Phytoalexins are substances that is produced by plant tissues in response to contact with a parasite and specifically inhibits the growth of that parasite.
Resveratrol and Pterostilbene are two phytoalexins
been detected especially in grapes’ skin and seeds. Both these phytoalexins are natural polyphenol (micronutrients that we get through certain plant-based foods, packed with antioxidants and potential health benefits).
Resveratrol, as a natural food ingredient, numerous studies have demonstrated that resveratrol possesses a very high antioxidant potential. Resveratrol also exhibit antitumor activity, and is considered a potential candidate for prevention and treatment of several types of cancer. Resveratrol anticancer properties have been confirmed by many in vitro and in vivo studies, which shows that resveratrol is able to inhibit all carcinogenesis stages (e.g., initiation, promotion and progression). Even more, other bioactive effects, namely as anti-inflammatory, anticarcinogenic, cardioprotective, vasorelaxant, phytoestrogenic and neuroprotective have also been reported.
Pterostilbene, based on animal studies it is thought to exhibit anti-cancer, anti-hypercholesterolemia, anti-hypertriglyceridemia properties, as well as the ability to fight off and reverse cognitive decline. It is believed that the compound also has anti-diabetic properties.
Resveratrol and Pterostilbene, are found in black grapes, both these compounds seem to help the body improve gut bacteria and regulate energy.
(Sources of Information: webmd.com, ncbi.nlm.nih.gov & definitions.net)