Plant part substitution--a way to conserve endangered medicinal plants?

Inhibition of pro-inflammatory cytokines by selected southern African medicinal plants in LPS-stimulated RAW 264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Bark is frequently used in southern African traditional medicine to treat inflammation, yet it remains to be rigorously examined for its immunological and anti-inflammatory activity.

AIM OF THE STUDY

Barks obtained from ten important and popular southern Africa plants were evaluated for their anti-inflammatory and immunomodulatory properties against the secretion of some pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ) as well as chemokines (monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein (MIP)-2) in murine RAW 264.7 macrophages.

MATERIALS AND METHODS

The inhibitory effects of aqueous and ethanol extracts were determined using cytokine multiplex-bead assays in lipopolysaccharide (LPS)-stimulated and unstimulated RAW 264.7 cells.

RESULTS

Overall, the ethanol extracts were more potent cytokine inhibitors compared to the aqueous extracts. The LPS-stimulated cells treated with the ethanol extracts of Erythrina lysistemon Hutch., Pterocelastrus rostratus Walp. Syzygium cordatum Hochst. ex Krauss and Warburgia salutaris (G. Bertol.) Chiov., demonstrated significant (p < 0.005) inhibition up to 85% of IL-1β, IL-6, and TNF-α secretion compared to the LPS control. Additionally, P. rostratus and S. cordatum aqueous bark extracts substantially decreased the secretion of all the tested cytokines and chemokines. Chemical investigation of the S. cordatum extract resulted in the identification of four ellagic acid derivatives: ellagic acid 4-O-α-rhamnopyranoside (1), ellagic acid 4-O-α-4″-acetylrhamnopyranoside (2), 3-O-methylellagic acid 4'-O-α-3″-O-acetylrhamnopyranoside (3) and 3-O-methylellagic acid 4'-O-α-4″-O-acetylrhamnopyranoside (4), along with mixtures of ellagic acid 4-O-α-2″-acetylrhamnopyranoside (5), ellagic acid 4-O-α-3″-acetylrhamnopyranoside (6) and ellagic acid (7). Their structures were confirmed by mass spectrometry, NMR spectroscopy, and comparison with data from literature.

CONCLUSION

The cytokine inhibition properties of most of the medicinal plants screened herein are reported for the first time. Our results provide insights into the mechanism of action by which the selected southern African medicinal plants regulate inflammation.

Interactive Effects of Water Deficiency and Endophytic Beauveria bassiana on Plant Growth, Nutrient Uptake, Secondary Metabolite Contents, and Antioxidant Activity of Allium cepa L

The main aim of this research study was to assess the interactive effects of water deficiency and the inoculation of a growth medium with Beauveria bassiana on plant growth, nutrient uptake, secondary metabolite contents, and antioxidant capacity of Allium cepa. A. cepa seedlings were simultaneously exposed to one of three watering regime treatments (3-day, 5-day, and 7-day watering intervals) and B. bassiana or no-fungus treatment. While the longest watering interval induced reduced plant growth, plants inoculated with B. bassiana had better results than those in the no-fungus treatment. Significant interactive effects (DF = 2.0; p < 0.05) between fungus and the watering regime on P, K, and Fe contents were observed. Remarkably, at the 7-day watering interval, the polyphenol content (64.0 mg GAE/L) was significantly higher in the plants treated with B. bassiana than in the no-fungus-treated plants. The watering interval significantly affected (DF = 2, 6; F = 7.4; p < 0.05) total flavonol contents among the fungus-treated plants. The interaction of the watering interval and B. bassiana inoculation (DF = 2.0; F = 3.8; p < 0.05) significantly influenced the flavonol content in the onion bulbs and the antioxidant activities of onion bulbs in the FRAP assay (DF = 2.0; F = 4.1; p < 0.05).

RNA-Seq analysis reveals the important co-expressed genes associated with polyphyllin biosynthesis during the developmental stages of Paris polyphylla

Background

Plants synthesize metabolites to adapt to a continuously changing environment. Metabolite biosynthesis often occurs in response to the tissue-specific combinatorial developmental cues that are transcriptionally regulated. Polyphyllins are the major bioactive components in Paris species that demonstrate hemostatic, anti-inflammatory and antitumor effects and have considerable market demands. However, the mechanisms underlying polyphyllin biosynthesis and regulation during plant development have not been fully elucidated.

Results

Tissue samples of P. polyphylla var. yunnanensis during the four dominant developmental stages were collected and investigated using high-performance liquid chromatography and RNA sequencing. Polyphyllin concentrations in the different tissues were found to be highly dynamic across developmental stages. Specifically, decreasing trends in polyphyllin concentration were observed in the aerial vegetative tissues, whereas an increasing trend was observed in the rhizomes. Consistent with the aforementioned polyphyllin concentration trends, different patterns of spatiotemporal gene expression in the vegetative tissues were found to be closely related with polyphyllin biosynthesis. Additionally, molecular dissection of the pathway components revealed 137 candidate genes involved in the upstream pathway of polyphyllin backbone biosynthesis. Furthermore, gene co-expression network analysis revealed 74 transcription factor genes and one transporter gene associated with polyphyllin biosynthesis and allocation.

Conclusions

Our findings outline the framework for understanding the biosynthesis and accumulation of polyphyllins during plant development and contribute to future research in elucidating the molecular mechanism underlying polyphyllin regulation and accumulation in P. polyphylla.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08792-2.

Ethnobotany and Toxicity Status of Medicinal Plants with Cosmeceutical Relevance from Eastern Cape, South Africa

The indigenous people of the Eastern Cape residing within the richest plant biodiversity in the world, including Africa’s floral ‘gold mine’, have a long history of plant use for skincare. However, such rich flora comes with numerous plants that have the potential to cause harm to humans through their usage. Therefore, the study was aimed at documenting the toxicity status of important medicinal plants used by the indigenous people from the Eastern Cape for skincare and supported by literature for cosmeceutical relevance. A list of plants used for skincare was produced following an ethnobotanical survey. In addition, data on the level of toxicity and cosmeceutical relevance of plants listed from the survey were collected from literature resources. The study listed a total of 38 plants from 25 plant families, the majority being represented by the Asphodelaceae and Asteraceae, both at 13.2%. The most preferred plant parts were the leaves (60.4%) indicating sustainable harvesting practices by the community. The literature reports validated 70% of the medicinal plants surveyed for skincare were nontoxic. Most of the plants can be incorporated in the formulation of products intended for skincare due to their low toxicity and high cosmeceutical relevance.

Traditionally used polyherbals in a southern African therapeutic context

ETHNOPHARMACOLOGICAL RELEVANCE

In African traditional medicine, there are several plant species that are used in combination with either other plant species or non-plant derived combinations such as sugar and honey, salt and vinegar, milk, fat etc. This review examines the role of these combinations and postulates the scientific and therapeutic validation of such combinations.

AIM OF THE STUDY

This study reviewed the ethnopharmacological literature and documented the use of southern African plant combinations to find a scientific rationale for such combinations, and provide recommendations for future studies.

MATERIALS AND METHODS

Ethnobotanical books and online databases such as Scopus, ScienceDirect, PubMed and Google Scholar were used to find ethnobotanical studies within the southern African context that focus on the combinations of plants with other plants or various additional ingredients. The scientific literature was examined to determine if evidence was available to substantiate such combinations.

RESULTS

One hundred and eighty-seven medicinal plant (plant-to-plant) combinations that are used in the southern African traditional healing system were recorded. These plant combinations were used against infections of the gastrointestinal tract, respiratory tract, and skin as well other non-infectious diseases such as reproductive and psychiatric disorders. Respiratory infections were the most documented infections to be treated using plant combinations. The plant that was documented to be most commonly used in combination with other plants was Artemisia afra Jacq. ex Willd. While plant-plant combinations have drawn a marked interest, comparatively, plant-adjuvant (e.g. milk, sugar, honey, salt, vinegar, fats) combinations have attracted less research interest. Milk was reported as the most used additional ingredient in combination with medicinal plants. The combination of animal urine and dung with medicinal plants has been reported as a treatment for treat prostate infections, the human immunodeficiency virus (HIV). Other ingredients such as clay and flour were also documented, and these are often mixed with medicinal plants to treat fever, stomach ailments, sexually transmitted infections (STI) and skin conditions. Although combination therapy has been frequently reported in ethnobotanical records, over 90% of the combinations reviewed still need to be scientifically validated.

