Hyaluronidase, phospholipase A2 and protease inhibitory activity of plants used in traditional treatment of snakebite-induced tissue necrosis in Mali, DR Congo and South Africa

The Composition and Biochemical Properties of Strophantus (Apocynaceae), with a Focus on S. sarmentosus

The genus Strophantus belongs to the Apocynaceae family of flowering plants which grows primarily in tropical Africa. The plants are widely used in traditional herbal medicine. S. sarmentosus, in particular, is used for the treatment of, e.g., joint pain and rheumatoid arthritis, wound infections, head lice, diarrhea, snake bite, and eye conditions. Despite its widespread use, dedicated research characterizing its bioactive plant components is scarce. Investigations have focused mainly on its cardenolides because of their cardioactivity and historical use as cardiotonic. There are also studies concerning the antibacterial, antioxidant, and anti-inflammatory activity of plant extracts. This review summarizes the present knowledge surrounding the biochemical and analytical research on Strophantus, in general, and S. sarmentosus, in particular, and describes the current state of the field based on the available scientific literature.

Exploring nature's antidote: unveiling the inhibitory potential of selected medicinal plants from Kisumu, Kenya against venom from some snakes of medical significance in sub-Saharan Africa

Background: The present study investigated the efficacy of Conyza bonariensis, Commiphora africana, Senna obtusifolia, Warburgia ugandensis, Vernonia glabra, and Zanthoxylum usambarense against Bitis arietans venom (BAV), Naja ashei venom (NAV), and Naja subfulva venom (NSV). Methods: 40 extracts and fractions were prepared using n-hexane, dichloromethane, ethyl acetate, and methanol. In vitro efficacy against snake venom phospholipase A2 (svPLA2) was determined in 96-well microtiter and agarose-egg yolk coagulation assays. in vivo efficacy against venom-induced cytotoxicity was determined using Artemia salina. Two commercial antivenoms were used for comparison. Results: The 96-well microtiter assay revealed poor svPLA2 inhibition of BAV by antivenom (range: 20.76% ± 13.29% to 51.29% ± 3.26%) but strong inhibition (>90%) by dichloromethane and hexane fractions of C. africana, hexane and ethyl acetate extracts and fraction of W. ugandensis, dichloromethane fraction of V. glabra, and the methanol extract of S. obtusifolia. The methanol extract and fraction of C. africana, and the hexane extract of Z. usambarense strongly inhibited (>90%) svPLA2 activity in NAV. The hexane and ethyl acetate fractions of V. glabra and the dichloromethane, ethyl acetate, and methanol extracts of C. africana strongly inhibited (>90%) svPLA2 in NSV. The agarose egg yolk coagulation assay showed significant inhibition of BAV by the dichloromethane fraction of C. africana (EC50 = 3.51 ± 2.58 μg/mL), significant inhibition of NAV by the methanol fraction of C. africana (EC50 = 7.35 ± 1.800 μg/mL), and significant inhibition of NSV by the hexane extract of V. glabra (EC50 = 7.94 ± 1.50 μg/mL). All antivenoms were non-cytotoxic in A. salina but the methanol extract of C. africana and the hexane extracts of V. glabra and Z. usambarense were cytotoxic. The dichloromethane fraction of C. africana significantly neutralized BAV-induced cytotoxicity, the methanol fraction and extract of C. africana neutralized NAV-induced cytotoxicity, while the ethyl acetate extract of V. glabra significantly neutralized NSV-induced cytotoxicity. Glycosides, flavonoids, phenolics, and tannins were identified in the non-cytotoxic extracts/fractions. Conclusion: These findings validate the local use of C. africana and V. glabra in snakebite but not C. bonariensis, S. obtusifolia, W. ugandensis, and Z. usambarense. Further work is needed to isolate pure compounds from the effective plants and identify their mechanisms of action.

Ethnobotanical study of medicinal plants used by the people of Mosop, Nandi County in Kenya

Background: Throughout the history, nature has provided mankind with most of their basic needs, which include food, shelter, medicine, clothes, flavours, scents as well as raw materials. Given that they are an integral part of cultural heritage, medicinal plants have played a significant role in human healthcare systems around the world. Investigating various biological resources for use as medicines requires ethnomedicinal studies. Methods: Data on utilization of ethnomedicinal plants from local healers in Kenya's Mosop Sub-County in Nandi County was documented through open-ended, semi-structured questionnaires. A number of quantitative indices, such as the Use Citation (UC), Informant Consensus Factor (ICF), Use Value (UV), Frequency of Citation (FoC) and Relative Frequency of Citation (RFC) were used to convey the potential medical benefits, vitality and variety of the ethnomedicine. Results: 102 informants provided information on 253 ethnomedicinal plant species, classified into 74 families. There were 249 native plant species identified, along with few exotic species: Senegalia senegal (L.) Britton, Persea americana Mill, Carica papaya L. and Solanum betaceum Cav. Of all recorded species, 32% and 27% were herbs and trees, respectively. Among plant parts, leaves were most frequently utilized (27%) and roots (26%), while decoctions (21%) were the most widely used formulations. The dominant family was Asteraceae, with 28 species, followed by Lamiaceae, with 19 species. The highest ICF value was 0.778 for a number of parasitic and infectious illnesses, including ringworms, athlete's foot rot, tetanus, typhoid, intestinal parasites, abscesses, malaria, and amoebiasis. The study's data validates the region's widespread use of traditional medicinal plant remedies. Conclusion: The current study will lay a foundation of knowledge for future research investigations. The abundance of knowledge regarding ethnomedicinal species and their medicinal applications will stimulate further phytochemical and pharmacological research, which could lead to the discovery of potentially significant pharmaceuticals.

Avicenna's pharmacopeia for the treatment of animal bites

Envenomation is a common medical problem. The Canon of Medicine written by Avicenna is one of the reliable sources of Persian medicine. The present study aims to identify Avicenna's clinical pharmacology approach and the pharmacopeia used for the treatment of animal envenomations and also to evaluate the related data in light of the current medicine. The Canon of Medicine was searched using related Arabic keywords for the contents about the treatment of animal bites. A literature search was conducted in scientific databases including PubMed, Scopus, Google Scholar, and Web of Science to obtain relevant data. Avicenna recommended one hundred and eleven medicinal plants for the treatment of bites of vertebrate and invertebrate venomous animals including snakes, scorpions, spiders, wasps, and centipedes. He mentioned different methods of administrating these drugs including oral drugs, lotions, sprayed drugs, slow-dissolving tablets in the mouth, and enemas. Moreover, he paid special attention to pain relief in addition to specific treatments for animal bites. In the Canon of Medicine, Avicenna recommended several medicinal plants alongside analgesics for the management and treatment of animal envenomations. The current research elucidates the clinical pharmacology and pharmacopeia of Avicenna for the treatment of animal envenomations. Further research is encouraged to evaluate the efficacy of these therapeutic agents for the treatment of animal bites.

