Antioxidative effect of Tripterygium wilfordii polyglycosides on diabetic rats / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE ToinvestigatethepossibleprotectiveeffectofTripterygiumwilfordiipolyg-lycoside (TWP ) on experi mental diabetic nephropathy (D N ) rats and its possible mechanis m. METHODS Thediabeticmodelwasinducedbyasingleintraperitonealinjectionofstreptozotocin (STZ)65 mg·kg -1 .Three weeks after modeling,TWP 4.5,9.0 and 1 8.0 mg·kg -1 was ig given to rats,once daily,for 8 consecutive weeks.During the experiment,the changes of body mass,hair, mental health of rats were observed.Two days before the end of the experi ment,the rats were placed into metabolic cages to collect 24 h urine in order to detect 24 h urinary albu min excretion rate (UAER). The rats were given TWP for 8 weeks and anesthetized with 1 0%chloral hydrate.The blood was collect-ed fro m the heart and centrifuged,seru m creatinine and urine creatinine were measured,and creatinine clearance (Clcr)was calculated.Blood urea nitrogen (BUN)and the serum catalase (CAT)activity were tested by optical method while the level of seru m superoxide oxygen anion(O2÷)was tested by col-orimetry.The level of malondialdehyde(MDA)was determined by thiobarbituric acid condensation,and glutathione peroxidase (GSH-Px)activity was tested by colorimetry.The right kidney was HE stained to observepathologicalchanges.RESULTS Comparedwithnormalcontrolgroup,theratsinmodel control group developed polydipsia,polyuria,polyphagia,body mass loss,unresponsiveness,brown hair,pale tail and apathy clammy.Besides,blood glucose,BUN and 24 h UAER were significantly higher (P<0.01 ),but Clcr was lower (P<0.01 ).The activity of serum CAT and GSH-Px in renal tissue was significantly lower(P<0.01 ),while the level of serum O2÷ and MDA in the renal tissue was significantly higher(P<0.01 ).Compared with model control group,TWP 9.0 and 18.0 mg·kg -1 could improve the general condition of rats.BUN and 24 h UAER were obviously reduced(P<0.01 ),Clcr and serum CAT were increased obviously(P<0.01 ),the level of MDA and O2÷ were reduced obviously(P<0.01 ),and GSH-Px level was increased(P<0.01 ).TWP 9.0 and 18.0 mg·kg -1 could significantly im-prove the renal histopathological changes of rats.TWP 4.5 mg·kg -1 had no significant effect on the aboveindicators.CONCLUSION TWPhasprotectiveeffectontherenalfunctionofexperimentalDN rats.The mechanis m may be related to inhibition of the oxidative stress and enhance ment of the body antioxidant capacity.