials supplied to pharmaceutical markets. Despite these growing challenges, there is limited knowledge of potential strategies to prevent or mitigate these impacts, particularly for vulnerable species collected from the wild or harvested from traditional production systems. Hence, effective strategies for preserving and increasing plant populations are urgently needed. In this study, we propose a new framework including the main sustainability factors to better understand and address the vulnerability of a species, hence mitigate the impact of climate change. We assess the applicability of our proposed framework via seven case studies of vulnerable species (i.e., Aquilaria malaccensis Lam., Boswellia sacra Flück., Crocus sativus L., Panax quinquefolius L., Pilocarpus microphyllus Stapf ex Wardlew., Rhodiola rosea L., and Warburgia salutaris (G.Bertol.) Chiov.) from main biogeographic realms, all widely used as medicinal plants. These species present various challenges related to the sustainability of their use, impacting their current and future status locally and globally. Their economic importance, combined with rising demands and specific risks of overexploitation, are also key factors considered here. The suggested framework for the sustainability of medicinal and other high-value plant-based products in the phytopharmaceutical industry emphasises strategies that promote conservation and sustainable resource use. It can also be adapted for other vulnerable species requiring urgent attention., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2025 Mykhailenko, Jalil, McGaw, Echeverría, Takubessi and Heinrich.)

Oxidative stress is a key factor that activates several transcription factors and mediators involved in the inflammatory pathways responsible for the pathogenesis of many chronic diseases. Targeting the expression of these mediators represents a promising approach to preventing these diseases. Cassinopsis ilicifolia leaf infusion is traditionally used for treating conditions such as inflammation and pain relief. Thus, the present study assessed the antioxidant and anti-inflammatory activities of the hydroethanolic leaf extract of C. ilicifolia using in vitro and cell-based assays. As a result, C. ilicifolia extract exhibited the highest DPPH • and ABTS •+ radical scavenging potential. At the same time, it weakly scavenged the Fe 3+ -TPTZ radical up to 200 µg/mL, thus suggesting a different antioxidant mechanism triggered during each assay. Additionally, C. ilicifolia extract inhibited NO production and 15-LOX activity with IC 50 values of 21.10 µg/mL and 40.28 µg/mL, respectively. Further, C. ilicifolia extract was found to strongly inhibit ROS production in LPS-activated RAW 264.7 cells, and the study of its mechanism of action showed that it exerts its anti-inflammatory effect by downregulating the expression of inflammatory mediators such as IL-1β, TNF-α, and COX-2. Overall, C. ilicifolia extract showed consistent potency in all assays, and the analysis of its phytochemical profile led to the identification of 30 compounds, among which the most abundant were secologanic acid (1), chlorogenic acid (3CQA) (2), monotropein (3), chlorogenic acid (5CQA) (4), geniposidic acid (5), rutin (6), quercetin 3-galactoside (7), astragalin-7-rhamnoside (8), and minecoside (9) that are possibly responsible for its anti-inflammatory and antioxidant activities. Therefore, our findings suggested the potential use of C. ilicifolia as an alternative source for developing plant-based products against oxidative stress and inflammation-related conditions.

The emergence of drug-resistant Mycobacterium tuberculosis strains is a threat to global health necessitating the discovery of novel chemotherapeutic agents. Natural products drug discovery, which previously led to the discovery of rifamycins, is a valuable approach in this endeavor. Against this backdrop, we set out to investigate the in vitro antimycobacterial properties of medicinal plants from Ghana and South Africa, evaluating 36 extracts and their 252 corresponding solid phase extraction (SPE) generated fractions primarily against the non-pathogenic Mycobacterium smegmatis and Mycobacterium aurum species. The most potent fraction was further evaluated in vitro against infectious M. tuberculosis strain. Crinum asiaticum (bulb) (Amaryllidaceae) emerged as the most potent plant species with specific fractions showing exceptional, near equipotent activity against the non-pathogenic Mycobacterium species (0.39 µg/ml ≤ MIC ≤ 25 µg/ml) with one fraction being moderately active (MIC = 32.6 µg/ml) against M. tuberculosis. Metabolomic analysis led to the identification of eight compounds predicted to be active against M. smegmatis and M. aurum. In conclusion, from our comprehensive study, we generated data which provided an insight into the antimycobacterial properties of Ghanaian and South African plants. Future work will be focused on the isolation and evaluation of the compounds predicted to be active., (© 2024. The Author(s).)

