Bioactive Compounds in Dietary Spices and Medicinal Plants

Abstract

Aim of this review is to show the most important bioactive compounds in hot spices such as black pepper (Piper nigrum L.), chilli pepper (Capsicum annuum L.) and medicinal plant such AS garlic (Allium sativum L.), and its modes of action. Piperine is an alkaloid responsible for the pungency of black pepper, along with chavicine (C17H19NO3) which is an alkaloid found in black pepper and other species of the genus Piper. It is one of the four geometric isomers of piperine. The active compound in black pepper is piperine (Bioperine; N-[(E,E)-Piperoyl]piperidine; Piperine (aliphatic); 1-[(2E,4E)-5-(1,3-benzodioxol-5-yl)penta-2,4-dienoyl]piperidine and etc.) which is responsible for bio enhancing effect. It has been found that piperine bioavailability enhancing property may be attributed to increased absorption, which may be due to alteration in membrane lipid dynamics and change in the conformation of enzymes in the intestines. Capsinoids is a family of compounds that are analogues of capsaicin, which is the pungent component in chilli peppers. Capsinoids are widely present at low levels in chilli pepper fruit which include capsiate, dihydrocapsiate, and nordihydrocapsiate. Capsaicin (C18H27NO3 or 8-Methyl-N-vanillyl-trans-6-nonenamide) is the active substance responsible for the irritating and pungent effects of various species of hot peppers. Allicin (C6H10S2O; allyl 2-propenethiosulfinate or diallyl thiosulfinate) is an organosulfur compound obtained from garlic, a species in the family Alliaceae. It was first isolated and studied in year 1944 and it is thought to be the principal bioactive compound present in aqueous garlic extract or raw garlic homogenate. When garlic is chopped or crushed, alliinase enzyme, present in garlic, is activated and acts on alliin (C6H11NO3S) to produce allicin. Other important sulfur containing compounds present in garlic are allyl methyl thiosulfonate, 1-propenyl allyl thiosulfonate, and γ-l glutamyl-S-alkyl-l-cysteine. These compounds provide garlic its characteristic odour and flavour. Small amounts of nonvolatile water-soluble sulfur compounds such as S-allyl cysteine are found in garlic as well. These biological responses of all this bioactive compounds have been largely attributed to reduction of risk factors for cardiovascular diseases and cancer, stimulation of immune function, enhanced detoxification of foreign compound, antihepatotoxicity, cholesterol content reduction, antimicrobial effect, antifungal effect, antiinflammatory effect and antioxidant effect when consumed by animals or humans.