Kurkumin

Bentuk keton dari kurkumin

Kurkumin (bahasa Inggris: diferuloylmethane adalah senyawa aktif yang ditemukan pada kunyit, berupa polifenol dengan rumus kimia C₂₁H₂₀O₆. Kurkumin memiliki dua bentuk tautomer: keton dan enol. Struktur keton lebih dominan dalam bentuk padat, sedangkan struktur enol ditemukan dalam bentuk cairan. Kurkumin merupakan senyawa yang berinteraksi dengan asam borat menghasilkan senyawa berwarna merah yang disebut rososiania.

Senyawa turunan kurkumin disebut kurkuminoid, yang hanya terdapat dua macam, yaitu desmetoksikurkumin dan bis-desmetoksikurkumin. Secara in vivo, kurkumin berubah menjadi senyawa metabolit berupa dihidrokurkumin atau tetrahidrokurkumin sebelum dikonversi menjadi senyawa konjugasi monoglusuronida.^[1]

Kurkumin dikenal karena sifat antitumor dan antioksidan yang dimilikinya, selain banyak kegunaan medis seperti;

• melindungi saraf,^[2] mengurangi risiko radang otak vasospasma^[3] dan mengembalikan homeostasis energi pada sistem otak yang terganggu akibat terluka atau trauma.^[4]
• menghambat dan mengurangi penumpukan plak amiloid-beta pada penderita Alzheimer.^[5][6][7][8]
• melindungi hati , antara lain dari hemangioendotelioma,^[9] hepatokarsinoma,^[10] Hepatitis B.^[11]
• melindungi pankreas dari akibat rasio sitokin yang berlebihan,^[12] bahkan setelah transplantasi,^[13] serta menurunkan resistansi terhadap insulin dan leptin^[14]
• melindungi sel Leydig dari pengaruh alkohol.^[15]
• menurunkan peradangan pada jaringan adiposa.^[16]

Selain itu, kurkumin juga:

• menghambat indoleamina 2,3-dioksigenase, sebuah enzim yang berperan dalam degradasi triptofan pada sel dendritik yang distimulasi oleh LPS atau interferon, dan menghambat matangnya sel dendritik. Ekspresi siklo oksigenase-2 yang diinduksi oleh LPS dan produksi prostaglandin E2 akan meningkat, dan mengakibatkan de-ekspresi molekul CD80, CD86 dan MHC I dan menghambat^[17] produksi sitokina IL-12 p70 dan TNF-α.^[18]
• menghambat angiogenesis.^[19]
• menghambat lintasan COX^[20] dan LO pada metabolisme eikosanoid. Kurkumin sangat efektif untuk menghambat pertumbuhan sel kanker, seperti kanker payudara, namun menunjukkan sifat toksik terhadap kultur sel punca.^[21]

Defisiensi COX dapat mengakibatkan sindrom Leigh, SCO2 (hypertrophic cardiomyopathy), SCO1 (gagal hati, koma ketoasidosis), and COX10 (encephalopathy, tubulopathy).^[22]