Background: Harungana madagascariensis (HM) and Psorospermum aurantiacum (PA), used traditionally for skin care, have been reported to upregulate the expression of intracellular antioxidant genes, thereby preventing melanoma and protecting fibroblast cell lines from Ultraviolet B (UVB)-induced intracellular oxidative stress., Aims: This investigation aimed to identify major compounds in bioactive fractions using bioassay- guided fractionation., Methods: The anti-inflammatory effect of fractions was determined by measuring their inhibitory activity on 15-lipoxygenase and nitric oxide (NO) in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. Additionally, the anti-aging efficacy of the fractions was determined by assessing the expression of markers for the aging process, i.e., expression of tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), procollagen type-1 (COL1A1), and matrix metalloproteinase- 1 (MMP-1) in UVB-induced photoaging in skin cell-lines. Furthermore, UHPLCMS- based identification of the bioactive compounds from the most prominent fraction was also carried out., Results: Hexane fraction of HM significantly inhibited (p <0.05) the 15-lipoxygenase (IC50 = 46.80 μg/mL) and NO production (IC50 = 66.55 μg/mL), whereas hexane fraction of PA was effective (p <0.05) in inhibiting 15-lipoxygenase activity (IC50 = 27.55 μg/mL). Furthermore, the hexane fraction of HM and methanol fraction of PA were significantly effective (p <0.05) in reverting the UVB-mediated altered expressions of MMP-1, TYR, TRP-1, and COL1A1. Furthermore, hexane fraction of HM revealed the presence of harunganin and betulinic acid, whereas vismion D, vismin, kenganthranol B, and bianthrone 1a were identified from the methanol fraction of PA., Conclusion: Overall, the hexane fraction of HM and methanol fraction of PA displayed effective anti-aging activities, with additional anti-inflammatory effects., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Secondary metabolites were isolated using chromatographic techniques after being extracted sequentially from the roots of Artemisia afra using organic solvents such as ethanol, ethyl acetate, dichloromethane, and n-hexane. The isolated compounds were evaluated for anti-fungal, anti-bacterial, and cytotoxicity activities. Spectroscopic techniques, including Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR), and liquid chromatography-mass spectrometry (LC-MS), were used to elucidate the structures of the isolated compounds. The phytochemical investigation of A. afra led to the isolation of eight ( A - H ) compounds which were identified as 3 β -taraxerol ( A ), 3 β -taraxerol acetate ( B ), dodecyl- p -coumarate ( C ), ferulic acid ( D ), scopoletin ( E ), sitosterol-3- O - β - D -glucopyranoside ( F ), 3,5-di- O -feruloylquinic acid ( G ) and Isofraxidin-7- O - β - D -glucopyranoside ( H ) based on spectroscopic data. Compounds A , B , C , F , G , and H are known but were isolated for the first time from the roots of A. afra . The isolated compounds and extracts from A. afra exhibited good anti-fungal and anti-bacterial activity with dichloromethane and ethyl acetate crude extracts (0.078 mg/mL) and compound E (62.5 µg/mL) showed good activities against Escherichia coli . Compounds C and F also showed good activity against Enterococcus faecalis with minimum inhibitory concentration (MIC) values of 62.5 and 31.25 µg/mL, respectively. Extracts and compounds ( A - H ) exhibited anti-fungal and anti-bacterial properties and showed no toxicity when tested on Vero monkey kidney (Vero) cells.

