Abstract

Saleh B. Alghamdi*

ABSTRACT

Cancer and microbial infections are main causes of morbidity and mortality all over the world. Pluchea is a genus of flowering plants belongs to Asteraceae (compositeae) family, Pluchea ovalis (PO) is one of its species growing in Albaha region. The volatile constituents were extracted with pet. ether and were identified using GC/MS analysis. It was found that, the volatile constituents consist of a mixture of 15 - selinene, humulene oxide and ?- eudesmol constitutes about 61%. The aerial parts of PO were extracted with pet ether. The pet ether extract was fractionated into unsaponifiable fraction and fatty acids and their constituents were identified by GC/MS analysis. In the present study Gram (+) bacteria such as Staphylococcus aureus, Bacillus subtilis and Gram (-) bacteria such as Escherichia coli, Pseudomonas aeuroginosa have been used. In addition; fungi such as Aspergillus flavus and Candida albicans were also studied. The results of antimicrobial activity of different extracts demonstrated that, pet. ether extract exhibited highest activity against B. subtilis, E. coli and S. aureus with MIC=6.4, 10.0 and 7.2 mg/ml respectively. The results of antitumor activity against colon carcinoma cell line (HCT-116) showed that alcoholic extract is most active extract with IC50 = 21.4 ± 1.3 ?g/ml.