[Absorption and metabolism of icariin in different osteoporosis rat models]

To compare the intestinal absorption and metabolism of icariin in different osteoporosis rat models. Ovariectomy and intragastric administration of cyclophosphamide were used to establish two kinds of rat osteoporosis models. Then the rat intestinal perfusion was conducted, and HPLC was used to measure and calculate the permeability coefficients of icariin in different intestines and production amount of metabolites. Western blot was used to detect LPH enzyme expression in two models. Experimental results showed that both ovariectomy and intragastric administration of cyclophosphamide 4.5 mg•kg⁻¹ could reduce rat bone density and successfully construct the rat osteoporosis models. The apparent permeability coefficient Papp of 20 μmol icariin in duodenum, jejunum, ileum, colon was 5.695, 5.224, 1.492, 0.520 respectively in sham operation group; 3.876, 3.608, 0.863, and 0.291 in ovariectomized group; 4.945, 3.601, 1.990, 1.042 in normal saline group; 3.301, 2.108, 1.209, 1.233 in cyclophosphamide-induced osteoporosis model group. In addition, the protein expression levels of LPH enzyme in two model groups were lower than those in normal group. The absorption and metabolism of icariin in two kinds of osteoporosis models was lower than that in sham operation group and normal saline group; the reduction of expression level of LPH enzymes in rat intestine of different osteoporosis models was one of the reasons for leading to the reduced intestinal absorption and metabolism of icariin.