Antioxidant Activities in Vitex Doniana and Saba Comorensis Fruits from Coastal Forests of Tanzania

Coastal forests of Tanzania are endowed with edible wild fruit plant species that can be used as dietary supplements to humans. The antioxidant activities of two common wild fruits Vitex doniana and Saba comorensis from two coastal regions (Tanga and Coastal) were determined using diphenly-1-picrylhydrazyl (DPPH). The antioxidant activities for V. doniana ranged between 71.0 +/- 0.4 and 49.11 +/- 0.04 in fruit samples from Tanga and 65.6 +/- 0.1 and 48.3 +/- 0.1 in fruit samples from Coast region. The activity in S. comorensis ranged between 56.28 +/- 0.02 and 44.22 +/- 0.03 for fruit samples from Coast region and between 61.77 +/- 0.00 and 51.8 +/- 0.1 for fruit samples from Tanga. However, the differences in antioxidant activity between fruits from the two regions were not significant (P > .05) as they performed on the same latitudinal gradient influenced by the similar coastal habitat conditions. Data indicated a positive correlation between concentration of the fruit extracts and the free radical scavenging capacity where higher antioxidant activity was observed at 1000 mu g/ml fruit extract concentration than in 62.5 mu g/ml. The regression analysis indicated significant influence of the wild fruit extracts on antioxidant activity in fruit samples from Tanga than it was in fruit samples from Coast regions. The considerable antioxidant activity depicted by the fruits of both V. doniana and S. comorensis indicated their neutraceutical potential as natural antioxidants.