The efficiency of random versus ethno-directed research in the evaluation of Sinai medicinal plants for bioactive compounds.

Hexane, ethyl acetate and ethanol extracts of sixty plant species (growing wild in Sinai, Egypt) were screened for antibacterial and antifungal activities against a range of Gram-positive and Gram-negative bacteria, a yeast and dermatophytic fungi. Plants were collected either by random or ethno-directed methods. Plants collected at random (36 species) were gathered from different districts of Sinai, while the ethnobotanical collection (24 species) comprised species used in the folk medicine of the Bedouins in Sinai. Results indicate that plant sampling based on ethnobotanical approach produced greater number of plants showing antimicrobial activity. The results are discussed with respect to the ethnobotanical correlation of active species.