The polyphenolic composition, oleoresin contents and antioxidant activities of 10 elite accessions of ginger (Zingiber officinale Roscoe) were investigated using standard procedures. The accessions of ginger contained significant quantities of polyphenols and oleoresin which suggested their therapeutic potentials. The antioxidant activities of extracts of the ginger accessions as determined by reducing power tests and their scavenging activities on 2, 2 diphenyl-1-picylhydrazyl radical, indicated that most of them possessed very strong antioxidant activities with higher reductive capacity than standard quercetin at higher concentrations. There was a negative correlation between percentage oleoresin versus phenol (r 2 =-0.328) but a positive correlation between oleoresin versus percentage inhibition of DPPH radical (r 2 =0.251) and reducing power (r 2 =0.494). We obtained a positive correlation between the percentage inhibition of DPPH radical versus phenol (r 2 =0.827) and reducing power (r 2 =0.736) suggesting that any of the three assays could be used to determine the antioxidant activity of ginger, but a negative correlation between the percentage inhibition of DPPH radical versus flavonoids (r 2 =-0.754). Finally, we obtained a negative correlation between flavonoids versus reducing power (r 2 =-0.926). Results show these accessions of ginger will possess high economic potentials and could be utilized in the treatment of diseases that implicate free radicals. In addition, the oleoresins in ginger could contribute significantly to the reductive capacity of ginger. Finally, the negative correlation we obtained between the percentage inhibition of DPPH radical versus flavonoids and reducing power suggest to us that the flavonoids in ginger may have no contribution to their reductive capacity or hydrogen donating ability.
The ameliorating potentials of cocoyam (Colocasia esculenta L.), ginger (Z.officinale Roscoe) and unripe plantain (Musa paradisiacae L.) incorporated feeds on the relative pancreatic weights of streptozotocin induced diabetic rats was investigated. The blood glucose level of all the rats was measured with a glucometer, the assay of the phytochemical and crude fibre compositions of the test feeds were carried out using standard techniques. The administration of the test feeds for 21 days to the diabetic rats of groups 5 to 7, resulted in 58.75%, 29.81% and 38.13% decreases in their hyperglycemia. Administration of the cocoyam incorporated feeds to the diabetic rats of group 5, resulted in 2.71% and 19.52% increases in their body weights and growth rates respectively, administration of the ginger incorporated feeds to the diabetic rats of group 6, resulted in 9.88% and 60.24% increases in their body weights and growth rates, unlike the diabetic rats of group 7, administered unripe plantain feed that had 5.12% decrease in weight with a corresponding 29.52% decrease in growth rate but higher than the diabetic control rats that recorded 28.69, 28.62% and 29.46% decreases in body weights with corresponding 248.9%, 239.9% and 250.14% decreases in growth rates. Chemical analysis of the test feeds indicate that they contained considerable amounts of phytochemicals and crude fibre. Results indicate the ability of cocoyam, ginger and unripe plantain to ameliorate the relative pancreatic weight of diabetics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.