Black locust ( Robinia pseudoacacia L.), an invasive tree in Europe, commonly known for its negative impact on biodiversity, is a rich source of phenolic compounds recognized in traditional medicine. Since the metabolite profile depends on the environment and climate, this study aimed to provide the first LC-MS phytochemical screening of the black locust from the Istria region (Croatia). The compounds were extracted from leaves and flowers with 70% ethanol and 80% methanol. Total phenolics (TP) and flavonoids (TF), as well as antioxidant capacity (AC) measured by ABTS (17.49-146.41 mg TE/g DW), DPPH (24.67-118.49 mg TE/g DW), and FRAP (7.38-77.53 mg TE/g DW) assays, were higher in leaf than in flower extracts. Higher TP and total non-flavonoid (TNF) values were displayed in ethanolic than in methanolic extracts. In total, 64 compounds were identified, of which flavonols (20) and hydroxycinnamic acid derivatives (15) were the most represented. Flavanols such as catechin dominated in leaf extracts, followed by flavonols, with kaempferol glucuronyl rhamnosyl hexosides as the main compound, respectively. Flower extracts had the highest share of flavones, followed by ellagitannins, with luteolin dirhamnosyl hexosides and vescalagin, respectively, being predominant. The extracts had good quorum sensing, biofilm formation prevention, and eradicating capacity. The results provided new insights into the phytochemical properties of R. pseudoacacia as the first step toward its potential pharmaceutical use.

Background: Sarcocephalus pobeguinii (Hua ex Pobég) is used in folk medicine to treat oxidative-stress related diseases, thereby warranting the investigation of its anticancer and anti-inflammatory properties. In our previous study, the leaf extract of S. pobeguinii induced significant cytotoxic effect against several cancerous cells with high selectivity indexes towards non-cancerous cells. Aim: The current study aims to isolate natural compounds from S. pobeguinii , and to evaluate their cytotoxicity, selectivity and anti-inflammatory effects as well as searching for potential target proteins of bioactive compounds. Methods: Natural compounds were isolated from leaf, fruit and bark extracts of S. pobeguinii and their chemical structures were elucidated using appropriate spectroscopic methods. The antiproliferative effect of isolated compounds was determined on four human cancerous cells (MCF-7, HepG2, Caco-2 and A549 cells) and non-cancerous Vero cells. Additionally, the anti-inflammatory activity of these compounds was determined by evaluating the nitric oxide (NO) production inhibitory potential and the 15-lipoxygenase (15-LOX) inhibitory activity. Furthermore, molecular docking studies were carried out on six putative target proteins found in common signaling pathways of inflammation and cancer. Results: Hederagenin ( 2 ), quinovic acid 3-O-[α-D-quinovopyranoside] ( 6 ) and quinovic acid 3-O-[β-D-quinovopyranoside] ( 9 ) exhibited significant cytotoxic effect against all cancerous cells, and they induced apoptosis in MCF-7 cells by increasing caspase-3/-7 activity. ( 6 ) showed the highest efficacy against all cancerous cells with poor selectivity (except for A549 cells) towards non-cancerous Vero cells; while ( 2 ) showed the highest selectivity warranting its potential safety as a chemotherapeutic agent. Moreover, ( 6 ) and ( 9 ) significantly inhibited NO production in LPS-stimulated RAW 264.7 cells which could mainly be attributed to their high cytotoxic effect. Besides, the mixture nauclealatifoline G and naucleofficine D ( 1 ), hederagenin ( 2 ) and chletric acid ( 3 ) were active against 15-LOX as compared to quercetin. Docking results showed that JAK2 and COX-2, with the highest binding scores, are the potential molecular targets involved in the antiproliferative and anti-inflammatory effects of bioactive compounds. Conclusion: Overall, hederagenin ( 2 ), which selectively killed cancer cells with additional anti-inflammatory effect, is the most prominent lead compound which may be further investigated as a drug candidate to tackle cancer progression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Mfotie Njoya, Ndemangou, Akinyelu, Munvera, Chukwuma, Mkounga, Mashele, Makhafola and McGaw.)

