A Simple and Rapid UPLC Method for the Determination of Rosavin in Rat Plasma and Its Application to a Pharmacokinetic Study.

Rosavin is a bioactive antidepressant component isolated from Rhodiola rosea L. In this work, an ultra-performance liquid chromatography (UPLC) method was established for the determination of rosavin in rat plasma. The chromatographic separation was achieved on a HSS T3 column (100 mm × 2.1 mm, 1.8 µm) with a gradient mobile phase consisting of acetonitrile and water (0.1% formic acid). Plasma samples were processed with one-step protein precipitation. Rutin was chosen as internal standard and the detection wavelength was 249 nm. The pharmacokinetic parameters were analyzed using the drug and statistics software. The results showed that the established method has an excellent linearity in the range of 10-1,000 ng/mL (R(2) = 0.992) with a lower limit of quantification (10 ng/mL). The intra- and interday precision (relative standard deviation) were from 2.0 to 10.6% and the extraction recovery was 92.4-95.1%. The simple and rapid UPLC method was successfully applied to the pharmacokinetic and bioavailability study of rosavin in rats.

Mayombian ethnic, vegetables low intake, insulin treatment, diabetic nephropathy and severe diabetic retinopathy are determinants of blindness in diabetic Africans.

AIM: To determine the frequency and causes of blindness in diabetic Africans. METHODS: The study was a cross-sectional survey carried out among known black diabetics consecutively admitted at the Teaching Hospital, University of Kinshasa, between 2005 and 2007. Examination methods included interviewer-administered structured questionnaire, eye examinations (visual acuity, tonometry, funduscopy), and fasting plasma glycaemia test. RESULTS: Of the 227 patients examined, 15.9% had blindness. Univariate analyses showed significant association between female, severity of diabetic retinopathy, Mayombian ethnic group, use of insulin treatment, low intake of vegetables, diabetic nephropathy, open angle glaucoma and blindness in all diabetics. After logistic regression, only diabetic nephropathy, use of insulin treatment, macular oedema, Mayombian ethnic group and vegetables low intake were the independent risk factors of blindness in all diabetics. However, after logistic regression in the sub-group with diabetic retinopathy, only open angle glaucoma and proliferative diabetic retinopathy were the independent determinants of blindness. CONCLUSION: The majority of the causes of blindness in these diabetic Africans are avoidable. It is recommended that appropriate diabetes care, nutrition education, periodic eye examination and laser photocoagulation facilities should be provided for treating diabetics in sub-Saharan Africa.