Molecular and Cellular Biochemistry

, Volume 194, Issue 1–2, pp 41–45 | Cite as

Protection against UVB inactivation (in vitro) of rat lens enzymes by natural antioxidants

  • G. Bhanuprakash Reddy
  • K. Seethraram Bhat


Oxidative damage, through increased production of free radicals, is believed to be involved in UV-induced cataractogenesis (eye lens opacification). The possibility of UVB radiation causing damage to important lenticular enzymes was assessed by irradiating 3 months old rat lenses (in RPMI-1640 medium) at 300 nm (100 μWcm-2) for 24 h, in the absence and presence of ascorbic acid, α-tocopherol acetate and β-carotene. UVB irradiation resulted in decreased activities of hexokinase, glucose-6-phosphate dehydrogenase, aldose reductase, and Na, K- ATPase by 42, 40, 44 and 57% respectively. While endopeptidase activity (229%) and lipid peroxidation (156%) were increased, isocitrate dehydrogenase activity was not altered on irradiation. In the presence of externally added ascorbic acid, tocopherol and β-carotene (separately) to the medium, the changes in enzyme activities (except endopeptidase) and increased lipid peroxidation, due to UVB exposure, were prevented. These results suggest that UVB radiation exerts oxidative damage on lens enzymes and antioxidants were protective against this damage.

