Curcumin as inhibitor of mammalian Cathepsin B, Cathepsin H, acid phosphatase and alkaline phosphatase: a correlation with pharmacological activities

Curcumin, a polyphenol, an important constituent of turmeric is used as dietary spice and herbal remedy. In the present work, we aim to assess the effect of curcumin on some physiologically significant enzymes such as lysosomal cysteine proteases-Cathepsin B, Cathepsin H and Phosphatases-acid and alkaline phosphatases. Elevated levels of these enzymes have been reported in various diseased conditions. The in vitro enzyme inhibition studies emphasizes on the pharmacological basis of various therapeutic uses of turmeric. The enzymes were first purified using the techniques of acetone powder preparation, homogenisation, (NH4)(2)SO4 fractionation, molecular sieve chromatography and cation exchange chromatography. Thereafter, the inhibitory effect of curcumin was evaluated on Cathepsin B [3.4.22.1], Cathepsin H [3.4.22.16], acid phosphatase [3.4.3.2] and alkaline phosphatase [3.4.3.1] using well characterized substrates for particular enzymes. The study showed that curcumin effectively inhibited these enzymes. In addition, the results were correlated with the in silico docking studies.