Cordyceps sobolifera extract ameliorates lipopolysaccharide-induced renal dysfunction in the rat

Cordyceps Sobolifera (CS), an economic traditional Chinese herb, may ameliorate nephrotoxicity-induced renal dysfunction in the rat via antioxidant, anti-apoptosis, and anti-autophagy mechanisms. We investigated the water extract of fermented whole broth of CS on lipopolysaccharide (LPS)-induced renal cell injury in vitro and in vivo. CS effect on LPS-induced epithelial Lilly pork kidney (PK1) and Madin-Darby canine kidney epithelial (MDCK) cell death was detected with MTT assay. Two-month treatment of CS effects on renal blood flow (RBF), glomerular filtration rate (GFR), plasma blood urea nitrogen, creatinine level and leukocytes (WBC) count were determined in the LPS-treated rats. We further examined the effects of CS supplement on renal tubular oxidative stress, endoplasmic reticulum stress, apoptosis and autophagy by Western blot analysis. LPS dose-dependently induced PK1 and MDCK cell death, which can be ameliorated by CS treatment. LPS significantly decreased RBF and GFR and increased blood leukocyte counts, plasma blood urea nitrogen and creatinine level in the rat after 24 hours of injury. LPS enhanced renal tubular ER stress, autophagy and apoptosis via by increase protein expressions of GRP78, caspase 12, Beclin-1 and Bax/Bcl-2 ratio. These findings are associated with the significant staining in renal proximal and distal tubular ED-1, GRP78, Beclin-1 autophagy, and TUNEL apoptosis in the LPS-treated kidneys. Two months of CS supplement significantly improved RBF, GFR and WBC values and reduced ED-1, GRP78, Beclin-1 autophagy and TUNEL apoptosis in the LPS-treated kidneys. Long-term CS treatment reduced LPS-induced stress responses and tissue damage possibly via blocking LPS-triggered signaling pathways.