Apoptosis of germ cells is an important feature of spermatogenesis, as this process allows the removal of excess germ cells from testicular tissue. This is crucial to control the number of germ cells that can be supported and nourished by the Sertoli cells. It has been established that up to 75 % of germ cells are lost during the development of spermatogonia. In this process, germ cells with defective genes are removed. Also, apoptosis regulates homeostasis of testicular tissue by maintaining a balance between germ cell proliferation and cell death. This is necessary as it guarantees normal spermatogenesis. Apoptosis also occurs during maturation divisions of spermatocytes and spermatids but albeit to a lesser extent. Several factors, known pro-apoptotic proteins, play a critical role in the process of apoptosis. The most vital pro-apoptotic proteins are caspase-3, B-cells lymphoma 2 (Bcl2), truncated BH3 interacting death domain (tBID), tumor suppressor protein (p53), and Bcl-2 associated protein (BAX). Execution of apoptosis may be triggered by either an extrinsic or an intrinsic pathway. The extrinsic pathway is initiated by death receptors and death ligands. Death receptors trigger pro-apoptotic proteins such as caspase-3 for the execution of apoptosis. The intrinsic pathway, on the other hand, is triggered by nutrient deprivation, stress, or DNA damage, which in turn activates Bcl2 families of pro-apoptotic proteins that foster apoptosis. The present review focuses on pro-apoptotic proteins and their mechanisms of action, with special emphasis on their involvement in germ cell apoptosis in the testicular tissues of mammalian and avian species., Competing Interests: Declaration of Competing Interest The authors declare that there are no competing interests., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: This study evaluated the in vitro antioxidant activity and comparison of anti-inflammatory and cytotoxic activity of Harpagopytum zeyheri with diclofenac., Methods: In vitro assays were conducted using water, ethanol, and ethyl acetate extracts of H.zeyheri. The antioxidant activity was evaluated using the 2,2'-diphenyl-1-picrylhydrazy (DPPH) and 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The anti-inflammatory activity was determined by measuring the inhibition of nitric oxide (NO) on lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages as well as cytokine (TNF-α and IL-10) expression on LPS-induced U937 human macrophages. For cytotoxicity, cell viability was determined using the 3-(4, 5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay., Results: The ethyl acetate extract had the lowest IC 50 values in the DPPH (5.91 μg/ml) and ABTS (20.5 μg/ml) assay compared to other extracts. Furthermore, the ethyl acetate extracts effectively inhibited NO and TNF-α and proved to be comparable to diclofenac at some concentrations. All extracts of H. zeyheri displayed dose-dependent activity and were associated with low levels of human-IL-10 expression compared to quercetin. Furthermore, all extracts displayed low toxicity relative to diclofenac., Conclusions: These findings show that H. zeyheri has significant antioxidant activity. Additionally, similarities exist in the inflammatory activity of H. zeyheri to diclofenac at some concentrations as well as low toxicity in comparison to diclofenac., (© 2021. The Author(s).)

Background: Owing to antibiotic resistance, alternative antimicrobials from medicinal plants are receiving attention as leads for anti-infective agents. This study aimed to investigate selected tree species and their constituents for activity against bacterial foodborne pathogens, particularly Salmonella serovars., Methods: Antibacterial activity of ten plant species was determined by serial microdilution against bacteria implicated in causing gastrointestinal ailments. Active compounds were isolated from Loxostylis alata using bioassay-guided fractionation. Antioxidant activity was determined using free-radical scavenging assays. Cytotoxicity and genotoxicity of the extracts was ascertained on Vero cells, and using the Ames assay respectively., Results: Extracts had low to moderate MIC values from 0.04 to 2.5 mg/mL. Protorhus longifolia and Loxostylis alata were most active and L. alata had the highest selectivity index value (2.51) against Salmonella Typhimurium, as well as high antioxidant activity. Cytotoxicity values ranged from 0.02 to 0.47 mg/mL, while tested extracts were not genotoxic. Bioactive compounds isolated from L. alata included delicaflavone and a polymethoxyflavone., Conclusions: The Loxostylis alata leaf extract had strong activity against Salmonella serovars but isolated compounds were less active, indicating likely synergistic effects. Extracts of L. alata are promising candidates for development of antimicrobial preparations or food additives against microbial contamination.

