Antifungal activity of Brazilian medicinal plants involved in popular treatment of mycoses

A survey of medicinal plants used to treat common mycoses was done in the Curituba district, Sergipe State, Brazil. One hundred inhabitants were interviewed by health agents and traditional healers. Four different plants were the most cited (more than 50% of the citations): Ziziphus joazeiro, Caesalpinia pyramidalis, Bumelia sartorum and Hymenea courbaril. The aqueous extracts obtained following traditional methods and using different parts of these plants, were submitted to drop agar diffusion tests for primary antimicrobial screening. Only the water infusion extract of Ziziphus joazeiro and Caesalpinea pyramidalis presented a significant antifungal activity against Trichophyton rubrum, Candida guilliermondii, Candida albicans, Cryptococcus neoformans and Fonsecaea pedrosoi, when compared to the antifungal agent amphotericin B. The minimal inhibitory concentration (MIC) of the bioactive extracts was evaluated by the microdilution method. Best activity with a MIC of 6.5 microg/ml for both extracts was observed against Trichophyton rubrum and Candida guilliermondii. Ziziphus joazeiro and Caesalpinea pyramidalis extracts presented also low acute toxicity in murine models. The present study validates the folk use of these plant extracts and indicates that they can be effective potential candidates for the development of new strategies to treat fungal infections.     

Four pentacyclic triterpenoids with antifungal and antibacterial activity from Curtisia dentata (Burm.f) C.A. Sm. leaves

ETHNOPHARMACOLOGICAL RELEVANCE: Curtisia dentata is used in southern Africa to treat various diseases of bacterial and fungal origin in humans and animals to such a degree that the species is vulnerable and declining [Dold, A.R., Cocks, M.L., 2001. Traditional veterinary medicine in the Alice district of the Eastern Cape Province, South Africa. South African Journal of Science 97, 375-379]. Preliminary studies indicated good activity against Candida albicans. AIM OF THE STUDY: The phytochemistry and antimicrobial activity of this plant species has not been extensively investigated, and a closer examination of the compounds responsible for antimicrobial activity was warranted. MATERIALS AND METHODS: Broth microdilution assay and bioautography were used to evaluate antibacterial and antifungal activity in Curtisia dentata leaf extracts and fractions. Bioassay-directed fractionation using column chromatography yielded four compounds characterised by spectroscopic methods. RESULTS: Lupeol (1), betulinic acid (2), ursolic acid (3) and 2alpha-hydroxyursolic acid (4) were isolated from Curtisia dentata leaves. Betulinic acid, ursolic acid and 2alpha-hydroxyursolic acid appreciably inhibited fungal growth with MIC values ranging from 8 to 63mug/mL. CONCLUSIONS: The isolation of four antibacterial and antifungal triterpenoids is reported for the first time from Curtisia dentata. This study provides information on the antimicrobial compounds of this species, as well as a preliminary rationale for the use in traditional South African medicine.     

Antimicrobial compounds isolated from Haematoxylon brasiletto

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of the bark of Haematoxylon brasiletto Karst. (Leguminosae), commonly known as "Palo Brasil", is used in the Mexican traditional medicine to treat mouth and kidney infections, hypertension, stomach upsets, gastric ulcers and diabetes. AIM OF THE STUDY: The present study was performed to evaluate the antimicrobial effects of the methanolic extract of the bark of Haematoxylon brasiletto. MATERIALS AND METHODS: A panel of 12 bacteria and the yeast Candida albicans were used. Minimum inhibitory concentrations (MICs) were determined by the standard broth microdilution method. RESULTS: The results indicate that the extract of Haematoxylon brasiletto inhibited the growth of eight of the tested microorganisms at a concentration limit of 128mug/mL. For the tested compounds the MIC values ranged from 8.7 to 128mug/mL. CONCLUSIONS: The overall results provide promising baseline information for the potential use of the extracts from Haematoxylon brasiletto as well as some of the isolated compounds in the treatment of bacterial infections.     