CONCLUSION

Scientific reports on the antimicrobial, anti-oxidant, anti-inflammatory and other pharmacological effects of these combinations may offer an understanding of traditional combination therapy. In addition, investigation into the mechanisms of action of these combinations are also recommended to supplement the findings. Nonetheless, the use of plant combinations is still an untapped research area in southern Africa and there is a need to validate the use of those documented combinations to obtain a better understanding of combined traditional medicinal plant use.

Medicinal Plants Used to Treat Human and Livestock Ailments in Basona Werana District, North Shewa Zone, Amhara Region, Ethiopia

This study was conducted on medicinal plants used for the treatment of human and livestock ailments in Basona Werana District, North Shewa Zone, Amhara Region. Data were collected through semi-structured interviews, field walk observation, preference, and direct matrix ranking with randomly and purposefully selected informants. A total of 80 respondents (46 men and 14 women) and 20 (16 men and 4 women) traditional healers participated in this study. A total of 76 plant species distributed in 75 genera and 45 families were collected and identified. Of the 76 medicinal plants collected from the study area, 85.5% were used to treat human ailments. The Lamiaceae came out as a leading family with 8 (10.5%) species followed by Asteraceae and 7 (9%) medicinal plant species each, while Solanaceae followed with 6 (7.8%) species. The majority of medicinal plants were collected from wild habitat and accounted for 56 plant species (73.6%). The result of growth form analysis showed that herbs constituted the highest proportion of medicinal plants represented by 33 species (43.4%), followed by shrubs with 30 species (39.4%) and trees with 10 species (13.1%). The medicinal plants were administered through oral, which accounts for 54 species (48.1%), followed by dermal with 38 species (33.9%) and nasal with 9 species (8%), respectively. Leaves were the most frequently used plant parts for the preparation of traditional herbal medicines in the study area. Crushing was the widely used preparation method (33.9%) followed by pounding (16%). Cucumis ficifolius A. Rich. was the most preferred plant used to treat stomachache. Phytochemical and pharmacological studies of this type of plant are recommended to get the most out of the plant.

Variation of Secondary Metabolite Contents and Activities against Bovine Diarrheal Pathogens among Zygophyllaceae Species in Benin and Implications for Conservation

Balanites aegyptiaca is a wild plant species largely used in folk medicine and a priority fruit tree in West Africa. In Benin, its overexploitation for ethnoveterinary uses could lead to its rarity or extinction in the long term. In this study, we evaluate the possibilities of its substitution by other Zygophyllaceae species. This study was based on optimal defense theory, which distinguished 2 categories of plants: K-strategist species and r-strategist species. Phytochemical screening was carried out based on aqueous extracts of the leafy stems of B. aegyptiaca and Guaiacum officinale (K-strategist species) and Tribulus terrestris and Kallstroemia pubescens (r-strategist species) for the identification of chemical compounds. The phenolic compounds were quantified by quercetin and vanillin methods. The extracts were tested against 5 bacterial strains responsible for severe diarrhea in bovines. Our results indicated the presence of many phytochemicals, such as alkaloids, flavonoids, saponosides, and tannins. The diversity in secondary metabolites is higher for r-strategist than K-strategist species. The contents of total polyphenols ranged from 4.82 ± 0.05 to 41.84 mg GAE/g of extract. The flavonoid contents varied from 30.64 ± 0.35 to 57.11 ± 0.13 mg QE/g of extract and those of the tannins from 0.04 ± 0.00 to 0.06 ± 0.01 mg PE/mL. The sensitivity of the bacterial strains showed a significant dependence on the extracts. Of the species, K. pubescens showed a bactericidal activity on the majority of strains tested and thus could be a potential substitute for B. aegyptiaca in the treatment of infectious diarrhea.

Plectranthus ecklonii Benth: A Comprehensive Review Into its Phytochemistry and Exerted Biological Activities

Ethnopharmacological Relevance: Plectranthus genus (Lamiaceae family) contain several species with acknowledged ethnopharmacological uses, such as, for gastrointestinal and respiratory-related problems, due to their anti-inflammatory, antibacterial and antifungal properties. The bioactivity of isolated medicinal compounds from this genus justifies the increased interest in recent times for species of Plectranthus, placing them in the spotlight for natural product drug development. Aim of the study: To the best of our knowledge, this is the first review on the biological activities of Plectranthus ecklonii Benth. As such, the aim of this review was three-fold: 1) to summarize the chemical compounds isolated from P. ecklonii; 2) to collate the biological activities and mechanisms of action of these compounds from in vitro studies; and 3) to evaluate the documented uses and potential applications of this species, in order to postulate on the direction of pharmaceutical uses of this species. Materials and methods: An extensive database retrieval was performed using the electronic databases Web of Science, PubMed, Google Scholar and ScienceDirect. The search criteria consisted of the keywords "Plectranthus ecklonii", "Plectranthus ecklonii + review", "Plectranthus ecklonii + diterpenes" or "Plectranthus ecklonii + abietanes", "ecklonii + parviflorone D", searched individually and as combinations. Eligibility criteria were set out and titles in English, Portuguese and Spanish were reviewed, with all references included dating from 1970 to 2021. A total of 169 papers were selected and included. Chemical structures were drawn using ChemDraw 20.0, CID numbers were searched in PubChem and the PRISMA diagram was created using PowerPoint 2012. Results: To date, a total of 28 compounds have been isolated from P. ecklonii, including diterpenes, triterpenes, flavonoids, and hydroxycinnamic acids. Most focused on the antimicrobial action of its constituents, although compounds have demonstrated other bioactivities, namely antioxidant, anti-inflammatory and antitumor. The most recent studies emphasize the diterpenoids, particularly parviflorone D, with the help of nanotechnology. Conclusions: The widespread ethnobotanical and traditional uses of P. ecklonii can be scientifically justified by a range of biological activities, demonstrated by isolated secondary metabolites. These bioactivities showcase the potential of this species in the development of economically important active pharmaceutical ingredients, particularly in anticancer therapy.

In vitro immuno-stimulatory and anticancer activities of Oroxylum indicum (L.) Kurz.: An evidence for substitution of aerial parts for conservation

BACKGROUND

In Ayurveda, "Dashamoolarishta" is one of the important composite herbal formulations. Mainly, the root and root bark of Oroxylum indicum are used as one of the ingredients in its preparation. This leads to over exploitation of medicinal plants owing, to excessive demand due to population expansion and its perceived importance in traditional herbal remedies.

OBJECTIVE

For the conservation of biodiversity, the present investigation had an objective to prepare the extracts of different parts of O. indicum plant and to, compare the chemo-profiles as well as to study the biological activities of the prepared extracts.

MATERIALS AND METHODS

Hydro-alcoholic (HA) and aqueous (Aq) extracts of various plant parts were prepared and chemical investigation was done with the help of (LC-MS/MS). Further, in vitro biological activities such as immuno-stimulation (IS) using a cytokine bioassay in RAW264.7 and in vitro anticancer in TNF-α ELISA in THP-1 cells were studied.

RESULTS

The mass spectral profile of the plant revealed the presence of markers such as oroxylin A and chrysin in HA and Aq extracts of stem, leaf, bark and root. Cytokine release and TNF-α secretion was observed in both hydro-alcoholic and aqueous extracts.

CONCLUSION

Based on the results from the present study, it can be concluded that it is possible to replace the roots and the bark of O. indicum with the stem of young plants and leaves. It paves a way for the conserving the medicinal plants without uprooting and extinguishing the whole plant.

