Screening for Biological Activities of Medicinal Plants Used in Traditional Arabic Palestinian Herbal Medicine

Aims: To evaluate eleven medicinal plants as natural sources that possess strong antidermatophytic, antibacterial, anticandidal and antioxidant substances with potential applications in therapeutics and food industry.

Place and Duration of Study: Biodiversity and Environmental Research Center, BERC, between December 2013 and April 2014.

Methodology: Twenty methanolic extracts were prepared from different parts of eleven plants used in traditional medicine in Palestine. The plants extracts were screened for total flavonoid and phenolic content using standard procedures. The crude extract was screened against six bacterial strains (Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, and Klebsiella pneumoniae), 5 Candida albicans strains, and 2 dermatophytes (Microsporum canis, and Trichophyton rubrum). The antioxidant potential of the crude extract was also determined using the DPPH assay.

Results: The best free-radical scavenging was for the leaves of Epilobium hirsutum (IC50=33 µg/ml) and Rhus coriaria (49 µg/ml) compared with BHA standard (9 µg/ml). The highest value of phenolics was in R. coriaria fruits (14.7 mg/g dried plant material) and for flavonoids was for Epi. hirsutum leaves (1.14 mg/g). The most active extracts against bacteria was the R. coriaria leaves (% inhibition, 66.2%) compared with gentamicin (100%) and against Candida were leaves of R. coriaria (100%) and Epi. hirsutum (72.4%) compared with amphotericin B (100%). On the other hand fruits of R. coriaria showed the best antifungal activity against all the tested dermatophytes, 97% and 86% inhibition were achieved against Microsporum canis and Trichophyton rubrum, respectively.

Conclusion: Our results introduce a natural source (R. coriaria and Epi. hirsutum) that possesses strong antidermatophytic, antibacterial, anticandidal and antioxidant substances with potential applications in therapeutics and food industry.