The effect of extracts of Searsia species on epileptiform activity in slices of the mouse cerebral cortex

ETHNOPHARMACOLOGICAL RELEVANCE: Searsia dentata and Searsia pyroides are used in traditional South African medicine to treat convulsions and epilepsy. Previous studies have demonstrated that extracts of these plants comprise compounds that bind to the flumazenil-sensitive site on the GABA(A) receptor. However, their use as anticonvulsant medicinal plants cannot be adequately explained by these findings. AIMS: The aim of this study was to examine the possible involvement of the glutamatergic system of extracts from the plants. MATERIALS AND METHODS: The mouse cortical wedge preparation was used for functional characterization of the extracts. The affinity towards the NMDA and the AMPA receptor was investigated using classical [(3)H]-GP39653 and [(3)H]-AMPA binding assays, respectively. RESULTS: The extracts of Searsia dentata and Searsia pyroides inhibited the spontaneous epileptiform discharges in mouse cerebral cortical slices with ED(50) of 0.62 and 1.67mg dry extract/mL, respectively. Both extracts displaced [(3)H]-GP39653 binding and significantly inhibited the NMDA-induced response during co-administration in cortical slices. CONCLUSION: In this study, the NMDA receptor antagonistic effect of the crude ethanolic extracts of these two South African medicinal plants was demonstrated.     

The antimicrobial,antioxidative, anti-inflammatory activity and cytotoxicity of different fractions of four South African Bauhinia species used traditionally to treat diarrhoea

Ethnopharmacological importance

Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.

Aims

Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.

Materials and Methods

The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS⁺) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.

Results

The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC₅₀ ranges from 0.64±0.05 to 1.51±0.07 and 0.88±0.18 to 1.49±0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC₅₀ ranges from 1.47±0.24 to 1.70±0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible.The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.

Conclusion

The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.     

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

Aim of the study

Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine.

Materials and methods

The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively.

Results

The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC = 6.3 μg/ml for both extracts). The lowest MIC value (1.6 μg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6).

Conclusion

These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.     

Study of embryotoxicity of Perovskia abrotanoides, an adulterant in folk-medicine, during organogenesis in mice

AIM OF THE STUDY: Perovskia abrotanoides is a medicinal herb which traditionally has been used as a topical application to treat leishmaniasis in Iran. Due to similarities of the flowers of Perovskia abrotanoides and Echium species, it is added as an adulterant to Echium preparations in Iran. Echium flowers have been used in Iranian traditional medicine as an "anti-stress", tranquilizer, and energizer drink, fighting common cold and bronchitis particularly during pregnancy. In this study, the in vivo embryotoxicity of 0.125 and 0.25 g/kg of ethanolic and aqueous extracts of Perovskia abrotanoides during organogenesis in mice has been investigated. MATERIALS AND METHODS: Maternal body weights were recorded and pregnant females were observed daily throughout gestation. After cesarean section, fetuses were weighed, lengthed and examined for gross external malformations. Others were fixed then stained with Alcian blue and Alizarin red to view any skeletal malformations. RESULTS: Our results indicated that this herb causes minimal maternal toxicity, while resorption, stillborn, fetal malformations including polydactyly, spina bifida, aglossia, tarsal extensor, gastroschisis, and numerous skeletal abnormalities were detected particularly in the ethanolic extract groups. Specific skeletal abnormalities based on type of extract were also observed. CONCLUSIONS: Since Perovskia abrotanoides is widely used in traditional medicine intentionally or inadvertently, it is advisable its use during pregnancy should be avoided and strict regulations are imposed to prevent its addition to commercial preparations of other herbal products.     

The traditional medical uses and cytotoxic activities of sixty-one Egyptian plants: Discovery of an active cardiac glycoside from Urginea maritima

Ethnopharmacological relevance

Medicinal plants from the Sinai desert are widely used in traditional Bedouin medicine to treat a range of conditions including, cancers, and may thus be useful sources of novel anti-tumor compounds. Information on plants used in this way was obtained through collaboration with Bedouin herbalists.

Aim of the study

To document the traditional uses of 61 species from 29 families of Egyptian medicinal plants and to investigate their biological activity using a cytotoxicity assay.