Cytotoxicity, acute and sub-chronic toxicities of the leaves of Bauhinia thonningii (Schumach.) Milne-Redh. (Caesalpiniaceae)

BACKGROUND

Bauhinia thonningii is a plant traditionally used against many human diseases such as gastric ulcers, fever, inflammations, coughs, dysentery, diarrhea, and malaria. In the present investigation, the cytotoxicity of methanol extract of Bauhinia thonningii leaves (BTL), fractions and the isolated phytoconstituents was determined in a panel of 9 human cancer cell lines including drug sensitive and multidrug-resistant (MDR) phenotypes. The acute and sub-chronic oral toxicity of BTL was investigated as well.

METHODS

Compounds were isolated using chromatographic techniques while their chemical structures were determined using spectroscopic methods. The resazurin reduction assay (RRA) was used to evaluate the cytotoxicity of samples, propidium iodide (PI) for apoptosis, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining for mitochondrial membrane potential (MMP) analysis, 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFH-DA) staining for the quantification of reactive oxygen species (ROS), whereas Caspase Glo assays were combined by means of flow cytometry. Furthermore, the toxicological investigations were performed as recommended by the Organization for Economic Cooperation and Development (OECD).

RESULTS

The botanicals as well as 6-C-methylquercetin-3,7-dimethyl ether (2), quercetin-3-O-L-rhamnopyranoside (5), quercetin-3-O-β-glucopyranoside (6), 6,8-C-dimethylkaempferol 3,7-dimethyl ether (7), and 6,8-C-dimethylkaempferol-3-methyl ether (8) had promising cytotoxic effects in the 9 tested cancer cell lines. The IC50 values below 20 µg/mL (botanicals) or 10 µM (compounds) on at least 1/9 tested cancer cell lines were considered. The best cytotoxic effects with IC50 values below 5 µM were achieved with compounds 7 against CEM/ADR5000 leukemia cells (2.86 µM) and MDA-MB-231-pcDNA breast adenocarcinoma cells (1.93 µM) as well as 8 against CCRF-CEM leukemia cells (3.03 µM), CEM/ADR5000 cells (2.42 µM), MDA-MB-231-pcDNA (2.34 µM), and HCT116 p53-/- cells (3.41 µM). BTL and compound 8 induced apoptotic cell death in CCRF-CEM cells through caspase activation, alteration of MMP, and increased ROS production. BTL did not cause any adverse effects in rats after a single administration at 5000 mg/kg or a repeated dose of 250 mg/kg body weight (b. w.).

CONCLUSION

Bauhinia thonningii and its constituents are sources of cytotoxic drugs that deserve more in-depth studies to develop novel antiproliferative phytomedicine to fight cancer including resistant phenotypes.

Three finger toxins of elapids: structure, function, clinical applications and its inhibitors

The WHO lists snakebite as a "neglected tropical disease". In tropical and subtropical areas, envenoming is an important public health issue. This review article describes the structure, function, chemical composition, natural inhibitors, and clinical applications of Elapids' Three Finger Toxins (3FTX) using scientific research data. The primary venomous substance belonging to Elapidae is 3FTX, that targets nAChR. Three parallel β-sheets combine to create 3FTX, which has four or five disulfide bonds. The three primary types of 3FTX are short-chain, long-chain, and nonconventional 3FTX. The functions of 3FTX depend on the specific toxin subtype and the target receptor or ion channel. The well-known effect of 3FTX is probably neurotoxicity because of the severe consequences of muscular paralysis and respiratory failure in snakebite victims. 3FTX have also been studied for their potential clinical applications. α-bungarotoxin has been used as a molecular probe to study the structure and function of nAChRs (Nicotinic Acetylcholine Receptors). Acid-sensing ion channel (ASIC) isoforms 1a and 1b are inhibited by Mambalgins, derived from Black mamba venom, which hinders their function and provide an analgesic effect. α- Cobra toxin is a neurotoxin purified from Chinese cobra (Naja atra) binds to nAChR at the neuronal junction and causes an analgesic effect for moderate to severe pain. Some of the plants and their compounds have been shown to inhibit the activity of 3FTX, and their mechanisms of action are discussed.

Pre-clinical efficacy of African medicinal plants used in the treatment of snakebite envenoming: A systematic review

The World Health Organization has listed Snakebite Envenoming (SBE) as a priority neglected tropical disease, with a worldwide annual snakebite affecting 5.4 million people and injuring 2.7 million lives. In many parts of rural areas of Africa and Asia, medicinal plants have been used as alternatives to conventional antisnake venom (ASV) due in part to inaccessibility to hospitals. Systemic reviews (SR) of laboratory-based preclinical studies play an essential role in drug discovery. We conducted an SR to evaluate the relationship between interventional medicinal plants and their observed effects on venom-induced experiments. This SR was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The Modified collaborative approach to meta-analysis and review of animal data from experimental studies (CAMARADES) and SYRCLE's risk of bias tools were used to appraise the included studies. Data were searched online in Medline via PubMed, Embase via OVID, and Scopus. Studies reporting in vivo and in vitro pharmacological activities of African medicinal plants/extracts/constituents against venom-induced pathologies were identified and included for screening. Data from the included studies were extracted and synthesized. Ten studies reported statistically significant percentage protection (40-100%) of animals against venom-induced lethality compared with control groups that received no medicinal plant intervention. Sixteen studies reported significant effects (p ≤ 0.05) against venom-induced pathologies compared with the control group; these include hemolytic, histopathologic, necrotic, and anti-enzymatic effects. The plant family Fabaceae has the highest number of studies reporting its efficacy, followed by Annonaceae, Malvaceae, Combretaceae, Sterculiaceae, and Olacaceae. Some African medicinal plants are preclinically effective against venom-induced lethality, hematotoxicity, and cytotoxicity. The evidence was extracted from three in vitro studies, nine in vivo studies, and five studies that combined both in vivo and in vitro models. The effective plants belong to the Fabaceae family, followed by Malvaceae, and Annonaceae.

Appraising the therapeutical potentials of Alchornea laxiflora (Benth.) Pax & K. Hoffm., an underexplored medicinal herb: A systematic review

Ethnopharmacological relevance: Alchornea laxiflora (Benth.) Pax & K. Hoffm. (Euphorbiaceae) is an important traditional medicinal plant grown in tropical Africa. The stem, leaves, and root have been widely used in the folk medicine systems in Nigeria, Cameroon, South Africa, and Ghana to treat various ailments, including inflammatory, infectious, and central nervous system disorders, such as anxiety and epilepsy. Material and methods: The scientific name of the plant was validated using the "The Plant List," "Kew Royal Botanic Gardens," and Tropicos Nomenclatural databases. The literature search on A. laxiflora was performed using electronic search engines and databases such as Google scholar, ScienceDirect, PubMed, AJOL, Scopus, and Mendeley. Results: To the best of our knowledge, no specific and detailed review has been reported on A. laxiflora. Consequently, this review provides an up-to-date systematic presentation on ethnobotany, phytoconstituents, pharmacological activities, and toxicity profiles of A. laxiflora. Phytochemical investigations disclosed the presence of important compounds, such as alkaloids, flavonoids, phenolics, terpenoids, and fatty acids. Furthermore, various pharmacological activities and traditional uses reported for this botanical drug were discussed comprehensively. Conclusion: This systemic review presents the current status and perspectives of A. laxiflora as a potential therapeutic modality that would assist future researchers in exploring this African botanical drug as a source of novel drug candidates for varied diseases.