Background: Some viruses play a key role in the disturbance of the digestive system. The common viruses which cause infectious diarrhoea (gastroenteritis) include astrovirus, caliciviruses, coronavirus and torovirus which are single-stranded RNA viruses. Influenza A virus (H1N1) also causes diarrhoea in addition to being associated with respiratory symptoms. In preliminary studies, Newtonia hildebrandtii and N. buchananii leaf extracts had good antibacterial activity against some bacteria implicated in causing diarrhoea. The aim of this study was to evaluate the anti-influenza activity of two Newtonia species extracts and the isolated compound (myricitrin)., Methods: N. hildebrandtii and N. buchananii acetone, and MeOH: DCM (methanol-dichloromethane) leaf and stem extracts, and an antibacterial compound myricetin-3-o-rhamnoside (myricitrin), isolated from N. buchananii, were evaluated for their antiviral efficacy against influenza A virus (IAV) PR8/34/H1N1 as a model organism. The MTT and hemagglutination assays were used to assess the extracts and compound interference with cell viability and viral surface HA glycoprotein. The quantitative real-time PCR was performed to assess the viral load., Results: Plant extracts of N. hildebrandtii and N. buchananii were effective against IAV. The extracts in combination with H1N1 showed highly significant antiviral activity (P < 0.01) and maintained cell viabilities (P < 0.05). Myricitrin was non-cytotoxic at concentration 104 μg/ml. Myricitrin was most effective against IAV in a co-penetration combined treatment, thereby confirming the inhibitory effect of this compound in the viral attachment and entry stages. Myricitrin treatment also resulted in the highest viability of the cells in co-penetration treatment. The activity of myricitrin indicates the potential of the extracts in controlling viral infection at the attachment stage. The antiviral effect of myricitrin on IAV load in MDCK cell culture was confirmed using quantitative real-time PCR., Conclusion: Data from this study support further research and development on Newtonia hildebrandtii, Newtonia buchananii and myricitrin to address diarrhoea and related conditions caused by viruses in both human and veterinary medicine. Further work needs to be conducted on the activity of the extracts and the purified compound on other viruses of importance which have similar symptoms to influenza virus such as the coronavirus which led to a recent global pandemic.

It has been established that excess germ cells in normal and in pathological conditions are removed from testicular tissue by the mechanism of apoptosis. Studies on germ cell apoptosis in avian species are grossly lacking, and there are only a few reports on induced germ cell degenerations in the testis tissue of birds. This study was designed to investigate the process of apoptosis of germ cells in the Japanese quail (Coturnix coturnix japonica). Germ cell degenerations were investigated in birds of all age groups, namely pre-pubertal, pubertal, adult, and aged. Apoptosis of germ cells in the quails, as shown by hematoxylin & eosin (H&E), TdT dUTP Nick End Labeling (TUNEL) assay and electron microscopy, was similar to that observed in previous studies of germ cells and somatic cells of mammalian species. The observed morphological features of these apoptotic cells ranged from irregular plasma and nuclear membranes in the early stage of apoptosis to rupture of the nuclear membrane, condensation of nuclear material, as well as fragments of apoptotic bodies, in later stages of apoptosis. In the TUNEL-positive cell counts, there was a significant difference between the mean cell counts for the four age groups (P < 0.05). Post hoc analysis revealed a highly significant difference in the aged group relative to the pubertal and adult age groups, while the cell counts of the pre-pubertal group were significantly higher than those of the pubertal group. However, there was no significant difference between cell counts of the pre-pubertal and the adult, and between the pre-pubertal and the aged groups., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Diarrhoea is a major health issue in both humans and animals and may be caused by bacterial, viral and fungal infections. Previous studies highlighted excellent activity of Newtonia buchananii and N. hildebrandtii leaf extracts against bacterial and fungal organisms related to diarrhoea-causing pathogens. The aim of this study was to isolate the compound(s) responsible for antimicrobial activity and to investigate efficacy of the extracts and purified compound against bacterial biofilms., Methods: The acetone extract of N. buchananii leaf powder was separated by solvent-solvent partitioning into eight fractions, followed by bioassay-guided fractionation for isolation of antimicrobial compounds. Antibacterial activity testing was performed using a broth microdilution assay. The cytotoxicity was evaluated against Vero cells using a colorimetric MTT assay. A crystal violet method was employed to test the inhibitory effect of acetone, methanol: dichloromethane and water (cold and hot) extracts of N. buchananii and N. hildebrandtii leaves and the purified compound on biofilm formation of Pseudomonas aeruginosa, Escherichia coli, Salmonella Typhimurium, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus., Results: Myricetin-3-o-rhamnoside (myricitrin) was isolated for the first time from N. buchananii. Myricitrin was active against B. cereus, E. coli and S. aureus (MIC = 62.5 μg/ml in all cases). Additionally, myricitrin had relatively low cytotoxicity with IC 50  = 104 μg/ml. Extracts of both plant species had stronger biofilm inhibitory activity against Gram-positive than Gram-negative bacteria. The most sensitive bacterial strains were E. faecalis and S. aureus. The cold and hot water leaf extracts of N. buchananii had antibacterial activity and were relatively non-cytotoxic with selectivity index values of 1.98-11.44., Conclusions: The purified compound, myricitrin, contributed to the activity of N. buchananii but it is likely that synergistic effects play a role in the antibacterial and antibiofilm efficacy of the plant extract. The cold and hot water leaf extracts of N. buchananii may be developed as potential antibacterial and antibiofilm agents in the natural treatment of gastrointestinal disorders including diarrhoea in both human and veterinary medicine.

