Alteration of glucose-6-phosphatase activity and regenerative, and total DNA concentrations in regenerating and normal rat liver of aqueous extracts of two Nigerian plants.

The effect(s) of an intraperitoneal (i.p.) administration of aqueous extracts of two Nigerian medicinal plants, Garcina cola and Vermonia amygdalina on the level of glucose-6-phosphatase activity, total protein content and regenerative and total DNA concentrations, was determined in liver homogenates of partially-hepatectomized and normal albino rat liver. The established control curves for the DNA and microsome syntheses rates after partial hepatectomy showed two waves of synthetic activity; the first occurring at 24 hrs., and the second at 32 hrs as judged by total regenerative DNA concentration and glucose-6-phosphatase activity. Garcina cola significantly inhibited the first wave of microsome and DNA syntheses by 31% and 24% respectively in a dose-related manner. However, the degree of inhibition of glucose-6-phosphatase activity by Garcina cola was substantially reduced in normal rat liver when administered simultaneously with carbon tetrachloride. Dilute and concentrated extracts of Vermonia amygdalina, on the other hand, elevated the levels of glucose-6-phosphatase activity in normal rat liver by 44% and 54%, respectively over the controls. Total DNA concentration was similarly increased, though to a lesser degree. The implication of these results are discussed in relation to the structural similarity of the furocoumarins contained in these plants to AFB1, and their likely modes of action.