Comparative biotransformation of luteolin and apigenin from the flower extract and the stem-and-leaf extract of Dendranthema morifolium Ramat. Tzvel. in rats

BACKGROUND

The flower of Dendranthema morifolium Ramat Tzvel has been widely used as a nutritional health supplement worldwide. However, most of the studies have focused on the flower and the rest of the plant was neglected. Our hypothesis is that similar flavonoids may be present at different parts of D. morifolium, and the flavonoids may undergo a similar biotransformation pathway within the body. To investigate this hypothesis, an in vivo pharmacokinetic experimental model was developed to explore the comparative biotransformation of luteolin and apigenin after administration of D. morifolium extracts (10 g kg^-1 , p.o.) in freely moving rats. Because luteolin and apigenin mainly underwent phase II metabolism, the metabolic enzymes of β-glucuronidase/sulfatase or β-glucuronidase were used to hydrolyze the plasma sample, depending on the biotransformation pathway involved.

RESULTS

The results revealed that luteolin and apigenin mainly went through glucuronide and sulfate conjugations, respectively, in both the extract of flowers and the stem-and-leaf group. In addition, the area under the concentration curve (AUC_last ) of luteolin glucuronides and sulfates in the group administered the stem-and-leaf extract was approximately 4.6 times higher than that of the flower extract group. The dominant products of biotransformation for apigenin were sulfates.

CONCLUSION

These findings support our hypothesis that not only the flower parts of D. morifolium, but also the stem-and-leaf parts contain rich flavones, including glycosides and aglycone, and they undergo similar biotransformation pathways. © 2021 Society of Chemical Industry.

Ethnobotanical survey, phytoconstituents and antibacterial investigation of Rapanea melanophloeos (L.) Mez. bark, fruit and leaf extracts

Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.

Ethnomedicinal uses, biological activities, phytochemistry and conservation of African ginger (Siphonochilus aethiopicus): A commercially important and endangered medicinal plant

ETHNOPHARMACOLOGICAL RELEVANCE

In sub-Saharan Africa, African ginger (Siphonochilus aethiopicus) is used for treating common illnesses including colds, coughs, inflammation and related symptoms. The available literature survey on this plant provided scarce anecdotal information, particularly in western and eastern Africa, with a few reports on its bioactivity. In addition, the indigenous knowledge and conservation strategies of this economically important and critically endangered species are currently fragmented.

AIM OF THE REVIEW

This review entails a critical appraisal of existing literature on the ethnomedicinal uses, biological activities, phytochemicals, research opportunities and prospects for the sustainable use of S. aethiopicus.

MATERIALS AND METHODS

This review was conducted using a comprehensive literature search on the ethnomedicinal uses, biological activities and phytochemistry of S. aethiopicus throughout its distributional range. The conservation status and associated bio-economy potential of African ginger were also assessed. We searched different online databases (e.g. Google Scholar, ScienceDirect, PubMed and Scopus) for peer-reviewed journals, conference outputs, international, regional and national organizational reports, published books and theses.

RESULTS

We established that S. aethiopicus is used to treat a wide variety of ailments such as respiratory problems (including cough, influenza), pain, inflammation and malaria. Extracts of African ginger are used as an ingredient in some commercialised products for nutraceutical, cosmeceutical and pharmaceutical purposes. The rhizome extract demonstrated anti-asthmatic, anti-inflammatory, and antiplasmodial activities, which led to the development of a patented novel extract for treating asthma and allergies. Phytochemical analysis of leaf, root and rhizome extracts of African ginger revealed the presence of flavonoids, phenolic acids, volatile and essential oils as the major constituents. These phytochemicals are known to possess bioactivities such as antimicrobial and anti-inflammatory activities. Particularly, the bioactive compounds, siphonochilone and eucalyptol, found in the roots and rhizomes have demonstrated potential to be used in remedies for treating asthma and allergic reactions. Furthermore, extracts of S. aethiopicus contained natural anti-inflammatory mediators with potential to combat and manage chronic inflammation. This plant is classified on the Red List of South African Plants as a critically endangered plant. Its high risk of extinction due to its unsustainable harvesting and exploitation necessitates its rapid propagation and cultivation to meet its increasing demand.

CONCLUSIONS

The review highlights the therapeutic potential of S. aethiopicus and rational prioritization of this plant species with the potential for isolating new bioactive compounds. In the light of the use of this plant extract in traditional medicine and many commercial products, there is a heightened need to explore the mechanism(s) of action of the identified extracts and bioactive compounds in order to fully understand their pharmacokinetics and probably elucidate the pathways of their activities.

The traditional use of southern African medicinal plants in the treatment of viral respiratory diseases: A review of the ethnobotany and scientific evaluations

ETHNOPHARMACOLOGICAL RELEVANCE

Viral respiratory infections are amongst the most common infections globally, with most of the world's population contracting at least one infection annually. Numerous plant species are used in traditional southern African healing systems to treat these diseases and to alleviate the symptoms. Despite this, the therapeutic potential of these plants against viral respiratory diseases remains poorly explored.

AIM OF THE STUDY

The aim of this study was to document the southern African plant species used in traditional medicine to treat viral respiratory infections. We also examined the extent of scientific evaluations of southern African plant species against the respiratory-infective viruses, with the aim of stimulating interest in this area and focusing on future studies.

MATERIALS AND METHODS

We undertook an extensive review of ethnobotanical books, reviews and primary scientific studies to identify southern African plants which are used in traditional southern African medicine to treat viral respiratory diseases. This information was used to identify gaps in the current research that require further study.

RESULTS

Two hundred and fifty-seven southern African plant species were identified as traditional therapies for viral respiratory diseases. Surprisingly, only one of those species (as well as twenty-one other species not recorded for these purposes) has been evaluated for the ability to block respiratory virus production. Furthermore, most of these studies screened against a single viral strain and none of those studies examined the mechanism of action of the plant preparations.

CONCLUSIONS

Despite well documented records of the use of southern African plants to treat respiratory viral diseases, the field is poorly explored. Nearly all of the plant species used in traditional healing systems to treat these diseases are yet to be tested. Substantial further work is required to verify the efficacy of these traditional medicines.

An Ethnobotanical Survey of a Dryland Botanical Garden and Its Environs in Kenya: The Mutomo Hill Plant Sanctuary

Mutomo hill plant sanctuary is a ten-hectare piece of land in Kenya listed as a botanical garden under the Botanical Gardens Conservation International, originally established in 1964 with the aim of conserving indigenous flora from destructive anthropogenic activities. This paper presents ethnobotanical documentation of medicinal plants of Mutomo hill plant sanctuary and its environs. An ethnobotanical survey was carried out in Mutomo hill plant sanctuary and its environs with 48 herbalists aged between 32 and 96 years from July 2018 to February 2019 using a semistructured open-ended questionnaire. The plants were collected through random surveys with each herbalist in different ecotypes around the villages and within the Mutomo hill plant sanctuary. The Relative Frequency of Citation (RFC) for each species reported was calculated to determine the plant species frequently collected. In total, 68 different plant species distributed in 28 families and 54 genera were reported. The frequently used plant families were Leguminosae (13 species), Lamiaceae (6 species), and Euphorbiaceae (6 species). Shrubs (37%) and trees (34%) were the dominant growth habits reported. The most cited plant species were Cassia abbreviata Oliv. (RFC = 0.63), Acacia nilotica (L.). Delile (RFC = 0.54), Strychnos heningsii Gilg (RFC = 0.46), and Aloe secundiflora Engl. (RFC = 0.31). Root (19 species) and bark (19 species) were the frequently collected plant parts. Infectious diseases (33) and digestive system disorders (24) were reported to be managed with the majority of the plant species. This study contributes to safeguarding the traditional knowledge on medicinal plants in the study area, which is useful in appreciating and acknowledging the cultural heritage of the Kamba people from the local perspective of Mutomo area in Kenya. It also adds to the knowledge base and documentation of medicinal plants, which is useful information as potential data for drug development.