Background: Urinary tract infections (UTIs) caused by opportunistic pathogens are among the leading health challenges globally. Most available treatment options are failing as a result of antibiotic resistance and adverse effects. Natural sources such as plants may serve as promising alternatives., Methods: Compounds were isolated from the South African weed Chromolaena odorata through column chromatography. Purified compounds were tested for antimicrobial activity using the p-iodonitrotetrazolium chloride (INT) colorimetric method, against uropathogenic Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Aspergillus fumigatus and Cryptococcus neoformans. Anti-biofilm, anti-adhesion and metabolic inhibition activities were investigated against selected strains. Safety of the compounds was determined against Vero monkey kidney, C3A human liver and colon (Caco2) cells., Results: Four compounds identified as pectolinaringenin (1), (±)-4',5,7-trimethoxy flavanone (2), 5-hydroxy-3,7,4'-trimethoxyflavone (3) and 3,5,7-trihydroxy-4'-methoxyflavone) (4) were isolated. Minimum inhibitory concentration (MIC) varied between 0.016 and 0.25 mg/mL. Compounds 2 and 3 showed promising antimicrobial activity against E. coli, S. aureus, K. pneumoniae, A. fumigatus and C. neoformans with MIC between 0.016 and 0.125 mg/mL, comparable to gentamicin, ciprofloxacin and amphotericin B used as positive controls. Compounds 2 and 3 showed good anti-biofilm and metabolic inhibition activities against E. coli and S. aureus but weak anti-adhesion activity against the organisms. Low toxicity with selectivity indexes between 1 and 12.625 were recorded with the compounds, indicating that the compounds were rather toxic to the microbial strains and not to the human and animal cells., Conclusion: Pharmacological activities displayed by compounds 2 and 3 isolated from C. odorata and low toxicity recorded credits it as a potential lead for the development of useful prophylactic treatments and anti-infective drugs against UTIs. Although known compounds, this is the first time these compounds have been isolated from the South African weed C. odorata and tested for antimicrobial, anti-biofilm, metabolic inhibition and anti-adhesion activities.

