TNF and oxidative stress: Interestingly, the addition of external TNF-α to the medium reversed the COS-mediated decrease in IL-6 and NO levels thereby indicating that the anti-inflammatory effect of COS was by modulation of TNF-α pathway Yoon et al. have also investigated the protective effects of COS against glycerol-induced acute renal failure (a model of renal oxidative stress) [34] and their data indicate that COS mitigates the glycerol-induced inflammatory response, improves renal function, and has antioxidant effects in kidney.