Material and methods

MeOH extracts of the 61 plant species investigated were dissolved in 10% DMSO and their cytotoxic activity was evaluated. The extracts were tested in duplicate on three separate occasions at three different concentrations (1, 10 and 100 μg/ml) against human lymphoma U-937 GTB. The most active extract was subjected to bioassay-guided fractionation using HPLC and LC/ESI–MS to isolate and identify its active components.

Results and discussion

The most potent extracts were those from Asclepias sinaica, Urginea maritima, Nerium oleander and Catharanthus roseus, followed by those from Cichorium endivia, Pulicaria undulate and Melia azedarach. Literature reports indicate that several of these plants produce cardiac glycosides. Bioassay-guided fractionation of alcoholic U. maritima extracts led to the isolation of a bioactive bufadienolide that was subsequently shown to be proscillaridin A, as determined by 1D and 2D NMR spectroscopy. This result demonstrates the value of plants used in traditional medicine as sources of medicinally interesting cytotoxic compounds.     

Sesquiterpene lactones from Gynoxys verrucosa and their anti-MRSA activity

Ethnopharmacological relevance

Because of its virulence and antibiotic resistance, Staphylococcus aureus is a more formidable pathogen now than at any time since the pre-antibiotic era. In an effort to identify and develop novel antimicrobial agents with activity against this pathogen, we have examined Gynoxys verrucosa Wedd (Asteraceae), an herb used in traditional medicine in southern Ecuador for the treatment and healing of wounds.

Materials and methods

The sesquiterpene lactones leucodine (1) and dehydroleucodine (2) were extracted and purified from the aerial parts of Gynoxys verrucosa, and their structure was elucidated by spectroscopic methods and single-crystal X-ray analysis. The in vitro anti-microbial activity of Gynoxys verrucosa extracts and its purified constituents was determined against six clinical isolates including Staphylococcus aureus and Staphylococcus epidermidis strains with different drug-resistance profiles, using the microtiter broth method.

Results

Compound 1 has very low activity, while compound 2 has moderate activity with MIC₅₀s between 49 and 195 μg/mL. The extract of Gynoxys verrucosa has weak activity with MIC₅₀s between 908 and 3290 μg/mL.

Conclusions

We are reporting the full assignment of the ¹H NMR and ¹³C NMR of both compounds, and the crystal structure of compound 2, for the first time. Moreover, the fact that compound 2 has antimicrobial activity and compound 1 does not, demonstrates that the exocyclic conjugated methylene in the lactone ring is essential for the antimicrobial activity of these sesquiterpene lactones. However, the weak activity observed for the plant extracts, does not explain the use of Gynoxys verrucosa in traditional medicine for the treatment of wounds and skin infections.     

Antimicrobial activity of the extracts of Craniotome furcata (Lamiaceae)

Ethnopharmacological relevance

Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity.

Aim of the study

To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi.

Materials and methods

The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method.

Results

The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41–4.58 mg/ml.

Conclusions

The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.     

In vitro and in vivo trypanocidal effect of lipophilic extracts of medicinal plants from Mali and Burkina Faso

AIM OF THE STUDY: To determine the in vitro and in vivo antitrypanosomal activity of extracts of traditionally used plants. MATERIALS AND METHODS: 47 dichloromethane extracts were tested in vitro in the Long-term Viability Assay (LtVA) on Trypanosoma brucei brucei. The most active ones were also tested in vivo using a standardised mouse test. RESULTS: 13 extracts (28%) were active in vitro with MIC-values相似文献   

Antimicrobial activity of the methanolic extracts and compounds from Vismia laurentii De Wild (Guttiferae)