Ethnomedicinal plants used for treatment of snakebites in Tanzania - a systematic review

CONTEXT

Snake envenomation is one of the neglected health problems in Tanzania. Since most people, especially in rural areas, suffer from its burden, their cases are not documented due to reliance on medicinal plants. Despite the pivotal role of medicinal plants in treating snakebites, there is a paucity of information.

OBJECTIVE

This review documents medicinal plants used to treat snakebites in Tanzania.

MATERIALS AND METHODS

A systematic search using electronic databases such as PubMed, Google Scholar, Scopus, Science Direct and grey literature was conducted to retrieve relevant information on medicinal plants used to treat snakebites in Tanzania. The review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The obtained information from 19 published articles was organized and analysed based on citation frequency.

RESULTS

A total of 109 plant species belonging to 49 families are used as snakebite antivenom in Tanzania. Fabaceae had the highest number of medicinal plants (19.3%). The dominant plant growth forms were trees (35%) and shrubs (33%). Roots were the most frequently used plant part (54%), followed by leaves (26%) and bark (11%). Annona senegalensis Pers. (Annonaceae), Dichrostachys cinerea (L.) (Fabaceae), Suregada zanzibariensis Baill. (Euphorbiaceae), Antidesma venosum E.Mey. ex Tul. (Phyllanthaceae), Cissampelos pareira L. (Menispermaceae) and Dalbergia melanoxylon Guill. & Perr. (Fabaceae) were the most cited medicinal plants.

CONCLUSIONS

Tanzania has diverse plants used for snakebite treatment; a few have been analysed for their bioactive components. Further study of the phytochemicals may provide scientific information to develop snakebite drugs.

Insights to the tribe Haemantheae of the South African Amaryllidaceae

ETHNOPHARMACOLOGICAL RELEVANCE

The family Amaryllidaceae has been documented in traditional systems of medicine around the globe. Its member tribe Haemantheae occurs chiefly in South Africa, where around twenty of its species are identifiable with a wide variety of functions in such practices.

AIM OF THE STUDY

This account details work published from 2013 to 2020 on the tribe Haemantheae involving Clivia, Cryptostephanus, Haemanthus, Scadoxus and Gethyllis. Focus is maintained on the traditional medicinal aspects, pharmacological activities and identification of the active principles. Significant effort is also made to outline the molecular basis to some of these effects.

MATERIALS AND METHODS

The major search engine platforms including, SciFinder, Scopus, ScienceDirect, PubMed and Google Scholar were utilized at the literature consolidation stage. Keywords engaged in the process included 'Amaryllidaceae' and 'Haemantheae' as well as individual genera and specie names.

RESULTS

Twenty-four species of the five genera were encountered over the designated time frame. New traditional medicinal information has emerged on nine of these species, where usage ranged from the treatment of wounds and infections, circulatory and gastrointestinal issues to AIDS and TB. Significant amounts of new data also appeared in relation to the antimicrobial, anti-inflammatory, antioxidant, anticholinesterase, antidepressive and cytotoxic effects of these plants. Potent activities were observed in some instances, as they were in regards to the anti-inflammatory effects of some Gethyllis species in their cyclooxygenase-inhibitory effects. The entities behind these activities, with few exceptions, were shown to be isoquinoline alkaloids which are known to dominate the chemistry of the Amaryllidaceae. Interesting observations were also made for the mechanisms behind some of the effects, notably in the inflammatory and motorneuron disease arenas.

CONCLUSIONS

The tribe Haemantheae has proved to be a rich and diverse platform for studies of the Amaryllidaceae in the key areas of traditional medicine, pharmacology and phytochemistry. Indigenous knowledge has played a significant role in guiding the biological evaluations, while identification of the active principles has been bolstered by the exceedingly rich alkaloid diversity of the Amaryllidaceae. As such, Haemantheae should continue to feature prominently in drug discovery efforts targeted at the family.

Health benefits and biological activities of spiny monkey orange (Strychnos spinosa Lam.): An African indigenous fruit tree

ETHNOPHARMACOLOGICAL RELEVANCE

Spiny monkey orange (Strychnos spinosa Lam.) is an African endemic fruit tree that is widely consumed by humans and animals for its nutritional value. In folk medicine, different parts of S. spinosa are widely used for the management of the health and well-being of humans and livestock.

AIM

We provide a critical appraisal on the ethnobotanical uses, nutritional and pytochemical as well as the biological activities of S. spinosa.

METHODS

Articles were mined from online databases such as Google Scholar, PubMed, Science Direct, SciELO and SpringerLink. We captured research outputs that aligned with the scope of the review.

RESULTS

Strychnos spinosa remains a commonly consumed fruit due to its high nutritional (e.g. carbohydrates, crude protein and fats) content and energy. In folk medicine, different parts of S. spinosa are prescribed as remedy for diverse medical conditions especially for treating malaria, diabetes, snakebites, skin-related conditions and sexually transmitted infections in humans as well as sleeping sickness in livestock. Together with essential oils, more than 25 compounds have been profiled using Gas chromatography-mass spectrometry (GC-MS), and approximately 45 compounds have been isolated and structurally elucidated using diverse spectroscopic techniques such as UV-visible, Infrared (IR), Nuclear Magnetic Resonance (NMR) and mass spectroscopy (MS). Strychnos spinosa exerts varying degrees of biological activities against different microorganisms (bacteria and fungi) and parasites (plasmodia, trypanosomes and ticks) responsible for many diseases in humans and livestock. Furthermore, low to moderate enzyme-inhibitory effects of S. spinosa extracts suggest its ability to mitigate pains, inflammations and diabetics as well as snakebite venom. Increasing evidence from the in vivo studies support the use of the plant as a popular remedy for managing diabetics in folk medicine. The low cytotoxic effect of the plant extracts against different cell lines could be an indication of its relative safety.

CONCLUSION

Strychnos spinosa exhibits various health-promoting benefits due to its diverse nutritional and phytochemical constituents. Given that the majority of the existing evidence on these aforementioned therapeutic properties and safety are in vitro-based, the clinical significance of these results remain limited.

