Antioxidant and hepatoprotective effects of aqueous and ethanol extracts of the stem bark of Baillonella toxisperma

CaHReF 2016, Yaoundé Conges hall, 23 – 26 August 2016 , PL144

Baillonella toxisperma (Sapotacae) is a medicinal plant widely used in Africa traditional medicine for the treatment of rheumatic pains, gastroenteritis and bronco-pulmonary diseases. The present study was designed to assess the antioxidant and hepatoprotective activity of the aqueous (decoction, AEBT) and ethanol (EEBT) extracts of the stem bark of Baillonella toxisperma.

The antioxidant activities of AEBT and EEBT were assessed in vitro against DPPH, OH and NO radicals. The reducing power, the total polyphenols and flavonoids contents of those extracts were also assessed. The hepatoprotective effects of B. toxisperma extracts given orally at the doses of 100, 200 and 300 mg/kg was assessed in vivo using CCl4 and acetaminophen-induced hepatotoxicity models in rats. Biochemical parameters of the hepatic function such as Alanine aminotransferase (ALAT) and Aspartate aminotransferase (ASAT), as well as oxidative stress parameter proteins, catalase, glutathione (GHS) and malondialdehyde (MDA) were assayed. 
In vitro tests showed that AEBT and EEBT are highly concentrated in polyphenols and flavonoids compounds. They exhibited a strong inhibitory activity on DPPH radical and a reducing power higher than that of ascorbic acid. Ethanol extract scavenged OH radical, while the aqueous extract instead increased the concentration. These two extracts inhibited NO production at low concentration and increased it at concentrations higher than 100 µg/ml. In vivo, the plant extracts at the dose of 300 mg/kg significantly reduced ALAT and ASAT by 80% in acetaminophen treated animals. Futhermore, EEBT significantly increased the glutathion level by 84.6 %. Proteins and nitrites levels, as well as catalase activity were not significantly modified by the plant extracts. In CCl4 induced hepatotoxicity, only AEBT at the dose of 200 mg/kg significantly protected liver, reducing ALAT level by 75.8 %. Catalase activity, GSH and MDA levels were not significantly modified by B. toxisperma extract.
These results corroborate and justify the use of the bark of Baillonella toxisperma in traditionnal medecine for their hepatoprotective effects. The hepatoprotective activity of aqueuos and ethanol extracts of B. toxisperma could be due to its antioxidant effects that might be related to polyphenol and flavonoids contents.

Baillonnella toxisperma, hepatoprotection, antioxidant, CCl4, acetaminophen