Chemopreventive effect of Toona sinensis leaf extract on 7, 12-dimethylbenz[a]anthracene-induced hamster buccal pouch squamous cell carcinogenesis. (October 2016)

• Record Type: Journal Article
• Authors: Wang, Wen-Chen; Chen, Ching-Yi; Hsu, Hseng-Kuang; Lin, Li-Min; Chen, Yuk-Kwan
• Is Part Of: Archives of oral biology. Volume 70(2016)
• Page Start: 130
• Page End: 142
• Publication Date: 2016-10
• Subjects: Toona sinensis -- DMBA-carcinogenesis -- Hamster -- Chemoprevention; Mouth -- Periodicals; Mouth -- Diseases -- Periodicals; Dentistry -- Periodicals; Electronic journals; 617.6005
• DOI: 10.1016/j.archoralbio.2016.06.015
• Languages: English
• ISSNs: 0003-9969

Abstract

Highlights: We demonstrate that Toona sinensis leaves extract (TSL) has chemopreventive potential in DMBA-induced hamster buccal pouch carcinogenesis. We confirm the anti-proliferative and apoptosis-inducing abilities of TSL. TSL has a better outcome in terms of chemoprevention than in the treatment of oral cancer. We suggest that TSL extract might be a promising candidate for the prevention of oral cancer. Abstract: Objective: Toona sinensis leaf extract (TSL) has been shown to have anti-tumor effects on cancer cell lines. This study aimed to investigate the chemopreventive potential and the underlying mechanism of TSL during 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Methods: One hundred hamsters were divided into control (n = 30), carcinogenic (n = 20), preventive (n = 42), and therapeutic (n = 8) groups. The animals in carcinogenic and preventive groups were administered reverse osmosis water (carcinogenic group) or TSL (1 g/kg bw) (preventive group) by gavage daily for 4 weeks, and their bilateral pouches were painted with a 0.5% DMBA solution for 4, 9, and 12 weeks. The animals in the therapeutic group were treated with DMBA for 12 weeks prior to TSL administration for 4 weeks. Expression levels of survivin, X chromosome-linked inhibitor of apoptosis (XIAP), proliferating cell nuclear antigen (PCNA), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) proteins were analyzed by immunohistochemistry. Apoptotic activity was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method, cytochrome C, and poly (ADP-ribose) polymerase (PARP). Results: In the preventive group, the results showed significant decreases not only in the incidences of squamous cell carcinoma (SCC) (50%) and epithelial dysplasia (62.5%) but also in the tumor number, tumor volume, tumor burden, and the severity of dysplastic lesions. The down-regulation of survivin, XIAP, PCNA, iNOS, and COX-2 proteins and the increased apoptotic activity indicated anti-proliferative and apoptosis-inducing abilities of TSL on DMBA-induced HBP carcinogenesis. Conclusions: The results suggested that TSL might be a promising candidate for the prevention of oral cancer.