Botanical treatments for snakebite in rural Ghana: A narrative review

ETHNOPHARMACOLOGICAL RELEVANCE

In the countryside, there are some limitations with the use of venom antisera to manage snake bites. Due to poor access to healthcare and as a result of the difficulty in receiving treatment for cases of snake bites, most rural people in Ghana, a West African country, rely on plant medicine as a first aid to manage cases of venomous snakebite. This calls for more research into the species of plants used to medically manage snakebite envenomation.

AIM OF THE STUDY

This review sought to present plants that are used in managing snakebite cases and also gather data supporting their use.

METHODOLOGY

This is a systematic search and review of information obtained from textbooks and databases such as PubMed and ScienceDirect between January 1975 and August 2020.

RESULTS

A search done identified 43 plant species and these were found to belong to 25 taxonomic families with the most frequent ones being, Fabaceae, Euphorbiaceae, Apocynaceae, and Solanaceae. Experimental data gathered indicate that among the many plants identified to be used to manage snakebites, only 5 were found with anti-venom in vitro and in vivo evidence-based data.

CONCLUSION

Data collated hint that a few plant species identified namely Anacardium occidentale, Euphorbia hirta, Mimosa pudica, Musa paradisiaca and Mangifera indica, work by targeting diverse physiopathological and biochemical processes involved in the clinical manifestations of snakebites. This review has also unearthed knowledge gaps that can form the basis for broad investigations and development of these and other medicinal plants into useful anti-venom medications.

Antihyaluronidase and Alkaline Phosphatase (ALP) Activities of Medicinal Plants to Combat Echis carinatus Venom-Induced Toxicities

Snakebite is one of the most neglected diseases of developing countries. Deaths due to snakebite envenoming are quite high in Pakistan, and many deaths are caused by Echis carinatus envenomation. Traditional use of medicinal plants against snakebites is a common practice in Pakistan due to countless benefits. The current study was performed with the objective to evaluate eighteen Pakistani medicinal plants inhibitory potential against hyaluronidase and alkaline phosphatase enzymes of Pakistani Echis carinatus venom. Hyaluronidase activity (0.2-1.6 mg/0.1 mL) and alkaline phosphatase activity (0.1-0.8 mg/0.1 mL) were measured in dose-dependent manner. Crude methanolic extracts of medicinal plants were used for in vitro investigation of their inhibitory activity against toxic enzymes. All active plants were fractioned using different solvents and were again analyzed for inhibitory activity of same enzymes. Results indicated all plants were able to neutralize hyaluronidase that Swertia chirayita (Roxb. ex Flem.) Karst., Terminalia arjuna Wight and Arn, Rubia cordifolia Thumb., and Matthiola incana (L.) R.Br. inhibited maximum hyaluronidase activity equivalent to standard reference (p > 0.5). Pakistani medicinal plants are dense with natural neutralizing metabolites and other active phytochemicals which could inhibit hyaluronidase activity of Pakistani Echis carinatus venom. Further advanced studies at molecular level could lead us to an alternative for envenoming of Pakistani Echis carinatus venom.

Ethnopharmacological uses, phytochemistry and pharmacological activities of Guiera senegalensis J.F. Gmel. (Combretaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Guiera senegalensis J.F. Gmel. (Combretaceae), commonly known as "Gubeish" in Sudan, is a small shrub abundant in semi-desert areas of the Sudano-Sahelian zone. It is widely used in African traditional medicine as a tonic and for the treatment of many complications such as respiratory and gastrointestinal disorders, microbial and parasitic infections.

AIM OF THE REVIEW

The aim of this review is to critically analyze the reports on the traditional uses, ethnopharmacological studies, chemical constituents and pharmacological activities of G. senegalensis.

METHODS

Scientific information on G. senegalensis was retrieved from the online bibliographic databases (e.g. like MEDLINE/PubMed, SciFinder, Web of Science, Google Scholar, Scopus, Elsevier, SpringerLink). Other scientific information was acquired from secondary resources including books and proceedings, library catalogs, and dissertations.

RESULTS

G. senegalensis is reported to be widely used traditionally for the treatment of various diseases in many African countries. Most of these studies are reported from Burkina Faso, Guinea, Mali, Nigeria, Senegal, and Sudan. Phytochemical studies have revealed the presence of a total of 46 compounds belonging to major phytochemical classes namely; phenolic compounds, alkaloids, and triterpenes. Among them, galloylquinic acid derivatives and flavonoids are the most frequently reported constituents. The extracts and compounds have shown diverse biological activities including antimicrobial, anti-inflammatory, antiprotozoal activities and activities against gastrointestinal and respiratory disorders.

CONCLUSION

G. senegalensis is widely used in most African traditional medicine systems and used among African people for the treatment of many diseases. Although there are many reports on its biological activities, most of these studies are based on in vitro systems and only very few are based on in vivo systems. Also, some of these pharmacological data are insufficient and lack essential parameters such as proper positive and negative controls, and calculating the minimum inhibitory concentration (MIC) values. From these studies, it is difficult to assess the future clinical potential of this plant without detailed studies in animal models or in humans. Similarly, there are not many reports on the action mechanism of the extracts and compounds. Future studies should focus to explore the therapeutic potential of G. senegalensis with advance experimental protocols and cutting-edge technologies.

Phytobiological-facilitated Production of Silver Nanoparticles From Selected Non-cultivated Vegetables in Nigeria and Their Biological Potential

Objectives

Plant-mediated synthesis [silver (Ag) to form Ag nanoparticles (AgNPs)] is becoming progressively well accepted in many scientific and pharmaceutical fields. The aim of this study was to synthesize AgNPs using air-dried leaves of four neglected vegetables, i.e. Ceratotheca sesamoides, Ceiba pentandra, Crassocephalum crepidioides, and Launaea taraxacifolia.

Materials and Methods

Ultraviolet-visible (UV-Vis) spectroscopy, fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) were used for characterization. Cell stabilization membrane and lipoxidase assays were used to determine used to assess the antiinflammatory activities while 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) assays were used to assess the antioxidant activities of AgNPs [L. taraxacifolia-AgNPs, C. sesamoides Ag nanoparticles (CS-AgNPs), C. pentandra Ag nanoparticles (CP-AgNPs), and C. crepidioides AgNPs (CC-AgNPs)].

Results

The UV-Vis spectra of the synthesized NPs displayed absorption bands at around 360-440 nm, which is a characteristic band for AgNPs. The SEM image showed that the AgNPs formed were spherical in morphology. CC-AgNPs exhibited the most significant inhibitory activity against human red blood cell membrane stabilizasyonu [median inhibitory concentration (IC₅₀): 32.2 μg/mL] while CS-AgNPs displayed the most significant inhibitory activity against lipoxygenases (IC₅₀: 32.8 μg/mL). CP-AgNPs exhibited the most significant antioxidant effect against both ABTS and DPPH (IC₅₀: 5.5 and 6.4 μg/mL) when compared to ascorbic acid (IC₅₀: 4.7 μg/mL).

