Osthol is a natural coumarin derivative predominantly found in the plant Cnidium monnieri and several other medicinal herbs. Its use for hepatitis is based on preliminary scientific evidence rather than a strong foundation of traditional medicine. Several in vitro (cell culture) and animal studies have investigated osthol’s pharmacological effects, including its anti-inflammatory, antioxidant, and hepatoprotective activities—properties relevant to liver protection and hepatitis management.

Research has shown that osthol can reduce liver enzyme levels, inhibit inflammatory cytokines, and protect hepatocytes from chemical-induced damage in animal models. For example, studies in rats with chemically induced liver injury (such as with carbon tetrachloride) have demonstrated that osthol administration can attenuate liver fibrosis, decrease oxidative stress, and lower markers of liver inflammation. The proposed mechanisms include inhibition of the TGF-β1/Smad signaling pathway, reduction of reactive oxygen species, and modulation of immune responses.

However, clinical evidence in humans is lacking, and there are no large-scale trials supporting its use for hepatitis in people. Thus, while the scientific rationale is plausible and supported by preclinical data, the evidence remains limited and preliminary. Osthol is not a standard or widely accepted treatment for hepatitis in modern medicine, and its use should be considered experimental until more robust human studies are conducted.