Insulin releasing and alpha-glucosidase inhibitory activity of ethyl acetate fraction of Acorus calamus in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: The radix of Acorus calamus L. (AC) is widely used in the therapy of diabetes in traditional folk medicine of America and Indonesia, and we previously reported the insulin sensitizing activity of the ethyl acetate fraction of AC (ACE). AIM OF THE STUDY: To investigate the insulin releasing and alpha-glucosidase inhibitory activity of ACE in vitro and in vivo. MATERIALS AND METHODS: Insulin releasing and alpha-glucosidase inhibitory effects of different fractions from AC were detected in vitro using HIT-T15 cell line and alpha-glucosidase enzyme. Furthermore, effects of ACE orally on serum glucose were detected in fasted and glucose/amylum challenged normal mice. RESULTS: AC and ACE increased insulin secretion in HIT-T15 cells as gliclazide did. As in vivo results, ACE (400 and 800 mg/kg) significantly decreased fasting serum glucose, and suppressed the increase of blood glucose levels after 2g/kg glucose loading in normal mice. In addition, ACE as a mixed-type inhibitor inhibited alpha-glucosidase activity in vitro with an IC(50) of 0.41 microg/ml, and 100mg/kg of it clearly reduced the increase of blood glucose levels after 5 g/kg amylum loading in normal mice. CONCLUSIONS: Apart from its insulin sensitizing effect, ACE may have hypoglycemic effects via mechanisms of insulin releasing and alpha-glucosidase inhibition, and thus improves postprandial hyperglycemia and cardiovascular complications.

[Effects of morphine dependence on the levels of neurosteroids in rat brain].

AIM: To establish the rat model of morphine-induced conditioned place preference (CPP) and to investigate the effects of morphine psychical dependence on the levels of neurosteroids in rat brain. METHODS: Rats were ip administered morphine 5 mg x kg(-1) for 10 days to induce CPP in morphine group. The concentrations of dehydroepiandrosterone (DHEA), pregnenolone (PREG), allopregnanolone (AP), dehydroepiandrosterone sulfate (DS) and pregnenolone sulfate (PS) in nucleus accumbens (Nac), hypothalamus (Ht), amygdale (A) and plasma of rats were determined with liquid chromatography-negative atmospheric pressure ionization mass spectrometry (LC-MS). RESULTS: Trained with morphine for 10 days resulted in the acquisition of CPP in morphine group with the time that the rats spent in drug-pairing room was longer than that of control group. Compared with control group, morphine treatment could significantly decrease the contents of DHEA in Nac and plasma, decrease that of PREG in Ht. CONCLUSION: Morphine could induce the CPP in rats and affected the contents of some neurosteroids in rat brain, which suggests that endogenous neurosteroids might he related to the development of morphine dependence.