Dark tea extracts: Chemical constituents and modulatory effect on gastrointestinal function oleh Zhi-ping Gong, Jian Ouyang, Xiang-lan Wu, Fang Zhou, Dan-Ming Lu, Chen-jie Zhao, Chun-fang Liu, Wan Zhu, Jing-chi Zhang, Neng-xin Li, Feng Miao, Yu-xin Song, Yi-long Li, Qi-ye Wang, Hai-yan Lin, Xin Zeng, Shu-xian Cai, Jian-an Huang, Zhong-hua Liu, Ming-zhi Zhu