Pharmacological anti-tumor effects of natural Chamaecyparis obtusa (siebold & zucc.) endl. Leaf extracts on breast cancer

• Published in: Journal of ethnopharmacology 2023-09, Vol.313, p.116598-116598, Article 116598
• Main Authors: Kwon, Yong-Jin, Seo, Eun-Bi, Kim, Seul-Ki, Lee, Hyun-Seung, Lee, Haeri, Jang, Young-Ah, Kim, Yu Mi, Kim, Yong-Nyun, Lee, Jin-Tae, Ye, Sang-Kyu
• Format: Article
• Language: English
• Subjects: Animals; Anti-Inflammatory Agents - pharmacology; Apoptosis; Breast cancer; C. obtusa; Cell Line, Tumor; Cell Proliferation; Chamaecyparis; Ethanol - pharmacology; Metastasis; Mice; Neoplasms - drug therapy; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; STAT3; Tumor growth; Water - pharmacology; Wound Healing
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2023.116598

Chamaecyparis obtusa (C. obtusa, cypress species) is a plant that grows mainly in the temperate Northern Hemisphere and has long been used as a traditional anti-inflammatory treatment in East Asia. C. obtusa contains phytoncides, flavonoids, and terpenes, which have excellent anti-cancer effects and have been reported to prevent the progression of various cancers. However, the detailed mechanisms underlying the anti-cancer effects of C. obtusa extracts are unknown. We sought to confirm the anti-cancer effects of C. obtusa leaf extracts and to reveal the mechanism of action, with the possibility of its application in the treatment or prevention of cancer. The cytotoxicity of C. obtusa leaf extracts was confirmed using an MTT assay. Intracellular changes in protein levels were measured by immunoblotting, and mRNA levels were measured with qRT-PCR. Wound healing assay and transwell migration assay were used to evaluate the metastatic potential of breast cancer cells. The extract-induced apoptosis was observed using IncuCyte Annexin V Red staining analysis. A syngeneic breast cancer mouse model was established by injecting 4T1-Luc mouse breast cancer cells into the fat pad of female BALB/c mice, and the extract was administered orally. Luciferin solution was injected intraperitoneally to assess primary tumor development and metastasis by bioluminescence. C. obtusa leaf extracts were extracted with boiling water, 70% EtOH, and 99% EtOH. Among the extracts, the 99% EtOH extract of C. obtusa leaf (CO99EL) most clearly inhibited the tyrosine phosphorylation of Signal Transducer and Activator of Transcription 3 (pY-STAT3) in MDA-MB-231 breast cancer cells at a concentration of 25 and 50 μg/mL. In addition, CO99EL strongly inhibited not only endogenous pY-STAT3 levels but also IL-6-induced STAT3 activation in various types of cancer cells, including breast cancer. CO99EL inhibited metastatic potential by downregulating the expression of N-cadherin, fibronectin, TWIST, MMP2, and MMP9 in MDA-MB-231 breast cancer cells. CO99EL also induced apoptotic cell death by increasing cleaved caspase-3 and decreasing anti-apoptotic proteins Bcl-2 and Bcl-xL. In an in vivo syngeneic breast cancer mouse model, 100 mg/kg CO99EL suppressed tumor growth and induced apoptosis of cancer cells. Moreover, CO99EL significantly inhibited lung metastasis from primary breast cancer. Our study demonstrated that 100 mg/kg CO99EL has potent anti-tumor effects against breast cancer, thus suggesti