Methanolic extracts prepared from the leaves, twigs and the roots of Vismia laurentii De Wild as well as nine compounds isolated from these crude extracts, were tested for their antimicrobial activity against Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and two Candida species using disc diffusion and well micro-dilution methods. The disc diffusion assay indicated that the crude extract was active against all the pathogens tested, whereas isolated compounds showed selective activities. The degree of sensitivity of the test organisms to purified compounds varied from 25 to 90%. Fridelin (8) was found to be the most active compound, while Bivismiaquinone (3) was the least active. The lowest minimum inhibition concentration (MIC) values as obtained by the micro-dilution assays were 19.53 and 1.22 microg/ml for the crude extracts and purified compounds, respectively. The lowest value for the purified compounds (1.22 microg/ml) was obtained with O(1)-demethyl-3',4'-deoxypsorospermin-3',4'-diol (6) on Candida gabrata and Bacillus subtilis; 1,8-dihydroxy-6-methoxy-3-methylanthraquinone (5) on Bacillus subtilis and 6-deoxyisojacareubin (7) on Bacillus stearothermophilus. These results provide promising baseline information for the potential use of these crude extracts as well as some of the isolated compounds in the treatment of bacterial and fungal infections.     

Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae)

The aim of this study was to evaluate the antimicrobial activity of the crude extract of the twigs of Dorstenia barteri (DBT) as well as that of four of the five flavonoids isolated from this extract. Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and fungi (four species) were used. The agar disc diffusion test was used to determine the sensitivity of the tested samples while the well micro-dilution was used to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentration (MMC) of the active samples. The results of the disc diffusion assay showed that DBT, isobavachalcone (1), and kanzonol C (4) prevented the growth of all the 22 tested microbial species. Other compounds showed selective activity. The inhibitory activity of the most active compounds namely compounds 1 and 4 was noted on 86.4% of the tested microorganisms and that of 4-hydroxylonchocarpin (3) was observed on 72.7%. This lowest MIC value of 19.06microg/ml was observed with the crude extract on seven microorganisms namely Citrobacter freundii, Enterobacter aerogens, Proteus mirabilis, Proteus vulgaris, Bacillus megaterium, Bacillus stearothermophilus and Candida albicans. For the tested compounds, the lowest MIC value of 0.3microg/ml (on six of the 22 organisms tested) was obtained only with compound 1, which appeared as the most active compound. This lowest MIC value (0.3microg/ml) is about 4-fold lower than that of the RA, indicating the powerful and very interesting antimicrobial potential of isobavachalcone (1). The antimicrobial activities of DBT, as well as that of compounds 1, 3, 4, amentoflavone (5) are being reported for the first time. The overall results provide promising baseline information for the potential use of the crude extracts from DBT as well as some of the isolated compounds in the treatment of bacterial and fungal infections.     

Terminalia macroptera, its current medicinal use and future perspectives

The tree Terminalia macroptera (Combretaceae) is widespread in Western Africa, and in this area, different parts have been utilized in the treatment of various diseases. In this article, we report on the medicinal use of T. macroptera in three different districts in Mali (Siby, Dioïla and Dogonland), based on interviews with 78 healers in these districts. Roots, root bark, stem bark, leaves and fruits have all been employed by healers, as has parasitic Loranthus species growing on the tree. Major areas of use comprise treatment of wounds and sores, infections, pain, cough, tuberculosis and hepatitis. Some of the medicinal uses of T. macroptera appear to be rationally explained by its chemical constituents.     

Effects of South African traditional medicine in animal models for depression

Ethnopharmacological relevance

The four South African medicinal plants Agapanthus campanulatus (AC), Boophone distica (BD), Mondia whitei (MW) and Xysmalobium undulatum (XU) are used in traditional medicine to treat depression.

Aim

To evaluate the effect of ethanolic extracts of the plants in models for depression.

Materials and methods

The extracts were screened for affinity for the serotonin transporter (SERT) in the [³H]-citalopram-binding assay. The inhibitory potency of the extracts towards the SERT, the noradrenalin transporter (NAT) and the dopamine transporter (DAT) were determined in a functional uptake inhibition assay. Antidepressant-like effects of the extracts were investigated using the tail suspension test (TST) and the forced swim test in both rats (rFST) and mice (mFST).

Results

All four plants showed affinity for SERT in the binding assay. AC and BD showed functional inhibition of SERT, NAT and DAT, MW affected SERT while XU showed no effect. BD showed significant effect in the TST and in the mFST/rFST, AC showed significant effect in mFST, MW showed significant effect in the rFST and XU showed significant effect in the mFST.

Conclusion

In this study we have demonstrated the antidepressant activity of four South African medicinal plants in vitro and in vivo, supporting their rational use in traditional medicine.     

