Journal of Food and Nutrition Research
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Journal of Food and Nutrition Research. 2014, 2(10), 738-743
DOI: 10.12691/jfnr-2-10-13
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Inhibitory Effect of Tea (Camellia Sinensis (L.) O. Kuntze, Theaceae) Flower Extracts on Oleic Acid-Induced Hepatic Steatosis in Hepg2 Cells

Xinghai Zhang1, 2, Ying Gao1, Jinwei Xu1, 2, Xiaohui Liu1, Feng Jin1, 2, Bo Li1 and Youying Tu1,

1Department of Tea Science, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, China

2Department of Applied Engineering, Zhejiang Economic and Trade Polytechnic, Hangzhou, China

Pub. Date: October 07, 2014

Cite this paper:
Xinghai Zhang, Ying Gao, Jinwei Xu, Xiaohui Liu, Feng Jin, Bo Li and Youying Tu. Inhibitory Effect of Tea (Camellia Sinensis (L.) O. Kuntze, Theaceae) Flower Extracts on Oleic Acid-Induced Hepatic Steatosis in Hepg2 Cells. Journal of Food and Nutrition Research. 2014; 2(10):738-743. doi: 10.12691/jfnr-2-10-13


Tea (Camellia sinensis (L.) O. Kuntze, Theaceae) flowers possess many physiological functions and have been used in traditional medicines for deodorization, skin care, cough suppressant and expectorant in China. However, there is little information about its effect on nonalcoholic fatty liver disease (NAFLD). In this study, an oleic acid-induced HepG2 cell model of steatosis was established, and the anti-NAFLD effects of tea flowers and the related mechanisms were investigated. Three tea flower extracts, 40% TFE, 80% TFE and TFRE couldn’t prevent triglyceride (TG) accumulation in oleic acid-treated HepG2 cells (p > 0.05), but significantly decreased the TG level in lipid-overloaded HepG2 cells after 48 h treatment (p < 0.05). RT-PCR analysis revealed that three tea flower extracts did not affect the mRNA levels of peroxisome proliferator-activated receptors α (PPARα) and Acyl-CoA oxidase-1 (ACOX-1) (p > 0.05), but up-regulated the mRNA level of carnitine palmitoyl-CoA transferase (CPT) (p < 0.05). Moreover, tea flower extracts could significantly reduce intracellular reactive oxygen species (ROS) level (p < 0.05). These results indicated tea flowers may be a potential natural resourse for the treatment of NAFLD.

