ABSTRACT
Magnolol, a hydroquinone containing an allyl side chain, is one of the major active components of magnolia for antioxidation and anti-aging. To enhance the anti-aging activity and improve the intramolecular hydrogen bonding of magnolol, magnolol was reacted with cinnamic acid to obtain 2-O-cinnamic acid magnolol by esterification. The anti-aging activity of magnolol 2-O-cinnamate was investigated based on Caenorhabditis elegans model. The results showed that 2-O-cinnamic acid magnolol can reduce lipofuscin accumulation in the nematode body, and the effect is better than that of magnolol. 2-O-Cinnamic acid magnolol can extend nematode lifespan, reduce ROS levels in nematodes during normal aging and oxidative stress and improve nematode stress resistance under heat stress and oxidative stress. 2-O-Cinnamic acid magnolol could induce DAF-16 translocation from the cytoplasm to the nucleus and upregulate the expression of the sod-3 gene encoding superoxide dismutase in the nematode TJ356 expressing DAF-16 fused with GFP. 2-O-Cinnamic acid magnolol did not improve the survival rate of hsp-16.2 gene deficient nematodes under oxidative stress, indicating that 2-O-cinnamic acid magnolol improves stress resistance of nematodes under oxidative stress may be associated with sod-3 and hsp-16.2. Moreover, 2-O-cinnamic acid magnolol did not extend the lifespan of daf-16 and age-1 mutants, indicating that age-1 and daf-16 are required for 2-O-cinnamic acid magnolol to delay aging. It showed that magnolol 2-O-cinnamic acid has the potential to improve antioxidant capacity and delay aging, and the mechanism may be related to the insulin/insulin-like growth factor signaling pathway.
ABSTRACT
Objective:To observe the effect of blood stasis syndrome on renal damage and endoplasmic reticulum stress (ERS) in diabetic kidney disease (DKD) rats, and to explore the relationship between renal syndrome of blood stasis damage and ERS in DKD rats. Method:The 50 Male SD rats of SPF level were selected to establish DKD rat model by high fat and high sugar diet combined with intra-abdominal injection of streptozotocin(STZ). They were randomly divided into normal group, diabetes mellitus group and diabetes mellitus and blood stasis syndrome group（0.05 mg·kg-1）, among which diabetes mellitus and blood stasis syndrome group was prepared by dextran method. The general conditions, hemorheology indexes, 24 h urine protein, serum creatinine and renal pathology of the rats in each group were observed. Immunohistochemical analysis, Western blot and Real-time fluorescent quantitative polymerase chain reaction(Real-time PCR)were used to detect mRNA and protein expressions of endoplasmic reticulum stress-related proteins glucose regulated protein 78(GRP78), activating transcription factor-6(ATF6) and renal fibrosis index fibronectin(FN), and alpha smooth muscle actin(α-SMA). Result:Compared with normal group, the rats in diabetes mellitus group showed polyphagia, polyuria and weight loss, increased hemorheology index of whole blood viscosity and plasma viscosity(P<0.05，P<0.01), increased 24 h urine protein, serum creatinine and urea nitrogen(P<0.01), and increased renal pathology, and increased mRNA and protein expression of GRP78, ATF6, FN and α-SMA(P<0.05，P<0.01). After dextran preparation of blood stasis model. Diabetes mellitus and blood stasis syndrome group increased mortality, signs of change is more obvious in the diabetic group, whole blood viscosity, plasma viscosity, 24 h urine protein ration, serum creatinine and urea nitrogen were significantly higher than those in diabetic rats(P<0.01), pathological changes aggravated in the diabetes group. At the same time， mRNA and protein expressions of GRP78, ATF6, FN, and α-SMA in renal tissue were significantly higher than those in diabetic mellitus group(P<0.05，P<0.01). Conclusion:Under the combined disease and syndrome model, the blood stasis syndrome may further aggravate the pathological damage of the kidney of DKD rats, and is related to the enhancement of ERS in the kidney of DKD rats.