AIM:To investigate the efficacy of Viusid,a nutritional supplement,as an antioxidant and an immunomodulator in patients with chronic hepatitis C.METHODS:Sixty patients with chronic hepatitis C who were non-responders to standard antiviral treatment were randomly assigned to receive Viusid(3 sachets daily,n=30) or placebo(n=30) for 24 wk.The primary outcome was the change in serum malondialdehyde and 4-hydroxyalkenals(lipid peroxidation products).Secondary outcomes were changes in serum tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ) and interleukin-10(IL-10).RESULTS:Statistically significant reductions in serum 4-hydroxyalkenals and malondialdehyde levels were observed in both groups in comparison with pretreatment values,but the patients who received Viusid showed a more marked reduction as compared with the control group(P=0.001).TNF-α levels significantly increased from 6.9 to 16.2 pg/mL(P< 0.01) in the patients who received placebo in comparison with almost unchanged levels,from 6.6 to 7.1 pg/mL(P=0.26),in the patients treated with Viusid(P=0.001).In addition,IL-10 levels were markedly increased in the patients treated with Viusid(from 2.6 to 8.3 pg/mL,P=0.04) in contrast to the patients assigned to placebo(from 2.8 to 4.1 pg/mL,P=0.09)(P=0.01).Likewise,the administration of Viusid markedly increased mean IFN-γ levels from 1.92 to 2.89 pg/mL(P< 0.001) in comparison with a reduction in mean levels from 1.80 to 1.68 pg/mL(P=0.70) in the placebo group(P< 0.0001).Viusid administration was well tolerated.CONCLUSION:Our results indicate that treatment with Viusid leads to a notable improvement of oxidative stress and immunological parameters in patients with chronic hepatitis C. AIM: To investigate the efficacy of Viusid, a nutritional supplement, as an antioxidant and an immunomodulator in patients with chronic hepatitis C. METHODS: Sixty patients with chronic hepatitis C who were non-responders to standard antiviral treatment were randomly assigned to receive Viusid ( 3 sachets daily, n = 30) or placebo (n = 30) for 24 wk.The primary outcome was the change in serum malondialdehyde and 4-hydroxyalkenals (lipid peroxidation products). Secondary outcomes were changes in serum tumor necrosis factor- TNFULTS: Statistically significant reductions in serum 4-hydroxyalkenals and malondialdehyde levels were observed in both groups in comparison with pretreatment values, but the patients who received Viusid showed a more marked reduction compared to the control group (P = 0.001) .TNF-α levels significantly increased from 6.9 to 16.2 pg / mL (P <0.01) in the patients who received placebo in comparison with almost unchanged levels , from 6.6 to 7.1 pg / mL (P = 0.26), in the patients treated with Viusid (P = 0.001) .In addition, IL- 10 levels were markedly increased in the patients treated with Viusid (from 2.6 to 8.3 pg / mL , P = 0.04) in contrast to the patients assigned to placebo (from 2.8 to 4.1 pg / mL, P = 0.09) .Likewise, the administration of Viusid markedly increased mean IFN-γ levels from 1.92 to 2.89 pg / mL (P <0.001) in comparison with a reduction in mean levels from 1.80 to 1.68 pg / mL (P = 0.70) in the placebo group (P <0.0001). Viusid administration was well tolerated. CONCLUSION: Our results indicate that treatment with Viusid leads to a notable improvement of oxidative stress and immunological parameters in patients with chronic hepatitis C