OBJECTIVETo observe the impact of Rhizoma Coptidis (drug-chemical extract parts-components) on 3T3-L1 pre-adipocytes differentiation and adipocytes insulin resistance, and reveal the pharmacodyamic material basis of Rhizoma Coptidis on insulin resistance.

METHOD3T3-L1 pre-adipocytes were well cultured, and then induced to differentiate into fat cells by using dexamethasone, 3-isobutyl-1-methyl-xanthine and insulin together, and establish the insulin resistance model. Based on the experience of traditional medicine use, the adipocytes differentiation and the glucose consumption in the cell culture medium were observed independently.

RESULTAqueous extract, different chemical extract fraction and different alkaloid extract from the herb showed inhibitory effects on 3T3-L1 pre-adipocytes differentiation, especially the compound coptisine significantly inhibited the differentiation in the concentration of 16.5 micromol x L(-1), but non-alkaloid extract from the herb promoted cell differentiation significantly in the concentration of 6.0 micromol x L(-1). Each treatment group, especially jatrorrhizine hydrochloride (in the concentration of 10.5 micromol x L(-1)) significantly decreased the concentration of glucose in 3T3-L1 adipocytes culture, at the same time improved insulin resistance. These effects are similar to the role of rosiglitazone maleate.

CONCLUSIONRhizoma Coptidis significantly improved insulin resistance, prevented pre-adipocytes differentiation. Its efficacy may be the synergistic effect of various components. Meanwhile, its role in inhibiting differentiation of pre-adipocytes indicates that coptis to increasing glucose uptake dose not cause fat accumulation and weight increasing. This has some clinical significance in the insulin resistance and metabolic syndrome.