Evaluation of In vitro antioxidant activities of different combinations of methanol extracts of Zingiber officinale and Allium sativum using 2,2-diphenyl-1-picrylhydrazyl assay

Antioxidants can scavenge reactive free radicals and thereby minimizing their negative impacts to the health of an animal. The presence of phytochemicals such as polyphenols, carotenoids, vitamins E and C in plants makes some of them a good candidate antioxidant. Some of these antioxidants are produced in the body during normal metabolism while others are gotten from food, fruits, vegetables and other plant products. Zingiber officinale (ginger) and Allium sativum (garlic) are plants known for their antioxidants, and hence were used in various combinations by the traditionalists. This study is thus aimed at determining the antioxidant activity of each plant alone or in various combinations using DPPH assay. Cold maceration extraction method was used to extract powdered dried samples of Zingiber officinale and Alliun sativum using methanol as solvent. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was carried out on 100% ginger; 100% garlic; 50% each of the combination of ginger and garlic; 75% ginger and 25% garlic; 25% ginger and 75% garlic. The percentage radical scavenging activity (%RSA) of each combination was calculated in order to determine which combination delivers the best antioxidant activity. The percentage radical scavenging activity of 100% Zingiber officinale was 1.58%; 100% Allium sativum was 9.72%; while 75% Zingiber officinale plus 25% of Allium sativum was 15.25%. 50% each of Zingiber officinale and Allium sativum gives 23.31% RSA while 25% Zingiber officinale plus 75% Allium sativum was 17.20%. The results showed that the combinations of the two plants gives better antioxidant activity with 50/50 % combination showing the best antioxidant activity. Keywords: Zingiber officinale, Allium sativum, Antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl