Phytochemical Of The Month - Beta - Carotene
Beta-carotene is the most common form of carotene and belongs to the group of terpenoids. Pure beta-carotene is red to purple coloured oil. It is not soluble in water. Beta-carotene which is used in drinks is encapsulated with starch or gelatin to make it soluble. Beta - Carotene is also known as Pro- vitamin A because it gets converted to vitamin A in the body. It is the most widely studied carotenoid. It is one of a group of natural chemicals known as carotenes or carotenoids. They are responsible for the orange colour of many fruits and vegetables such as carrots, pumpkins and sweet potatoes. It is an antioxidant, like vitamin E and C. Carotenoids serve two key roles in plants and algae i.e they absorb light energy for use in photosynthesis, and they protect chlorophyll from photo damage. In humans, carotenoids such as beta- carotene are a precursor to vitamin A, a pigment essential for good vision, and carotenoids can also act as antioxidants.
Chemistry:
IUPAC: 3,7,12,16-tetramethyl-1,18-bis ( 2,6,6,-trimethyl-1-cyclohexenyl )-octadeca- 1,3,5,7,9,11,13,15,17 - nonaene
Molecular formula: C40 H56
Molecular weight: 536.87
Chemical structure:
Chemical Properties: Beta-carotene has received a lot of attention as potential anti-cancer and anti-aging phytochemical. Beta-carotene is a powerful antioxidant, protecting the cells of the body from damage caused by free radicals. Studies indicate that diets low in beta-carotene can increase the body's susceptibility to damage from free radicals, resulting in an increased risk of chronic diseases like heart disease and cancers. Beta-carotene supplements may help reduce sun induced skin damage. Smokers should avoid large doses of beta carotene supplements. Beta-carotene is one of the many carotenoids that our body can convert into vitamin A (retinol).
Pharmacological Investigations:

1. Anti-cancer: Beta-carotene acts as an anti-cancer agent through its antioxidant property but it also seems to stimulate cell to cell communication. Poor communication between cells may eventually lead to cancer. However, beta-carotene may cause adverse effects on smokers. Two studies indicate that heavy smokers and drinkers may have an increased risk of lung cancer or heart disease, when taking daily more than 20 mg synthetic beta-carotene as supplements. A study by Harvard School of Public Health published in January 2004 issue of Cancer Epidemiology Biomarkers and Prevention indicates that beta-carotene consumed as part of natural foods has no such negative effects.

2. Skin protection: Studies have demonstrated that beta-carotene may be used for skin protection: it reduces UV-induced redness of the skin and improves melasma. Beta-carotene is often use in supplements or topical creams to protect our skin. Too much intake of beta-carotene can result in carotenodermia, a condition that shows a yellowish discolouration of the skin. This is reversible and harmless.

3. Heart health: Epidemiological studies show that beta-carotene may improve our heart health by decreasing blood pressure. Beta-carotene may also help to prevent arteriosclerosis by inhibiting the oxidation of lipids.
References
  •  Armstrong GA, Hearst JE (1996). "Carotenoids 2: Genetics and molecular biology of carotenoid pigment biosynthesis". FASEB J. 10 (2): 228-37. PMID 8641556.
  •  Bjelakovic G, et al (2007). "Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis". JAMA 297 (8): 842-57. doi:10.1001/jama.297.8.842. PMID 17327526.
  •  It is known that taking beta-carotene supplements is harmful for smokers, and the meta-analysis of Bjelakovic et al. was influenced by inclusion of these studies. See the letter to JAMA by Philip Taylor and Sanford Dawsey and the reply by the authors of the original paper.
  •  Unlu N, et al (2005). "Carotenoid Absorption from Salad and Salsa by Humans Is Enhanced by the Addition of Avocado or Avocado Oil". Human Nutrition and Metabolism 135 (3): 431-6. PMID 15735074.
  •  Choo Yuen May Palm oil carotenoids
  •  Alija AJ, Bresgen N, Sommerburg O, Siems W, Eckl PM (2004). "Cytotoxic and genotoxic effects of {beta}-carotene breakdown products on primary rat hepatocytes". Carcinogenesis 25 (5): 827-31. doi:10.1093/carcin/bgh056. PMID 14688018.
  •  Liu GY, Essex A, Buchanan JT, et al (2005). "Staphylococcus aureus golden pigment impairs neutrophil killing and promotes virulence through its antioxidant activity". J. Exp. Med. 202 (2): 209-15. doi:10.1084/jem.20050846. PMID 16009720. PMC:2213009.
  •  Information on vitamins at www.nytimes .com
  •  Healthy diet on Indianwomen Health.com/HealthBody.
  •  Buy solaray vitamins at www.vitaminlife.com
  •  130 Whole foods at www. Ultimatehealth.com.
  •  Vitamins & oxygen therapy at www.thepundit.com.
  •  Zechmeister; Pinckard (J. Am. Chem. Soc), 1947
  •  Caris-Veyrat, Catherine; Amiot, Marie-Josephe; Ramasseul, Rene; Marchon, Jean-Claude (New J. Chem), 2001.