Anti-hyperuricemia activity and its mechanism of flavonoid extract from saffron floral bio-residues / 中国中药杂志

A hyperuricemic rat model induced by adenine and ethambutol was established to investigate the anti-hyperuricemia activity and its mechanism of the flavonoid extract from saffron floral bio-residues. Sixty-seven SD rats were randomly divided into control group, model group, positive control group, and flavonoid extract groups(with 3 doses), respectively, and each group contained 11 or 12 rats. The hyperuricemic model was established by continuous oral administration of adenine(100 mg·kg~(-1)) and ethambutol(250 mg·kg~(-1)) for 7 days. At the same time, the positive control group was given allopurinol(20 mg·kg~(-1) per day) and the flavonoid extract groups were given the flavonoid extract at doses of 340, 170 and 85 mg·kg~(-1) per day, respectively. On day 8, rat serum, liver, kidney, and intestinal tissues were collected, and the levels of uric acid in serum and tissue, the xanthine oxidase activities and antioxi-dant activities in serum and liver were evaluated, and the kidney histopathology was explored. In addition, an untargeted serum metabolomics study was performed. According to the results, the flavonoid extract effectively reduced the uric acid levels in serum, kidney and ileum and inhibited the xanthine oxidase activities and elevated the antioxidant activities of serum and liver in hyperuricemic rat. At the same time, it reduced the levels of inflammation factors in kidney and protected renal function. Moreover, 68 differential metabolites of hyperuricemic rats were screened and most of which were lipids and amino acids. The flavonoid extract significantly retrieved the levels of differential metabolites in hyperuricemic rats, such as SM(d18:1/20:0), PC[18:0/18:2(92,12Z)], palmitic acid and citrulline, possibly through the following three pathways, i.e., arginine biosynthesis, glycine, serine and threonine metabolism, and histidine metabolism. To sum up, the flavonoid extract of saffron floral bio-residues lowered the uric acid level, increased the antioxidant activity, and alleviated inflammatory symptoms of hyperuricemic rats, which may be related to its inhibition of xanthine oxidase activity and regulation of serum lipids and amino acids metabolism.

Analysis of flavonoids from saffron floral bio-residues / 中国中药杂志

In order to better utilize saffron floral bio-residues(SFB), a qualitative and quantitative analysis of flavonoids in SFB was conducted using UPLC-MS and UPLC, respectively. On the one hand, 50 flavonols and 5 anthocyanins were putatively characte-rized by using UPLC-Q-TOF-MS. On the other hand, an UPLC method was established for determining the fingerprint of SFB as well as testing the main flavonoids kaempferol-3-O-sophoroside and delphinidin-3,5-di-O-glucoside. Contents of kaempferol-3-O-sophoroside and delphinidin-3,5-di-O-glucoside of 10 batches of samples were 44.21-58.73 mg·g~(-1) and 2.11-6.37 mg·g~(-1), respectively, and the similarities of 10 batches were more than 0.99. In addition, the color of the samples was digitized by using electronic eye technology, and it was found that the color of the samples was significantly correlated with the content of delphinidin-3,5-di-O-glucoside. The richness of flavonoids in SFB indicated its potential for development and utilization, and the large variation in anthocyanin content among samples from different regions suggested that more attention should be paid to the methods of sample pretreatment and storage.