Ameliorative effects of standardized extract from Trigonella foenum-graecum L. seeds on painful peripheral neuropathy in rats.

OBJECTIVE: To evaluate the effects of the standardized extract of fenugreek (Trigonella foenum-graecum L. Family: Leguminasae) seed (IND01) in animal models of peripheral neuropathy. METHODS: IND01 was prepared from fenugreek seeds and standardized by high performance liquid chromatography to a marker compound, trigonelline. The effects of daily oral administration of IND01 (50, 100 and 200 mg/kg) were studied in rats after partial sciatic nerve ligation (PSNL) and sciatic nerve crush injury (SNCI) during 30-days period. The measurements on thermal hyperalgesia (TH), motor function test (MFT) score and motor nerve conduction velocity (MNCV) were recorded. RESULTS: IND01 offered sustained protection against TH and deranged MFT scores in both models from 7-day onwards. Fifteen days of daily oral administration of IND01 restored MNCV reduction in rats with SNCI but not with PSNL. CONCLUSIONS: IND01 was found to be effective in rat models of painful peripheral neuropathy.

Effect of kappa-opioid receptor agonists U69593, U50488H, spiradoline and salvinorin A on cocaine-induced drug-seeking in rats.

Our previous work indicated that pretreatment with the selective kappa-opioid receptor (KOPr) agonist, U69593, attenuated the ability of priming injections of cocaine to reinstate extinguished cocaine-seeking behavior. The present study expanded these initial tests to include other traditional KOPr agonists, U50488H, spiradoline (SPR), and salvinorin A (Sal A), an active constituent of the plant Salvia divinorum. Following acquisition and stabilization of cocaine self-administration, cocaine-produced drug-seeking was measured. This test was conducted in a single day and comprised an initial phase of self-administration, followed by a phase of extinguished responding. The final phase examined reinstatement of extinguished cocaine self-administration followed by a priming injection of cocaine (20.0mg/kg, intraperitoneal (I.P.)) in combination with the various KOPr agonists. Cocaine-induced drug-seeking was attenuated by pretreatment with U69593 (0.3mg/kg, subcutaneous (S.C.)), U50488H (30.0mg/kg, I.P.), SPR (1.0, 3.0mg/kg, I.P.) and Sal A (0.3, 1.0mg/kg, I.P.). Sal A (0.3, 1.0mg/kg, I.P.) had no effect on operant responding to obtain sucrose reinforcement or on cocaine-induced hyperactivity. These findings show that Sal A, like other traditional KOPr agonists attenuates cocaine-induced drug-seeking behavior.