Effects of Coadministration of Extract of Carica papaya Linn (family Cariaceae) on Activity of Two Oral Hypoglycemic Agents

Purpose: To investigate the interacting effects of co-administration of Carica papaya leaf extract on the hypoglycemic activity of metformin and glimepiride in an animal model. Method: Experimental factorial design was used to evaluate the individual and interaction influence of three variables ie nature (N), dose administered (C) and duration of administration (D), in a 2^3(=8) employed at two levels - ‘’high’’ and ‘‘low’’ - on blood glucose of diabetic rats on administration of ethanolic leaf extract of Carica papaya and two hypoglycemic agents, metformin and glimepiride. Unpaired t-test was used to test for significant difference due to administration of the combination Results: Extract of Carica papaya at 5.0 mg/kg produced significant blood glucose reduction with no significant reduction at the higher dose of 10 mg/kg (p 0.05). Changing nature from “low” (Carica papaya extract) to “high” (glimepiride or metformin) did not significantly change hypoglycemic activity. Generally, the ranking of the interacting effects was ND CD NC for glimepiride/extract, and CD ND NC for metformin/extract. Administration of higher dose of the extract led to significant (p 0.01) increase in onset of activity of glimepiride. The onset of activity of metformin was not affected, but a significant lowering (p 0.05) of blood glucose was observed at 24 hr with all combinations of extract and metformin. Conclusion: Leaf extract of Carica papaya significantly delays the onset of hypoglycaemic activity of glimepiride, and increases the hypoglycaemic effect of metformin with the variables interacting differently for each drug-extract combinations.