Ethnobotanical uses, biological activities and chemical properties of Kei-apple [Dovyalis caffra (Hook.f. & Harv.) Sim]: An indigenous fruit tree of southern Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Dovyalis caffra (Hook.f. & Harv.) Sim (commonly called Kei-apple) is an indigenous fruit tree that has medicinal values for various ethnic groups in southern Africa.

AIM OF THE REVIEW

This review aims to provide a critical appraisal of the existing knowledge on the ethnobotanical value, biological activities and phytochemicals of Dovyalis caffra. In addition, the potential of producing a functional health product from Kei-apple due to its therapeutic effects and rich pool of phytochemicals was explored.

METHODS

A detailed literature search was conducted using various online search engines, such as Scopus, Google Scholar, Mendeley and Web of Science. Additional information was sourced from ethnobotanical literature focusing on southern African flora.

RESULTS

Dovyalis caffra has diverse uses in local and popular medicine, specifically for relieving pain and rheumatism in humans. Ethno-veterinary potential of Kei-apple has also been documented in East Africa. Non-medicinal uses of the tree include its role in biological hedging and as a traditional herb for African magical purpose. Regarding its biological activities, polar extracts from the seeds exhibited noteworthy antibacterial (minimum inhibitory concentration of 1 μg/ml against Staphylococcus aureus) activity. Quantitative analysis (e.g. GC-MS, HPLC) indicated the presence of a rich (>80) pool of chemicals, including sterols, phenolic acids and fatty acids from different parts of the plant while 11 compounds have been isolated from its leaves and twigs.

CONCLUSIONS

Dovyalis caffra has been tested for various biological activities and the extracts (seeds in particular) demonstrated promising antibacterial potential. A lack of alignment between the ethno-medicinal uses and existing biological screenings was observed, indicting the need for anti-inflammatory and anti-rheumatism potential of Dovyalis caffra to be explored. In vivo validation of antibacterial and anti-parasitic activities against clinical bacterial strains and parasites, respectively is required. Other areas that need investigation are safety evaluations and development of integrated cultivation approach in order to fully explore the plant's potential.

Plant parts substitution based approach as a viable conservation strategy for medicinal plants: A case study of Premna latifolia Roxb

BACKGROUND

Rapid population growth and catastrophic harvesting methods of wild medicinal plants especially trees, result in the exploitation of natural sources and its management is the need of the hour. Dashamoolarishta is an amalgam of roots of ten plants of a popular Ayurvedic FDC formulation consisting of the root of Premna latifolia Roxb. as one of its ingredients. Presently, their populations like many other trees are under threat due to extensive use of the roots by the herbal drug industry.

OBJECTIVE

With an aim to conserve the biodiversity, a systematic study based on a rational approach by substituting root/root bark with alternative and renewable parts was conducted.

MATERIALS AND METHODS

The fingerprint profile together with anti-inflammatory and analgesic effect of different parts of the plant was established for comparison.

RESULTS

The results based on chemical and biological study indicated close similarity between the roots and the leaves and suggest the possible use of latter over root/root bark.

CONCLUSION

The study proposes that the substitution of the root with alternate renewable parts of the same plant shall form the best strategy towards conservation of the trees like P. latifolia.

Antiplasmodial activities of a Thai traditional antipyretic formulation, Bencha-Loga-Wichian: A comparative study between the roots and their substitutes, the stems

ETHNOPHARMACOLOGICAL RELEVANCE

Bencha-Loga-Wichian (BLW) is a polyherbal antipyretic formulation that is comprised of Capparis micracantha, Clerodendrum indicum, Ficus racemosa, Harrisonia perforata, and Tiliacora triandra. A traditional medical textbook has documented the use of this formulation for the treatment of many types of fever, including malaria-like fever. Traditionally, BLW is composed of the root parts of those plants. However, in current practice, the stem parts are frequently substituted. Thus, this study aimed to evaluate the antiplasmodial activities of BLW and compare the efficacy between the stem and root parts.

MATERIALS AND METHODS

BLW formulations produced from either the stem or root parts of the various constituent plants as well as the stems or roots of the individual plants were separately extracted and tested against the chloroquine-sensitive (Pf3D7) and -resistant (PfW2) strains Plasmodium falciparum using flow cytometry. The cytotoxicity against peripheral blood mononuclear cells was evaluated using the WST-8 assay to determine the selectivity index (SI). The active compounds of BLW were isolated using antiplasmodial-guided isolation and quantified using Ultra-Performance Liquid Chromatography (UPLC).

RESULTS

The stem and root parts of BLW and the individual plants exhibited antiplasmodial activities at the same levels with good SI values in the range of 3.55-19.74. The extracts of BLW exhibited promising antiplasmodial activity against both Pf3D7 (IC₅₀<5µg/mL) and PfW2 (IC₅₀=6-10µg/mL). Among the five component plants, T. triandra was the most active and exhibited an IC₅₀<5µg/mL against both strains of parasites with SI values >10. We isolated tiliacorinine and yanangcorinine as the major active compounds (IC₅₀<2µg/mL). However, these two compounds demonstrated cytotoxic effects (SI<1). The UPLC analysis identified these compounds in both the stem and root parts of BLW in the range of 0.57-7.66%, which correlated with the antiplasmodial activity. The concentrations of these compounds in BLW, at comparable efficacy, were much less than those at the IC50s for the single compounds alone. It suggested that synergistic interactions increased the antiplasmodial effects as well as alleviated the toxicity of the active compounds in BLW.

CONCLUSION

This study described a promising antiplasmodial activity of BLW that had good selectivity and a toxicity-alleviating effect. The results provided scientific support for the use of this formulation for the treatment of malaria. In addition, the stem and root parts of the plants in BLW exhibited equivalent activities, which indicates the potential for the substitution of the stem parts in the formulation. Thus, we recommend additional study of the stem parts of these plants for further development on the basis of the availability and sustainability.

Evaluation for substitution of stem bark with small branches of Myrica esculenta for medicinal use - A comparative phytochemical study

Background

Over exploitation of many traditional medicinal plants like Myrica esculenta has become a threat and in the near future, many medicinal plants may be unavailable for use of industry.

Objective

Present study outlines the concept of plant part substitution. Stem bark and small branches of M. esculenta are compared on the basis of physicochemical analysis, phytochemical analysis, total phenolic contents, total flavonoid contents and high performance thin layer chromatography (HPTLC) to evaluate the possibilities of using small branches in place of stem bark.

Material and methods

Physicochemical parameters and preliminary phytochemical screening were carried out using standard methods. Total phenolic and total flavonoid contents were estimated spectrophotometrically using Folin-Ciocalteu and aluminum chloride method, respectively. CAMAG HPTLC system equipped with semi-automatic applicator was used for HPTLC profiling. n-Hexane, ethyl acetate and ethanol extracts of stem bark and small branches were developed in suitable mobile phase using standard procedures and visualized in UV 254 and 366 nm and in white light after derivatization within anisaldehyde-sulphuric acid reagent.

Results

Phytochemical analysis and HPTLC profile of different extracts showed the presence of almost similar phytochemicals in both stem bark and small branches.

Conclusion

Similarities in phytochemical analysis and HPTLC profile of various extracts suggests that small branches may be used in place of stem bark. The study provides the base for further study to use small branches as a substitute of stem bark of M. esculenta.