Conclusion

The synthesized AgNPs were found to be stable and the FTIR evidence suggested that the phytochemicals in the vegetables might have played an important role in the reduction and stabilization of AgNPs. This work showed that the synthesized AgNPs from non-cultivated vegetables can find relevance and application in health, drugs, food and environmental science. The evidences herein further confirmed their ethnopharmacological applications.

Efficient identification of Acetylcholinesterase and Hyaluronidase inhibitors from Paeonia parnassica extracts through a HeteroCovariance Approach

ETHNOPHARMACOLOGICAL RELEVANCE

On the basis of the relevant reference in the poem Theriaca of the ancient Greek physician Nicander and its traditional use, Paeonia parnassica was selected for the evaluation of two extracts obtained from the roots and aerial parts to inhibit hydrolytic enzymes involved in snake envenomation. The secondary metabolites which contribute to these activities were detected through a novel HeteroCovariance NMR based approach. Afterwards these ingredients were isolated, identified and evaluated for their inhibitory potency.

AIM OF THE STUDY

The identification of acetylcholinesterase and hyaluronidase inhibitors from Paeonia parnassica extracts was used as a case study for the introduction of a recently developed methodology to evaluate ethnopharmacological data and exploit them for the discovery of bioactive natural compounds. This process is based on the fractionation of the selected extracts and the simultaneous phytochemical analysis and biological assessment of the resulting fractions, which permits the rapid detection of the specified secondary metabolites prior to any laborious and time-consuming purification.

MATERIALS AND METHODS

The roots and aerial parts of P. parnassica were extracted using methanol: water 50:50 and the two resulted extracts were fractionated by Centrifugal Partition Chromatography. The obtained fractions were evaluated in-vitro for their ability to inhibit acetylcholinesterase and hyaluronidase enzymes and their ¹H NMR spectra were recorded. The biological activity was statistically correlated with the spectral data through the HeteroCovariance Approach (HetCA). Finally the purification, identification and biological evaluation of targeted secondary metabolites were carried out.

RESULTS

The general chemical structures and some explicit secondary metabolites which contribute (e.g. gallotannins, gallic acid derivatives) or not (characteristic "cage-like" monoterpenes of the genus, glycosylated flavonoids) to the anti-acetylcholinesterase and anti-hyaluronidase activities were detected through HetCA. The consequent isolation and biological evaluation of targeted compounds were performed in order to validate the effectiveness and precision of the methodology. This procedure revealed the most active ingredients of both extracts obtained from roots and aerial parts against the above mentioned biological targets, as well as other compounds possessing moderate activity.

CONCLUSIONS

The results of this study contributed to the verification of the ancient text Theriaca regarding the use of Paeonia parnassica to treat the snake bite symptoms. Furthermore, the ingredients of the Paeonia parnassica extracts, which were responsible for their anti-cholinesterase and anti-hyaluronidase activities, were determined applying a HetCA methodology before their isolation. Therefore, the current work provides clear evidence that HetCA could consist an efficient tool for the exploitation of traditional medicine information in order to discover bioactive natural compounds and develop new pharmacotherapies which serve the needs of contemporary medicine.

A review of traditional uses, phytochemistry and pharmacology of the genus Indigofera

ETHNOPHARMACOLOGICAL RELEVANCE

Indigofera is the third-largest genus in the family of Fabaceae, with approximately 750 species. It is distributed across all tropical regions. Indigofera species are widely employed in traditional medicine all around the world, against many ailments. Thus, based on these medicinal properties, various investigations have been undertaken in order to appraise the pharmacological activities and the chemical composition of these species. A recent paper provides a summary of the phytochemistry and pharmacology of the genus Indigofera. Consequently, this review is a continuation of this previous study by updating some data and adding information about the phylogeny and traditional uses of the genus.

AIM OF THE STUDY

To provide an overview of the phylogeny, traditional uses, phytochemistry, pharmacology and toxicity of the genus Indigofera, and to identify the remaining gaps and thus supply a basis for further investigations.

MATERIALS AND METHODS

A review of the literature was performed by consulting scientific databases such as 'ScienceDirect', 'PubMed', 'Google Scholar' and 'SpringerLink' and using the keyword Indigofera.

RESULTS

Over 60 Indigofera species are reported in traditional medicine. The uses depend on the country and the species, but similarities have been noticed. Indeed, treatments of gastrointestinal disorders, inflammatory conditions and pain, skin ailments, and respiratory and infectious diseases are recurring. Phytochemical studies have led to the identification of more than 200 compounds, notably flavonoids and terpenoids. Many pharmacological activities have been demonstrated, particularly antimicrobial, cytotoxic and anti-inflammatory activities, and thus allowed to assert most of the traditional uses of the genus. Some active compounds have been isolated and have shown remarkable therapeutic potential, like the alkaloid indirubin, which is currently being clinically trialed.

CONCLUSIONS

The data on the genus Indigofera are extensive, but gaps still remain. Indeed, some promising species have not been assessed for their phytochemistry and/or pharmacology and thus remain unexplored. Moreover, relatively few active compounds have been isolated and tested for their biological activity, and studies to explain their mechanism of action are nearly inexistent. Furthermore, some pharmacological studies have inappropriate methodologies that make the results difficult to interpret. Consequently, further in-depth and relevant research is required to supplement the knowledge on this wide-ranging genus and to confirm its reported therapeutic potential.

Perspective on the Therapeutics of Anti-Snake Venom

Snakebite envenomation is a life-threatening disease that was recently re-included as a neglected tropical disease (NTD), affecting millions of people in tropical and subtropical areas of the world. Improvement in the therapeutic approaches to envenomation is required to palliate the morbidity and mortality effects of this NTD. The specific therapeutic treatment for this NTD uses snake antivenom immunoglobulins. Unfortunately, access to these vital drugs is limited, principally due to their cost. Different ethnic groups in the affected regions have achieved notable success in treatment for centuries using natural sources, especially plants, to mitigate the effects of snake envenomation. The ethnopharmacological approach is essential to identify the potential metabolites or derivatives needed to treat this important NTD. Here, the authors describe specific therapeutic snakebite envenomation treatments and conduct a review on different strategies to identify the potential agents that can mitigate the effects of the venoms. The study also covers an increased number of literature reports on the ability of natural sources, particularly plants, to treat snakebites, along with their mechanisms, drawbacks and future perspectives.

