Mahabir P. Gupta

A search for anti-viral properties in Panamanian medicinal plants.: The effects on HIV and its essential enzymes

Aqueous and methanolic extracts of 39 Panamanian medicinal plants were tested for anti-human immunodeficiency virus (HIV) effects. The extracts were tested for the inhibition of HIV-induced cytopathic effects in cultured cells, HIV-reverse transcriptase (RT) and HIV-protease (PR) enzymes. The water extract of the branches of Jatropha curcas (Euphorbiaceae) inhibited strongly the HIV-induced cytopathic effects with low cytotoxicity. On the other hand, the water extracts of the whole plant of Chamaesyce hyssopifolia (Euphorbiaceae), the leaves of Cordia spinescens (Boraginaceae) and the aerial parts of Hyptis lantanifolia (Labiatae), and the methanol extract of the aerial parts of Tetrapteris macrocarpa (Malpighiaceae) were potent inhibitors of HIV-RT (IC50: 6-8 microg/ml). Seven out of 39 plants were found to be moderate inhibitors of HIV-PR (IC50: 43-100 microg/ml). Furthermore, we report on the respective inhibitory substances of J. curcas, C. hyssopifolia and C. spinescens, and their possible mechanism of action.

Value of the ethnomedical information for the discovery of plants with antifungal properties. A survey among seven Latin American countries.

ETHNOPHARMACOLOGICAL RELEVANCE This study reports the antifungal evaluation of 327 plant species (92 families and 251 genera) from seven Latin American countries which were selected on the basis of their reported ethnomedical uses and compared them with plants selected at random. AIM OF THE STUDY (a) The main aim of this study was to investigate whether the probability of detecting antifungal plants is higher when plants have reports of ethnopharmacological uses related to fungal infections (PAU group) than when they are selected at random (PNAU group). (b) The second objective was to determine, within the PAU group, whether the probability of obtaining a positive result will be higher when the plants are tested against dermatophytes, than against yeasts or Aspergillus spp. (c) The third goal was to investigate, within all MICs<or=1000 microg/mL, if the MICs displayed by the PAU group are comparatively lower than MIC values of the PNAU group; that is to say, if they can be expected more potent antifungal plants within the group of plants that have a history of traditional use related to fungal infections than when they do not have one. MATERIALS AND METHODS A five-stage process of documentation, evaluation and analysis of results was conducted: (1) selection of words that could describe the ethnopharmacological use related to fungal infections; (2) a survey of specialized literature in each country; (3) collection and preparation of an extract of each plant; (4) antifungal evaluation of the selected plants and (5) statistical analysis of the results. For the antifungal evaluation, the microbroth dilution assay recommended by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) was used against a panel of eleven human opportunistic and pathogenic fungi. For the statistical analysis the Pearsons Chi Square test and the Scores test were used. RESULTS (a) A significantly higher probability of detecting plants with antifungal activity against at least one fungus was found within the PAU (40.3%) than the PNAU group (21.3%) (p<0.01). (b) A similar higher probability than in (a) (39.6% vs. 20.8%) was found when plants were tested against dermatophytes (p<0.01) but not against yeasts or Aspergillus spp. (p>0.05). (c) Within the detected antifungal plants from both groups, plants of the PAU group displayed higher activities (lower MICs) than those of PNAU group against dermatophytes (p<0.05) but not against yeasts or Aspergillus spp. CONCLUSIONS Considering that dermatophytes are the cause of superficial fungal infections, which can be easily detected and followed by traditional healers, our findings suggest that the ethnopharmacological approach is useful in guiding the detection of antifungal plants in Latin America mainly for infections in which the pathological expression is obvious and, therefore, the cure can be clearly observed.

Antifungal and larvicidal cordiaquinones from the roots of Cordia curassavica

In addition to the known cordiaquinones A and B, two novel meroterpenoid naphthoquinones, named cordiaquinones J and K, have been isolated from the roots of Cordia curassavica. Their structures were elucidated by spectrometric methods including EI, D/CI mass spectrometry, 1H, 13C and 2D-NMR experiments. The four naphthoquinones demonstrated antifungal activities against Cladosporium cucumerinum, Candida albicans and toxic properties against larvae of the yellow fever-transmitting mosquito Aedes aegypti.

