Pyrethrins In Soil and Water From Selected Pyrethrum Growing Areas In Nakuru County, Kenya

Introduction: Pyrethrum also known as Chrysanthemum is a plant from which compounds known as pyrethrins are derived. The pyrethrins have  been used for many years as insecticides. Incidentally due to their high instability they have slowly been replaced by synthetic pyrethroids.  Pyrethrins are generally regarded as safe compared to the pyrethroids. However, the amounts released into the environment have not been well documented especially in pyrethrum growing regions.Objective:  The aim of the study was to determine the concentration of pyrethrins that come from pyrethrum plants and released into the  environment through their use as insecticides, thus, into drinking water and soil, in pyrethrum growing regions in Kenya.Methodology: Quantification to amounts of pyrethrins from pyrethrum plants, in soil and water bodies in and around pyrethrum farms in Kiambogo and Naivasha (Nakuru County). The study was carried out using High Performance Liquid Chromatography (HPLC). Water samples (0.5L) were collected from the following water bodies: rivers, streams, dams, wells and boreholes near or within pyrethrum farms.Conclusion: It was established that, the quantity of pyrethrins present in water and soil samples werebelow detectable levels within the WHO recommended range. Hence safe for the environment,more so for the farmers and the people living around pyrethrum farms. Key words: Pyrethrum, pyrethrins, chromatography, water, soil

Antimicrobial activity of organic total extracts of three Kenyan medicinal plants

In recent years, drug resistance to human pathogenicbacteria and fungi has increasingly been reported all over the world (Levy and Marshall, 2004; WHO 2004). Consequently, the increasing prevalence of multidrugresistant strains of microorganisms raises an urgent need to search for new sources of antimicrobial agents (Sieradzki et al, 1999) alongside other strategies such as regulated and rational use of antibiotics (Hernandez, 2005). The vast majority of traditionally used medicinal plants have not been adequately evaluated. This study was therefore undertaken to screen organic extracts obtained from three Kenyan medicinal plants for antibacterial and antifungal activity as a basis for further phytochemical studies. The plants to be studied were selected on the basis of ethnopharmacological reports of their use in traditional medicine; this approach is generally considered effective in the discovery of new bioactive agents from higher plants (Kloucek et al, 2005)

Diastereoselective arylation of l-proline derivatives at the 5-position

Diastereoselective introduction of nucleophiles into L-proline derivatives at the 5-position was achieved with suitable selection of N-protecting group. N-Methoxycarbonylated or benzyloxycarbonylated L-proline derivatives reacted with arene to give cis-arylated products. On the other hand, N-benzoylated L-proline derivative preferentially gave trans-arylated product which could be easily transformed into optically active C2-symmetrical pyrrolidine derivative. Such derivative 5, worked well as an organic activator in the asymmetric reduction of aromatic imines by Cl3SiH

Efficacy and safety evaluation of a novel trioxaquine in the management of cerebral malaria in a mouse model

Abstract Background The emergence of multidrug-resistant strains of Plasmodium falciparum poses a great threat of increased fatalities in cases of cerebral and other forms of severe malaria infections in which parenteral artesunate monotherapy is the current drug of choice. The study aimed to investigate in a mouse model of human cerebral malaria whether a trioxaquine chemically synthesized by covalent linking of a 4,7-dichloroquinoline pharmacophore to artesunate through a recent drug development approach termed ‘covalent bitherapy’ could improve the curative outcomes in cerebral malaria infections. Methods Human cerebral malaria rodent model, the C57BL/6 male mice were infected intraperitoneally (ip) with Plasmodium berghei ANKA and intravenously (iv) treated with the trioxaquine from day 8 post-infection (pi) at 12.5 and 25 mg/kg, respectively, twice a day for 3 days. Treatments with the trioxaquine precursors (artesunate and 4,7-dichloroquine), and quinine were also included as controls. In vivo safety evaluation for the trioxaquine was done according to Organization for Economic Co-operation and Development (OECD) guidelines 423, where female Swiss albino mice were orally administered with either 300 or 2000 mg/kg of the trioxaquine and monitored for signs of severity, and or mortality for 14 days post-treatment. Results The trioxaquine showed a potent and a rapid antiplasmodial activity with 80% parasite clearance in the first 24 h for the two dosages used. Long-term parasitaemia monitoring showed a total parasite clearance as the treated mice survived beyond 60 days post-treatment, with no recrudescence observed. Artesunate treated mice showed recrudescence 8 days post-treatment, with all mice in this group succumbing to the infection. Also, 4,7-dichloroquinoline and quinine did not show any significant parasitaemia suppression in the first 24 h post-treatment, with the animals succumbing to the infection. Conclusion Covalent bitherapy proves to be a viable source of urgently needed new anti-malarials for management of cerebral malaria, and this polypharmacology approach could be a potential strategy to protect artesunate from parasite resistance and in potentially improving clinical outcomes in severe forms of malaria infections