ABSTRACT
Objective:To investigate the antioxidant activity of Maca polysaccharides in vitro.Methods:A chemical reaction system was established to explore the scavenging activity of Maca polysaccharides within the concentration range of 0.18-5.00 mg ·ml-1on hydroxyl radicals (·OH),superoxide anion free radicals (O2-·) and DPPH·,and then the total antioxidant capacity was calculated. The protective effects of Maca polysaccharides on H2O2-induced damage in SH-SY5Y cells were determined. SH-SY5Y cells were divided into the control group,H2O2model group and Maca polysaccharide groups(25,50,100 μg·ml-1). In the Maca polysaccharide groups,SH-SY5Y cells were pre-protected by Maca polysaccharides for 24 h, and then incubated in the presence of 300 μmol·L-1H2O2for 6 h. The detection index was SH-SY5Y cell viability detected by MTT assay. Results:Maca polysaccharide within the concentration range of 0.18-5.0 mg·ml-1all exhibited strong scavenging activity on·OH,O2-· and DPPH·in a dose-dependent manner. When the concentration of Maca polysaccharides reached 2.5 mg·ml-1,the scavenging rate was 60.36% for DPPH·,34.66% for O2-·and 36.01% for·OH,the total antioxidant activity was equivalent to 0.179 μmol FeSO4. Maca polysaccharides at the concentration of 25, 50 and 100 μg·ml-1all showed significant protective effects on H2O2-induced injury in SH-SY5Y cells, and the cell survival rate was 61.71 ± 2.45%,61.73 ± 4.51% and 60.98 ± 3.12%, respectively,which were all significantly higher than those in the model group (P < 0.05). Conclusion:Maca polysaccharides has good antioxidant activity,which is worthy of further research and development as a natural antioxidant.
ABSTRACT
Objective To observe the effects ofLiuwei Dihuang Decoction on cAMP and PDE3B in adipose tissues of rats with type 2 diabetes;To explore its mechanism.MethodsTotally 80 SD rats were randomly divided into two groups:control group and molding group. Rats in the molding group established the type 2 diabetic models by feeding high sugar and fat diet combined with intraperitoneal injection of Streptozotocin. The successful modeling rats were divided into model group, Rosiglitazone group, andLiuwei Dihuang Decoction group. Administration groups were given relevant medicine for gavage, while model group and blank group were given the same amount of normal saline for 30 days. FBG levels were detected, and cAMP and INS levels were detected by ELISA. The protein expressions of PDE3B in adipose tissues were determined by Western blot. The mRNA expressions of PDE3B in adipose tissues were detected by RT-PCR.Results Compared with the model group, the FBG and INS levels in type 2 diabetic rats were reduced in Rosiglitazone group andLiuwei DihuangDecoction group (P<0.05,P<0.01). InLiuwei Dihuang Decoction group, the protein and mRNA expressions of PDE3B in the adipose tissues were higher, and cAMP levels were lower than the model group (P<0.01).ConclusionLiuwei Dihuang Decoction can increase PDE3B expression, and decrease cAMP level, which may be one of the mechanisms for improving insulin resistance in type 2 diabetic rats.