Screening Of Antioxidant Effective Fraction From Petals Of Crocus Sativus And Its Preventive Effect On Hyperlipidemia

Saffron(Crocus sativus L.) is a kind of precious chinese medicinal herb. Pharmacology study showed that saffron possessed medicinal properties to against cancer, coronary heart disease, atherosclerosis and hyperlipidemia. The saffron stigma, which has also been used in preventive medicine, is a very expensive spice because of its low yield. In the production of 0.45 kg of saffron, more than 75,000 flowers of C. sativus are needed. In comparison with the stigma, the flower petal, one of the by-products, is almost completely neglected in commercial terms. The amount of this by-product is wasted as useless material. Earlier investigations had reported that some of the bioactive constituents in petals exhibited significant activity. In order to find the possibility of using the huge amount of petal, the biological activity of saffron petal was evaluated in this paper.This paper deals with the petals of C. sativus, and trys to screen out its active site, by using four methods of antioxidant activity in vitro system. Then the chemical constituents and bioactivities in vitro were studied. Thus, the prevention activity on hypolipidemic was investigated. The aim of this experiment is to make best use of this valuable plant.This dissertation includes three parts as follows:1.Bioactivity-guided Fractionation for Antioxidant Activities of Extract from Petals of Crocus sativus (EPC)The research aimed to investigate antioxidant activities in vitro of different polarity fractions of EPC. Five extracts were obtained in different fractions by using different polarities of solvents such as petroleum ether, chloroform, ethyl acetate and n-butanol. The results indicated that EPC and the five fractions had strong scavenging capacity on DPPH·,·OH and O2-, especially the ethyl acetate fraction and EPC. Considering the cost, and the harm to the environment in the actual production, EPC was selected as the research object. In this study, the protective effects on the hemolysis of mice erythrocytes and lipid peroxidation of mice homogenate were measured in vitro system. The inhibition rate of EPC on the hemolysis and lipid peroxidation were 38.36% and 89.78%; the inhibition rate of EPC on hemolysis and lipid peroxidation induced by H2O2 were 75.45% and 59.18% when EPC concentration was 5 mg/mL. According to data obtained from these antioxidant tests, the EPC demonstrated significant antioxidant capacity.2. Purification, composition analysis and bioactivity evaluation of EPCHPD826 resin was used to purificating the EPC. The purification conditions as follows:the best time of static and dynamic adsorption were 2 h, sample concentration 50 mg/mL at the volume of 1BV, eluent concentration 60% ethanol at the volume of 5BV. Thus, purification of ethanol extract from the petal of C. sativus (PEPC) was obtained. Results showed that the yield of PEPC by this process was (9.71±1.18)%. The various functional components of PEPC were analyzed and the results showed the contents of total flavonoids, polyphenols, saponins, polysaccharides and nitrogen reached (19.2±0.08)%, (18.22±0.07)%, (16.7±0.52)%, (9.2±0.45)% and (1.71±0.09)% respectively.The scavenging effect of PEPC on DPPH was much stronger than EPC. Results showed that the PEPC could effectively inhibit the XOD activity and its IC50 was 1.75 mg/mL. Thus, the antitumor effect of PEPC were evaluated in 3 cancer cell lines and the results showed the cytotoxic effects of PEPC on cancer cell lines in a concentration dependent manner. And IC50 were 1.19 mg/mL,1.53 mg/mL,0.90 mg/mL respectively.3. The acute toxicity and hypolipidemic effect of PEPCThe acute toxicity test was done to evaluate the security of PEPC.3 mice were died at the dose of 4.9,7, and 14 g/kg BW and 1 for each group. The cause of death was poke injury when administered. It was suggested that PEPC was actual non-toxic and its LD50 was 14.91 g/kg BW.To evaluate the antihyperlipidemic effect of PEPC, hyperlipidemia mice were used. Treatments of PEPC 500 and 200 mg/Kg BW significantly decreased body weight (p<0.01). Moreover, fat pad gain, TC and LDL-C were evidently decreased after PEPC treatment (p<0.01).All dose of PEPC can effectively decrease the serum TC respectively:30.80% for PEPC 500 mg/Kg BW,33.39% for PEPC 200 mg/Kg BW,23.89% for PEPC 100 mg/Kg BW. These findings concluded that the PEPC is able to regulate the level of serum lipid and has the ability to anti-athemsclerosis.