Introduction: Curcumin (CUR) is a hydrophobic molecule with poor bioavailability.Piperine is reported to enhance the bioavailability of drugs by increasing absorption in the small intestine and decreasing glucuronidation in the liver.
Objective:The objective of the present investigation was to evaluate the neuroprotectiveeffect of curcuminincombinationwith piperine innicotinamide- streptozotocin (NIC-STZ) induced diabetic rats.
Methods:MaleWistar rats were divided into groups viz.vehicle control, disease control,glibenclamide (1), glibenclamide+ piperine(1+50), curcumin (50) and curcumin (50) with piperine10, 30 and 50.All the groups except vehicle control were induced diabetes by injecting NIC-STz. The animals received treatment daily for six weeks after the confirmation of diabetic status.Behavioural, biochemical and histological parameters were evaluated to access the neuroprotective effect.
Results: Oral administration of curcumin + piperine (50+50 mg/kg) caused a significant fall in blood glucose level. Disease control showed increased paw withdrawal latency and nociceptive threshold compared with vehicle control. Curcumin + piperine treated animals showed decreased paw withdrawal latency. Combination of curcumin + piperine (50+50 mg/kg, p.o.) showed significant antioxidant property by increasing tissue GSH and SOD and lowering lipid content (MDA) compared to the disease control group. The histopathological study showed reduced damage to the sciatic nerve in curcumin + piperine (50+50 mg/kg, p.o.) treated group.
Conclusion: Itis concluded that the curcumin-piperine combination reducedthe degeneration of sciatic nerve by reduction of lipid peroxidation and lowering oxidative stress indicating the neuroprotective effect in diabetic neuropathy.
Background-Curcumin is one of the principle substances found in the rhizome of Curcuma longa L. Piperine, an alkaloid separated from Piper nigrum L., has bioenhancer property.
Objective- The objective of the present study was to evaluate the nephroprotective activity of curcumin when administered concomitantly with piperine in diabetic rats.
Methods- Male Wistar rats were divided into eight groups viz. vehicle control,Â disease control, Â Â glibenclamide (1), glibenclamide + piperine (1+50) , curcumin (50), curcumin+ piperine (50+10), curcumin + piperine (50+30), curcumin + piperine (50+50). Overnight fasted rats were administered nicotinamide (110 mg/kg, i.p.) and 15 min after nicotinamide injection, streptozotocin (65 mg/kg, i.p.) was injected in all groups except group 1. Curcumin and piperine combination was administered as 2% Tween 80 suspension. Curcumin was administered (50 mg/kg) by oral route. Piperine was administered (10, 30, 50 mg/kg) through the oral route in combination with curcumin. Treatment proceeded up to 6 weeks. Biochemical, antioxidant parameters and histopathological studies were carried out at the end of the study.
Â Result- Curcumin + piperine (50+50 mg/kg) administration caused a significant decrease in blood glucose, triglyceride, serum creatinine, serum uric acid, urine creatinine, and urine albumin levels. The antioxidant activity of the combination was evident as there was a significant increase in kidney GSH and SOD levels along with significant decrease in MDA. The histopathological study showed reduced damage to kidney in curcumin + piperine (50+50 mg/kg) group.
Conclusion- It is thus concluded that curcumin in combination with piperine showed enhanced nephroprotective activity in diabetic rats.