| Rosmarinus officinalis L is a shrub plant of the genus Rosemary in the Labiaceae.In addition to Rosemary essential oil,Rosmarinus officinalis L also contains ursolic acid,oleanolic acid,rosmarinic acid,carnosic acid and other components,which have the effects of anti-oxidation,lowering blood sugar and blood lipid.In the field of veterinary medicine,it can be useful to maintain the oxidative balance of the body and prevent the high blood sugar and fat caused by obesity in pets.However,ursolic acid and oleanolic acid are hardly soluble in water and have very low bioavailability,which affects their clinical application in veterinary medicine.Therefore,Rosemary extract(containing 28%of ursolic acid,14%of oleanolic acid)was prepared by solid dispersant technique as a solid dispersant to improve its dissolution rate and evaluated its effect on antioxidant activity in rats.In this paper,Rosemary extract as raw material,polyethylene glycol 6000 and polyvinylpyrrolidone K30 as the carrier,they were prepared to make solid dispersants by the melting and solvent method in the mass ratio of 1:3,1:5 and 1:10.The solid dispersants were characterized by infrared spectroscopy and X-ray diffraction.And a method was established for simultaneous determination of ursolic acid and oleanolic acid by high performance liquid chromatography(HPLC)in order to determine the cumulative dissolution of solid dispersants in vitro.Basing on the characterization and solubility in vitro results,the best solid dispersant was selected to feed rats.The rats,which were divided into low-dose,medium-dose,high-dose solid dispersant(equivalent to Rosemary extract 7,14,28 mg/100g bw·d),raw material(the dose was consistent with medium-dose solid dispersant group)and blank control group,were gavaged for 28 days continuously.Growth performance was recorded.Serum,liver and leg muscle were collected for antioxidant performance detection,and intestinal tracts were collected to observe the development status of intestinal villi.after the feeding test.The infrared spectroscopy and X-ray diffraction results showed that Rosemary extract did not react with the carrier in the solid dispersant made by melting method,and Rosemary extract in the solid dispersant made by solvent method might form hydrogen bond with the carrier,and disperse in the carrier in an amorphous form.The HPLC method showed good linearity in the range of 1.5625μg/m L-50μg/m L(ursolic acid R~2=0.9989,oleanolic acid R~2=0.9980),and the results of specificity,stability,precision and sample recovery test were conform to relevant regulations.The results of dissolution in vitro showed that the solubility of Rosemary extract was significantly improved by both melting method and solvent method(p<0.05).The results of rat experiment showed that feed conversion rate of experimental group decreased.The high-dose solid dispersant made by solvent method increased glutathione peroxidase(GSH-PX)content in serum,the total antioxidant capacity(T-AOC),superoxide dismutase(SOD)contents in liver and T-AOC,GSH-PX,SOD contents in leg muscle(p<0.05),and decreased malondialdehyde(MDA)content in liver and leg muscle(p<0.05).The height of jejunum villus also increased in low,medium-dose groups(p<0.05).On the whole,the antioxidant performance of high-dose solid dispersant by solvent method was the best,medium-dose solid dispersant was better than Rosemary extract,and low-doses solid dispersant was partially superior to Rosemary extract.In this paper,solid dispersant of Rosemary extract was prepared and its effect on antioxidant performance of rats was evaluated,which provided experimental basis for its development as Chinese veterinary medicine. |
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