Chemical, Biological, and Pharmacological Prospects of Caffeic Acid

There are many proven beneficial pharmacological effects of polyphenols, and these compounds have been tremendously studied for their role in the human body. Daily intake of polyphenols has shown beneficial effects on the immune system. Polyphenols are the natural compounds present in plants as secondary metabolites. Caffeic acid (CA) is the major one among other compounds of hydroxycinnamic acid, which plays an important role as an antioxidant, anticancer, antidiabetic, antihypertensive, antimicrobial, hepatoprotective, antiviral, etc. It is found in most herbal plants. CA produces its pharmacological effect by altering the activity of various key enzymes. It reduces the blood glucose level by inhibiting enzymes α-amylase and α-glucosidase in type-2 diabetes. It shows anticancer and anti-inflammatory activity by inhibiting various transcript factors. The small part of the esterified form of CA is absorbed in the stomach, and the rest of the part is the breakdown in its free form by the microbial esterases in the colon. It enters intestinal cells via active transport mediated by MCT. The maximum plasma concentration is seen after one hour of food ingestion. Methylation, sulphation, and glucuronidation take place after absorption and are excreted primarily through urine. The purpose of this review is to enhance researchers' knowledge to conduct more studies to reveal and optimize CA's biological and pharmacological properties. Based on its pharmacological activity, this compound can be used as a natural safeguard to replace synthetic antibiotics and other synthetic medicine to reduce the medicinal cost and side effects.