Overview of Chemistry and Medicinal Effects of Major Spices

Spices, apart from imparting flavor and aroma to foods, have also been recognized for their health-beneficial attributes since time immemorial, several of them being used in the traditional systems of medicine. During the last three to four decades, several scientists in India conducted exhaustive experiments and documented a wide range of health-beneficial effects of spices. The contribution of Indian scientists to the field of health-beneficial physiological effects of spices is significant and noteworthy. Exhaustive animal studies documented the beneficial influence of some spices and their active principles on lipid metabolism, especially antihypercholesterolemic and antilithogenic effect. The antidiabetic effects of turmeric/curcumin, onion, and cumin seeds were also evidenced with particular ameliorative influence of curcumin and onion on diabetic nephropathy. The antioxidant effects of curcumin, capsaicin, and eugenol were evidenced both in in vitro and in vivo systems, and the consequential health-beneficial anti-inflammatory influence in experimentally induced arthritis was documented. The mechanism of digestive stimulant action of common spices examined in experimental animals was shown to be mediated through significant stimulation of bile secretion with an enhanced bile acid concentration (ingredients essential for fat digestion and absorption), as well as a stimulation of the activities of digestive enzymes of pancreas and small intestine. The protective influence of hypolipidemic spices, curcumin, capsaicin, and garlic on the altered fluidity of erythrocytes under hypercholesterolemic situation was evidenced in experimental animal models. Antioxidant spices were also shown to greatly reduce LDL-oxidation and also modulate the synthesis of prostaglandins and leukotrienes. Several spices or their extracts were also found to beneficially inhibit platelet aggregation. The safety of the consumption of some of the spices and their active principles was also established in animal studies by observing the influence on growth, organ weights, nitrogen balance, and blood constituents upon feeding at levels close to human intake as well as up to 100 times the normal human intake.