DPP4 and type 2 diabetes mellitus: Besides bromophenols, the inhibition of enzymes related with type-2 diabetes has been reported to sulphated polysaccharides from K. alvarezii and G. opuntia extracts, exhibiting a potent inhibition of α-amylase, α-glucosidase, and DPP-4 (Makkar and Chakraborty 2017), and the protein hydrolysate from P. palmata, acting as inhibitor of DPP-4 (Harnedy and FitzGerald 2013).