Hydnocarpus: An ethnopharmacological,phytochemical and pharmacological review

Ethnopharmacological relevance

The genus Hydnocarpus (Flacourtiaceae) includes forty species that are spread across the globe. In the Indian System of Medicine, Hydnocarpus pentandrus (Buch.-Ham.) Oken. is primarily used for treating leprosy and other skin disorders. It is known as “Chaulmoogra” and is also used to treat other indications including constipation, inflammation, blood disorders, and worm infestations. Various species of Hydnocarpus are also used in traditional medicine in China, Thailand, Malaysia, and Myanmar for several skin disorders. To assess the therapeutic potential of species from the Hydnocarpus genus and to determine future avenues for research.

Methods

All relevant scientific literature published up to the end of December 2013 was retrieved via a library and electronic search (SciFinder, PubMed, ScienceDirect, and Google Scholar). Manual searches of traditional books like to ancient classics, including Vaidya Yoga Ratnavali, Siddha Materia Medica, and contemporary references including The Ayurvedic Pharmacopoeia of India and The Ayurveda Formulary, were also performed.

Results

Seed oil from species of the Hydnocarpus genus is used for medicinal purposes, predominantly for various skin disorders. This oil is reported to contain a characteristic class of compounds known as cyclopentenyl fatty acids. Furthermore, seeds of this genus are reported to contain triglycerides of fatty acids, sterols, flavonoids, and flavonolignans. Hydnocarpin, a flavonolignan, is reported to potentiate antimicrobial and anticancer activity. The extracts and compounds isolated from this plant show a wide spectrum of pharmacological properties, including antibacterial, antileprotic, antitubercular, antipsoriatic, antirheumatic, hypolipidemic, antidiabetic, anticancer, anti-inflammatory, and antioxidant activities. The antileprotic activity is postulated to be due to the cyclopentenyl fatty acids present in the seed oil.

Conclusion

Flavonolignans have an interesting chemical motif, and hydnocarpin and its congeners should be investigated for their activities and the mechanism underlying these activities. Multi-drug-resistant microbes are on the increase, and the possible inhibitory effect of these compounds when used with current antimicrobials should also be evaluated. Furthermore, unique cyclopentenyl fatty acids should also be investigated to understand the exact mechanism of action underlying antileprotic activity. Additional in depth phytochemical investigations of seed oil and extracts are required to tap the true potential of species from the Hydnocarpus genus.     

An ethnopharmacological survey and in vitro confirmation of ethnopharmacological use of medicinal plants used for wound healing in Bosomtwi-Atwima-Kwanwoma area,Ghana

Aims of the study

Wounds represent a major health burden and drain on healthcare resources in the world including Ghana and Africa. The majority of the people of Ghana and Africa still patronize traditional medicine for their health needs including various forms of wounds. The aim of this study is the identification of medicinal plants, type of wounds, dosage forms and collection methods used traditionally in treating wounds in the Bosomtwi-Atwima-Kwanwoma district, Ghana. In vitro screening of selected extracts from these plants on cell physiology of human dermal fibroblasts and keratinocytes was to be performed.

Materials and methods

Validated questionnaires were administered to 78 traditional healers in 54 communities of the district. Interviews and structured conversations were used to administer the questionnaires. Selected herbal material dominantly used by the healers was collected, identified and aqueous and ethanolic extracts were investigated in vitro on influence on cell physiology of keratinocytes and dermal fibroblasts (MTT-, BrdU-, LDH-assay). Antioxidant activities of ethanolic extracts were determined by free radical scavenging activity. Antiadhesive activity against Helicobacter pylori on human stomach cells was investigated for extracts reported to be used for stomach ulcer treatment.

Results

The ethnopharmacological survey revealed 104 plants species belonging to 47 families. The detailed use of these plants is documented. Aqueous extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni influenced the mitochondrial activity and proliferation of dermal fibroblasts and keratinocytes significantly. Ethanolic extracts of selected plants exhibited strong antioxidant activities comparable to α-tocopherol. For Spathodea campanulata, Hoslundia opposita and Pycnanthus angolensis, which were reported by the healers to be used also for wound healing in case of stomach ulcers, strong antiadhesive activity against Helicobacter pylori was demonstrated, while the extracts did not exhibit any direct cytotoxicity against the bacterium.