Management and cost of snakebite injuries at a teaching and referral hospital in Western Kenya

Background: Data on the cost of snakebite injuries may inform key pillars of universal health coverage including proper planning, allocation, and utility of resources. This study evaluated the injuries, management, and costs resulting from snakebites at Jaramogi Oginga Odinga Teaching and Referral Hospital (JOOTRH) in Kenya.  Methods: In total, medical records of 127 snakebite victims attending JOOTRH between January 2011 and December 2016 were purposely selected and data on the age, gender, type of residence (urban or rural), part of the body bitten, time of bite, injuries, pre-hospital first aid, time to hospital, length of stay, treatment, and costs were collected. Regression analysis was used to predict the total indirect cost of snakebite injuries and p≤ 0.05 was considered significant. Mortality and loss of income of hospitalized victims were considered as direct costs. Results: It was found that 43 victims were 13-24 years of age, 64 were female, 94 were from rural areas, 92 were bitten on the lower limbs, 49 were bitten between 6.00 pm and midnight, 43 attempted pre-hospital first aid, and the median time to hospital was 4.5 hours. Antivenom, supportive therapy, antibiotics, antihistamines, corticosteroids, analgesics, and non-steroidal anti-inflammatory drugs were used. Cellulitis, compartment syndrome, gangrenous foot, psychiatric disorder, and death were the main complications. Most victims spent 1-5 days in hospital and the median cost of treating a snakebite was 2652 KES (~$26). Drugs, ward charges, and nursing procedures were the highest contributors to the total indirect cost. Victims hospitalized for 6-10 days and >10 days incurred 32% and 62% more costs, respectively, compared to those hospitalized for 1-5 days.  Conclusions: The longer snakebite victims are hospitalized, the higher the cost incurred. Continuous medical education on the correct management of snakebites should be encouraged to minimize complications that may increase hospital stays and costs incurred.

Ethnomedicinal plants used for snakebite treatments in Ethiopia: a comprehensive overview

Traditional medicine plays an important role in the daily lives of people living in rural parts of Ethiopia. Despite the fact that Ethiopia has a long history of using traditional medicinal plants as an alternative medicine source, there is no checklist compiling these plants used for snakebite treatment. This review collected and compiled available knowledge on and practical usage of such plants in the country. A literature review on medicinal plants used to treat snakebites was conducted from 67 journal articles, PhD dissertation and MSc theses available online. Data that summarize scientific and folk names, administration methods, plant portion used for treatment and method of preparation of recipes were organized and analyzed based on citation frequency. The summarized results revealed the presence of 184 plant species distributed among 67 families that were cited for treating snakebite in Ethiopia. In this literature search, no single study was entirely dedicated to the study of traditional medicinal plants used for the treatment of snakebite in Ethiopia. Most of the species listed as a snakebite remedy were shrubs and climbers (44%) followed by herbs (33%) and trees (23%). Fabaceae was the most predominant family with the greatest number of species, followed by Solanaceae and Vitaceae. Remedies are mainly prepared from roots and leaves, through decoctions, infusions, powders and juices. Most remedies were administered orally (69%). The six most frequently mentioned therapeutically important plants were Nicotiana tabacum, Solanum incanum, Carissa spinanrum, Calpurnia aurea, Croton macrostachyus and Cynodon dactylon. Authors reviewed the vegetal substances involved in snakebite management and their action mode. In addition to screening the biologically active ingredients and pharmacological activities of these plant materials, future studies are needed to emphasize the conservation and cultivation of important medicinal plants of the country.

Biochemical and molecular characterization of the hyaluronidase from Bothrops atrox Peruvian snake venom

Snake venoms are a rich source of enzymes such as metalloproteinases, serine proteinases phospholipases A2 and myotoxins, that have been well characterized structurally and functionally. However, hyaluronidases (E.C.3.2.1.35) have not been studied extensively. In this study, we describe the biochemical and molecular features of a hyaluronidase (Hyal-Ba) isolated from the venom of the Peruvian snake Bothrops atrox. Hyal-Ba was purified by a combination of ion-exchange and gel filtration chromatography. Purified Hyal-Ba is a 69-kDa (SDS-PAGE) monomeric glycoprotein with an N-terminal amino acid sequence sharing high identity with homologous snake venom hyaluronidases. Detected associated carbohydrates were hexoses (16.38%), hexosamines (2.7%) and sialic acid (0.69%). Hyal-Ba selectively hydrolyzed only hyaluronic acid (HA; specific activity = 437.5 U/mg) but it did not hydrolyze chondroitin sulfate or heparin. The optimal pH and temperature for maximum activity were 6.0 and 40 °C, respectively, and its Km was 0.31 μM. Its activity was inhibited by EDTA, iodoacetate, 2-mercaptoethanol, TLCK and dexamethasone. Na⁺ and K⁺ (0.2 M) positively affect hyaluronidase activity; while Mg²⁺, Br²⁺, Ba²⁺, Cu²⁺, Zn²⁺, and Cd²⁺ reduced catalytic activity. Hyal-Ba potentiates the hemorrhagic and hemolytic activity of whole venom, but decreased subplantar edema caused by an l-amino acid oxidase (LAAO). The Hyal-Ba cDNA sequence (2020 bp) encodes 449 amino acid residues, including the catalytic site residues (Glu135, Asp133, Tyr206, Tyr253 and Trp328) and three functional motifs for N-linked glycosylation, which are conserved with other snake hyaluronidases. Spatial modeling of Hyal-Ba displayed a TIM-Barrel (α/β) fold and an EGF-like domain in the C-terminal portion. The phylogenetic analysis of Hyal-Ba with other homologous Hyals showed the monophyly of viperids. Further, Hyal-Ba studies may extend our knowledge of B. atrox toxinology and provides insight to improve the neutralizing strategies of therapeutic antivenoms.

Anti-Influenza Triterpene Saponins from the Bark of Burkea africana

In an in vitro cytopathic effect inhibition assay with the H3N2 influenza virus A/Hong Kong/68 (HK/68), the bark extract of Burkea africana was found to be a promising antiviral lead with an IC₅₀ value of 5.5 μg/mL without noteworthy cytotoxicity in Madin Darby canine kidney cells. After several chromatographic steps, triterpene saponins of the lupane and oleanane types were identified as the bioactive principles. In total, eight new triterpene saponins (1-8) with four so far undescribed aglycone structures were isolated and characterized via HRESIMS, GC-MS, and 1D and 2D NMR spectroscopy. Their anti-influenza virus activity on HK/68 and the 2009 pandemic H1N1 strain A/Jena/8178/09 revealed the most potent effects by compounds 7 and 8, with IC₅₀ values between 0.05 and 0.27 μM. This is the first time triterpene saponins have been reported as constituents of the investigated plant material.

Cosmetic potentials of Prunus domestica L. leaves

BACKGROUND

The current study presents new insight on the phytochemical content and biological activities of five Prunus domestica L. varieties ('Quetsche blanche de Létricourt', 'Mirabelle de Nancy', 'Perdrigon violet', 'Mirabelle de Provence', 'Reine-claude dorée').

