|Jmol 3D model||Interactive image|
|Molar mass||208.12 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
There are four isomers, (+)- and (-)-hydroxycitric acid, and (+)- and (-)-allo-hydroxycitric acid. The (-)-hydroxycitric acid isomer is the one found in Garcinia.
Laboratory and animal studies of HCA have produced results that indicate a potential for modulation of lipid metabolism. However, a clinical study has demonstrated that HCA has no effect in terms of weight loss or reduction of fat mass. A meta-analysis published in 2010 revealed that gastrointestinal adverse effects were twice as likely for users of hydroxycitric acid. The use of HCA is contraindicated in patients suffering Colitis or Inflammatory Bowel Disease.
One isomer of HCA, known as (2S,3R)-HCA, inhibits pancreatic alpha-amylase and intestinal alpha-glucosidase, leading to a reduction in carbohydrate metabolism in vitro. In a study in Zucker rats, which are genetically predisposed to obesity, Garcinia cambogia extract containing HCA showed that high doses led to significant suppression of epididymal fat accumulation, but also had high testicular toxicity. However, this study has been criticized because of possible contamination of the HCA used and various design flaws.
Researchers at the University of Houston reported hydroxycitrate is capable of dissolving calcium oxalate crystals, a component of human kidney stones. This is an unusual effect because it is rare for a crystal to dissolve while in a supersaturated growth solution. The researchers believe the effect could lead to the development of new drugs for human kidney stones.
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- Jena et al 2002, Chemistry and Biochemistry of (−)-Hydroxycitric Acid from Garcinia, Journal of Agricultural and Food Chemistry 50(1):10-22
- Shara M, Ohia SE, Yasmin T, et al. (2003). "Dose- and time-dependent effects of a novel (−)-hydroxycitric acid extract on body weight, hepatic and testicular lipid peroxidation, DNA fragmentation and histopathological data over a period of 90 days". Mol. Cell. Biochem. 254 (1–2): 339–46. doi:10.1023/A:1027358106407. PMID 14674714.
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- Saito M, Ueno M, Ogino S, Kubo K, Nagata J, Takeuchi M (2005). "High dose of Garcinia cambogia is effective in suppressing fat accumulation in developing male Zucker obese rats, but highly toxic to the testis". Food Chem. Toxicol. 43 (3): 411–9. doi:10.1016/j.fct.2004.11.008. PMID 15680676.
- Madhusudan Soni Burdock Group (2005). "Garcinia cambogia toxicity is misleading". Food and Chemical Toxicology. 43 (11): 1683–1684. doi:10.1016/j.fct.2005.05.011. PMID 15993998.
- Hayamizu, K; Tomi, H; Kaneko, I; Shen, M; Soni, MG; Yoshino, G (2008). "Effects of Garcinia cambogia extract on serum sex hormones in overweight subjects". Fitoterapia. 79 (4): 255–61. doi:10.1016/j.fitote.2007.12.003. PMID 18316163.
- Chung J, Granja I, Taylor M, Mpourmpakis G, Asplin J. "Molecular modifiers reveal a mechanism of pathological crystal growth inhibition". Nature. doi:10.1038/nature19062.