Tulbaghia--A Southern African Phytomedicine

The phytomedicine Tulbaghia consists of the fresh or dried subterranean organs of various Tulbaghia species. The genus is endemic to Southern Africa and includes about 20 species, of which only T. alliacea and T. capensis are naturally found in the winter rainfall climate area (the Western Cape). The genus forms part of the Alliaceae family and is a geophyte (plants with an underground perennation organ and leaves that die back annually). Their habitat can range from semi-desert to wet and boggy terrain. Wild garlic is most commonly prepared as an infusion or boiled in water and taken orally. Externally, as a medicated bath, wild garlic is used to treat paralysis and rheumatism and to reduce the temperature in a feverish patient. Internally, rhizome or bulb preparations are taken orally to treat fever; as a remedy for colds and influenza, asthma, tuberculosis, and stomach problems; as an antihypertensive; or to expel intestinal worms. It is also used as a prophylactic against winter infections. Rhizome pieces are often placed in castor oil to make eardrops. For fever and high blood pressure, a tea is made from the bulbs or rhizomes and a small cup taken three times daily. The leaves of the plant are used to treat esophageal cancer and may also be eaten as a vegetable. The demand for Tulbaghia in both formal and informal markets has grown exponentially. Sustainable harvesting focuses on only harvesting enough of the plant so that it still has the capacity for self-renewal. However, because both the above-ground and underground parts of Tulbaghia are commonly used in African traditional medicine, destructive harvesting of the whole plant is inevitable, thus necessitating the large-scale organized propagation of these plants. It is therefore important to establish a new strategy for the sustainable harvesting of these plants as commercial crops.

Acute and sub-chronic toxicity studies of three plants used in Cameroonian ethnoveterinary medicine: Aloe vera (L.) Burm. f. (Xanthorrhoeaceae) leaves, Carica papaya L. (Caricaceae) seeds or leaves, and Mimosa pudica L. (Fabaceae) leaves in Kabir chicks

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm. f. (Xanthorrhoeaceae), Carica papaya L. (Caricaceae) and Mimosa pudica L. (Fabaceae) are widely used in the Cameroonian ethnoveterinary medicine as a panacea, and specifically for gastrointestinal disorders as well as an anthelmintic and antibacterial.

AIM OF THE STUDY

The present study evaluated the potential toxicity of the hydroalcoholic extracts of Aloe vera leaves, Carica papaya leaves or seeds, and Mimosa pudica leaves after acute and sub-chronic administration in chicks.

MATERIALS AND METHODS

For the acute toxicity test a single administration of each of the four hydroalcoholic extracts was given orally at doses ranging from 40 to 5120 mg/kg (n=5/group/sex). In the sub-chronic study, these extracts were given orally as a single administration to chicks at doses of 80, 160, 320 and 640 mg/kg/day for 42 days. The anti-angiogenic properties of these extracts (5-320 µg/mg) were investigated in the chick chorioallantoic membrane in vivo.

RESULTS

In the acute toxicity test, none of the four studied hydroalcoholic extracts induced mortality or significant behavioural changes. The sub-acute treatment with the four plant extracts did not alter either the body weight gain or the food and water consumption. However, the results indicated that Aloe vera leaf extract acute treatment by oral route at doses up to 2560 mg/kg did not produce death in 50% (5/10) of chicks during 24h or 14 days of observation, but 20% (2/10) chicks died. The haematological and biochemical analyses did not show significant differences in any of the parameters examined in female or male groups, with the exception of a transient rise in white blood cell counts at high doses (640 mg/kg). Additionally, these extracts did not have the potential for anti-angiogenic effects through the inhibition of neo-angiogenesis in the chick chorioallantoic membrane in vivo.

CONCLUSION

The results showed that the therapeutic use of the hydroalcoholic extracts of Aloe vera leaves, Carica papaya leaves or seeds and Mimosa pudica leaves had very low toxicity in oral acute high dose administration and no toxicity in oral sub-chronic low dose administration and indicate that the plants could be considered safe for oral medication in chicks.

Accumulation pattern of endogenous cytokinins and phenolics in different organs of 1-year-old cytokinin pre-incubated plants: implications for conservation

A better understanding of phytohormone physiology can provide an essential basis to coherently achieve a conservation drive/strategy for valuable plant species. We evaluated the distribution pattern of cytokinins (CKs) and phenolic compounds in different organs of 1-year-old greenhouse-grown Tulbaghia simmleri pre-treated (during micropropagation) with three aromatic CKs (benzyladenine = BA, meta-topolin = mT, meta-topolin riboside = mTR). The test species is highly valuable due to its medicinal and ornamental uses. Based on UHPLC-MS/MS quantification, mT and mTR pre-treated plants had the highest total CK, mostly resulting from the isoprenoid CK-type, which occurred at highest concentrations in the roots. Although occurring in much lower concentrations when compared to isoprenoid CKs, aromatic CKs were several-fold more abundant in the root of mT pre-treated plants than with other treatments. Possibly related to the enhanced aromatic CKs, free bases and ribonucleotides, plants pre-treated with mT generally displayed better morphology than the other treatments. A total of 12 bioactive phenolic compounds, including four hydroxybenzoic acids, five hydroxycinnamic acids and three flavonoids at varying concentrations, were quantified in T. simmleri. The occurrence, distribution and levels of these phenolic compounds were strongly influenced by the CK pre-treatments, thereby confirming the importance of CKs in phenolic biosynthesis pathways.

Medicinal Plants: Their Use in Anticancer Treatment

Globally cancer is a disease which severely effects the human population. There is a constant demand for new therapies to treat and prevent this life-threatening disease. Scientific and research interest is drawing its attention towards naturally-derived compounds as they are considered to have less toxic side effects compared to current treatments such as chemotherapy. The Plant Kingdom produces naturally occurring secondary metabolites which are being investigated for their anticancer activities leading to the development of new clinical drugs. With the success of these compounds that have been developed into staple drugs for cancer treatment new technologies are emerging to develop the area further. New technologies include nanoparticles for nano-medicines which aim to enhance anticancer activities of plant-derived drugs by controlling the release of the compound and investigating new methods for administration. This review discusses the demand for naturally-derived compounds from medicinal plants and their properties which make them targets for potential anticancer treatments.

An ethnobotanical survey of medicinal plants used by traditional health practitioners to manage HIV and its related opportunistic infections in Mpoza, Eastern Cape Province, South Africa

ETHNOPHARMACOLOGICAL RELEVANCE

The aim of the study was to identify and document plants traditionally used to manage HIV and treat its opportunistic infections (OIs) in Mpoza, a rural village located in the Mount Frere Alfred Nzo District, Eastern Cape Province, South Africa.

MATERIALS AND METHODS

Semi-structured interviews and focus group discussions (FGDs) were conducted with 18 traditional health practitioners from January 2012 to August 2012 to obtain information about medicinal plants used in the management of HIV and treatment of OIs.

RESULTS

Seventeen plant species belonging to 12 families were identified for the management of HIV and treatment of OIs in Mpoza. The identified plant species belonged mostly to the families Asparagaceae (12%), Araliaceae (12%), Apiaceae (12%), Xanthorrhoeaceae (12%) and Lamiaceae (12%). The remaining 40% of identified plant species was evenly split over seven families - Urticaceae, Hypoxidaceae, Leguminosae, Verbenaceae, Rosaceae, Compositae and Rutaceae. The most frequently used medicinal plants were Hypoxis hemerocallidea (85%), Asparagus densiflorus (68%) and Lessertia frutescens (68%). The leaves (43.5%) and roots (21.7%) were the most frequently used plant parts, usually prepared as infusions and decoctions for oral administration.

CONCLUSION

This study provides documentation of medicinal plants used in the management of HIV and treatment of commonly associated OIs, which might provide a potential lead that will significantly contribute in reducing the burden of HIV infections in South Africa. We envisage that this paper will provide some background for further studies in developing new, effective, safe and affordable plant-derived medicines.

Warburgia: a comprehensive review of the botany, traditional uses and phytochemistry

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Warburgia (Canellaceae) is represented by several medicinal trees found exclusively on the African continent. Traditionally, extracts and products produced from Warburgia species are regarded as important natural African antibiotics and have been used extensively as part of traditional healing practices for the treatment of fungal, bacterial and protozoal infections in both humans and animals. We here aim to collate and review the fragmented information on the ethnobotany, phytochemistry and biological activities of ethnomedicinally important Warburgia species and present recommendations for future research.

MATERIALS AND METHODS

Peer-reviewed articles using "Warburgia" as search term ("all fields") were retrieved from Scopus, ScienceDirect, SciFinder and Google Scholar with no specific time frame set for the search. In addition, various books were consulted that contained botanical and ethnopharmacological information.

