Identification of polyphenolic contents, in vitro evaluation of antioxidant and antidiabetic potentials of a polyherbal formulation-Mehani.

Diabetes has become a global disease that needs an alternative drug treatment with lesser side effects. The present study was aimed to evaluate the antioxidant and antidiabetic activities of soxhlet and microwave assisted extraction of a polyherbal formulation-Mehani using aqueous, hydroalcoholic and hexane solvents. Preliminary investigation shows that the heavy metal contents were within the permissible limits. Comparative antioxidant studies showed that hydroalocoholic soxhlet (HAS) and microwave (HAM) extracts possessed highest activity as assessed through DPPH assay (93.8 ± 0.04%, 94.85 ± 0.04%), H2O2 assay (88.7 ± 0.9%, 87.2 ± 1.4%), reducing power assay (absorbance-1.61 ± 0.12, 2.08 ± 0.03) and nitric oxide scavenging activity (51.1 ± 0.9%, 56.5 ± 0.18%) at 500 µg/mL concentration. HAS and HAM also exhibited 80.3 ± 1.12% and 85.3 ± 1.86% of α-amylase inhibitory activity and 78.7 ± 0.15% and 80.0 ± 0.63% of glucosidase inhibitory activity. HPLC analysis in both the extracts reveals the presence of eight polyphenols with gallic acid being the predominant compound; these might be responsible for the highest activities.