Hyaluronidase inhibitors: a biological and therapeutic perspective

The hyaluronidases (HAases) are a group of less extensively studied glycosidases distributed throughout the animal kingdom and are popularly known as 'spreading factors'. In recent years, HAases received much attention due to their ability to abruptly alter the hyaluronic acid (HA) homeostasis. HAases preferentially degrade HA, which is a megadalton acidic structural polysaccharide found exclusively in the extracellular matrix (ECM) of animals. The HA-HAase system has been suggested to participate in many pathophysiological conditions. The HA degradation in ECM, crack down the structural integrity with an eventual increased tissue permeability that is attributed for the spreading property. The spreading property has been widely accepted in functions including envenomation, acrosomal reaction/ovum fertilization, cancer progression, microbial pathogenesis such as wound infections, pneumonia, and other sepses like, bacteremia and meningitis. HA fragmentation has dual effects; generation of a wide molecular range bioactive oligosaccharides of angiogenic, pro-inflammatory, and immunostimulatory properties; and impairment in the reservoir capacity of ECM that holds metal ions, growth factors, cytokines and various enzymes for signal transduction. Hence, inhibition of HA degradation appears critical and imperative in HAase mediated pathological conditions. HAase inhibitors are thus potent regulators that maintain HA homeostasis and they might serve as anti-inflammatory, anti-aging, anti-microbial, anticancer and anti-venom/toxin and contraceptive agents. In addition, HAase inhibitors may serve as tools to understand several unexplained and complex functions of HAases in HA metabolism. Therefore, this review is expected to provide an integrated update as of 2008 on the HAase inhibitors and their possible role as therapeutics in the management of a wide range of pathological conditions.