Five Libyan medicinal plants Thapsia garganica, Hammada scoparia, Euphorbia serrata, Hyoscyamus albus andRetama rateam were selected to evaluate their biological activities. Their total phenolic and flavanoid contents were assessed. The antioxidant activity was estimated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) as free radical scavenger. Their crude extracts showed reducing potential proportional to their concentration. The correlation coefficient (R 2 ) 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.

The natural forests and meadows of the Green Mountain of Libya are classified as the richest floristic region of the country. Among various species Cynara scolymus L. (Asteraceae), is the most used medicinal plant. C. scolymus L., has long been regarded as noncrop food and also as an effective medicinal plant. In the current study, total phenols as well as flavanoids were determined in methanolic and aqueous extracts the of C. scolymus L. rhizomes in order to assess their contribution to the antioxidant activity. Free radical scavenging activity of the extracts was investigated and compared with ascorbic acid. Methanolic extract exhibited a higher total phenols (45.11 mg GAE/g DW) and flavonoids (37.00 mg Rutin/g), that results in a high antioxidant activity with IC 50 (17.77 µg/ml). In contrast, aqueous extract showed a lower total phenolic and flavonoid contents (37.79 mg GAE/g DW and 15.51 mg Rutin/g DW, respectively) and IC 50 (66.3 µg/ml). Isolated flavonoids showed the highest free radical scavenging activities (IC 50 = 13.33 µg/ml). The in vitro antibacterial activity of C. scolymus L. rhizomes was investigated against various strains of bacteria by hole-plate diffusion method. The minimum inhibitory concentrations (MICs) of the crude methanol, flavonoids and alkaloids extracts found to be between 0.03 and 200 mg/ml for the susceptible organisms, with that of MRSA being the least.