The Effect of Wogonin Isolated from Skullcap Flowers in Hepatitis-B Treatment

Background: Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) that affects the liver, it is a type of
viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during the initial
infection. In acute infection, some may develop a rapid onset of sickness with vomiting, yellowish skin, tiredness, dark
urine and abdominal pain. Often these symptoms last a few weeks and rarely does the initial infection result in death.
About a third of the world population has been infected at one point in their lives. Over 750,000 people die of hepatitis
B each year.

Methods: Scutellaria radix has been used for thousands of years, mainly for the treatment of inflammatory conditions
including hepatitis B. The major active constituent, Wogonin (WG), isolated from S. radix has attracted increasing
scientific attention in recent years due to its effective biological activities. Wogonin is a type of flavonoid, effectively
inhibiting the HBV antigen secretion with an IC50 value of 4 mg/mL for both HBsAg and HBeAg and also reduced HBV
DNA level in hepG2 cells. By using an HBV-producing cell line in vitro culture system, it is found that wogonin can
suppress HBV surface antigen production without any trace of cytotoxicity.

Results: An assay of endogenous HBV DNA polymerase activity shows that both the relaxed circular and the linear
forms of HBV DNA are significantly reduced in the wogonin-treated group.. DHBV DNA polymerase was clearly
suppressed by wogonin with an IC50 value of 0.57 mg/mL. In ducks with DHBV infection, wogonin decreased the
plasma level of DHBV DNA with a 50% effective dose (ED50) of 5 mg/kg. In human HBV-transgenic mice, wogonin
significantly reduced plasma HBsAg level. Immunohistological staining of the liver confirmed the HBsAg reduction by
wogonin.

Conclusion: The results establish that wogonin possesses potent anti-HBV activity both in vitro and in vivo. Wogonin
is under primary development as an anti-HBV drug candidate at present. This paper review aims to study the efficacy of
wogonin in the treatment of Hepatitis B.