Pulmonary, Gastrointestinal and Urogenital Pharmacology Modulatory effect of hesperidin on benzo(a)pyrene induced experimental lung carcinogenesis with reference to COX-2, MMP-2 and MMP-9 Sattu Kamaraj, Pandi Anandakumar, Sundaram Jagan, Gopalakrishnan Ramakrishnan, Thiruvengadam Devaki ⁎ Department of Biochemistry, University of Madras, Chennai 600 025, India abstract article info Article history: Received 20 February 2010 Received in revised form 30 August 2010 Accepted 7 September 2010 Available online 29 September 2010 Keywords: Lung cancer Hesperidin COX-2 (cyclooxygenase-2) Mast cell density MMP-2 (matrix metalloproteinase-2) MMP-9 (matrix metalloproteinase-9) Hesperidin is a naturally occurring flavonoid that has been reported to possess anticancer effects. The purpose of this study is to evaluate the effect of hesperidin in modulating the expressions of cyclooxygenase-2 (COX-2), mast cells (MCs) and matrix metalloproteinases (MMPs) during benzo(a)pyrene (B(a)P) induced lung carcinogenesis in mice. B(a)P (50 mg/kg body weight) induced animals showed increased mast cell density (MCD) as revealed by toluidine blue staining and severe expression of COX-2 along with upregulated expression of MMP-2 and MMP-9 as revealed by Western blotting and immunohistochemistry. Supplementation of hesperidin (25 mg/kg body weight) to lung cancer bearing mice attenuated MCD and downregulated the expressions of COX-2, MMP-2 and MMP-9. These observations show that hesperidin exerts its anti-carcinogenic activity against lung cancer by altering the expressions of COX-2, MMP-2 and MMP-9. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Lung cancer remains a major cause of death from cancer in the world, causing more than one million deaths each year (Koizumi, 2006). Smoking is undoubtedly the main risk factor, to which 90% of lung cancer cases are attributable (Hecht, 1999; Ruano-Ravina et al., 2003; Winterhalder et al., 2004). Benzo(a)pyrene (B(a)P) is a highly carcinogenic polycyclic aromatic hydrocarbon (PAH) present in tobacco smoke that is involved in the aetiology of lung cancer (Hecht, 1999). B(a)P is metabolically activated into benzo(a)pyrene 7,8-diol-9,10-epoxide (BPDE) which reacts with DNA predominantly to form an adduct and progression of the disease (Osborn et al., 1976). The influence of fruits and vegetables on the appearance of lung cancer continues to be debated, though in general these foods are said to play a protective role against lung cancer (Yong et al., 1997; Nyberg et al., 1998; De Stefani et al., 1999; Speizer et al., 1999; Voorrips et al., 2000). Hesperidin (5,7,3′-trihydroxy-4′-methoxy- flavanone 7-rhamnoglucoside) belongs to the class of flavonoids called flavanones and is found mainly in citrus fruits. The effects of hesperidin in the prevention and treatment of disease have recently received considerable attention (Montanari et al., 1998) with particular interest as anticancer compounds (Tian et al., 2001; Winawer et al., 2003). It has several biological functions such as antioxidant properties, anti-inflammatory effects, prostaglandin- synthesis inhibition, anti-mutagenic activity, modulation of drug- metabolizing enzymes and anti-tumor promoter effects (Huang et al., 1983; Fujiki et al., 1986; Ratty and Das, 1988; Galati et al., 1994). Nevertheless, there are very few studies addressing the effect of hesperidin consumption on lung cancer. We have recently reported the antioxidant and anticancer potential of hesperidin during experimental lung cancer (Kamaraj et al., 2009). Current challenges in lung cancer treatment include the search of the most promising new agents which can be integrated into current methods of treatment and the clarification of the mechanism by which lung cancer cells undergo growth, proliferation, differentiation, metasta- sis and apoptosis (Thatcher, 2006). Cyclooxygenase 2 (COX-2) is an inducible form of cyclooxygenase and is also known as prostaglandin (PG) H synthase. The expression of COX-2 is induced by various stimuli, such as growth factors and cytokines. Recent reports on COX-2 expression in cancers show that this enzyme can stimulate angiogenesis and is associated with tumor growth, invasion, and metastasis (Tang et al., 2005). Cancer metastasis, the spread of cancer cells from the primary neoplasm to distant sites and their growth there, is the major cause of death for many cancer patients (Weiss, 1990). Metastasis of cancer cells involves multiple processes and various cytophysiological changes, including changed adhesion capability between cells and extracel- lular matrix (ECM) and damaged intercellular interaction. Thus, degradation of the ECM and components of the basement membrane caused by a concerted action of proteinases, such as serine proteinase, matrix metalloproteinases (MMPs), cathepsins, and plasminogen activator, play a critical role in tumor invasion and metastasis (Westermarck and Kahari, 1999; Yoon et al., 2003). Among these enzymes, MMP-2 and MMP-9 could degrade most European Journal of Pharmacology 649 (2010) 320–327 ⁎ Corresponding author. Tel.: + 91 44 22351269; fax: + 91 44 22352494. E-mail address: devakit@yahoo.co.uk (T. Devaki). 0014-2999/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.ejphar.2010.09.017 Contents lists available at ScienceDirect European Journal of Pharmacology journal homepage: www.elsevier.com/locate/ejphar