Objective: To observe the effect of total saponins from Panax notoginseng (PNS) on melatonin receptor (MR) expression and its content in gastric mucosa of stress rats.
Methods: Water-immersion restraint stress (WRS) was used to induce stress rat models. RevertAid First Strand cDNA Synthesis Kit was used for the reverse transcription of the total RNA from gastric mucosa of stress rats. The PCR product was analyzed by agarose gel electrophoresis firstly and then by KODAK 1 D Image system. The expression level of melatonin 1 (MT1) receptor mRNA was calculated with the optimal density of ratio of MT, receptor and GAPDH.
Results: Six hours after WRS, there were 360 bp positive bands in RT-PCR product of MT1. The relative content of MR was lower in the model group than that in the normal group. MR content in PNS group and ranitidine group were both higher than that in the normal group and the model group (P < 0.05 or P < 0.01).
Conclusion: There is mRNA expression of MT1 receptor in gastric mucosa of stress rats indeed. PNS has protective effect on gastric mucosa of stress rats by up-regulating MR expression, and its protective mechanism may be related to promoting melatonin secretion or increasing the binding capacity of melatonin to its receptor.