An in vitro evaluation of extracts from some medicinal plants in Kenya against herpes simplex virus.

The extracts from 21 medicinal plants commonly used in traditional remedies in Kenya were screened for antiviral activity against wild type 7401H strain herpes simplex virus type 1. The plant extracts exhibited antiviral activity against the virus in the plaque and yield reduction assays. The results reveal that twelve plants may contain constituents that could be exploited for the management of HSV infections. Although the extracts used in these experiments contain a complex matrix of a large number of compounds the results indicate that useful compounds can be isolated for further exploitation.

Liquid chromatographic analysis of a formulation containing polymyxin, gramicidin and neomycin.

The development of a liquid chromatographic essay system for the stability study of a formulation containing polymyxin, gramicidin and neomycin is described. For the determination of each group of antibiotics, poly(styrenedivinylbenzene) is used as the stationary phase. The mobile phase for the determination of polymyxin consists of an aqueous solution containing 7 g l-1 of sodium sulfate, 50 ml l-1 of 1 M phosphoric acid and 160 ml l-1 of acetonitrile. UV detection is performed at 215 nm. An aqueous solution containing 70 g l-1 of sodium sulfate, 1.4 g l-1 of sodium octanesulfonate and 50 ml l-1 of 0.2 M phosphate buffer pH 3.0 is used as the mobile phase for the determination of neomycin. Since neomycin has no UV-absorbing chromophore, pulsed electrochemical detection is chosen to determine neomycin. For each method, the influence of the different chromatographic parameters on the separation, the selectivity towards the other active compounds and the excipients, the repeatability and the linearity were investigated. The stability of the formulation was examined at 0, 6 and 12 months.

Molluscicidal activity of Solanum aculeatum (family: Solanaceae) berries against Biomphalaria pfeifferi, Bulinus globosus and Lymnaea natalensis.

Aqueous suspensions of powder of sun- or freeze-dried berries of the plant Solanum aculeatum (Family Solanaceae), indigenous in Kenya, were tested for molluscicidal activity against Biomphalaria pfeifferi, Bulinus globosus and Lymnaea natalensis under laboratory conditions. One hundred or 50 mg powder L-1 of sun- or freeze-dried berries killed over 60% of the test B. pfeifferi, Bul. globosus and L. natalensis. Whereas 25 mg L-1 of the sun dried material killed less than 60% of the test snails, similar concentrations of the freeze dried molluscicide produced 60-80% mortality in the snails, under similar conditions. Using L. natalensis as the target snail, it was shown that the freeze dried material was more potent than the freeze-dried berries of S. incanum, S. nigrum or leaves of Polygonum senegalensis (Family Polygonaceae), all present in Kenya, and known to possess molluscicidal properties. The powdered material retained molluscicidal activity even after several months storage at room temperature. These findings suggest that S. aculeatum is a potent plant molluscicide, and has the potential for the control of vectors of schistosomiasis and fascioliasis in Kenya.