Anti-inflammatory and antioxidant activity of coumarins designed as potential fluorescent zinc sensors

Abstract

A series of coumarin analogs, designed and synthesised as potential fluorescent zinc probes were evaluated for their biological activity as anti-inflammatory and antioxidant agents. The effect of the synthesised compounds on inflammation, using the carrageenin-induced rat paw oedema model, was studied. In general, the compounds were found to be potent anti-inflammatory agents (26.5–64%). Compound 5 was found to interact significantly with 1,1-diphenyl-2-picryl-hydrazyl stable free radical (DPPH) whereas the remainder were inactive in this assay. The compounds inhibit in general the soybean lipoxygenase and scavenge superoxide anion radicals. The anti-inflammatory activity seems to be connected with their reducing activity. Their R_M values were determined as an expression of their lipophilicity. Theoretical calculations of their lipophilicity as clog P were performed indicating that only a poor relationship exists between their lipophilicity and anti-inflammatory activity.

Keywords::

• Carrageenin paw oedema
• anti-inflammatories
• antioxidants
• coumarins

Acknowledgements

We would like to thank Dr C. Hansch and Biobyte Corp. 201 West 4^th Str., Suite 204, Claremont CA California, 91711, USA for free access to the C-QSAR program and MEBGAL for the kind offer of carrageenin.