Comparative Pharmacokinetic Study of Mangiferin in Normal and Alloxan-Induced Diabetic Rats after Oral and Intravenous Administration by UPLC-MS/MS.

BACKGROUNDS: Diabetes mellitus (DM)-induced morphological and/or functional complications may alter the pharmacokinetic profiles of mangiferin. This study aims to compare pharmacokinetic profiles of mangiferin in normal and alloxan-induced diabetic rats after oral and intravenous administration. METHODS: Mangiferin was administered orally (10 mg/kg) and intravenously (2 mg/kg) to normal and alloxan-induced diabetic Sprague-Dawley (SD) rats (n = 8). Blood samples were collected at different time points post-dose. Mangiferin and esculentoside (internal standard)  were analyzed by Waters Acquity ultra-performance liquid chromatography system and TSQ Quantum Ultra triple quadrupole mass spectrometer (UPLC-MS/MS). RESULTS: Mangiferin in normal and alloxan-induced diabetic rats experienced serious first-pass effect, which resulted in 1.71 and 0.80% of oral bioavailability respectively. Meanwhile, mangiferin was predominantly restricted to blood but not extensively distributed to organ tissues after intravenous administration. Compared with normal rats, the diabetic condition induced 53.26 and 50.90% decreases in Cmax and AUC0-t, respectively, for mangiferin after oral administration, and 63.08% decreases in Cmax after intravenous administration. CONCLUSIONS: Compared to normal rats, pharmacokinetic parameters of mangiferin were altered in diabetic condition induced by alloxan. The findings might help to provide useful evidence for modeling of diabetic rats and the clinical applications of mangiferin.

[Spatial distribution and scale effect of species diversity of secondary forests in montane region of eastern Liaoning Province, China.] / è¾½ä¸œå±±åŒºæ¬¡ç”Ÿæž—ç‰©ç§å¤šæ ·æ€§çš„ç©ºé—´åˆ†å¸ƒåŠå°ºåº¦æ•ˆåº”.

With secondary forest in the montane region of eastern Liaoning Province as research object, this paper analyzed the spatial distribution and scale effect of Gleason richness index, Simpson dominance index, Shannon diversity index and Pielou evenness index in a 4 hm2 plot. The results showed that spatial distributions of the four diversity indices showed higher spatial heterogeneity. Variance of the four diversity indices varied with increasing scale. Coefficients of variation of the four diversity indices decreased with increasing scale. The four diversity indices of the tree layer were higher than those of the shrub layer, and the variation tendency varied with increasing scale. The results indicated that sampling scale should be taken into account when studying species diversity in the montane region of eastern Liaoning Province.