Efficacy and tolerability of diphenyl-dimethyldicarboxylate plus garlic oil in patients with chronic hepatitis

Abstract

To investigate the hepatoprotective effect, safety and tolerability of oral preparation comprising dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) plus garlic oil (GO) in chronic hepatitis patients. In this double-blind, placebo-controlled clinical trial conducted for 6 weeks with 1-week follow-up, a total of 88 patients with histologically confirmed chronic hepatitis and persistently elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were enrolled and randomly assigned to one of 4 treatment groups: placebo (Group A) and 3 escalating dose groups (2, 3, or 6 study drug capsules a day) (Groups B - D). Each study drug capsule contains 25 mg DDB plus 50 mg GO. Efficacy was assessed by monitoring changes in the circulating activities of ALT and AST as surrogate markers for liver injury. Safety and tolerability were assessed based on the evaluation of clinically adverse events and laboratory test results. Of 88 patients, 83 took at least one dose of study drug and 79 completed the study without any protocol violation. The majority of patients (81/83, 98%) had been infected with HBV. The proportions of patients whose ALT levels returned to normal ranges at Week 6, a primary outcome, were significantly different among 4 groups: 16% (3/19), 41% (9/22), 52% (11/21), and 88% (15/17) in Groups A, B, C, and D, respectively (p < 0.001). The proportions were significantly higher in Groups C (p = 0.022) and D (p < 0.001) but not in Group B compared to Group A. Interestingly, the proportion of Group D was higher than that of Group C (p = 0.034), suggesting a dose-response effect of DDB plus GO on the decrease of ALT levels. The mean ALT levels started to decrease from Week 1 in patients treated with DDB plus GO, whereas no decrease was seen in placebo group. The mean AST levels had a decreasing trend in all doses of DDB plus GO groups. Notably, patients treated with 6 capsules of DDB plus GO daily exhibited the statistically significant decrease in AST levels from Week 3. However, there was no difference in the proportions of patients with the AST decrease to normal ranges after 6-week therapy among 4 groups. The effects of DDB plus GO on decreases in ALT and AST levels lasted until 1 week after completion of treatment. Additionally, the ratios of ALT to AST gradually decreased in patients treated with DDB plus GO over time, suggesting higher degrees of reduction in ALT than in AST in those groups. No clinically meaningful adverse events and laboratory abnormalities were observed during the study period. The 6-week treatment of DDB plus GO lowered serum aminotransferase activities in patients with chronic hepatitis induced by HBV and/or HCV and was well tolerated. For the treatment of viral hepatitis patients, the optimal dose of this preparation was 3 to 6 capsules per day.