RESULTS

The ethnopharmacology, phytochemistry and biological activity of Warburgia are reviewed. Most of the biological activities are attributed to the drimane sesquiterpenoids, including polygodial, warburganal, muzigadial, mukaadial and ugandensial, flavonoids and miscellaneous compounds present in the various species. In addition to anti-infective properties, Warburgia extracts are also used to treat a wide range of ailments, including stomach aches, fever and headaches, which may also be a manifestation of infections. The need to record anecdotal evidence is emphasised and conservation efforts are highlighted to contribute to the protection and preservation of one of Africa's most coveted botanical resources.

An ethnobotanical study of plants used for the treatment of livestock diseases in Tikamgarh District of Bundelkhand, Central India

OBJECTIVE

To explore and document the information regarding usage of ethnoveterinary medicinal plants utilized by rural farmers and traditional herbal healers for livestock healthcare in Tikamgarh District of Bundelkhnad, Central India.

METHODS

The remote villages of Tikamgarh district were regularly visited from July 2011 to June 2012. Following the methods of Jain and Goel (1995) information regarding the usage of ethnoveterinary medicinal plants was collected.

RESULTS

A total of 41 plant species in 39 genera and 25 families were used traditionally with various plant parts and their combinations for the treatment of more than 36 diseases in the studied area. Trees (17 species) were found to be the most used Ethnoveterinary medicinal plants followed by herbs (15 species), shrubs (6 species) and grasses (3) in descending order. The most common diseases cough, diarrhoea and fever were treated by 04 ethnoveterinary medicinal plant species.

CONCLUSIONS

The present study recommended that the crop and medicinal plant genetic resources cannot be conserved and protected without conserving/managing of the agro-ecosystem or natural habitat of medicinal plants and the socio-cultural organization of the local people. The same may be applied to protect indigenous knowledge, related to the use of medicinal and other wild plants. Introduction of medicinal plants in degraded government and common lands could be another option for promoting the rural economy together with environmental conservation, but has not received attention in the land rehabilitation programs in this region.

Structure, histochemistry and phytochemical profile of the bark of the sobol and aerial stem of Tontelea micrantha (Celastraceae - Hippocrateoideae)

The bark of the underground stem of Tontelea micrantha (Mart. ex. Schult.) A. C. Sm., a native Brazilian Cerrado species, is used in folk medicine for treating kidney ailments. The structures of the underground and the aerial stems were examined and their barks were analyzed for the presence of secondary metabolites. Bark fragments were processed according to conventional techniques in plant anatomy and their chemical compositions examined using histochemical and phytochemical tests, thin layer chromatography, and high-efficiency liquid chromatography. The underground stem is a sobol with unusual cambial activity. Laticifers that secrete terpenoids were present in the cortex and phloem of both organs and can contribute to the identification of the species in field. Druses were present in both barks, but mono-crystals were only observed in the sobol. Tannins, flavonoids, alkaloids, and terpenoids occurred in both types of bark, but carotenoids were only detected in the sobol. The similarities between these two organs indicate that the aerial stem bark has potential medicinal use and represents a plausible alternative to harvesting the sobol, which could contribute to the preservation of natural populations of this species.

The genus Warburgia: a review of its traditional uses and pharmacology

CONTEXT

Warburgia (Canellaceae) species have a long history of ethnomedicinal uses in east, central and southern Africa. Due to the popularity of Warburgia as a source of ethnomedicines; all the species are severely over-harvested throughout their distributional ranges.

OBJECTIVE

This review documents fragmented information on traditional uses and pharmacological evidence of the genus Warburgia.

METHODS

Information on Warburgia species was collected from scientific journals, books, theses and reports via library and electronic search using Medline, Pubmed, Google Scholar, ScienceDirect and Web of Science.

RESULTS

Ethnomedicinal uses of Warburgia species have been recorded from east, central and southern Africa for 30 human and 7 animal ailments. Warburgia species are used to treat gastro-intestinal disorders, cold, cough and sore throat; fever or malaria, respiratory and odontological ailments. Warburgia species are rich in drimane and colorotane sesquiterpenoides, and other compounds. The extracts of Warburgia, particularly those from stem bark and leaves, exhibited a wide range of pharmacological effects, including antibacterial, antifungal, antimycobacterial, antioxidant, anti-inflammatory, antifeedant, antiplasmodial, antileishmanial, anthelmintic, cytotoxic and molluscicidal activities.

CONCLUSION

Pharmacological results have validated the use of this genus in traditional medicine. Further investigations are needed to explore the bioactive compounds responsible for the in vitro and in vivo pharmacological effects and their mode of action.

Hypoxis (Hypoxidaceae) in African traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Hypoxis species (Hypoxidaceae) are popular medicinal plants used in the African traditional medicine to treat numerous ailments and are reported to have a wide spectrum of pharmacological properties. In this paper we reviewed and evaluated the traditional uses, pharmacological, phytochemistry and toxicity aspects of the genus Hypoxis. Potential medicinal prospects and possible knowledge gaps and pitfalls are discussed.

MATERIALS AND METHODS

A comprehensive and systematic review of literature on Hypoxis species was done using numerous resources such as books and scientific databases that include Pubmed, Scopus, Scirus, Google scholar, Web of Science and others. Information on the various pharmacological and chemical properties of Hypoxis extracts was critically analysed and discussed under the various topics.

RESULTS

The literature indicated a broad range of uses, pharmacological and toxicological properties of different Hypoxis species extracts and their relevance to African healthcare systems. Several compounds, mostly glucosides, sterols and sterolins, have been isolated, identified and tested in various in vitro and in vivo models as well as in a couple of clinical trials with a lot of promising prospects reported in some studies.

CONCLUSION

A critical analysis of the available literature and studies identifies positive potential for the future use of Hypoxis species in both traditional and modern medicine and concurrently so with possible pitfalls and research gaps in current knowledge. An integrated and holistic approach to addressing research issues, particularly toxicology aspects could be more effectively applied and incorporate conservation strategies for the species.

Pharmacological potential and conservation prospect of the genus Eucomis (Hyacinthaceae) endemic to southern Africa

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Eucomis (Hyacinthaceae) consists of 10 species that are extensively used in African traditional medicine. This review is an appraisal of current information on the distribution and morphology, traditional uses, pharmacology, toxicology and approaches devised to enhance the conservation of the genus.

METHODS

A systematic and comprehensive literature search using electronic searches such as Scopus, Google Scholar, Web of Science and ethnobotanical books was conducted.

RESULTS

Evidence from traditional medicine usage shows wide utilization of this genus for ailments such as respiratory, venereal diseases, rheumatism as well as kidney and bladder infections. Pharmacological screening reported antimicrobial, antiplasmodial, antitumor, cytotoxic, phytotoxic and anti-inflammatory properties.

CONCLUSIONS

The potential of the genus Eucomis especially in terms of pharmacology cannot be overemphasized. Apart from the anti-inflammatory properties, the antifungal activity of Eucomis remains a valuable reservoir with potential application in the agriculture sector as a source of an affordable biocontrol agent. Based on the speculated toxic constituents in the genus Eucomis, it will be valuable to conduct detailed toxicological studies. Extensive utilization of members of the genus Eucomis is causing severe strain on wild populations. Although conventional propagation has been relatively effective in the alleviation of the declining status, micropropagation of members may be vital to guarantee the conservation of wild populations.

Conservation strategy for Pelargonium sidoides DC: phenolic profile and pharmacological activity of acclimatized plants derived from tissue culture

ETHNOPHARMACOLOGICAL RELEVANCE

Pelargonium sidoides DC (Geraniaceae), a popular medicinal plant used in folk medicine in the treatment of respiratory-related infections has gained international prominence due to its usage in several herbal formulations. This has led to high demand and the subsequent decimation of wild populations.

AIM OF THE STUDY

Using plant tissue culture techniques, Pelargonium sidoides plants were cloned in vitro, acclimatized under greenhouse conditions and evaluated for their phytochemical content and pharmacological activity.