Ethnobotanical inventory of medicinal plants used by the Guaymi Indians in Western Panama. Part II

A list of newly identified plants is presented to supplement Part I (Joly et al. (1987) Journal of Ethnopharmacology 20, 145-171). A comparative analysis is made between our work and two other recent inventories of plants used by the Guaymi Indians of Panama and Costa Rica. As in Part I, the results of a literature survey are also provided, including medicinal uses, known constituents and pharmacological effects.

In vitro antiplasmodial activity of Central American medicinal plants

Summary The in vitro antiplasmodial activities of 14 plant species traditionally used in Central America for the treatment of malaria or fever were evaluated. Lipophilic extracts of Piper hispidum, Siparuna andina, S. pauciflora, S. tonduziana, and Xylopia cf. frutescens, proved to be active against both a chloroquine‐sensitive and a resistant strain of Plasmodium falciparum. IC50 values ranged between 3.0 μg/ml and 21.9 μg/ml; however, moderate cytotoxicity of active extracts was observed. Bioactivity‐guided fractionation of Piper hispidum yielded 2′,4,6′‐trihydroxy‐4′‐methoxydihydrochalcone (asebogenin) as an active compound.

Composition and biological activity of the essential oil from leaves of Plinia cerrocampanensis, a new source of α-bisabolol.

The essential oil from fresh leaves of Plinia cerrocampanensis Barrie (Myrtaceae), obtained by hydrodistillation, was analysed by GC-FID and GC-MS. Forty components, representing more than 91% of the oil, were identified. Oxygenated sesquiterpenes represented the main fraction with alpha-bisabolol (42.8%) as the major constituent, making this plant a new and good source of this substance. Biological activity of the essential oil was evaluated against several bacterial and fungal strains as well as larvae from Aedes aegypti. The highest activity was found against Staphylococcus aureus, Pseudomonas aeruginosa, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum with MIC values from 32 to 125 microg/ml. The essential oil also showed potent inhibitory and bactericidal activities against three H. pylori strains, with MIC and MBC values of 62.5 microg/ml, and caused 100% mortality of A. aegypti larvae at a concentration of 500 microg/ml.

ALKALOIDS AND OTHER COMPOUNDS FROM PSYCHOTRIA CORREAE

Abstract From extracts of the leaves and/or the roots of Psychotria correae , isodolichantoside and the new alkaloids correantoside, 10-hydroxycorreantoside, correantines A to C, and 20-epi-correantine B were isolated, in addition to two cerebrosides and some isoprenoids. Structures were established by spectroscopic studies in combination with chemical interconversions and partial synthesis.

Molluscicidal saponins from Swartzia simplex

Abstract One monodesmosidic saponin and six bidesmosidic saponins have been isolated from the methanolic extract of the leaves of Swartzia simplex . They were shown to be glucuronides of oleanolic acid, gypsogenin and gypsogenic acid by chemical and spectral means. The monodesmosidic saponins exhibit various molluscicidal activities against the schistosomiasis-transmitting snail Biomphalaria glabrata .

Using ecological criteria to design plant collection strategies for drug discovery

Tropical forests are one of the most diverse and endangered habitats on earth. They have also been portrayed as a source of future pharmaceuticals, yet finding useful compounds can be both scientifically and politically challenging. Increasingly, over the past decade, the potential value of medicinal compounds derived from plants, microorganisms, and animals has been proposed as a tangible benefit of biodiversity, and therefore a basis for promoting its preservation. Ecological theories of plant defense can increase the probability of discovering compounds with activity in bioassays against human disease targets. In addition, conducting research in tropical countries with local scientists provides immediate and lasting benefits for the sustainable use of biodiversity. This new approach to drug discovery has been effective in identifying bioactive leads. It is both an important step towards understanding the medicinal value of biodiversity, and a practical way to link drug discovery with conservation.

Antifungal and larvicidal meroterpenoid naphthoquinones and a naphthoxirene from the roots of Cordia linnaei

Three new meroterpenoid naphthoquinones, the known cordiaquinone B and a new naphthoxirene have been isolated from the roots of Cordia linnaei. Their structures were established by spectrometric methods including EI, D/CI and FAB mass spectrometry, 1H, 13C and 2D NMR experiments. The naphthoquinones showed activity against Cladosporium cucumerinum, Candida albicans and the larvae of the yellow fever-transmitting mosquito Aedes aegypti, while the naphthoxirene derivative was found to be inactive in the same bioassays.