Eggplant (Solanum melongena), also known as aubergine in some countries or brinjal in Asia, originates from Asia, where it has been cultivated since historic time, is a fruit commonly used in cooking recipes from Mediterranean and Asian regions. As in most of the plant foods, many phenolic compounds can be found in eggplants. While these phenolic compounds are mostly known for their antioxidant properties they often display other biological activities waiting to be exploited for health benefits.
Eggplant’s beneficial health properties should be better recognized.
1. Antithypertension
The most well-known and studied of the compounds found in eggplants is known as chlorogenic acid. It has been found that chlorogenic acid can reduce high blood pressure (hypertension). Scientific studies showed that chlorogenic acid inhibits the activity of the enzyme (an enzyme is a protein which catalyzes a chemical reaction) which causes blood vessels to constrict (when a blood vessel constricts the blood pressure will rise). The enzyme is known as Angiotensin Converting Enzyme or ACE. It may also inhibit another enzyme involved in the production of hormones that raise the blood pressure (11-βHSD1). Therefore an intake of chlorogenic acid may be an additional tool to reduce high blood pressure.
2. Anti-diabetic
Chlorogenic acid found in eggplant’s extracts may be anti-diabetic. It has been shown to reduce glucose levels in the blood. It helps glucose metabolism. It shows a potent ability to inhibit alpha glucosidases, a family of enzymes involved in glucose release. These enzymes are key targets for diabetes type 2 treatments. It may also reduce the sudden glucose spikes after a meal. Therefore supplementing the diet with eggplant could potentially represent a good way to help reduce high blood sugar.
3. Protection against diet-induced obesity
Obesity leads to many illnesses including fatty liver and insulin resistance (diabetes). A study on chlorogenic acid intake in obese mice showed promising results. Chlorogenic acid appears to block the further development of obesity and its related metabolic syndromes and increase fat loss.
4. Antivenom and anti-inflammatory properties
A recent publication demonstrated that chlorogenic acid can act as an inhibitor of another enzyme named Secretory Phospholipase A2 found in the venom of Crotalus durissus terrificus, a South American Rattlesnake. But Phospholipase A2 is also an important human enzyme involved in inflammatory mechanisms. Eggplant intake therefore may have an interesting anti-inflammatory property.
5. And Also…..
Eggplant also contains Delphinidin, which is a potent anti-oxidant (reducing possible damage caused by ‘free radicals’ from normal metabolism), and also has anti-inflammatory properties. Some researchers have suggested it may reduce the spread of certain cancers, reducing the growth of the cancer by killing cancer cells. These are from studies in mice.
Sources:
In vitro studies of eggplant (Solanum melongena) phenolics as inhibitors of key enzymes relevant for type 2 diabetes and hypertension. Kwon YI, Apostolidis E, Shetty K. Bioresour Technol. 2008 May;99(8):2981-8. Epub 2007 Aug 13.
Antihypertensive effect of caffeic acid and its analogs through dual renin-angiotensin-aldosterone system inhibition.
Bhullar KS, Lassalle-Claux G, Touaibia M, Rupasinghe HP. Eur J Pharmacol. 2014 May 5;730:125-32. doi: 10.1016/j.ejphar.2014.02.038. Epub 2014 Mar 11.
Chlorogenic Acid Improves High Fat Diet-Induced Hepatic Steatosis and Insulin Resistance in Mice. Ma Y, Gao M, Liu D. Pharm Res. 2014 Sep 24. [Epub ahead of print]
Effect of Chlorogenic Acid (5-Caffeoylquinic Acid) Isolated from Baccharis oxyodonta on the Structure and Pharmacological Activities of Secretory Phospholipase A2 from Crotalus durissus terrificus. Toyama DO, Ferreira MJ, Romoff P, Fávero OA, Gaeta HH, Toyama MH. Biomed Res Int. 2014;2014:726585. doi: 10.1155/2014/726585. Epub 2014 Sep 2.
Reducing Capacity, Chlorogenic Acid Content and Biological Activity in a Collection of Scarlet (Solanum aethiopicum) and Gboma (S. macrocarpon) Eggplants. Plazas M, Prohens J, Cuñat AN, Vilanova S, Gramazio P, Herraiz FJ, Andújar I. Int J Mol Sci. 2014 Sep 26;15(10):17221-41. doi: 10.3390/ijms151017221.
Suppressive properties of extracts from Japanese edible plants regarding nitric oxide generation. Lee JK, Murakami A, Watanabe S, Ohigashi H. Asian Pac J Cancer Prev. 2009 Apr-Jun;10(2):263-72.
Inhibitory effect of delphinidin from Solanum melongena on human fibrosarcoma HT-1080 invasiveness in vitro. Nagase H, Sasaki K, Kito H, Haga A, Sato T. Planta Med. 1998 Apr;64(3):216-9.
Glycoalkaloids and metabolites inhibit the growth of human colon (HT29) and liver (HepG2) cancer cells. Lee KR, Kozukue N, Han JS, Park JH, Chang EY, Baek EJ, Chang JS, Friedman M. J Agric Food Chem. 2004 May 19;52(10):2832-9.