METHODS

Phenolic content in extracts of in vitro-derived, greenhouse-acclimatized and wild Pelargonium sidoides plants were analyzed using UPLC-MS/MS. The oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and minimum inhibitory concentration (MIC) of the extracts against bacterial and fungal strains were evaluated.

RESULTS

Similarities in phenolic profiles were identified confirming the chemical signatures that characterize Pelargonium sidoides plants. Extracts of greenhouse-acclimatized and wild plants exhibited comparable antimicrobial and antioxidant properties.

CONCLUSIONS

Overall, the study highlights the potential of integrating plant tissue culture technologies in conservation strategies of medicinal plants. In particular, the results strongly suggest the feasibility of both large-scale cultivation and plant part substitution as alternative solutions to the current destructive overharvesting practices of wild Pelargonium sidoides populations.

The genus Tulbaghia (Alliaceae)--a review of its ethnobotany, pharmacology, phytochemistry and conservation needs

ETHNOPHARMACOLOGICAL RELEVANCE

Tulbaghia is a monocotyledonous genus of herbaceous perennial bulbs predominantly found in Africa. The approximately 63 species have nutritive, ornamental and medicinal value. For centuries, several Tulbaghia species have found diverse uses in traditional medicine.

AIM OF THE REVIEW

To evaluate and document the uses, especially the medicinal value of the genus Tulbaghia. The existing gaps in knowledge and possible means for greater development are highlighted.

METHODS

A comprehensive and detailed literature search using electronic search (for example, Google Scholar, Scirus and Web of Science) and ethnobotanical books was conducted.

RESULTS

Findings based on their traditional uses and scientific evaluation indicates that Tulbaghia violacea remain the most widely used species. Compiled data indicate their efficacy in several in vitro and in vivo pharmacological properties such as antimicrobial, anti-hypertensive, antioxidant and anti-cancer activities. Some phytochemicals which are partly associated with the exhibited bioactivities have been identified and isolated from Tulbaghia violacea and Tulbaghia alliacea. The increasing high usage especially the underground organs, as well as the incessant reliance on the wild population, will eventually affect their abundance and possibly make them susceptible to extinction.

CONCLUSIONS

The great potential of the genus Tulbaghia, particularly other less popular species, remain to be exploited. Further studies on the structural activity relationship of some of the isolated compound may improve their biological potency. Their characteristic alliaceous aroma may also be of great interest to the food industry seeking novel source of unusual aromas to satisfy increasing consumer demands. In order to derive the much anticipated benefits from the species without compromising their conservation status, the use of different biotechnological approaches highlighted in this review will certainly guarantee their continuous availability.

Commercially Important Medicinal Plants of South Africa: A Review

There is a growing interest in natural plant-based remedies as a source for commercial products. Around 80% of the South African population use traditional medicines to meet their primary health care needs; however, only a few South African medicinal plants have been exploited to their full potential in terms of commercialization. The opportunity for bioprospecting of plant compounds for novel pharmaceuticals remains largely untapped. Certain renowned medicinal plants of international acclaim including buchu and rooibos are currently contributing to local enterprise; however, other exciting opportunities exist for commonly used plants which have not yet reached the international arena. This paper focuses on the key research and development contributions of 10 commercially important medicinal plants of South Africa. Traditional uses, scientific validation, commercialisation developments, as well as both potential opportunities and setbacks are discussed.

Anti-ulcer polysaccharides from Cola cordifolia bark and leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Aqueous extracts of bark and leaves of C. cordifolia are traditionally used in Mali (West Africa) in the treatment of wounds and gastric ailments like abdominal pain, gastritis and gastric ulcers.

AIM OF THE STUDY

To evaluate and compare the anti-ulcer and immunological activities, as well as the toxicity of polysaccharide rich water extracts from the bark and leaves of C. cordifolia.

MATERIALS AND METHODS

Gastric ulcers were induced in rats and the inhibition of ulcer formation was calculated based on lesion index. Immunological activities were measured by complement fixation and macrophage activation. Toxicity was tested on brine shrimps. The two extracts were characterised by GC, Yariv-precipitation and quantification of phenolic compounds. An ethnomedical survey on C. cordifolia was carried out in Siby (Mali, West-Africa) to generate more knowledge about the traditional use.

RESULTS

Bark and leaf extracts from C. cordifolia significantly inhibited the formation of gastric lesions in rodents in a dose depending manner. CCbark50 showed a high complement fixation activity in vitro. No toxicity was found. The ethnomedical survey showed that C. cordifolia was mainly used for treating pain and wounds.

CONCLUSIONS

Our results shows that the bark and the leaves comprise a dose dependant anti-ulcer activity in an experimental rat model (no statistical difference between the plant parts). Clinical studies should be performed to evaluate the effect of both bark and leaves of C. cordifolia as a remedy against gastric ulcer in human.

Knowledge of ethnoveterinary medicine in the Province of Granada, Andalusia, Spain

ETHNOPHARMACOLOGICAL RELEVANCE

This paper constitutes an important contribution to the knowledge of biological resources used in ethnoveterinary practices (EVPs) in southern Europe, a territory with a clear lack of information on the subject.

AIM OF THE STUDY

To catalogue, analyze, and disseminate the knowledge of plant and animal use in ethnoveterinary practices in the province of Granada. Data have been analyzed to highlight the similarities between ethnoveterinary practices and human ethnopharmacology for the same study area.

METHODOLOGY

Information was gathered through open and semi-structured interviews with local people, mainly elderly shepherds and farmers, in the western part of the province. The primary data have been supplemented with information on EVPs from previous ethnobotanical works for the province. Data were gathered using the same field methods.

RESULTS

A total of 88 ethnoveterinary uses are documented for the treatment of 24 animal conditions. Of these, 82 uses involve 60 different plant species. Over three-quarters of these plants are also used for some human conditions in the same study area. Moreover, 6 animal species were catalogued for 6 other ethnoveterinary uses; four of these species were also used for similar conditions in humans. Ritual and health-prevention practices are also discussed.

CONCLUSIONS

EVPs in southern Spain involve a high number of species and conditions and are strongly linked to folk tradition (i.e. how local people understand certain conditions and their treatment, sometimes in a ritual manner). Unfortunately, some evidence of their slow disappearance has been found.

Applications of phytochemical and in vitro techniques for reducing over-harvesting of medicinal and pesticidal plants and generating income for the rural poor

Plants provide medicine and pest control resources for millions of poor people world-wide. Widespread harvesting of medicinal and pesticidal plants puts pressure on natural populations, thus severely compromising their contribution to the income and well-being of traders and consumers. The development of in vitro propagation techniques appropriate for developing countries will provide a robust platform for effective propagation and cultivation of endangered plants. This review focuses on advances in the application of phytochemical and in vitro tools to identify and rapidly propagate medicinal and pesticidal plants. Problems of over-harvesting can be alleviated and ex situ cultivation in agroforestry systems can be facilitated through improving seed germination, in vitro cloning and the use of mycorrhizal fungi. We also present a case for effective use of phytochemical analyses for the accurate identification of elite materials from wild stands and validation of the desired quality in order to counter loss of efficacy in the long run through selection, propagation or ex situ management in agroforestry systems. Future prospects are discussed in the context of medicinal activity screening, sustainable propagation, on-farm planting, management and utilization.

Effect of cadmium accumulation on anti-inflammatory activity in two Eucomis species

Eucomis species (Hyacinthaceae) are widely used in South Africa as traditional medicine. The bulbs are used to alleviate a variety of symptoms including pain and inflammation. High levels of cyclooxygenase-1 and -2 (COX-1 and COX-2) inhibitory activity have been associated with certain Eucomis species. The aim of this study was to quantify cadmium(Cd) accumulation and examine its effect on COX-1 and COX-2 anti-inflammatory activity in Eucomis autumnalis and Eucomis humilis. Cadmium application at 2 mg L(-1) over a 6 week period revealed a substantial difference in total Cd accumulation in E. autumnalis and E. humilis (40.2 and 15.3 mg Cd kg-1, respectively). When supplied with Cd at 2 mg L(-1), E. humilis bulbous extracts showed lower inhibitory activity than the control for both COX-1 and COX-2. E. autumnalis bulbous extracts had greater COX-1 activity compared to the control. While COX-2 activity was suppressed. Researchers should be aware of the effect of environmental contaminants when reporting on biological activity of crude plant extracts.

