Effect of cianidanol on natural killer cell activity in patients with chronic B virus hepatitis.

The hepatoprotective antioxidant bioflavonoid cianidanol has beneficial therapeutic and immunomodulatory effects in chronic hepatitis. Its action on natural killer (NK) cell activity has not yet been studied in hepatitis B virus (HBV) infection. In the present study, the in vitro and in vivo effects of the drug on NK cell activity have been determined in six patients with chronic HBV hepatitis and in ten healthy control subjects. Two methods were used: an enzyme release assay and a cytotoxicity test based on the assessment of endogenous alkaline phosphatase activity of the target cells. The in vitro effect of the drug was assessed using cianidanol at 10(-6), 10(-5) and 10(-4) M concentrations. For in vivo studies, HBV hepatitis patients were treated with cianidanol at a daily dose of 3.0 g cianidanol for seven days and were investigated before and after the treatment. Chronic HBV hepatitis patients showed a moderate decrease in NK cell activity compared to the controls, but after the cianidanol therapy their NK cell activity significantly rose to 68.0% +/- 9.5% (p less than 0.01). Cianidanol in vitro inhibited the NK cell activity both in hepatitis and healthy groups when using K-562 target cells and the lactic acid dehydrogenase enzyme release assay, but did not influence or even slightly enhance the NK activity when human embryonic fibroblast cells and alkaline phosphatase assay were used for the test. After the 7-day in vivo treatment, the in vitro inhibitory action of the drug was diminished or absent.(ABSTRACT TRUNCATED AT 250 WORDS)