RESULTS

The plum leaves were found to possess promising anti-aging activities by their capacity to inhibit 1,1-diphenyl-2-picrylhydrazyl (DPPH), elastase, hyaluronidase and lipoxygenase. After solid phase extraction (SPE), chlorogenic acid, rutin, quercetin and their derivatives were putatively identified by high-performance liquid chromatography coupled with tandem mass spectrometry using an electrospray ionization source (HPLC/ESI-MS/MS).

CONCLUSION

The plum leaf, a by-product, provides an interesting valuable resource for use as a natural cosmetic product or as a food supplement. © 2017 Society of Chemical Industry.

Naphthalene glycosides in the Thai medicinal plant Diospyros mollis

This study evaluated methanol extracts from the leaves and branches of the Thai medicinal plant Diospyros mollis (Ebenaceae). Seven triterpenes and 22 aromatic compounds, including five new compounds, were isolated, and their structures were determined. The new compounds had the following structures: diospyrol glycoside (makluoside A, 1), 8,8'-di-O-6-β-D-apiofuranosyl-β-D-glucopyranosyl-6,6'-dimethyl-2,3'-binaphthalene-1-ol-1',4'- dione (makluoside B, 2), and 3-methyl-1,8- naphthalenediol glycosides (makluosides C-E, 3-5). Makluoside B is the first example of a naphthoquinone glycoside that has both a 3-methyl-1,8-naphthalenediol unit and a 5-hydroxy-7-methyl-1,4-naphthoquinone unit. The hyaluronidase inhibitory activity of the isolates was evaluated, revealing that one of the triterpene derivatives possessed moderate inhibitory activity.

Medicinal Plants for the Treatment of Local Tissue Damage Induced by Snake Venoms: An Overview from Traditional Use to Pharmacological Evidence

Snakebites are a serious problem in public health due to their high morbimortality. Most of snake venoms produce intense local tissue damage, which could lead to temporary or permanent disability in victims. The available specific treatment is the antivenom serum therapy, whose effectiveness is reduced against these effects. Thus, the search for complementary alternatives for snakebite treatment is relevant. There are several reports of the popular use of medicinal plants against snakebites worldwide. In recent years, many studies have been published giving pharmacological evidence of benefits of several vegetal species against local effects induced by a broad range of snake venoms, including inhibitory potential against hyaluronidase, phospholipase, proteolytic, hemorrhagic, myotoxic, and edematogenic activities. In this context, this review aimed to provide an updated overview of medicinal plants used popularly as antiophidic agents and discuss the main species with pharmacological studies supporting the uses, with emphasis on plants inhibiting local effects of snake envenomation. The present review provides an updated scenario and insights into future research aiming at validation of medicinal plants as antiophidic agents and strengthens the potentiality of ethnopharmacology as a tool for design of potent inhibitors and/or development of herbal medicines against venom toxins, especially local tissue damage.

Medicinal plants used to treat snakebite in Central America: Review and assessment of scientific evidence

ETHNOPHARMACOLOGICAL RELEVANCE

Every year between 1.2 and 5.5 million people worldwide are victims of snakebites, with about 400,000 left permanently injured. In Central America an estimated 5500 snakebite cases are reported by health centres, but this is likely to be an underestimate due to unreported cases in rural regions. The aim of this study is to review the medicinal plants used traditionally to treat snakebites in seven Central American countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama.

MATERIALS AND METHODS

A literature search was performed on published primary data on medicinal plants of Central America and those specifically pertaining to use against snakebites. Plant use reports for traditional snakebite remedies identified in primary sources were extracted and entered in a database, with data analysed in terms of the most frequent numbers of use reports. The scientific evidence that might support the local uses of the most frequently reported species was also examined.

RESULTS

A total of 260 independent plant use reports were recorded in the 34 sources included in this review, encompassing 208 species used to treat snakebite in Central America. Only nine species were reported in at least three studies: Cissampelos pareira L., Piper amalago L., Aristolochia trilobata L., Sansevieria hyacinthoides (L.) Druce, Strychnos panamensis Seem., Dorstenia contrajerva L., Scoparia dulcis L., Hamelia patens Jacq., and Simaba cedron Planch. Genera with the highest number of species used to treat snakebite were Piper, Aristolochia, Hamelia, Ipomoea, Passiflora and Peperomia. The extent of the scientific evidence available to understand any pharmacological basis for their use against snakebites varied between different plant species.

CONCLUSION

At least 208 plant species are traditionally used to treat snakebite in Central America but there is a lack of clinical research to evaluate their efficacy and safety. Available pharmacological data suggest different plant species may target different symptoms of snakebites, such as pain or anxiety, although more studies are needed to further evaluate the scientific basis for their use.

Ethnopharmacology, Chemistry and Biological Properties of Four Malian Medicinal Plants

The ethnopharmacology, chemistry and pharmacology of four Malian medicinal plants, Biophytum umbraculum, Burkea africana, Lannea velutina and Terminalia macroptera are reviewed. These plants are used by traditional healers against numerous ailments: malaria, gastrointestinal diseases, wounds, sexually transmitted diseases, insect bites and snake bites, etc. The scientific evidence for these uses is, however, limited. From the chemical and pharmacological evidence presented here, it seems possible that the use in traditional medicine of these plants may have a rational basis, although more clinical studies are needed.

Protective Effect of the Plant Extracts of Erythroxylum sp. against Toxic Effects Induced by the Venom of Lachesis muta Snake

Snake venoms are composed of a complex mixture of active proteins that induce toxic effects, such as edema, hemorrhage, and death. Lachesis muta has the highest lethality indices in Brazil. In most cases, antivenom fails to neutralize local effects, leading to disabilities in victims. Thus, alternative treatments are under investigation, and plant extracts are promising candidates. The objective of this work was to investigate the ability of crude extracts, fractions, or isolated products of Erythroxylum ovalifolium and Erythroxylum subsessile to neutralize some toxic effects of L. muta venom. All samples were mixed with L. muta venom, then in vivo (hemorrhage and edema) and in vitro (proteolysis, coagulation, and hemolysis) assays were performed. Overall, crude extracts or fractions of Erythroxylum spp. inhibited (20%-100%) toxic effects of the venom, but products achieved an inhibition of 4%-30%. However, when venom was injected into mice before the plant extracts, hemorrhage and edema were not inhibited by the samples. On the other hand, an inhibition of 5%-40% was obtained when extracts or products were given before venom injection. These results indicate that the extracts or products of Erythroxylum spp. could be a promising source of molecules able to treat local toxic effects of envenomation by L. muta venom, aiding in the development of new strategies for antivenom treatment.

Nutritional and pharmacological potential of the genus Ceratotheca--An underutilized leafy vegetable of Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Ceratotheca (Pedaliaceae) is an endemic African genus comprising of five species. The genus is commonly used as a leafy vegetable with medicinal properties.

AIM OF THE REVIEW

The review aims to highlight the unexplored nutritional and pharmacological potential of African indigenous leafy vegetables Ceratotheca sesamoides and triloba, in order to conserve and domesticate these species.

