Effect of season and production location on antioxidant activity of Moringa oleifera leaves grown in Pakistan

Antioxidant activity (AA) of methanolic extracts from Moringa oleifera leaves, as function of seasons and agroclimatic locations, was investigated. Total phenolic content (TPC), total flavonoid content (TFC), ascorbic acid (AAcid) content, reducing power, AA in linoleic acid system and scavenging power of superoxide anion radical were taken as parameters for evaluation of AA. Significant differences were observed in the AA of the extracts from different locations and seasons. Generally, samples from Mardaan exhibited highest AA followed by Balakot, Chakwal, Jamshoro, and Nawabshah. Overall antioxidant efficacy was greater in December or March depending upon location, and least in June. Antioxidant potential of M. oleifera leaves from Pakistan was quite comparable or higher than literature values for M. oleifera from other countries and some other potent antioxidants. This work shows that season and agroclimatic locations have profound effect on the AA of M. oleifera leaves. (c) 2005 Elsevier Inc. All rights reserved.