Antibacterial and antifungal activities of extracts of Zanthoxylum chalybeum and Warburgia ugandensis, Ugandan medicinal plants.
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Measles is a killer disease of children in Uganda. The treatment of the disease is mainly directed at the secondary microbial infections. A large proportion of the population in Uganda still relies on the use of herbal remedies, which have been claimed to produce beneficial responses. In this study, the efficacy of Warburgia ugandensis and Zanthoxylum chalybeum against common bacteria and fungi was investigated. Bactericidal and antifungal assays were done using extracts derived from Z. chalybeum and W. ugandensis (agar well diffusion, disc diffusion and colony count assays). All extracts (ethanolic, petroleum ether and aqueous) of Z. chalybeum did not show antimicrobial activity. Phytochemical investigations of Zanthoxylum chalybeum (seed) yielded a pure crystalline alkaloid (27-135 D) which was characterized as skimianine based on (1)H-NMR spectroscopy and comparison with spectra of authentic samples. Skimmianine did not have antimicrobial activity in this test system. W. ugandensis water extracts elicited antibacterial activity against both Escherischia coli and Staphylococcus aureus in the agar well assay but not in the disc diffusion assay. Warburgia ugandensis water extracts and fraction 27-163 D also showed antifungal activity against Candida albicans. Chromatography of extracts of Warburgia ugandensis stem bark afforded compound 49-169 K, which was characterized as the sesquiterpine muzigadial (by (1)H-NMR spectroscopy), which did not show antibacterial activity but had antifungal activity against C. albicans. Therefore, the claimed efficacy of W. ugandensis could be attributable to antibacterial and antifungal activity of its components. Since Z. chalybeum extracts had neither antifungal nor antibacterial activities, its mode of action is unclear from these results. (+info)
Effect of methanol extract of Zanthoxylum piperitum leaves and of its compound, protocatechuic acid, on hepatic drug metabolizing enzymes and lipid peroxidation in rats.
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The effect of methanol extract and protocatechuic acid from the leaves of Zanthoxylum piperitum on lipid peroxidation and drug metabolizing enzymes were investigated in the liver of bromobenzene-treated rats. The methanol extract and protocatechuic acid reduced the level of lipid peroxide induced by bromobenzene. The methanol extract and protocatechuic acid reduced the activity of aniline hydroxylase that had been increased by bromobenzene, while did not affect the activities of aminopyrine N-demethylase and glutathione S-transferase. The methanol extract and compound effectively restored the activity of epoxide hydrolase which had been decreased by bromobenzene. These results may suggest that the methanol extract of Z. piperitum and protocatechuic acid prevented lipid peroxidation by reducing the activity of aniline hydroxylase, an epoxide-producing enzyme, and by enhancing the activity of epoxide hydrolase, an epoxide-removing enzyme, in rats that had been intoxicated with bromobenzene. (+info)
Acute toxicity effects of the methanolic extract of Fagara zanthoxyloides (Lam.) root-bark.
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BACKGROUND: Fagara zanthoxyloides is a well known medicinal plant in Uganda. It is used extensively in malaria and other infections. However nothing is known about its toxicity. OBJECTIVE: The objective of the study was to evaluate the acute toxicity of the methanolic extract of the root-bark of F. zanthoxyloides, in mice. METHODS: Methanolic extract of the root-bark of the plant was administered orally to mice at various dose levels to determine the acute toxic effects and the median lethal dose (LD50) in mice. RESULTS: The LD50 of the methanolic extract was found to be 5.0 g/Kg body weight within 95% confidence limits. The mice showed signs of cerebral irritation before dying. Histopathological examinations of the viscera showed congestion and focal necrosis of the liver and renal tubules. CONCLUSION: It was concluded that the extract of F. zanthoxyloides is safe, however the cerebral mechanism that lead to the death of the mice need to be investigated further. (+info)
Evaluation of botanicals as repellents against mosquitoes.
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Repellent properties of three plant extracts--essential oil (steam distillate) of Zanthoxylum limonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits) were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut (Parachute) oil base under laboratory conditions. Three concentrations--10, 20 and 30% of the repellents were evaluated. Repellents in mustard oil afforded longer protection time against the bites of Aedes (S.) albopictus mosquitoes than those in coconut oil. At 30% concentration, 296-304 min protection time was achieved by the test repellents in mustard oil base while repellents in coconut oil exhibited 223.5-245 min protection time at the same concentration. Oil of Z. limonella gave the highest protection time against the bites of Aedes (S.) albopictus mosquitoes at all the concentrations than other herbal repellents tested both in mustard and coconut oil. (+info)
Tyrosinase inhibitor isolated from the leaves of Zanthoxylum piperitum.
