Computational and Experimental Progress on the Structure and Chemical Reactivity of Procyanidins: Their Potential as Metalloproteinases Inhibitors

Matrix metalloproteinases (MMPs) are enzymes involved in various physiological processes essential for living beings, but the loss of the regulatory control by endogenous inhibitors of MMPs, leads to the development of serious diseases such as cardiovascular system affections, cancer, and metastasis. For these reasons, exogenous inhibitors are required for these enzymes, which are able to control the proteolytic activity and are selective towards the different MMPs, besides properties which, from the pharmacological point of view, are necessary to be effective under physiological conditions. Based on these expectations, some bioactive compounds that are abundant in the human diet, like procyanidins (PCs) have emerged as potential exogenous inhibitors of MMPs. This review presents the advances of experimental and computational investigations carried out to date on the structure and chemical reactivity of PCs, to support the basis of their potential use as MMP inhibitors. For such purpose, specific sites among MMPs identified for a selective inhibition, the role of PCs in the regulation of MMPs by posttranscriptional mechanisms at the level of microRNAs, modulation of reactive oxygen species (ROS), effects on tissue inhibitors of MMPs (TIMPs), the crosslinking of PCs with the extracellular matrix proteins, as well as direct interaction between PCs and MMPs, are discussed. Methods for isolation and synthesis of PCs, as well as hydrophilicity properties, bioavailability, and susceptibility to be metabolized in oral intake, are also addressed. The information gathered in this review could additionally help to visualize future research related to this topic.