Ethnobotanical uses and phytochemical analysis of Cyperus articulatus

Abstract

It may be possible to use plant extracts to develop environmental friendly repellents for effective insects control through screening of plants for repellent activity. Recently, the environmental friendly and biodegradable natural insecticides of plant origin have been receiving attention as an alternative green measure of control of insect vectors. Thermal expulsion and direct burning of some aromatic plants believed to have repellent effects on mosquitoes before sleeping continue to play a very important role in household protection against mosquito vectors of dangerous diseases such as malaria, yellow fever and dengue fever and elephantiasis. It is for this reason that this research was carried out in Tharaka to find out if Cyperus articulutus could repel mosquitoes and other effects such as treat malaria, stomach-ache and skin rush as claimed by the traditional medicine practitioners in Meru. The chemical constituents of the root tubers of Cyperus articulatus, from Tharaka were obtained by solvent extraction and analyzed by GC/MS. The root tubers of Cyperus articulatus were collected and extracted with organic solvents (CH2Cl2, CH2Cl2/CH3OH [1:1], 5% H2O/CH3OH), The crude extract of 100% CH2Cl2 was subjected to a combination of chromatographic techniques including column chromatography and preparative thin layer chromatography for the separation of compounds; an exercise which proved futile due to complexity of the mixture. GC- MS analysis carried at the University of Surrey (U.K.) in order to determine the structures of the compounds revealed a total of 59 compounds, of which 48 (82.76%) were terpenes; amongst the terpenes were 27 sesquiterpenes (45.76%), 20 monoterpenes (33.90%) 1 triterpene (1.69%). There were 11 non-terpenes (18.64 %). The major sesquiterpene identified was α cubenene and the major monoterpene was 5-Isopropenyl-2-methyl-7-oxabicyclo[4.1.0]heptan-2-ol. The crude extract was subjected to anti-bacterial tests using Staphyloccocus aureus, Streptococcus pneumonae and Salmonella typhi bacterial strains. The zones of inhibition diameters were taken then averaged and positive activity against the three bacterial strains was seen with the 100% dichloromethane crude extract which inhibited the growth of the micro-organisms with S. aureus, 1.5cm, S. pneumonia, 1.2