Antioxidant, antimicrobial activity and phytochemical analysis of Pistacia Vera L. skin

Şermet, Muhammed Ömer
Pistacia vera L. commonly grows in Mediterranean region, mainly in the Southeast of Turkey. Traditionally it is used for the treatment of several diseases such as asthma, rheumatism and hypertension. Pistachios are very rich sources of phenolic compounds however the skins are excluded from the nut as waste. This study was designed to investigate the antioxidant and antimicrobial effects of P. vera skin and to evaluate its phenolic compounds. P. vera skin extracts were prepared in different solvents and methanol was found to be the most suitable solvent in terms of the phenolic yield. Antioxidant capacities were examined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH)• scavenging method. Total phenolic and flavonoid contents were also determined. Furthermore, antimicrobial activities of extracts were detected by using Kirby-Bauer disc diffusion method together with MIC and MBC methods. EC50 of radical scavenging capacity was determined as 0.0375±0.006 mg/ml. Further, total phenolic content was determined as 145.32±7.14 GAE mg/g and flavonoid content as 92.74±9.24 µg QE/mg extract. The highest antimicrobial activity of P. vera skin extract was observed against S. aureus with 17.1 ± 0.7 mm zone of inhibition. The MIC values against examined bacteria were ranging from 0.5 to 2.0 mg/ml. MBC values have also been determined as minimum 1.0 mg/ml for Bacillus subtilis and maximum 2.5 mg/ml for Serratia marcences. The results of Chromatographic (LC-MS/MS) analyses indicated that P.vera skin is very rich in quercetin and gallic acid. Methanol extract of P. vera skin can be regarded as a strong antioxidant agent relative to the standards considering total phenol and flavonoid contents in addition to DPPH radical scavenging activity and moderate to strong antimicrobial agent against different bacteria regarding to the zone of inhibition, MIC and MBC values.
Citation Formats
M. Ö. Şermet, “Antioxidant, antimicrobial activity and phytochemical analysis of Pistacia Vera L. skin,” M.S. - Master of Science, Middle East Technical University, 2015.