Design, synthesis and anti-inflammatory activity of structurally simple anthranilic acid congeners devoid of ulcerogenic side effects

Simple, three classes of new anthranilic acid derivatives were aimed at, synthesized and tested for their toxicity, anti-inflammatory, analgesic, antipyretic activity. Also, their potential protective role against ulcerative colitis in rats was performed. Furthermore, their effect on liver and kidney functions was detected through measurement of the serum level of alanine transaminase (ALT), aspartate aminotransferase (AST), urea, creatinine and other parameters. Compounds 4, 5, 6b, 6c, 7c and 7e showed significant anti-inflammatory activity. From those 6b and 7e best improved the inflammatory indices even producing better reduction in the intensity of lesion score, ulcer area and wet weight/length ratio and showed good analgesic activity. Fortunately, none of the tested compounds showed any hepatotoxicity or nephrotoxicity. None of the tested compounds showed any antipyretic activity. Conclusively, presence of a phenyl ring in the substituent added is a must, since any alteration in its nature led to decrease in activity. Also, the presence of an extra halogen in addition to the one already embedded in the main structure was detrimental to activity.