METHODS

The information was obtained from various search engines such as Scopus, Google Scholar and Web of Science as well as Ethnobotanical books.

RESULTS

Ceratotheca sesamoides and triloba have good nutritional potential. The species are high in energy levels, fat content, proteins and carbohydrate values. The species have also been reported to have good antibacterial, antidiarrhoeal, antidiabetic, antiplasmodial and antiviral properties. These species have slight toxicity and cytotoxic activity when extracted at high concentrations but no mutagenic activity was detected.

CONCLUSIONS

To date, few studies have documented the usage (nutrition and pharmacology) of Ceratotheca sesamoides and triloba. More studies investigating the nutritional content as well as methods of its improvement are necessary if the plant is to be included as a domesticated vegetable crop. Safety and toxicity analysis of this leafy vegetable need to be extensively studied as the plants are consumed in high quantities.

High-resolution hyaluronidase inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of anti-necrosis constituents in Chinese plants used to treat snakebite

Inhibition of the necrotizing hyaluronidase, phospholipase A2 and protease enzymes in four snake venoms by crude water and ethanol extracts of 88 plant species used against snakebites in traditional Chinese medicine was measured. High-resolution hyaluronidase inhibition profiles were constructed for the 22 plants showing highest hyaluronidase inhibition, and the results were used to guide subsequent structural analysis towards specific hyaluronidase inhibitors. Structural analysis was performed by high-performance liquid chromatography, high-resolution mass spectrometry, solid-phase extraction and nuclear magnetic resonance spectroscopy, i.e., HPLC-HRMS-SPE-NMR. This allowed identification of four non-tannin inhibitors, i.e., lansiumamide B (6) from Clausena excavata Burm.f., myricetin 3-O-β-D-glucopyranoside (7) from Androsace umbellata (Lour.) Merr., and vitexin (8) and 4',7-dihydroxy-5-methoxyflavone-8-C-β-D-glucopyranoside (9) from Oxalis corniculata L. Absolute configuration of 2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide (1) was determined using the Mosher method, which revealed two enantiomers, i.e., (2S,3R)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide and (2R,3S)-2,3-dihydroxy-N-methyl-3-phenyl-N-[(Z)-styryl]propanamide with a ratio of 7:3.

Ethnomedicinal uses of plants for the treatment of snake and scorpion bite in Northern Pakistan

ETHNO-PHARMACOLOGICAL RELEVANCE

Medicinal plants represent one of the most accessible resources available for snake and scorpion bite among the rural communities of Northern Pakistan. This first ethno-botanical study aimed to document the indigenous knowledge and practices of using plants for snake and scorpion bite disorders in Northern Pakistan.

METHODS

Ethno-medicinal data is documented from 187 informants using semi-structured interviews. The data is analyzed using quantitative ethno-botanical indices of frequency citation (FC) and relative Frequency of Citation (RFC). In addition to this, the ethno-medicinal findings of this survey were compared with 10 previous published studies in order to report novel uses of medicinal plants against snake and scorpion bite disorders.

RESULTS

In total 62 medicinal plants belonging to 40 families are reported against snake and scorpion bite in this study. Our results showed that Asteraceae is the most used family (10 species), dominant life form is herb (48.38%), leaves were the most used plants part (18 Use-reports) and the paste is most used method of administration (22 reports). The range of RFC was 0.08-0.27 about the use of documented species. Compared to previous published studies, 33.87% similarity index while 66.12% novelty index is reported. About 40 plant species are first time reported with medicinal uses against snake and scorpion bite from Northern Pakistan.

CONCLUSIONS

This study presents useful traditional knowledge of rural communities for the control of snake and scorpion bite using medicinal plants. The study mainly focused on ethno-medicinal documentation to preserve the valuable traditional knowledge that can be used in future phytochemical and pharmacological studies on medicinal plants of the area.

Honey shows potent inhibitory activity against the bovine testes hyaluronidase

The purpose of this study was to investigate the anti-hyaluronidase activities of honeys from different botanical origins honeys in order to determine their anti-inflammatory properties. The total phenolic contents, total flavonoids and total tannin levels of six types of honey, chestnut, oak, heather, pine, buckwheat and mixed blossom, were determined. Concentration-related inhibition values were tested turbidimetrically on bovine testis hyaluronidase (BTHase) as IC50 (mg/mL). All honeys exhibited various concentration-dependent degrees of inhibition against BTHase. Inhibition values varied significantly depending on honeys' levels of phenolic contents, flavonoid and tannin. The honeys with the highest anti-hyaluronidase activity were oak, chestnut and heather. In conclusion, polyphenol-rich honeys have high anti-hyaluronidase activity, and these honeys have high protective and complementary potential against hyaluronidase-induced anti-inflammatory failures.

Investigation of skin permeation, ex vivo inhibition of venom-induced tissue destruction, and wound healing of African plants used against snakebites

ETHNOPHARMACOLOGICAL RELEVANCE

Snakebite envenomation causes 5000-10,000 mortalities and results in more than 5-15,000 amputations in sub-Saharan Africa alone every year. The inaccessibility of antiserum therapy is a vast problem, and only about 2.5% of the actual need for antiserum in Africa is covered. Numerous plants have shown in vitro inhibitory activity against one or more of the hydrolytic enzymes involved in snakebite-induced necrosis. However, a more thorough examination of the plant species in ex vivo and in vitro cell assay models is needed to test their ability to inhibit necrosis.

MATERIALS AND METHODS

Extracts which had previously shown in vitro inhibitory activity against necrosis enzymes, were tested in an ex vivo air-liquid-interface model, and a wound healing scratch assay as well as for their ability to permeate the skin barrier and inhibit venom induced cell death.

RESULTS

Of the 14 water extracts and 16 ethanol extracts tested at a concentration of 10 μg/mL, only the ethanol extracts of Tamarindus indica and Paullinia pinnata resulted in a small but significant increase in cell migration of around 10% compared to treatment with buffer after 24h treatment. The remaining extracts showed no effect, or they even delayed the cell migration compared to the treatment with buffer. After 48 h treatment, 10 of the tested extracts showed a decreased cell migration compared to no treatment. At a 100 μg/mL concentration all the extracts inhibited cell migration and five extracts killed some of the cells, while four extracts killed all the cells. Ten of the thirty extracts were tested in a Franz cell set-up but none of the extracts tested did permeate the skin barrier over a 48 h period, and will therefore be of very limited use topically in the initial treatment of snakebites in its present form. None of the extracts were able to directly interact with the enzyme to lower the cell toxicity of the venom. Two extracts, Dichrostachys cinerea and Grewia mollis, were tested in the ex vivo model, but none of them inhibited the tissue destruction caused by venom.

CONCLUSION

On the basis of this study, topical treatment with plant extracts for snakebite-induced tissue necrosis cannot be recommended.