番石榴叶水提物降低妊娠期糖尿病大鼠血糖的作用及机制

Effect on Blood Glucose of GDM Rats Administrated with Water Extract of Leaves of Psidium Guajava Linn. and Its Possible Mechanism

目的观察番石榴叶水提物降低妊娠期糖尿病(GDM)大鼠血糖的作用,并探讨其可能的作用机制。方法选用妊娠5 d的Wistar大鼠,以链脲佐菌素(STZ,35 mg·kg^(-1))溶液尾静脉注射,注射72 h后,测空腹血糖(FBG),FBG在11.1 mmol·L^(-1)以上者为GDM模型。将模型大鼠随机分成GDM模型组、番石榴叶水提物组(高剂量)、番石榴叶水提物组(低剂量)和二甲双胍组,每组8只。另取8只正常妊娠大鼠,作为妊娠对照组。2周后观察大鼠FBG、C-反应蛋白(CRP)及肿瘤坏死因子(TNF-α)的变化情况。结果在改善血糖、CRP及TNF-α指标方面,二甲双胍组优于番石榴水提物组,但与番石榴水提物组(高剂量)差异无统计学意义(P>0.05);与GDM模型组比较,除番石榴水提物组(低剂量)的CRP水平降低不显著外(P>0.05),番石榴叶水提物组(高剂量)、番石榴叶水提物组(低剂量)及二甲双胍组FBG、CRP和TNF-α均明显降低,差异有统计学意义(P<0.05)。结论番石榴叶水提物与西药二甲双胍有近似的降糖作用,能有效改善妊娠期糖尿病大鼠的血糖水平,其作用机制可能与调节CRP及TNF-α的水平有关。

OBJECTIVE To investigate the effect on blood glucose of GDM rats administrated with water extract of leaves of Psidium guajava Linn. （ WELPGL ） and its possible mechanism. METHODS Rats with gestation for 5 days received one-dose injection of STZ 35 mg. kg-1 into caudal vein. After injection for 72 hours, rats with blood sugar over 11.1 mmol. L-1 indicated the modeling being successful.Then the model rats were divided into GDM model group, WELPGL（ low dose） group, WELPGL （high dose） group and metformin group with 8 rats for each group.8 normal gestational rats were used as control group.Two weeks later, the changes of blood sugar, C-reactive protein （CRP） and tumor necrosis factor-α （TNF-α） were observed. RESULTS In improving blood glucose, CRP and TNF-α, the metformin group was superior to the guava extract group, but the difference was not significant （P〉0.05） between metformin and WELPGL （high dose） group.Compared with the model group, the level of FBG, CRP and TNF-α for WELPGL （low dose） group,WELPGL （high dose） group and the metformin group decreased significantly （P〈0.05）, except that the CRP for WELPGL （low dose） group （P〉 0.05）. CONCLUSION WELPGL has similar action in decreasing blood sugar with metformin, which can effectively meliorate blood glucose of GDM rat.And its mechanism may be due to regulate the revel of CRP and TNF-α.