Brine shrimp lethality test and acetylcholine esterase inhibition studies on selected South African medicinal plants

Abstract

Research into traditional medicines is often conducted in a multidisciplinary approach as motivated by a desire to understand them in as complete a manner as possible,realizing their chemistry, biology and pharmacology. One biological approach involves monitoring the cytotoxicity of the extracts of subfractions against the nauplii,Artemia salina (brine shrimp). Organic and aqueous extracts of seven South African medicinal plants was investigated for biological activity. Selected plant extracts was also evaluated for AChE inhibitory activity. The objectives of this study was to look for any correlation between known biological activities of the investigated plants and BSLT lethality data and also to look for any correlation between AChEI activity and BSLT lethality data for selected plant extracts. The most active of the plants was the n-hex extract of T.alliacea, followed by the aqueous extract of C.mellei and the MeOH extract of C.quadrifidus; the MeOH and the DCM extracts of A.afra; the DCM extract of P.undulatum and the EtOAc extract of A.annua. The results from this study show a good correlation with antitumor, antimicrobial and anti-trypanocidal activity.The various plants extracts investigated showed good inhibitory activity towards AChE using the TLC bioautography method. The results obtained from this study indicate that this type of activity is not only subject to plants containing alkaloids, but rather a diverse class of compounds may exhibit this kind of activity. The extracts that showed good AChE inhibitory activity also showed good cytotoxicity towards brine shrimp nauplii.