Alteration in antioxidant and antimicrobial attributes of leaves of Zizyphus species in response to maturation

This study was conducted to assess the antioxidant and antimicrobial potential of leaves extracts of five different species of Zizyphus. The methanol extracts of both young and mature leaves were prepared, and their antioxidant phytoconstituents (total phenol, total flavonoid) and activities (inhibition of linoleic acid peroxidation, DPPH scavenging ability, and reducing power) were subsequently determined. The total phenolic (19.0 to 28.2 GAE mg/g) and total flavonoid (38.1 to 61.8 CE mg/g) contents of young leaves were significantly higher (P < 0.05) than that of mature one (19.0 to 25.1 GAE mg/g) and (33.6 to 50.3 CE mg/g), respectively. Total phenolic contents, total flavonoid contents and DPPH scavenging activity decreased with maturation. All the extracts also showed remarkable antimicrobial activity against a panel of micro-organisms. Overall results of study showed that Zizyphus leaves are a good source of natural antioxidant and antimicrobial compounds, and thus can be utilized in herbal formulations.   Key words: Antimicrobial, antioxidant, extracts, leaves, species, Zizyphus.