ABSTRACT
The aim of this chapter is to review and highlight our current understanding of bioactive compounds derived from the shark, particularly those with immunomodulating properties. Historically, shark-derived products have been used in traditional medicine in certain countries for centuries. However, the last several decades have seen a worldwide increase in the intake of shark products as dietary supplements and in their use as natural remedies. Sharks possess robust immune capacity, exhibiting all of the major innate and adaptive immune mechanisms present in higher vertebrates such as man. Their relatively high degree of immunological resilience along with other physical and behavioral aspects of shark biology has fueled the notion that consuming shark products could be beneficial to human health. In this chapter, we review the various shark-derived components that are believed to be effective anticancer agents because of their anti-angiogenic properties and those that exhibit a range of bioactive properties including antimicrobial activity and the ability to modulate immune function, that is, immunomodulatory agents. For example, squalamine exhibits a variety of distinct bioactive properties ranging from anti-angiogenic to antiviral effects. Some products have 288made their way through early stages of the clinical pipeline and entered clinical trials with varying degrees of success. Our present knowledge of the immunomodulatory properties of shark liver oil and shark cartilage-derived products will be reviewed along with their use as dietary supplements and as therapeutic and prophylactic agents against disease. In case of the latter, the impact on public health will be examined, particularly because there is an absence of strong scientific corroborative evidence in support of their purported effectiveness. In addition, the impact of shark harvests and of the trade in shark products on environmental health will be addressed, taking into account the role that sharks play in the health of marine ecosystems.
