The Study of Chinese Medicinal Herb Tradescantia albiflora Kunth on Rat Plasma Uric Acid Reduction, Antioxidantion and Toxicity

Serum uric acid was be elevated because of urate overproduction and/or underexcretion, and it will cause hyperuricemia. Hyperuricemia may cause the deposition of uric acid in joints and lead to painful inflammation. There were also many researches indicated that hyperuricemia was related with atherosclerosis, hypertension, cardiovascular diseases, diabetes mellitus and renal disease. Xanthine oxidase (XO) will catalyze the hypoxanthine and xanthine to uric acid, which is the main enzyme in hyperuricemia. The current agent used to treat the hyperuricemia is XO inhibitor, but the allopurinol used in clinical will cause side effect and prompt the development of XO inhibitor. Reactive oxygen species (ROS) had been known to cause lipid peroxidation which induce nutritional degradation of food products. ROS were also related to chronic cardiac failure, ageing, acute respiratory distress syndrome. Because of the side effect of the medicine and the fashion of healthy food, many scholars start to pay attention to the research of non side effect or low side effect compound from traditional medicine. Among these researches, most scholars are focusing on XO inhibitor agents and antioxidant. Although the natural antioxidant is safe in general, daily usage may cause potential complication, for example it may affect the function of liver and kidney or it may also impact on fertilized egg implantation and fetal organogenesis when the rats were oral administration with high dosage during the period of pregnancy. Therefore this study was investigated to the bioactivity and toxicity of extractive from the leaves of Tradescantia albiflora Kunth, which is a Chinese medicine plant to reduce serum uric acid level on rat.
The experiment was designed to use oxonate to be injected intraperitonelly to induce rat in hyperuricemic model, then these rats were oral administration crude extractive from the leaves, stem of T. albiflora or PBS respectively. Blood samples were collected to process hematology and biochemistry study every 90 mins, and monitored the change of blood pressure in the same time. We have used hexane, ethyl acetate, butanol and distilled water to extract the dry leaves of T. albiflora then got hexane extractive (HE), ethyl acetate extractive (EAE), butanol extractive (BE) and water extractive (WE) respectively. The experiment of decrease the plasma uric acid (PUA) level with extractives used by rat in hyperuricemic model to oral administration with HE, EAE, BE and WE extractive respectively, and bloods samples were collected to process PUA test every 30 mins.
The experiments of eliminated uric acid were utilized by rat in hyperuricemic model to oral administration with the PBS or WE respectively, and urine samples were collected to process urine uric acid (UUA) test after 30、90、150 and 210 mins. These tests of the efficiency for scavenge of DPPH and the ferric thiocyanate (FTC) have utilized different concentration of extractives belonging to 4 layers react with agents, and tested the absorption with 517 and 500 nm respectively. Crude extractives were divided into three groups. One was the control group (oral phosphate buffer). Second group was tested for oral consumption of 50 times the effective dosage of reducing plasma uric acid level (625 mg/kg) for 1~4 days during pregnancy. Third group was tested during 8~11 days of pregnancy. Subacute toxicities were tested the consumption of the 10 times effective dosage of reducing plasma uric acid level (125 mg/kg) for 28 days and blood samples were collected to be conducted hematology, biochemistry and histology study.
The results of these studies indicated that T. albiflora can decrease the level of blood uric acid, these 4 different types of extractive had the same ability, but the WE had the best affect in last estimative point (240 min). These 4 different types of extractive can also inhibit the XO, and WE had the best efficacy. The result of eliminated uric acid test revealed that WE hadn’t affect to eliminate uric acid. The BE had better efficacy in the scavenge of DPPH testing and the FTC testing. The toxicological result showed that fertilized egg implantation rate, fetal organogenesis and resorption rate were not be impacted on the femate rat after oral administrateion with 50 times the effective dosage extractives of reducing plasma uric acid level (625 mg/kg) from the leaves of T. albiflora extractive during the pregnant period.The test of subacute toxicity revealed the Hb, HCT and RBC had significant increase (p＜0.05); the ALKP and BUN had significant decrease (p＜0.05) compared with control group.
This study has shown that T. albiflora can decrease the blood uric acid by inhibiting XO, and it also can eliminate free radical by preventing fatty oxidantion to achieve antioxidant. Female rat oral administrated high dosage during the period of pregnancy may not impact fertilized egg implantation, fetal organogenesis and resorption, but oral administrated T. albiflora for long and high dosage may cause hepatic cell swelling and slightly hyperplasia of bile duct, it could suggest that T. albiflora is not suitable to medicate in long and high dosage.