| Hyperlipidemia is a type of lipid metabolism disorder which is one of the major pathogenic risk factors for coronary heart disease, hypertension, obesity, atherosclerosis and cardiovascular diseases. Reducing the level of lipids in plasma by chemical drugs, such as statins, nicomol, fibrate, bile acid saquestrants, can lead side effects to the body. Therefore, the search for new agents with less toxicity to reduce serum lipid level has become an important research focus. Chinese herbal medicines are generally considered to be less toxic and less prone to side effects than chemical medicine. Camellia nitidissima Chi belonging to Theaceae family, is honored as "the Queen of Camellia family" and "the panda of the plants", with high ornamental value, it is also rich in a variety of natural active ingredients, therefore it has very high health care value. It is characterized by golden waxy petals. In addition, it has been reported that Camellia nitidissima Chi is of great value as food and Chinese traditional medicine. Previous studies have reported that the leaves of Camellia nitidissima Chi has a good lipid-lowering effect, but no studies have been carried out to evaluate the lipid-lowering function of the flowers and to explore the hypolipidemic mechanisms. Therefore, this study aims to systematically investigate the hypolipidemic effects of Camellia nitidissima Chi extracts in vivo and vitro and its mechanisms of function. Major results are as following:(1) Fistly, the water-soluble and alcohol-soluble components have been extracted from the flowers of Camellia nitidissima Chi and the active ingredients are analyzed. The results showed that the contents of total polyphenols, flavonoids, polysaccharide and saponin in Chi Camellia nitidissima Chi aqueous extract were 31.03%,30.71%,5.11% and 7.39%, while in ethanolic extract the contents were 44.54%,16.14%,8.88% and 10.65%, respectively.(2) Hypolipidemic effect of extracts of Camellia nitidissima Chi in mice with hyperlipidemia, which is induced by a high-fat diet, has been evaluated. The results showed that Camellia nitidissima Chi extracts can significantly improve the symptom of erect, yellow, greasy of hair in hyperlipidemia mice; In hyperlipidemia mice, oral gavage of the aqueous extract and ethanolic extract were highly effective in significantly (P<0.05) decreasing the level of serum TC, TG, LDL-C and increasing the level of serum HDL-C. Furthermore, Camellia nitidissima Chi extracts can also improve the antioxidant capability in the body of mice. Camellia nitidissima Chi extracts can lower glutamic-pyruvic transaminase level in serum, improve hepatic cell damage. (3) The hypolipidemic function in vitro and mechanisms of remedying hyperlipidemic were further investigated using HepG2 cells treated with oleic acid to induce fat accumulation. The results showed that Camellia nitidissima Chi extracts can effectively reduce fat accumulation in HepG2 cells induced by oleic acid (P<0.05). Furthermore, the RT-PCR results indicated that Camellia nitidissima Chi aqueous extract can down-regulate the FAS, HMGCR and GPAT mRNA expression, Camellia nitidissima Chi ethanolic extract can down-regulate the HMGCR mRNA expression. These results suggest that the flower of Camellia nitidissima Chi can inhibit fat accumulation in liver by regulating FAS, HMGCR and GPAT expression potentially.In conclusion, this study confirmed the hypolipidemic function of the extracts of Camellia nitidissima Chi flower, preliminarily explored its hypolipidemic mechanism, and provided a theoretical basis for the prevention and treatment of hyperlipidemia by the flower of Camellia nitidissima Chi. |
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