Synthetic and Natural Lipase Inhibitors

Lipases are enzymes that catalyse the hydrolysis of ester bonds of triglycerides ranging among biocatalysts of considerable physiological significance and industrial potential. Better understanding of the catalytic functions and achieving the possibility to control the biocatalysis process, in particular exploring some activators and inhibitors of lipases, seems to be crucial in the context of novel applications. The lipase activity is a function of interfacial composition: the enzyme can be there activated as well as denaturated or deactivated and the interface is an appropriate site for modulating lipolysis. Lipase inhibitor, interacts directly with the enzyme and inhibits lipase action. Alternatively, some compounds can postpone the lipolytic reaction via adsorption to the interphase or to the substrate molecules. The aim of this review is to summarise the current knowledge concerning human, animal and microbial lipase inhibitors, which were grouped into two categories: synthetic lipase inhibitors (including phosphonates, boronic acids and fats analogues) and natural compounds (including beta-lactones and some botanical foodstuffs - plant extracts and plant metabolites, mainly polyphenols and saponins as well as peptides and some dietary fibers). The topics discussed include also inhibition issues from the viewpoint of obesity treatment. Among natural compounds able to inhibit lipase activity are beta-lactones including orlistat. Orlistat is the only registered drug for obesity treatment in many countries and lipases are essential enzymes for lipid absorption - thus fat absorption or obesity can be controlled by lipase inhibition, especially pancreatic lipase which is responsible for the hydrolysis of over 80% of total dietary fats. Its effectiveness in obesity treatment was also described.