Background: Influenza A virus (IAV) is still a major health threat. The clinical manifestations of this infection are related to immune dysregulation, which causes morbidity and mortality. The usage of traditional medication with immunomodulatory properties against influenza infection has been increased recently. Our previous study showed antiviral activity of quercetin-3-O-α-L-rhamnopyranoside (Q3R) isolated from Rapanea melanophloeos (RM) (L.) Mez (family Myrsinaceae) against H1N1 (A/PR/8/34) infection. This study aimed to confirm the wider range of immunomodulatory effect of Q3R on selective pro- and anti-inflammatory cytokines against IAV in vitro, to evaluate the effect of Q3R on apoptosis pathway in combination with H1N1, also to assess the physical interaction of Q3R with virus glycoproteins and RhoA protein using computational docking., Methods: MDCK cells were exposed to Q3R and 100CCID 50 /100 μl of H1N1 in combined treatments (co-, pre- and post-penetration treatments). The treatments were tested for the cytokines evaluation at RNA and protein levels by qPCR and ELISA, respectively. In another set of treatment, apoptosis was examined by detecting RhoA GTPase protein and caspase-3 activity. Molecular docking was used as a tool for evaluation of the potential anti-influenza activity of Q3R., Results: The expressions of cytokines in both genome and protein levels were significantly affected by Q3R treatment. It was shown that Q3R was much more effective against influenza when it was applied in co-penetration treatment. Q3R in combination with H1N1 increased caspase-3 activity while decreasing RhoA activation. The molecular docking results showed strong binding ability of Q3R with M2 transmembrane, Neuraminidase of 2009 pandemic H1N1, N1 and H1 of PR/8/1934 and Human RhoA proteins, with docking energy of - 10.81, - 10.47, - 9.52, - 9.24 and - 8.78 Kcal/mol, respectively., Conclusions: Quercetin-3-O-α-L-rhamnopyranoside from RM was significantly effective against influenza infection by immunomodulatory properties, affecting the apoptosis pathway and binding ability to viral receptors M2 transmembrane and Neuraminidase of 2009 pandemic H1N1 and human RhoA cellular protein. Further research will focus on detecting the detailed specific mechanism of Q3R in virus-host interactions.

Background: Many studies have revealed that bioactive compounds for different indications are not extracted from plants with water, the only extractant practically available to rural communities. We compared the acaricidal activity of acetone extracts of 13 species used traditionally to protect cattle against ticks. We also investigated if the extraction of biologically active compounds against Rhipicephalus (Boophilus) decoloratus ticks could be enhanced by adding a liquid soap that is locally available to smallholder farmers., Methods: A total of 13 plant species selected based on reported traditional use in Zimbabwe, were dried and finely ground before extraction with water, or water plus a surfactant, or acetone. The adapted Shaw Larval Immersion Test (SLIT) method was used to determine the activity of acetone and crude water extracts with or without liquid soap against the tick larvae. The activity of four fractions of crude acetone extracts (extracted using solvents of different polarity), of the most active plant species, Maerua edulis (tuber and leaf) was also compared to identify the most active fraction., Results: Aqueous plant extracts were not toxic to ticks, but the addition of 1% liquid soap as a surfactant increased mortality of the R. (B) decoloratus larvae significantly. With the Maerua edulis tuber extract, the efficacy of the 1% liquid soap was comparable to that of the amitraz based commercial synthetic acaricide. The use of acetone as an extractant, also increased the mortality of the tick larvae in all the plant species. With M. edulis (tuber and leaf), Monadenium lugardae and Kleinia sp. acetone extracts, the activity was comparable to that of the positive control (a commercially available amitraz-based synthetic acaricide). The non-polar fractions of the acetone extract of leaf and tuber of M. edulis caused up to 100% mortality. This indicates that non-polar to intermediate polarity compounds are responsible for the acaricidal activity., Conclusion: Organic solvents such as acetone extracted active compounds but water did not. By adding commonly available dishwashing soap to water active compounds were extracted leading to a high acaricidal activity of the plant extracts. In some cases, it was as active as non-polar extracts and a synthetic commercial acaricide (positive control). This approach makes it possible for the smallholder farmers and traditional healers to extract biologically active compounds from plants by using water.

