Author(s)

Rabia Alghazeer, Hussein El-Saltani, Nabeel Saleh, Asma Al-Najjar, Fatma Hebail

Chemistry Department, Faculty of Sciences, Tripoli University, Tripoli, Libya;.
Soil Department, Faculty of Agriculture, Tripoli University, Tripoli, Libya.

Five Libyan medicinal plants Thapsia garganica, Hammada scoparia, Euphorbia serrata, Hyoscyamus albus and Retama rateam were selected to evaluate their biological activities. Their total phenolic and flavanoid contents were assessed. The antioxidant activity was estimated using 2, 2-di- phenyl-1-picrylhydrazyl (DPPH) as free radical scavenger. Their crude extracts showed reducing potential proportional to their concentration. The correlation coefficient (R²) between antioxidant activity and their total phenolics and flavanoids content is 0.77 and 0.98 respectively. Crude aqueous, methanolic as well as alkaloids extracts of the five plants were tested against a number of G+ve and G-ve sensitive resistant (e.g MRSA) bacteria beside some fungal species. The aqueous extracts displayed weak antibacterial activity whereas methanolic extracts were profoundly effective against both G+ve and G-ve bacteria. The extracts of E. serrata and H. scoparia were highly effective against E. coli in particular. The alkaloid-rich extracts of H. albus and H. scoparia induced remarkable bacteriostatic and fungistatic effects. The bioactive ingredients of H. scoparia, E. serrata and R. rateam extracts are shown to be potential sources of natural antioxidant and antimicrobial ingredients favoring their possible use in industrial pharmacology on large scale.

Medicinal Plants; Flavonoids; Free Radical Scavenging Capacity; Antioxidant; Phenolics; Antibacterial; Antifungal

Alghazeer, R. , El-Saltani, H. , Saleh, N. , Al-Najjar, A. and Hebail, F. (2012) Antioxidant and antimicrobial properties of five medicinal Libyan plants extracts. Natural Science, 4, 324-335. doi: 10.4236/ns.2012.45045.