Abstract: A water-soluble extract of asiaticoside and madecassoside from Centella asiatica and an isolating method thereof. In the isolating method an aqueous alcohol containing Centella asiatica is subjected to cold-precipitation to obtain an extract. The extract in the aqueous alcohol is treated with a halogenide solvent for layer separation, and then the aqueous layer is extracted with a higher alcohol. The extract in the alcohol layer is washed first with sodium hydroxide and then with water. After being concentrated, the extract is crystallized with ethyl acetate to obtain crystals and the crystals are washed. A method for treating liver cells in a mammal includes administering to a mammal an effective amount of the extract from Centella asiatica containing asiaticoside and madecassoside.