Background: Antimicrobial resistance (AMR) remains an important global health issue but the gap between AMR and development of new antimicrobials is increasing. Plant extracts may have good activity per se or may be sources of effective antimicrobial compounds which can act against planktonic and/or biofilms of pathogens. We determined the antimicrobial efficacy and cytotoxicity of some under-investigated plants from the Myrtaceae family endemic to South Africa. The ability of the plant extracts to inhibit or destroy pre-formed bacterial biofilms was also determined., Methods: Based on previous preliminary in vitro screening and on chemotaxonomy, nine species from the Myrtaceae family were selected. The antimicrobial activity of the crude acetone leaf extracts was determined against six common nosocomial pathogens, namely: Gram-positive bacteria (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) using a two-fold serial microdilution assay with p-iodonitrotetrazolium violet as growth indicator. The number of antimicrobial compounds present in extracts was determined by bioautography. Cytotoxicity of extracts was determined against Vero kidney cells using a colorimetric tetrazolium-based assay. The total antibacterial activity (TAA) in ml/g and selectivity index (LC 50 /MIC) of the plant extracts were calculated. A modified crystal violet assay was used to determine the antibiofilm activity of the extracts., Results: Syzygium legatii, Syzygium masukuense, and Syzygium species A had the best activities against Gram-negative and Gram-positive bacteria (MIC) values ranging from 0.04-0.08 mg/ml. Eugenia erythrophylla had the best MIC (0.02 mg/ml) against Bacillus cereus. Many extracts had relatively low cytotoxicity (LC 50  > 20 μg/ml) leading to reasonable selectivity indices. Three leaf extracts (Syzygium masukuense, Syzygium species A, and Eugenia natalitia) were moderately cytotoxic (20 μg/ml < LC 50  < 100 μg/ml). The plant extracts had a good capacity to reduce biofilm formation and good to poor potential to destroy pre-formed biofilms., Conclusions: The plant species examined in this study had varying degrees of antibacterial activity against bacterial planktonic and biofilm forms with some having good activity against both forms. Several of these selected species may be potential candidates for further investigation to isolate antimicrobial compounds and to determine the mechanism of activity.

Background: Tuberculosis is a deadly disease caused by Mycobacterium species. The use of medicinal plants is an ancient global practice for the treatment and prevention of diverse ailments including tuberculosis. The aim of this study was to isolate and characterize antimycobacterial compounds by bioassay-guided fractionation of the acetone leaf extract of Oxyanthus speciosus., Methods: A two-fold serial microdilution method was used to determine the minimum inhibitory concentration (MIC) against mycobacteria. Cytotoxicity and nitric oxide inhibitory activity of the isolated compounds was determined to evaluate in vitro safety and potential anti-inflammatory activity. Intracellular efficacy of the crude extract against Mycobacterium-infected macrophages was also determined., Results: Two compounds were isolated and identified as lutein (1) and rotundic acid (2). These had good antimycobacterial activity against the four mycobacteria tested with MIC values ranging from 0.013 to 0.1 mg/mL. Rotundic acid had some cytotoxicity against C3A human liver cells. Lutein was not cytotoxic at the highest tested concentration (200 μg/mL) and inhibited nitric oxide production in RAW 264.7 macrophages by 94% at a concentration of 25 μg/mL. The acetone crude extract (120 μg/mL) of O. speciosus had intracellular antimycobacterial activity, reducing colony forming units by more than 90%, displaying bactericidal efficacy in a dose and time-dependent manner., Conclusion: This study provides good proof of the presence of synergism between different compounds in extracts and fractions. It is also the first report of the antimycobacterial activity of lutein and rotundic acid isolated from Oxyanthus speciosus. The promising activity of the crude extract of O. speciosus both in vitro and intracellularly in an in vitro macrophage model suggests its potential for development as an anti- tuberculosis (TB) herbal medicine.

The menace caused by ticks and tick-borne diseases is a major limitation to the livestock industry in Africa. The high costs and non-availability of synthetic, chemical acaricides to resource-limited farmers, resistance of ticks to available acaricides and residue problems in meat and milk consumed by humans further complicate matters. The use of plant extracts as a possible source of new acaricides has received much interest in the last decade. In our endeavour to discover natural acaricidal compounds, tick toxicant bioassays were conducted and the chloroform fraction of Calpurnia aurea ethanol leaf extract had good acaricidal activity. Further purification of the fraction revealed two flavonoids, isolated from C. aurea for the first time. These flavonoids were characterized as apigenin-7-O-β-D-glycoside and isorhoifolin by means of NMR spectroscopic and mass spectrometry analysis. Isorhoifolin was the most potent compound (LC 50  = 0.65 mg/ml), was not cytotoxic and should be further investigated for its potential as an acaricidal agent.