Comparative Effects of Solvents on the Herbal Extraction of Antidiabetic Phytochemicals

Aims: The study determined and compared the herbal extraction yields using water, ethanol and hydromethanol solvent and the solvent extracting the highest antidiabetic constituents.

Place: The study took place in the Department of Chemistry (Organic Laboratory), Federal University of Technology Owerri, Nigeria.

Methodology: The antidiabetic contents of Moringa oleifera (Moringa) and Vernonia amygdalina (bitter leaf) were extracted by soaking using water, ethanol and hydromethanol (1:1) as solvents. The phytochemicals analysis was done both qualitatively and quantitatively (using Spectrophotometer (UV-V15)). Data collected were statistically analysed using SPSS version 10 tools.

Results: The crude ethanolic extraction was found to give the highest extract yield of 46.06% and 38.91% from Moringa and bitter leaf, respectively. There were more phytochemicals obtained from Moringa (28+) than from Vernonia crude extracts (21+). The antidiabetic phytochemicals identified in both plants included Steroids, Phenols, Cardiac glycosides and Terpenoids. Ethanol extracted the Glycosides, Terpenoids and Phenols in relative abundance.. Hydromethanol solvent extraction yielded the highest concentrations of Steroids from Moringa (59.87mg/100g) and bitter leaves (75.43mg/100g) as well as highest extraction of Cardiac glycosides from both plants. Water extracted the highest concentrations of Phenols from both Moringa (0.32mg/g); bitter leaf (0.25mg/g) and Terpenoids from Moringa.

Conclusion: This study suggests that the choice of solvent (s) for phytochemical extraction (s) should consider factors such as the plant material (s) and the phytochemical (s) involved. So, Water > Hydromethanol > ethanol could be used for extracting phytochemicals for diabetes therapy.