Larvicidal, antimicrobial and brine shrimp activities of extracts from Cissampelos mucronata and Tephrosia villosa from coast region, Tanzania

<p>Abstract</p> <p>Background</p> <p>The leaves and roots of <it>Cissampelos mucronata </it>A. Rich (Menispermaceae) are widely used in the tropics and subtropics to manage various ailments such as gastro-intestinal complaints, menstrual problems, venereal diseases and malaria. In the Coast region, Tanzania, roots are used to treat wounds due to extraction of jigger. Leaves of <it>Tephrosia villosa </it>(L) Pers (Leguminosae) are reported to be used in the treatment of diabetes mellitus in India. In this study, extracts from the roots and aerial parts of <it>C. mucronata </it>and extracts from leaves, fruits, twigs and roots of <it>T. villosa </it>were evaluated for larvicidal activity, brine shrimps toxicity and antimicrobial activity.</p> <p>Methods</p> <p>Powdered materials from <it>C. mucronata </it>were extracted sequentially by dichloromethane followed by ethanol while materials from <it>T.villosa </it>were extracted by ethanol only. The extracts obtained were evaluated for larvicidal activity using <it>Culex quinquefasciatus </it>Say larvae, cytotoxicity using brine shrimp larvae and antimicrobial activity using bacteria and fungi.</p> <p>Results</p> <p>Extracts from aerial parts of <it>C. Mucronata </it>exhibited antibacterial activity against <it>Staphylococcus aureus</it>, <it>Escherichia coli</it>, <it>Pseudomonas aeruginosa</it>, <it>Salmonella typhi</it>, <it>Vibrio cholera</it>, <it>Bacillus anthracis</it>, <it>Streptococcus faecalis </it>and antifungal activity against <it>Candida albicans </it>and <it>Cryptococcus neoformans</it>. They exhibited very low toxicity to brine shrimps and had no larvicidal activity. The root extracts exhibited good larvicidal activity but weak antimicrobial activity. The root dichloromethane extracts from <it>C. mucronata </it>was found to be more toxic with an LC₅₀value of 59.608 μg/mL while ethanolic extracts from root were not toxic with LC₅₀>100 μg/mL). Ethanol extracts from fruits and roots of <it>T. villosa </it>were found to be very toxic with LC₅₀values of 9.690 μg/mL and 4.511 μg/mL, respectively, while, ethanol extracts from leaves and twigs of <it>T. villosa </it>were found to be non toxic (LC₅₀>100 μg/mL).</p> <p>Conclusion</p> <p>These results support the use of <it>C. mucronata </it>in traditional medicine for treatment of wounds. Extracts of <it>C. mucronata </it>have potential to yield active antimicrobial and larvicidal compounds. The high brine shrimp toxicity of <it>T. villosa </it>corroborates with literature reports that the plant is toxic to both livestock and fish. The results further suggest that <it>T. villosa </it>extracts have potential to yield larvicidal and possibly cytotoxic compounds. Further studies to investigate the bioactive compounds responsible for the observed biological effects are suggested.</p

INVESTIGATION OF THE ANTIULCER PROPERTIES OF THE METHANOLIC LEAF FRACTION OF CISSAMPELOS MUCRONATA

Fraction F1 containing alkaloids and sterols/triterpenes isolated from the methanolic leaf extract of Cissampelos mucronata A.Rich (Menispermaceae) was assayed for anti-ulcer activity using histamine- and stress-induced ulcer models. The fraction and crude methanolic extract (CME) were screened for anti-spasmodic activity using the spontaneously contracting smooth muscle of the rabbit jejunum. Their antimicrobial potency was assessed using different Gram-negative and Grampositive bacteria as well as two species of fungi. The result indicate that the fraction and CME exhibited 63.25 % and 57.26 % inhibition of ulcer induced by histamine while 57.15 % and 47.14 % inhibition were recorded against stress-induced ulcer respectively. The inhibitions of ulcer induction were significant (P < 0.05) except for the CME against stress-induced ulcer. In addition, the fraction exhibited better antimicrobial property than the CME; however, none of them displayed fungistatic activity. Both the fraction and CME slightly inhibited the spontaneous pendular movement of the rabbit jejunum. The exact mechanism responsible for the anti-ulcer property of the fraction is not precisely known but the results indicate that inhibitions of various inciting stimuli in ulcer pathogenesis are involved. Key Words: Cissampelos mucronata, fraction, histamine, stress African Journal of Science and Technology Vol.5(1) 2004:109-11

Anti-ulcer activity of aqueous leaf extract of Persea americana (family-Lauraceae)

The study was carried out to investigate the anti-ulcer activity of aqueous leaf extract of Persea americana. Groups of albino rats were pre-treated orally with aqueous leaf extract of the plant before administration of the ulcerogenic drugs-indomethacin and ethanol. The animals were sacrificed by a blow on the head, their stomachs removed and examined for ulcers. The extract produced significant (