ABSTRACT

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 µg/ml fruit extract concentration than in 62.5 µg/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.

摘要

坦桑尼亚的沿海森林拥有可食用的野生水果植物物种，可用作人类的膳食补充剂。使用 diphenly-1-picrylhydrazyl (DPPH) 测定了来自两个沿海地区（Tanga 和沿海地区）的两种常见野生水果Vitex doniana和Saba comorensis的抗氧化活性。V. doniana的抗氧化活性在来自坦噶的水果样品中介于 71.0 ± 0.4 和 49.11 ± 0.04 之间，在来自海岸地区的水果样本中介于 65.6 ± 0.1 和 48.3 ± 0.1 之间。S. comorensis的活性来自海岸地区的水果样本介于 56.28 ± 0.02 和 44.22 ± 0.03 之间，而来自坦噶的水果样本介于 61.77 ± 0.00 和 51.8 ± 0.1 之间。但两地区果实抗氧化活性差异不显着（P> .05），因为它们在受相似沿海栖息地条件影响的相同纬度梯度上进行。数据表明水果提取物的浓度与自由基清除能力之间呈正相关，其中在 1000 µg/ml 水果提取物浓度下观察到的抗氧化活性高于 62.5 µg/ml。回归分析表明，野生水果提取物对坦噶水果样品抗氧化活性的影响显着高于沿海地区水果样品。V. doniana和S. comorensis的果实所描述的相当大的抗氧化活性表明它们作为天然抗氧化剂的营养潜力。