tea flowers NAFLD triglyceride CPT ROS

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[1]  Ekstedt, M., Franzén, L. E., Mathiesen, U. L., Thorelius, L., Holmqvist, M., Bodemar, G., & Kechagias, S. (2006). Long-term follow-up of patients with NAFLD and elevated liver enzymes. Hepatology, 44, 865-873.
[2]  Yu, A. S., & Keeffe, E. B. (2002). Nonalcoholic fatty liver disease. Reviews in gastroenterological disorders, 2, 11-19.
[3]  Day, C. P., & James, O. F. W. (1998). Steatohepatitis: a tale of two “hits”? Gastroenterology, 114, 842-845.
[4]  Liu, Y., Wang,D., Zhang, D., Lv, Y., Wei, Y., Wu, W., Zhou, F., Tang, M., Mao, T., Li, M., & Ji, B. (2011). Inhibitory effect of blueberry polyphenolic compounds on oleic acid-induced hepatic steatosis in vitro. Journal of Agricultural and Food Chemistry, 59, 12254-12263.
[5]  Ayyad, C., & Andersen, T. (2000). Long-term efficacy of dietary treatment of obesity: a systematic review of studies published between 1931 and 1999. Obesity Review, 1, 113-119.
[6]  Müller, C., Gardemann, A., Keilhoff, G., Peter, D., Wiswedel, I., & Schild, L. (2012). Prevention of free fatty acid-induced lipid accumulation, oxidative stress, and cell death in primary hepatocyte cultures by a Gynostemma pentaphyllum extract. Phytomedicine, 19, 395-401.
[7]  Masterjohn, C., & Bruno, R. S. (2012). Therapeutic potential of green tea in nonalcoholic fatty liver disease. Nutrition Reviews, 70, 41-56.
[8]  Li, B., Jin,Y., Xu, Y., Wu, Y., Xu, J., & Tu, Y., 2011. Safety evaluation of tea (Camellia sinensis (L.) O. Kuntze) flower extract: Assessment of mutagenicity, and acute and subchronic toxicity in rats. Journal of Ethnopharmacology, 133, 583-590.
[9]  Yoshikawa, M., Wang, T., Sugimoto, S., Nakamura, S., Nagatomo, A., Matsuda, H., & Harima, S. (2008). Functional saponins in tea flower (flower buds of Camellia sinensis): gastroprotective and hypoglycemic effects of floratheasaponins and qualitative and quantitative analysis using HPLC (in Japanese). Yakugaku Zasshi, 128, 141-151.
[10]  Yang, Z. Y., Tu, Y. Y., Baldermann, S., Dong, F., Xu, Y., & Watanabe, N. (2009). Isolation and identification of compounds from the ethanolic extract of flowers of the tea (Camellia sinensis) plant and their contribution to the antioxidant capacity. LWT-Food Science and Technology, 42, 1439-1443.
[11]  Xu, R. J., Ye, H., Sun, Y., Tu, Y. Y., & Zeng, X. X. (2012). Preparation, preliminary characterization, antioxidant, hepatoprotective and antitumor activities of polysaccharides from the flower of tea plant (Camellia sinensis). Food and Chemical Toxicology, 50, 2473-2480.
[12]  Ling, Z. J., Xiong, C. Y., Han, Q., & He, P. M. (2011). Study on preventive effect of tea plant flower on obesity and hyperlipidemia of rats (in Chinese). Journal of Chinese Institute of Food Science and Technology, 11, 50-54.
[13]  Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (A.Q.S.). (2003a). Determination of amino acids in foods. National Standard of China, GB/T 5009.124-2003.
[14]  Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (A.Q.S.). (2008). Determination of total polyphenols and catechins content in tea. National Standard of China, GB/T8313-2008.
[15]  Dini, I., Tenore, G. C., & Dini, A. (2009). Saponins in Ipomoea batatas tubers: isolation, characterization, quantification and antioxidant properties. Food Chemistry, 113, 411-419.
[16]  Dreywood, R. (1946). Qualitative test for carbohydrate material. Industrial and Engineering Chemistry, Analytical Edition 18, 499.
[17]  Masuko, T., Minami, A., Iwasaki, N., Majima, T., Nishimura, S. I., & Lee, Y. C. (2005). Carbohydrate analysis by a phenol-sulfuric acid method in microplate format. Analytical Biochemistry, 339, 69-72.
[18]  Pourmorad, F., Hosseinimehr, S. J., & Shahabimajd, N. (2006). Antioxidant activity, phenol and flavonoid contents of some selected Iranian medicinal plants. African Journal of Biotechnology, 5, 1142-1145.
