Antioxidant, antibacterial activity and phytochemical screening of ethanolic seeds extract of Libyan Peganum Harmala and Cuminum Cyminum / Abdulmutalib Alabeed Alkamil

Self-medication using medicinal plants for prevention and treatment purposes is very common in Libya due to its rich biodiversity. Therefore present study was carried out to assess the antioxidant and antimicrobial activities as well as the phytochemical screening of ethanol extracts of Libyan Peganum harmala and Cuminum cyminum seeds. The antioxidant activity of extracts was determined by free radical scavenging activity using DPPH. The antimicrobial activity against two Gram-negative (S. typhi ATCC 14028 and E.coli ATCC 25922) and two Gram-positive bacteria (B. subtilis ATCC 6633 and S. aureus ATCC 33591) was determined using the broth dilution method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) of the crude extracts were determined using a resazurin assay. The phytochemical screening was done using Gas Chromatography-Mass Spectrometry. The IC50 value of the ethanol extract of P. harmala was 179.62 μg/mL while that of C. cyminum was 70.02 μg/mL. The MIC result for ethanolic extract of Libyan C. cyminum against S. typhi ATCC 14028, E.coli ATCC 25922, B. subtilis ATCC 6633 and S. aureus ATCC 3359 were 31.25 mg/mL, 31.25 mg/mL,1.95 mg/mL, and 15.62 mg/mL, respectively. Meanwhile, MIC values for ethanolic extract of Libyan P. harmala against S. typh , E.coli ATCC 25922, B. subtilis ATCC 6633 and S. aureus ATCC 3359 were 1.95 mg/mL, 15.62 mg/mL, 3.9 mg/mL, and 3.9 mg/mL, respectively. In the GCMS analysis of Libyan P. harmala, eight different compounds were identified. The highest compounds in the seed ethanolic extract of Libyan P. harmala were harmine and harmaline with high peak areas of 51.98 and 42.93%, respectively. On the other hand, nine different compounds were identified in the ethanolic extract of C. cyminum, with the most abundant being 9-octadecanoic acid, oleic acids, and 5-hydroxymethylfurfural with peak areas of 32.65, 32.65, and 10.31%, respectively. The results indicated that the ethanolic extracts of these seeds have antioxidant and antimicrobial activities against the tested bacteria possibly due to the presence of phytochemicals compounds. The Libyan seeds, tested in this study, may be potential sources for the isolation of natural antioxidant and antimicrobial compounds.