Rujukan

1. (Inggris) "Biotransformation of curcumin through reduction and glucuronidation in mice". Institute of Biochemistry, College of Medicine, National Taiwan University; Pan MH, Huang TM, Lin JK. Diakses tanggal 2011-08-23. 
2. (Inggris) "Curcumin Exerts Neuroprotective Effects Against Homocysteine Intracerebroventricular Injection-Induced Cognitive Impairment and Oxidative Stress in Rat Brain". Neuroscience Research Center; Ataie A, Sabetkasaei M, Haghparast A, Moghaddam AH, Ataee R, Moghaddam SN. Diakses tanggal 2010-06-30. 
3. (Inggris) "Curcumin attenuates vascular inflammation and cerebral vasospasm after subarachnoid hemorrhage in mice". Department of Neurosurgery, Medical College of Georgia; Wakade C, King MD, Laird MD, Alleyne CH Jr, Dhandapani KM. Diakses tanggal 2010-06-30. 
4. (Inggris) "Dietary curcumin supplementation counteracts reduction in levels of molecules involved in energy homeostasis after brain trauma". Department of Physiological Science, UCLA; Sharma S, Zhuang Y, Ying Z, Wu A, Gomez-Pinilla F. Diakses tanggal 2010-07-04. 
5. (Inggris) "Curcumin inhibits formation of amyloid beta oligomers and fibrils, binds plaques, and reduces amyloid in vivo". Department of Medicine, UCLA; Curcumin inhibits formation of amyloid beta oligomers and fibrils, binds plaques, and reduces amyloid in vivo. Diakses tanggal 2010-06-27. 
6. (Inggris) "Inhibitory effect of curcuminoids on acetylcholinesterase activity and attenuation of scopolamine-induced amnesia may explain medicinal use of turmeric in Alzheimer's disease". Department of Biological and Biomedical Sciences, The Aga Khan University Medical College; Ahmed T, Gilani AH. Diakses tanggal 2010-06-27. 
7. (Inggris) "Optimized turmeric extracts have potent anti-amyloidogenic effects". Center for Excellence in Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine; Shytle RD, Bickford PC, Rezai-zadeh K, Hou L, Zeng J, Tan J, Sanberg PR, Sanberg CD, Roschek B Jr, Fink RC, Alberte RS. Diakses tanggal 2010-06-27. 
8. (Inggris) "Immune defects in Alzheimer's disease: new medications development". Human BioMolecular Research Institute, San Diego; Cashman JR, Ghirmai S, Abel KJ, Fiala M. Diakses tanggal 2010-06-27. 
9. (Inggris) "Potential response to curcumin in infantile hemangioendothelioma of the liver". University of Oklahoma Health Sciences Center; Hassell LA, Roanh LD. Diakses tanggal 2010-06-30. 
10. (Inggris) "[Anticancer activities of curcumin on human hepatocarcinoma cell line Sk-hep-1]". Guangdong Pharmaceutical University; Wang W, Zhang B, Chen H, Zhang L. Diakses tanggal 2010-06-30. 
11. (Inggris) "Curcumin inhibits hepatitis B virus via down-regulation of the metabolic coactivator PGC-1alpha". The Institute of Gastroenterology and Liver Disease; Rechtman MM, Har-Noy O, Bar-Yishay I, Fishman S, Adamovich Y, Shaul Y, Halpern Z, Shlomai A. Diakses tanggal 2010-06-30. 
12. (Inggris) "Novel role of curcumin in the prevention of cytokine-induced islet death in vitro and diabetogenesis in vivo". Tissue Engineering and Banking Laboratory, National Centre for Cell Science; Kanitkar M, Gokhale K, Galande S, Bhonde RR. Diakses tanggal 2010-06-30. 
13. (Inggris) "Induction of antioxidant enzymes by curcumin and its analogues in human islets: implications in transplantation". Diabetes Institute for Immunology and Transplantation, University of Minnesota; Balamurugan AN, Akhov L, Selvaraj G, Pugazhenthi S. Diakses tanggal 2010-06-30. 
14. (Inggris) "[The study of insulin resistance and leptin resistance on the model of simplicity obesity rats by curcumin]". Department of Public Health, Xi'an Jiaotong University School of Medicine; Yu Y, Hu SK, Yan H. Diakses tanggal 2010-06-30. 
15. Giannessi, Francesco; Giambelluca, Maria Anita; Grasso, Lucia; Scavuzzo, Maria Concetta; Ruffoli, Riccardo (2008-11). "Curcumin protects Leydig cells of mice from damage induced by chronic alcohol administration". Medical Science Monitor: International Medical Journal of Experimental and Clinical Research. 14 (11): BR237–242. ISSN 1643-3750. PMID 18971866.  Periksa nilai tanggal di: |date= (bantuan)
16. Gonzales, Amanda M.; Orlando, Robert A. (2008-06-12). "Curcumin and resveratrol inhibit nuclear factor-kappaB-mediated cytokine expression in adipocytes". Nutrition & Metabolism. 5: 17. doi:10.1186/1743-7075-5-17. ISSN 1743-7075. PMC 2441623 . PMID 18549505. 
17. (Inggris) "Role of pro-oxidants and antioxidants in the anti-inflammatory and apoptotic effects of curcumin (diferuloylmethane)". Cytokine Research Laboratory, Department of Experimental Therapeutics, Box 143, The University of Texas M. D. Anderson Cancer Center; Sandur SK, Ichikawa H, Pandey MK, Kunnumakkara AB, Sung B, Sethi G, Aggarwal BB. Diakses tanggal 2010-07-04. 
18. (Inggris) "COX-2 and PGE2 signaling is essential for the regulation of IDO expression by curcumin in murine bone marrow-derived dendritic cells". Department of Microbiology and Immunology and National Research Laboratory of Dendritic Cell Differentiation & Regulation, School of Medicine, Pusan National University; Jung ID, Jeong YI, Lee CM, Noh KT, Jeong SK, Chun SH, Choi OH, Park WS, Han J, Shin YK, Kim HW, Yun CH, Park YM. Diakses tanggal 2010-07-04. 
19. (Inggris) "Curcumin inhibits VEGF-mediated angiogenesis in human intestinal microvascular endothelial cells through COX-2 and MAPK inhibition". Department of Surgery, Medical College of Wisconsin; Binion DG, Otterson MF, Rafiee P. Diakses tanggal 2010-07-04. 
20. (Inggris) "Comparison of Anti-inflammatory Activities of Six Curcuma Rhizomes: A Possible Curcuminoid-independent Pathway Mediated by Curcuma phaeocaulis Extract". Tohda C, Nakayama N, Hatanaka F, Komatsu K. Diakses tanggal 2010-07-04. 
21. (Inggris) "Control of the growth of human breast cancer cells in culture by manipulation of arachidonate metabolism". Walter Reed Army Institute of Research; Hammamieh R, Sumaida D, Zhang X, Das R, Jett M. Diakses tanggal 2010-07-04. 
22. (Inggris) "A missense mutation of cytochrome oxidase subunit II causes defective assembly and myopathy". University Department of Clinical Neurosciences, Royal Free and University College Medical School; Rahman S, Taanman JW, Cooper JM, Nelson I, Hargreaves I, Meunier B, Hanna MG, García JJ, Capaldi RA, Lake BD, Leonard JV, Schapira AH. Diakses tanggal 2010-07-04. 

Lihat pula

• Lesitin