Some biological activities of Pycnanthus angolensis (Welw.) Warb

Abstract

Pycnanthus angolensis (family Myristicaceae) is used in a variety of herbal therapies for treating skin, oral chest and gastro-intestinal ailments. However, its use in malaria control at the larval stage and potential for anti-tumor activity are yet to be investigated. Hence the anti-microbial, larvicidal and brine-shrimp lethality studies on leaves, stem and roots were carried out. The extracts and fractions of leaves elicited good anti-microbial activity against Bacillus subtilis, Staphylococcus aureus and none against Escherichia coli, Salmonella typhi and Klebsiella pneumoniae but gave minimal activity against fungal isolates (Aspergilus niger and Candida albicans). Both the stem and roots however, afforded lesser activities. The larvicidal assay determined in terms of percentage mortality showed that the leaves gave very weak larvicidal activity (LA%) of 20% and 35% (at 5%w/v) while the activity was somewhat moderate at 45% and 50% (10%w/v) both at 12 and 24h incubation respectively. However, the activity displayed by both the stem and roots was insignificant. The brine- shrimp lethality assay; analyzed using the Finney probit method, showed that the leaves displayed a ‘significant' LD50 value at 2.5ppm while the stem and roots gave ‘moderate' LD50 values at 362ppm and 310ppm respectively compared with literature values below the 200ppm are generally considered ‘significant'. These findings indicate a correlation in the activities of the leaves and as such serve as panacea for infectious diseases and therefore scientific justification to some of the folkloric uses of the plant.

Keywords: Antimicrobial; Larvicidal; Brine shrimp lethality; Pycnanthus angolensis

Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: pp. 49-55