Ethnoveterinary knowledge in pastoral Karamoja, Uganda

ETHNOPHARMACOLOGICAL RELEVANCE

The people of Karamoja of northern Uganda chiefly rely on ethnoveterinary knowledge (EVK) to control common livestock health problems. In spite of cattle's central role in Karamojong culture and livelihoods, there has been no systematic recording of their ethnoveterinary plant-based cures to date.

AIM OF STUDY

To document the remedies used to treat livestock diseases, their preparation and administration.

METHODS

Data were collected using semi-structured interviews, guided questionnaires, group discussions, direct observations and collection trips.

RESULTS

We present information on 209 plant species and 18 non-plant materials. Plant species are distributed over 116 genera and 54 families. The most common medicinal use was treatment against anaplasmosis. Balanites aegyptiacus, Carissa spinarum, Warburgia salutaris and Harrisonia abyssinica had the most uses of all species. All different plant parts were used; bark and underground parts were exploited more frequently than other plant parts. Most remedies listed used a single ingredient, typically soaked in water; only 12.8% remedies used multiple plants. The route of administration was primarily oral followed by topical applications. Almost all plants are collected from the wild; none of the few cultivated plants used had been planted for medicinal purposes.

CONCLUSIONS

The pastoralists in the study site possess a wealth of EVK which they use to maintain animal health. Their rich knowledge and high diversity of plants were recorded here for the first time.

The bioactivity of novel furanoterpenoids isolated from Siphonochilus aethiopicus

AIM OF THE STUDY

This study investigated the medicinal plant Siphonochilus aethiopicus (Zingiberaceae) for antiplasmodial activity.

MATERIALS AND METHODS

The ethyl acetate extract of Siphonochilus aethiopicus rhizomes was fractionated using solid phase extraction (SPE) and purified by high performance liquid chromatography. Structure elucidation was performed with nuclear magnetic resonance and mass spectrometry. The in vitro cytotoxicity and antiplasmodial activity was determined. In vivo schizontocidal activity was performed in a malaria mouse-model. Additional in vitro testing was done against Staphylococcus aureus, Klebsiella pneumoniae and Mycobacterium tuberculosis.

RESULTS AND DISCUSSION

The ethyl acetate extract showed in vitro activity against the chloroquine-sensitive (CQS) and chloroquine-resistant (CQR) strains of Plasmodium falciparum with IC(50)-values of 2.9 microg/ml and 1.4 microg/ml, respectively. Bioassay-guided fractionation led to the isolation of three novel furanoterpenoids with moderate in vitro antiplasmodial activity. The crude extract showed very good in vivo activity. The compounds and crude extract were more active against the CQR strain than the CQS strain of Plasmodium falciparum. The SPE fractions were more active than the isolated compounds. The compounds did not show good activity against the micro-organisms tested. No in vitro cytotoxicity was observed.

CONCLUSION

This study provides evidence of antiplasmodial compounds present in Siphonochilus aethiopicus.

Current perspectives on an emerging formal natural products sector in South Africa

Indigenous medical plants contribute significantly to a large South African population as part of a long-standing healthcare system intimately linked to folklore and for livelihood security. For the economically marginalized, access to such plants is largely through herbal markets which are part of an informal economy. Otherwise the formal natural products economy services those with a better socio-economic standing. Recently, the latter has experienced tremendous growth which largely mirrors the global cultural trend for organic naturopathies. Commercialisation of traditional plants and their contribution to the cosmeceutical, nutraceutical and pharmaceutical industries locally and abroad is reviewed. Traditional plant knowledge of southern African people is a source of inspiration for new product development. Concomitantly, an upsurge in research activities emanating from South Africa which confirms the pharmacological efficacy of these plants is fuelling a greater trust in indigenous flora. The escalating consumption of ethnomedicinals as highly valued commodities not only presents South Africa with socio-economic opportunities but also with challenges. Sustainable utilization benefiting the commodification of ethnoherbals, plus meeting aims of poverty alleviation and people empowerment, is a new paradigm in South Africa. The future sustainability of local ecosystems depends upon scientific conservation management practices that recognize the importance of involving local communities. Conservationists should remain aware and sensitive of socio-cultural dynamics within communities in order to manage natural resources.

Anthelmintic efficacy and dose determination of Albizia anthelmintica against gastrointestinal nematodes in naturally infected Ugandan sheep

Weight loss, stunted growth, and death caused by gastrointestinal parasites are major constraints to livestock productivity, especially in tropical and developing countries where regular use, and misuse, of anthelmintics has led to nematode resistance. Albizia anthelmintica Brong. (Fabaceae) is traditionally employed throughout East Africa to treat helminth parasitosis in livestock. Reported efficacy has varied from 90% against mixed nematodes to just 19% against Haemonchus contortus alone. The objective of this study was to assess the anthelmintic effect of A. anthelmintica against naturally occurring infections of mixed gastrointestinal parasites, and to establish an effective treatment dose, in sheep under pastoral field conditions of northern Uganda. A. anthelmintica bark was collected and prepared according to local custom and packed into gel capsules. Fifty-five young female local mixed-breed lambs were randomly assigned to six groups, including a positive control group that received levamisole (synthetic anthelmintic) and a negative control group that received no treatment. Following the World Association for the Advancement of Veterinary Parasitology (WAAVP) dose determination guidelines, the other four groups were treated with varying doses of A. anthelmintica. Statistical analyses (using generalized linear models) were performed to assess treatment effect. There was a significant treatment (group) effect on parasite egg/oocyte counts per gram (EPG) for nematodes, but not for coccidia. The most effective dose against nematodes (0.8g, 58.7mg/kg) closely approximates what is usually given by traditional healers, 0.9g/adult sheep. It provided major and significant reduction in EPG as compared to the negative control. Anthelmintic efficacy was estimated using percent faecal egg count reduction (FECR). Other than the positive control, animals in the standard dose group showed the greatest decline in shedding of nematode eggs, with an FECR of 78%. This study indicates that A. anthelmintica holds potential as part of an integrated management plan for the control of helminths in developing countries.

Traditional management of ear, nose and throat (ENT) diseases in Central Kenya

Diseases of ear, nose and throat (ENT) often have serious consequences including hearing impairment, and emotional strain that lower the quality of life of patients. In Kenya, upper respiratory infections are among the most common infections encountered in outpatient facilities. Some of these infections are becoming difficult to control because some of the causing microorganisms have acquired antibiotic resistance and hence the need to develop new drugs with higher efficacy. Ethnobotanical studies have now been found to be instrumental in improving chances of discovering plants with antimicrobial activity in new drug development. In Kenya the majority of local people are turning to herbal remedies for primary health care needs. In most cases the sources of these remedies are undocumented and the knowledge about them passed orally form generation to generation, hence under threat of disappearing with current rates of modernisation. This study explored the traditional remedies used in managing various ENT diseases in seven districts of the Central Province of Kenya. The most common ENT conditions managed using traditional therapies include: common cold, cough, tonsillitis, otitis-media, chest pains and asthma. The results indicate that 67 species belonging to 36 plant families were utilized in this region. These plants were of varying habits; herbs (37.3%), shrubs (34.4%), trees (25.4%) as well as some grasses and sedges (3%). The traditional preparations were found to be made mainly from leaves (49%), roots (20.5%) and barks (12.5%). For each of the ENT conditions multiple species are utilized mainly as individual preparations but occasionally as polyherbal concoctions. In the case of common cold for example, 30 different species are used. Plants reported in this survey are important candidates for antimicrobial tests against ENT disease causing micro-organisms, especially those with antibiotic resistance.