Screening methods for natural products with antimicrobial activity: a review of the literature.

This paper reviews the literature on recent antimicrobial plant products (1978–1988) and medicinal plants used for the treatment of infectious diseases. The review includes accounts of extracts, essential oils and other active principles isolated from plants that have been used in folk medicine as antimicrobial agents. The name and part of the plants studied, the spectrum of activity, type of active compounds and methods used are discussed, as are their mechanisms of action.

A review of some antimicrobial compounds isolated from medicinal plants reported in the literature 1978–1988

Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Petiveria alliacea, Renealmia alpinia, Justicia secunda, Phyllanthus urinaria,Phyllanthus niruri,Momordica charantia, Xiphidium caeruleum, Ottonia ovata, Lepianthes peltata, Capsicum frutescens, Costus scaber, Dendropanax arboreus, Siparuma guianensis, Syngonium podophyllum, Monstera dubia, Solanum species, Eclipta prostrata, Spiranthes acaulis, Croton gossypifolius, Barleria lupulina, Cola nitida, Acrocomia ierensis (tentative ID). Plant use is based on odour, and plant morphological characteristics and is embedded in a complex cultural context based on indigenous Amerindian beliefs. It is suggested that the medicinal plants exerted a physiological action on the hunter or his dog. Some of the plants mentioned contain chemicals that may explain the ethnomedicinal and ethnoveterinary use. For instance some of the plants influence the immune system or are effective against internal and external parasites. Plant baths may contribute to the health and well being of the hunting dogs.

https://link.springer.com/content/pdf/10.1186%2F1472-6882-1-10.pdf

Medicinal and ethnoveterinary remedies of hunters in Trinidad.

Lantana (Lantana camara Linn) is a noxious weed that grows in many tropical and subtropical parts of the world. Ingestion of lantana foliage by grazing animals causes cholestasis and hepatotoxicity. Both ruminants and nonruminant animals such as guinea pigs, rabbits, and female rats are susceptible to the hepatotoxic action of lantana toxins. The hepatotoxins are pentacyclic triterpenoids called lantadenes. Molecular structure of lantadenes has been determined. Green unripe fruits of the plant are toxic to humans. Lantana spp. exert allelopathic action on the neighboring vegetation. The allelochemicals have been identified as phenolics, with umbelliferone, methylcoumarin, and salicylic acid being the most phytotoxic. In addition to phenolics, a recent report indicates lantadene A and B as more potent allelochemicals. Management of lantana toxicosis in animals is achieved by drenching with activated charcoal and supportive therapy. Recent reports on the bilirubin clearance effect of Chinese herbal tea Yin Zhi Huang (decoction of the plant Yin Chin, Artemisia capillaries, and three other herbs) or its active ingredient 6,7-dimethylesculetin, in jaundice are very exciting and warrant investigations on its, possible, ameliorative effects in lantana intoxicated animals. Research is being conducted on new drug discovery based on natural products in different parts of the lantana plant.

A review of the hepatotoxic plant Lantana camara.

We evaluated the antibacterial activities of the crude methanol extract,fractions (I-V) obtained after acid-base extraction and pure com-pounds from the stem bark of Aspidosperma ramiflorum . The mini-mum inhibitory concentration (MIC) was determined by the microdi-lution technique in Mueller-Hinton broth. Inoculates were prepared inthis medium from 24-h broth cultures of bacteria (10 7 CFU/mL).Microtiter plates were incubated at 37oC and the MICs were recordedafter 24 h of incubation. Two susceptibility endpoints were recordedfor each isolate. The crude methanol extract presented moderateactivity against the Gram-positive bacteria B. subtilis (MIC = 250 µg/mL) and S. aureus (MIC = 500 µg/mL), and was inactive against theGram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 µg/mL). Fractions I and II were inactive against standard strains atconcentrations of ≤1000 µg/mL and fraction III displayed moderateantibacterial activity against B. subtilis (MIC = 500 µg/mL) and

/pdf/antibacterial-activity-of-indole-alkaloids-from-aspidosperma-5fikyph9sk.pdf

Antibacterial activity of indole alkaloids from Aspidosperma ramiflorum.

From ASPIDOSPERMA EXCELSUM, rootbark, which has previously been shown to exhibit antimicrobial activity, 6 antimicrobial active alkaloids were isolated and identified: 11-methoxytubotaiwine, ochrolifuanine A, tetrahydrosecamine, 16-demethoxycarbonyltetrahydrosecamine, 16-hydroxytetrahydrosecamine and 16-hydroxy, 16-demethoxycarbonyltetrahydrosecamine. The minimum inhibitory concentration was determined for some of the alkaloids, using BACILLUS SUBTILIS as test organism. Didemethoxycarbonyltetrahydrosecamine was also shown to exhibit antimicrobial activity. No activity against gram negative bacteria could be found for the alkaloids by means of biograms. The site of demethoxycarbonylation in demethoxycarbonyltetrahydrosecamine was established as C-16. The structures of the two new secamine type alkaloids, 16-hydroxytetrahydrosecamine and 16-hydroxy,16-demethoxycarbonyltetrahydrosecamine were determined by means of their spectral data. During the isolation of the antimicrobially active alkaloids some inactive alkaloids were also isolated: compactinervine, N a -acetylaspidospermidine, O-dimethylaspidospermine, aricine, yohimbine and O-acetylyohimbine.

E. Kos-Kuyck

Papers

Medicinal Plants of Surinam

Medicinal plants of surinam. III: Antimicrobially active alkaloids from aspidosperma excelsum.