Co-administration of omega-3 fatty acids and metformin showed more desirable effects than the single therapy on indices of bone mineralisation but not gluco-regulatory and antioxidant markers in diabetic rats

Although metformin (Met) is the most recommended anti-diabetogenic drug in type 2 diabetic state, the drug is known to compromise bone integrity. Like metformin, omega-3 fatty acids (omega-3) have gluco-regulatory action; however, it aids bone health. Therefore, the present study investigated the effects of omega-3 and/or metformin in diabetic rats. Fifty rats of ten animals per group were divided into the following: Control; Diabetic untreated; Diabetic + omega-3; Diabetic + metformin (metfm) and Diabetic + omega-3 + metf groups. Diabetes was induced by the administration of streptozotocin (65 mg/kg b.w., i.p.), 15 min after the administration of nicotinamide (110 mg/kg b.w., i.p.). Five days afterwards, treatments started and they lasted for 28 days. omega-3 and metformin were administered at 200 and 180 mg/kg b.w., p.o. respectively. The results showed that the induced diabetes was characterised by significant increases in calcium to phosphorus ratio, tartrate resistant acid phosphatase (TRAP), glucose and insulin resistance; but significant decreases in parathyroid hormone(PTH), phosphorus, TAC and hepatic glycogen. Relative to the diabetic control, treatments with omega-3 or metformin caused significant elevations in hepatic glycogen, total alkaline phosphatase (TALP), osteocalcin, PTH, estradiol, and calcium; however, significant decreases in TRAP and glucose. Co-administration of omega-3 and metformin caused more desirable effects on TALP, c-terminal telopeptide of type 1 collagen, estradiol and calcium to phosphorus ratio compared to the single administration. Relative to omega-3, melatonin showed a more favourable effect on calcium to phosphorus ratio; however, the former proved to have more desirable actions on insulin and TAC. Hence, it was concluded that the combined but not the single administration of omega-3 and metformin could be preferably used in the management of bone health in diabetic state.