Synthesis and biological activity of NOSH-naproxen (AVT-219) and NOSH-sulindac (AVT-18A) as potent anti- inflammatory agents with chemotherapeutic potential† Ravinder Kodela, Mitali Chattopadhyay and Khosrow Kashfi * Nitric oxide- (NO) and hydrogen sulfide- (H 2 S) releasing naproxen (NOSH-naproxen) and NO and H 2 S- releasing sulindac (NOSH-sulindac) were synthesized and their cell growth inhibitory properties were evaluated in four different human cancer cell lines. These cell lines are of adenomatous (colon, pancreas), epithelial (breast), and lymphocytic (leukemia) origin. Using HT-29 human colon cancer cells, NOSH-naproxen and NOSH-sulindac increased apoptosis, and inhibited proliferation. NOSH-naproxen caused a G 0 /G 1 block whereas NOSH-sulindac caused a G 2 /M block in the cell cycle. Both compounds exhibited significant anti-inflammatory properties, using the carrageenan rat paw edema model. Reconstitution and structure–activity studies representing a fairly close approximation to the intact molecule showed that NOSH-naproxen was approximately 8000-fold more potent than the sum of its parts in inhibiting cell growth. Our data suggest that these compounds merit further investigation as potential anti-cancer agents. 1. Introduction Non-steroidal anti-inammatory drugs (NSAIDs) in general and aspirin in particular are recognized as prototypical che- mopreventive agents against cancer. However, the long-term use of NSAIDs may lead to signicant side effects, mainly gastrointestinal, ranging from dyspepsia to gastrointestinal bleeding, obstruction, and perforation, renal, and cardiovas- cular (reviewed in ref. 1). Amongst patients using NSAIDs, it is estimated that about 16 500 deaths occur every year in the United States. This gure is considerably greater than the number of deaths from multiple myeloma, asthma, cervical cancer, or Hodgkin's disease. 2 Unfortunately, many physi- cians and most patients are unaware of the magnitude of the problem. The gastric damage is as a result of direct epithelial damage due to their acidic properties and also through the breakdown of mucosal defence mechanisms (leukocyte adherence, decreases in blood ow, bicarbonate and mucus secretions) due to a reduction of mucosal prostaglandin (PG) synthesis. 3 In our search for a “better NSAID” we developed NOSH-aspirin, 4 a hybrid entity capable of releasing both, nitric oxide (NO) and hydrogen sulde (H 2 S), two gaso- transmitters of physiological signicance. Our rationale was based on the observations that NO and H 2 S could enhance the local gastric mucosal defence mechanisms, thereby decreasing NSAID-induced gastric toxicity. 5–8 Here we report on the synthesis and some of the biological properties of two other NO- and H 2 S-releasing NSAIDs, NOSH-naproxen and NOSH-sulindac, Fig. 1. Fig. 1 Structural components of NOSH-naproxen and NOSH-sulindac. The parent compounds, naproxen and sulindac are shown in the shaded boxes. ADT–OH releases H 2 S and ONO 2 releases NO, both shown in dotted ellipses. Department of Physiology, Pharmacology and Neuroscience, Sophie Davis School of Biomedical Education, City University of New York Medical School, New York, NY 10031, USA. E-mail: kash@med.cuny.edu; Fax: +1-212-650-7692; Tel: +1-212-650- 6641 † Electronic supplementary information (ESI) available. See DOI: 10.1039/c3md00185g Cite this: Med. Chem. Commun., 2013, 4, 1472 Received 1st July 2013 Accepted 27th August 2013 DOI: 10.1039/c3md00185g www.rsc.org/medchemcomm 1472 | Med. Chem. Commun., 2013, 4, 1472–1481 This journal is ª The Royal Society of Chemistry 2013 MedChemComm CONCISE ARTICLE