Conclusions

Traditional use of many wound-healing plants from Ghana can be well rationalized by the in vitro investigation of aqueous extracts. E.g. extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni exhibited significant influence on the cell viability and proliferation of keratinocytes and dermal fibroblasts.     

Pharmacological properties and protein binding capacity of phenolic extracts of some Venda medicinal plants used against cough and fever

Ethnopharmacology relevance

Several ailments are caused by infectious bacteria and in other diseases; they act as co-infection which complicate human life by causing health hazards. In Venda (South Africa), many plants are used in traditional medicine to treat cough and fever.

Aim of the study

This study was aimed at evaluating the antibacterial and antifungal properties, cyclooxygenases (COX), acetylcholinesterase (AChE) enzyme inhibitory effects and the phenolic composition as well as mutagenic properties of six medicinal plants used by the Venda people of Limpopo Province of South Africa against cough and fever.

Materials and methods

The petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of six plants were tested against four infectious bacteria (Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus) and a fungus Candida albicans. The same extracts were evaluated for their ability to inhibit COX-1 and -2 enzymes. Methanolic and water extracts of the same plant were tested for acetylcholinesterase inhibitory effects. Total phenolics, flavonoids, gallotannins and condensed tannins were determined. The ability of the extracts to bind and precipitate proteins was also investigated. The extracts were investigated for genotoxicity with and without S9 (metabolic activation) against three Salmonella typhimurium tester strains TA98, TA100 and TA102.

Results

The organic extracts of Rhus lancea leaves exhibited the best antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.0061 to 0.049 mg/ml. The best antifungal activity was observed from a DCM extract of Syzygium cordatum leaves with a MIC value of 0.195 mg/ml. The methanolic and water extracts of the same plant exhibited high inhibitory effects towards AChE with IC₅₀ values of 0.22 and 0.26 mg/ml, respectively. The highest levels of flavonoids and gallotannins were detected in Spirostachys africana bark; 11.57 and 48.88 μg/g, respectively. The highest percentages (1.2%) of condensed tannins were detected in Uvaria caffra leaves. The high levels of phenolic compounds may have been responsible for high antimicrobial activities for extracts of S. africana bark and U. caffra leaves. S. cordatum leaves represented the highest affinity for protein binding with 93%. All the extracts were non-mutagenic towards the three tested strains with and without S9 metabolic activation.

Conclusion

The result obtained in this study goes a long way in validating the ethnobotanical usage of these medicinal plants in the treatment of cough and fever by the Venda people. However, more evidence obtainable from other assays not performed here are urgently required to confirm these results.     

The potential of South African plants against Mycobacterium infections

ETHNOPHARMACOLOGICAL RELEVANCE: In South Africa, tuberculosis (TB) caused by Mycobacterium tuberculosis is the most commonly notified disease and the fifth largest cause of mortality, with one in ten cases of TB resistant to treatment in some areas. Many plants are used locally in traditional medicine to treat TB-related symptoms. AIM OF THE STUDY: The aim was to summarize currently available knowledge on South African plants used to treat TB symptoms, and antimycobacterial efficacy of plant-derived extracts and compounds. MATERIALS AND METHODS: The traditional uses of plants for respiratory ailments and TB were collated and tabulated. The antimycobacterial activity tests of extracts and chemical constituents of several of these plants and others using different methods and target organisms were summarized. RESULTS: Almost 180 plants used for TB-related symptoms in South African traditional medicine were documented. About 30% of these have been tested for antimycobacterial efficacy, mostly against fast-growing, non-pathogenic Mycobacterium species. CONCLUSIONS: Many plant species are used in traditional South African medicine to alleviate symptoms of TB, and several interesting leads have originated for further inquiry following in vitro antimycobacterial activity evaluation. However, much work remains to be done on the systematic assessment of anti-TB efficacy of local plants against pathogenic Mycobacterium species, both in vitro and in vivo.