IN VITRO ANTIOXIDANT AND ANTIHYPERGLYCEMIA PROPERTIES OF VERBENONE ENHANCED WITH SELECTED SOLUBILIZING COMPOUNDS

Abstract

The pharmacological activities of verbenone had been reported in several diseased states. This study evaluated the in vitro antioxidant and antihyperglycemia properties of verbenone through linkage with selected solubilizing compounds. Oral Glucose Tolerance Test (OGTT) was conducted in non-diabetic mice overloaded with 2 g/kg bwt. glucose solution. In vitro α amylase and α glucosidase inhibitory activities were evaluated for verbenone and selected solubilizing compounds. 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and hydroxyl (OH) radical scavenging activity were evaluated for verbenone and selected solubilizing compounds using references procedures. In OGTT assay, verbenone, lysine, cyclodextrin and metformin significantly (p<0.05) lowered glucose concentration compared with the control from 30 - 120 minutes. Lysine and verb-lysine (12.5 μg/mL) steadily raised the percentage α amylase inhibitory activity, while at the same concentration significantly (p<0.05) increased amylase activity from 70 to 95%. Acarbose and all concentrations of compound examined (12.5 - 200 μg/mL) significantly (p<0.05) increased the percentage inhibitory activity of α glucosidase. All concentrations of verbenone significantly increased the percentage scavenging activities of DPPH, H2O2 and OH. Lysine, cyclodextrin verb-lysine showed a significantly (p<0.05) high hydroxyl scavenging while verb-cyclodextrin and acarbose displayed a lower hydroxyl scavenging. The results indicated that verbenone and its linked solubilizing compounds exhibited in vitro antihyperglycemic properties in glucose loaded mice, increased inhibitory activities of α amylase and α glucosidase as well as increased in vitro antioxidant scavenging activities.