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Two flavonols, quercetin (1) and quercitrin (2), were isolated from the leaves of Zanthoxylum piperitum. Their structures were established by UV, one- and two-dimensional NMR, and mass spectroscopic methods. Quercetin showed significant inhibition against mushroom tyrosinase with an IC50 value of 3.8 microg/ml, and appeared to inhibit the polyphenol oxidase activity of tyrosinase in a competitive manner (Ki = 10 +/- 0.20 microM) when L-tyrosine was used as a substrate, although it did not inhibit the melanin production of Streptomyces bikiniensis. (+info)
The essential oils from Zanthoxylum schinifolium pericarp induce apoptosis of HepG2 human hepatoma cells through increased production of reactive oxygen species.
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The volatile extract from dried pericarp of Zanthoxylum schinifolium that was obtained by simultaneous distillation with dichloromethane and water was composed of 29.9% geranyl acetate, 15.8% citronella, 15.4% sabinene and the minor volatile components included beta-myrcene, linalool, (-)-isopulegol, citronellyl acetate, 1,4-dimethyl pyrazole, alpha-terpinene, 3-methyl-6-(1-methylethyl)-2-cyclo-hexene-1-o1 and trans-geraniol. The volatile extract decreased the cell viability and induced apoptotic death in HepG2 human hepatoma cells in a concentration- and time-related manner. In addition, the volatile extract increased the production of reactive oxygen species in a dose-dependent manner. Pretreatment of the cells with Trolox, a well-known antioxidant, significantly suppressed the generation of reactive oxygen species and cell death induced by the extract. However, caspase-3 activity was not changed in the extract-treated cells, suggesting that the extract-induced apoptosis of HepG2 cells is caspase-3 independent. Furthermore, in nude mice inoculated with Huh-7 human hepatoma cells, the extract significantly inhibited tumor development. These results suggest that the volatile extract from Zanthoxylum schinifolium pericarpium is a good candidate for hepatocellular carcinoma (HCC) therapy and that reactive oxygen species are the key signaling molecules in the volatile extract-induced cell death in HepG2 cells. (+info)
Sichuan pepper extracts block the PAK1/cyclin D1 pathway and the growth of NF1-deficient cancer xenograft in mice.
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There is increasing evidence that more than 70% of cancers including pancreatic, breast and prostate cancers as well as neurofibromatosis (NF) are highly addicted to abnormal activation of the Ser/Thr kinase PAK1 for their growth. So far FK228 is the most potent among the HDAC (histone deacetylase) inhibitors that block the activation of both PAK1 and another kinase AKT, downstream of PI-3 kinase. However, FK228 is still in clinical trials (phase 2) for a variety of cancers (but not for NF as yet), and not available for most cancer/NF patients. Thus, we have been exploring an alternative which is already in the market, and therefore immediately useful for the treatment of those desperate cancer/NF patients. Here we provide the first evidence that extracts of Chinese/ Japanese peppercorns (Zanthoxyli Fructus) from the plant Zanthoxylum piperitum called "Hua Jiao"/"Sansho", block selectively the key kinase PAK1, leading to the downregulation of cyclin D1. Unlike FK228, these extracts do not inhibit AKT activation at the concentrations that block either cancer growth or PAK1 activation. The Chinese pepper extract selectively inhibits the growth of NF1-deficient malignant peripheral nerve sheath tumor (MPNST) cells, without affecting the growth of normal fibroblasts, and suppresses the growth of NF1-deficient human breast cancer (MDA-MB-231) xenograft in mice. Our data suggest that these peppercorn extracts would be potentially useful for the treatment of PAK1-dependent NF such as MPNST, in addition to a variety of PAK1-dependent cancers including breast cancers. (+info)
Polyphenolic constituent structures of Zanthoxylum piperitum fruit and the antibacterial effects of its polymeric procyanidin on methicillin-resistant Staphylococcus aureus.
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Zanthoxylum piperitum (Rutaceae) is used as a spice and a natural medicine in Japan. Our study found that ZP-CT-A, a polymeric proanthocyanidin purified from the fruit of this species, noticeably decreased the minimum inhibitory concentrations of beta-lactam antibiotics for methicillin-resistant Staphylococcus aureus (MRSA). The structure of ZP-CT-A was characterized on the basis of (13)C NMR and size exclusion chromatographic data and the results of thiolytic degradation. A mechanistic study of the effects of ZP-CT-A indicated that it suppressed the activity of beta-lactamase and largely decreased the stability of the bacterial cell membrane of MRSA, as shown by a reduction in the tolerance of MRSA to low osmotic pressure and high ionic strength solutions. (+info)