title: Green tea (Camellia sinensis) extract inhibits both the metastasis and osteolytic components of mammary cancer 4T1 lesions in mice.
abstract: Green tea (Camellia sinensis, CS), a kind of Chinese tea commonly consumed as a healthy beverage, has been demonstrated to have various biological activities, including antioxidation, antiobesity and anticancer. Our study aims to investigate the antitumor, antimetastasis and antiosteolytic effects of CS aqueous extract both in vitro and in vivo using metastasis-specific mouse mammary carcinoma 4T1 cells. Our results showed that treatment of 4T1 cells with CS aqueous extract resulted in significant inhibition of 4T1 cell proliferation. CS extract induced 4T1 apoptosis in a dose-dependent manner as assessed by annexin-V and propidium iodide staining and caspase-3 activity. Western blot analysis showed that CS increased the expression of Bax-to-Bcl-2 ratio and activated caspase-8 and caspase-3 to induce apoptosis. CS also inhibited 4T1 cell migration and invasion at 0.06-0.125 mg/ml. In addition, CS extract (0.6 g/kg, orally fed daily for 4 weeks) was effective in decreasing the tumor weight by 34.8% in female BALB/c mice against water treatment control (100%). Apart from the antitumor effect, CS extract significantly decreased lung and liver metastasis in BALB/c mice bearing 4T1 tumors by 54.5% and 72.6%, respectively. Furthermore, micro-computed tomography and in vitro osteoclast staining analysis suggested that CS extract was effective in bone protection against breast cancer-induced bone destruction. In conclusion, the present study demonstrated that the CS aqueous extract, which closely mimics green tea beverage, has potent antitumor and antimetastasis effects in breast cancer and could protect the bone from breast cancer-induced bone destruction.
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Ke-Wang
authors.initials: KW
authors.lastname: Luo
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Chun-Hay
authors.initials: CH
authors.lastname: Ko
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Grace Gar-Lee
authors.initials: GG
authors.lastname: Yue
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Julia Kin-Ming
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Kai-Kai
authors.initials: KK
authors.lastname: Li
authors.affiliation: Discipline of Orthopaedics and Trauma, University of Adelaide, Adelaide, SA, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Kwok-Pui
authors.initials: KP
authors.lastname: Fung
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors.forename: Ping-Chung
authors.initials: PC
authors.lastname: Leung
authors.affiliation: Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong; State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong. Electronic address: claralau@cuhk.edu.hk.
authors.forename: Clara Bik-San
authors.initials: CB
authors.lastname: Lau
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000187:drug effects; D028241:Camellia sinensis / Q000737:chemistry*; D053148:Caspase 3 / Q000378:metabolism; D005260:Female; D008113:Liver Neoplasms / Q000178:diet therapy / Q000556:secondary; D008175:Lung Neoplasms / Q000178:diet therapy / Q000556:secondary; D008325:Mammary Neoplasms, Experimental / Q000178:diet therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010010:Osteoclasts / Q000187:drug effects / Q000473:pathology; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494827:Bax protein, mouse; D010936:Plant Extracts; D059808:Polyphenols; D051028:bcl-2-Associated X Protein; D053148:Caspase 3
keywords: 4T1 cells; Antimetastasis; Antitumor; Bone destruction; Camellia sinensis (CS); Green tea