Abstract:

Objective: We investigated the effects of cordyceps sinensis (CS) on renal Klotho expression and oxidative stress in spontaneously hypertensive rats (SHR) in order to study the therapeutic mechanism of CS in hypertensive renal damage. Methodology: Fifteen 22-week-old male SHR were divided into three groups by the means of random number table (each of five rats): model (SHR) group, CS group [5 g/(kg.d)], Losartan (Los) group [50 mg/(kg.d)]. Five 22- week-old male Wistar-Kyoto (WKY) rats were regarded as the control group. After 8 weeks, 24 hours urinary protein (Upro)，urinary N-acetyl-β-D-glucosaminidase (NAGase), blood urea nitrogen (BUN) and serum creatinine (Scr) were measured; renal pathological changes were viewed under light microscopy by HE and Masson staining; the mRNA and protein expression of Klotho in kidney were determined by RT-PCR, immunohistochemical staining and Western Blot respectively; the levels of total antioxidant capacity (T-AOC), malondialdehyde (MDA), Cu/Zn superoxide dismutase (Cu/Zn-SOD), Mn superoxide dismutase (Mn-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were evaluated. Results: The pathological characteristics of hypertensive renal damage were showed in the kidney of SHR group．After treatment with CS or Losartan, the renal pathological damage was ameliorated, the levels of Upro, urinary NAGase, BUN and Scr were lower than SHR group; as well as Klotho expression was up-regulated; the content of MDA was decreased, the activities of T-AOC, Cu/Zn-SOD, CAT and GSH-Px were increased (compared with SHR group, P<0.05 or P<0.01). There was no apparent change in level of Mn-SOD between four groups (P>0.05). Conclusion: Abnormal expression of Klotho gene and oxidative stress play an important role in pathogenesis of hypertensive renal damage. CS can up-regulate Klotho expression and resist oxidative stress, which may be one of the protective mechanisms in hypertensive renal damage.

Key words: cordyceps sinensis, , oxidative stress, , Klotho, , spontaneously hypertensive rats, , hypertensive renal damage