[19]  Sedmak, J. J., & Grossberg, S. E. (1977). A rapid, sensitive, and versatile assay for protein using Coomassie brilliant blue G250. Analytical Biochemistry, 79, 544-552.
[20]  Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (A.Q.S.). (2003b). Determination of caffeine content-Method using high-performance liquid chromatography. National Standard of China, GB/T19182-2003.
[21]  Browning, J.D., & Horton, J.D. (2004). Molecular mediators of hepatic steatosis and liver injury. Journal of Clinical Investigation, 114, 147-152.
[22]  Li, X., Wang, R., Zhou, N, Wang, X., Liu, Q., Bai, Y., Bai, Y., Liu, Z., Yang, H., Zou, J., Wang, H., & Shi, T., 2013. Quercetin improves insulin resistance and hepatic lipid accumulation in vitro in a NAFLD cell model. Biomedical Reports, 1, 71-76.
[23]  Kim, M.S., Kung, S., Grewal, T., & Roufogalis, B.D. (2012). Methodologies for investigating natural medicines for the treatment of nonalcoholic fatty liver disease (NAFLD). Current Pharmaceutical Biotechnology, 13, 278-291.
[24]  Cui, W., Chen, S. L., & Hu, K. Q. (2010). Quantification and mechanisms of oleic acid-induced steatosis in HepG2 cells. American Journal of Translational Research, 2, 95-104.
[25]  Hou, Y. F., Wang, D. F., Zhou, X. L., Zhang, L., Wang, J. F., & Bucheli, P. (2008). Effect of tea polysaccharides on blood lipids and liver trace elements in hyperlipidemic rats. Acta Nutrimenta Sinica, 30, 269-272.
[26]  Wu, W. H., & Wu, W. J. (2006). Anti-hyperlipidemic effect of polysaccharides from Pu’er tea (in Chinese). Tea in Fujian, 2, 42-43.
[27]  Deng, X., & Huang, H. H. (2013). In vitro binding of bile salts by water-soluble protein extract from tea flower (in Chinese). Modern Food Science and Technology 29, 63-67.
[28]  Yoshikawa, M., Morikawa, T., Yamamoto, K., Kato, Y., Nagatomo, A., & Matsuda, H. (2005). Floratheasaponins A-C, acylated oleanane-type triterpene oligoglycosides with anti-hyperlipidemic activities from flowers of the tea plant (Camellia sinensis). Journal of Natural Products, 68, 1360-1365.
[29]  Lee, S.M., Kim, C.W., Kim, J.K., Shin, H.J., & Baik, J.H. (2008). GCG-rich tea catechins are effective in lowering cholesterol and triglyceride concentrations in hyperlipidemic rats. Lipids, 43, 419-429.
[30]  Chinetti, G., Fruchart, J. C., & Staels, B. (2000). Peroxisome proliferator-activated receptors (PPARs): Nuclear receptors at the crossroads between lipid metabolism and inflammation. Inflammation Research, 49, 497-505.
[31]  Dreyer, C., Keller, H., Mahfoudi, A., Laudet, V., Krey, G., & Wahli, W. (1993). Positive regulation of the peroxisomal β-oxidation pathway by fatty acids through activation of peroxisome proliferator-activated receptors (PPAR). Biology of the Cell, 77, 67-76.
[32]  Li, Q., Liu, Z. H., Huang, J. N., Luo, G. A., Liang, Q. L., Wang, D., Ye, X. Y., Wu, C. B., Wang, L.L., & Hu, J. H., 2013. Anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extract in high-fat diet-induced obese rats. Journal of the Science of Food and Agriculture, 93, 1310-1316.
[33]  Shimoda, H., Tanaka, J., Kikuchi, M., Fukuda, T., Ito, H., Hatano, T., & Yoshida, T., (2009). Effect of polyphenol-rich extract from walnut on diet-induced hypertriglyceridemia in mice via enhancement of fatty acid oxidation in the liver. Journal of Agricultural and Food Chemistry, 57, 1786-1792.
[34]  Madan, K., Bhardwaj, P., Thareja, S., Gupta, S.D., & Saraya, A. (2006). Oxidant stress and antioxidant status among patients with nonalcoholic fatty liver disease (NAFLD). Journal of Clinical Gastroenterology, 40, 930-935.
[35]  Yang, Z., Xu, Y., Jie, G., He, P., & Tu, Y. (2007). Study on the antioxidant activity of tea flowers (Camellia sinensis). Asia Pacific Journal of Clinical Nutrition, 16 (Suppl 1), 148-152.
[36]  Lv, X. L., Qiu, S. S., Sun, X. X., & Li, Z. J. (2005). Preliminary study on the capability of antioxidation and scavenging free radicals of sasanquasaponins. Food Science, 26, 86-90.