Abstract
Diabetes mellitus is a global health issue related to insulin that is associated with a high rate of morbidity and mortality. Synthetic hypoglycemic medications can be used to treat diabetes; however, long-term use of these medications has several negative effects. As a result, there is a paradigm change in favor of using natural agents that may be antidiabetic. The marine environment is a rich source of both biological and chemical diversity, which is being investigated to identify novel compounds with potential for use in the pharmaceutical, cosmetic, and nutritional supplement industries. Marine organisms, especially marine macroalgae, comprise numerous significant novel secondary metabolites possessing strong pharmacological characteristics that have been identified. Sources of marine macroalgae include various bioactive compounds exhibiting various health-promoting properties. Hence, the present chapter aimed to discuss the different antidiabetic mechanisms of bioactive compounds from marine macroalgae and also talked about the variety of marine macroalgal bioactive substances that could help avoid or manage type 2 diabetes by focusing on several pharmacologically significant pathways, such as preventing the activity of enzymes like lipase, α-glucosidase, α-amylase, aldose reductase, protein tyrosine phosphatase 1B, and dipeptidyl-peptidase-4.