UVB-irradiation lens enzymes photoinactivation ascorbic acid α-tocopherol β-carotene 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Spector A: The lens and oxidative stress. In: H. Seis (ed). Oxidative stress-oxidants and antioxidants. Academic Press. London, 1991, 529–558Google Scholar
  2. 2.
    Bhat KS: Nutrition and cataract. NFI Bullet 14: 1–3, 1993Google Scholar
  3. 3.
    Verma SD, Devamanoharan PS, Morris SM: Prevention of cataracts by nutritional and metabolic antioxidants. CRC Crit Rev Food Sci Nutr 35: 111–129, 1995Google Scholar
  4. 4.
    Balasubramanian D, Bhat KS, Rao GN: Factors in the prevalence of cataract in India-Analysis of the recent Indo-US study of age-related cataracts. Curr Sci 59: 498–505, 1990Google Scholar
  5. 5.
    Thylefors B, Negrel AD, Parajasegaram R, Dadzie KY: Global data on blindness. WHO Bullet 73: 115–121, 1995Google Scholar
  6. 6.
    Andley UP: Photodamage to the eye. Photochem Photobiol 46: 1057–1066, 1987PubMedGoogle Scholar
  7. 7.
    Goosey JD, Zigler JS, Kinoshita JH: Crosslinking of lens crystallins in a photodynamic system-A process mediated by singlet oxygen. Science 208: 1278–1280, 1980PubMedGoogle Scholar
  8. 8.
    Jedziniak J, Arrendondo M, Andley UP: Oxidative damage to human lens enzymes. Curr Eye Res 6: 345–350, 1987PubMedGoogle Scholar
  9. 9.
    Bhuyan KC, Bhuyan DK, Podos SM: Evidence for increased lipid peroxidation in cataracts. IRCS Med Sci 9: 126–127, 1981Google Scholar
  10. 10.
    Kleiman NJ, Spector A: DNA single strand breaks in human epithelial cells from patients with cataract. Curr Eye Res 12: 423–431, 1993PubMedGoogle Scholar
  11. 11.
    Bhat KS: Scavengers of peroxide and related oxidants in human brunescent cataracts. In: S.K. Gupta (ed). Ocular pharmacology-recent advances. IOPS. New Delhi, 1991, 32–38Google Scholar
  12. 12.
    Taylor HR, West SK, Rosenthal FS, Munoz B, Newland HS, Abbey H, Emmett EA: Effect of ultraviolet radiation on cataract formation. New Engl J Med 319: 1429–1433, 1988PubMedGoogle Scholar
  13. 13.
    van Kuijk FJGM: Effect of ultraviolet light on the eye. Role of protective glasses. Environ Health Perspect 96: 177–184, 1991Google Scholar
  14. 14.
    Andley UP, Clark BA: Generation of oxidants in the near-UV photooxidation of human lens α-crystallin. Invest Ophthalmol Vis Sci 30: 706–713, 1989PubMedGoogle Scholar
  15. 15.
    Borkman RF: Cataracts and photochemical reactions in the lens. In: Human cataract formation. Pitman, London, 1984, 88–109Google Scholar
  16. 16.
    Krishna CM, Uppuluri S, Riesz P, Zigler JS, Balasubramanian D: A study of the photodynamic efficiencies of some eye lens constituents. Photochem Photobiol 54: 51–58, 1991PubMedGoogle Scholar
  17. 17.
    Reddy GB, Bhat KS: UVB irradiation alters activities and kinetic properties of the enzymes of energy metabolism in rat lens during aging. J Photochem Photobiol B Biol 42: 40–46, 1998.Google Scholar
  18. 18.
    Reddy GB, Bhat KS: Synergistic effect of UVB-radiation and age on HMPS enzymes in rat lens homogenate. J Photochem Photobiol B Biol 43: 56–60, 1998Google Scholar
  19. 19.
    Reddy GB: Alterations in rat lens metabolism on UVB irradiation in vitro. Ph.D. thesis. Osmania University, Hyderabad, 1996Google Scholar
  20. 20.
    Harding JJ, Crabbe MJC: The lens: development, proteins, metabolism and cataract. In: H Davson (ed). The Eye IB. Academic Press, London, 1984, 207–492Google Scholar
  21. 21.
    Cheng HM, Chylack LT: Lens metabolism. In: H Maisel (ed). The ocular lens structure. function and pathology. Marcel Dekker Inc. New York, 1985, 223–264Google Scholar
  22. 22.
    Beutler E: Red cell metabolism. A manual of biochemical methods. Grune & Stratton, New York, 1975Google Scholar
  23. 23.
    Selvaraj RJ, Bhat KS: Phagocytosis and leucocyte enzymes in protein-calorie malnutrition. Biochem J 127: 255–259, 1972PubMedGoogle Scholar
  24. 24.
    Lai JCK, Clark JB: Preparation and properties of mitochondira derived from synaptosomes. Biochem J 154: 423–432, 1976PubMedGoogle Scholar
  25. 25.
    Hayman S, Kinoshita JH: Isolation and properties of lens aldose reductase. J Biol Chem 240: 877–882, 1965PubMedGoogle Scholar
  26. 26.
    Kobayashi S, Roy D, Spector A: Sodium/potassium ATPase in normal and cataractous human lenses. Curr Eye Res 2: 327–334, 1983Google Scholar
  27. 27.
    Tse SS, Orteworth BJ: Inactivation of the bovine lens trypsin inhibitor by ultraviolet radiation. Exp Eye Res 31: 313–325, 1980PubMedGoogle Scholar
  28. 28.
    Babu V, Misra RB, Joshi PC: Ultaviolet-B effects on ocular tissues. Biochem Biophys Res Commun 210: 417–423, 1995PubMedGoogle Scholar
  29. 29.
    Zigman S: Photobiology of the lens. In: H Maisel (ed). The ocular lens-structure, function and pathology. Marcel Dekker Inc, New York, 1985: 301–347Google Scholar
  30. 30.
    Grossweiner LI: Photochemical inactivation of enzymes. Curr Topics Radiat Res Q11: 141–199, 1976Google Scholar
  31. 31.
    Milton KP, Trevithick JR: Chromatography-electrochemical detection of antioxidants in vertebrate lens: Glutathione tocopherol and ascorbate. In: L. Packer (ed). Methods Enzymol 233. Academic Press, London, 1994, 523–539Google Scholar
  32. 32.
    Machlin LJ, Bendich A: Free radical tissue damage: Protective role of antioxidant nutrients. FASEB J 1: 441–445, 1987PubMedGoogle Scholar
  33. 33.
    Delaye M, Tardieu A: Short range order of crystallin proteins account for eye lens transparency. Nature 302: 415–417, 1983PubMedGoogle Scholar
  34. 34.
    Hockwin O, Ohrloff C: Enzymes in normal, aging and cataractous lenses. In: H. Bloemendal (ed). Molecular and cellular biology of the eye lens. John Wiley & Sons, New York, 1981: 367–413Google Scholar
  35. 35.
    Ohrloff C: Age changes of enzyme proteins in crystalline lens. Interdiscipl Topic Gerontol 12: 158–179, 1978Google Scholar
  36. 36.
    Dovrat A, Ding LL, Horwitz J: Enzyme activities and crystallin profiles of clear and cataractous lenses of RCS rat. Exp Eye Res 57: 217–224, 1993PubMedGoogle Scholar
  37. 37.
    Dovrat A, Horwitz J, Sivak JG, Weinreb O, Scharf J, Silberman M: DL-propanol inhibits lens hexokinase activity and affects lens optics. Exp Eye Res 57: 747–752, 1993PubMedGoogle Scholar
  38. 38.
    Blondin J, Baragi V, Schwartz E, Sadowski JA, Taylor A: Delay of UV-induced eye lens protein damage in guinea pigs by dietary ascorbate. J Free Rad Biol Med 2: 275–281, 1986Google Scholar
  39. 39.
    Zigler JS, Jernigan HM, Perlimutter NS, Kinoshita JH: Photodynamic crosslinking of polypeptides in intact rat lens. Exp Eye Res 35: 239–249, 1982PubMedGoogle Scholar
  40. 40.
    Varma SD, Kumar S, Richards RD: Light-induced damage to ocular lens cation pump: Prevention by vitamin C. Proc Natl Acad Sci (USA) 76: 3504–3506, 1979Google Scholar
  41. 41.
    Tung WH, Chylack LT, Andley UP: Lens hexokinase deactivation by near-UV radiation. Curr Eye Res 7: 257–263, 1988PubMedGoogle Scholar
  42. 42.
    Zigman S, Rafferty NS, Soudi S: Natural antioxidants reduce near-UV induced opacification and filamentous actin damage in Dogfish (Mustellus canis) lenses. Biol Bullet 183: 372–373, 1992Google Scholar
  43. 43.
    Fryer MJ: Photoprotective effects of Vitamin E. Photochem Photobiol 58: 304–312, 1994Google Scholar
  44. 44.
    Krinsky NI: Antioxidant functions of carotenoids. Free Rad Biol Med 7: 617–635, 1989PubMedGoogle Scholar
  45. 45.
    Taylor A, Jacques PF, Epstein EM: Relations among aging, antioxidant status and cataract. Am J Clin Nutr 62: 1439S–1447S, 1995PubMedGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • G. Bhanuprakash Reddy
    • 1
  • K. Seethraram Bhat
    • 1
  1. 1.Ocular Biochemistry Division, National Institute of NutritionHyderabadIndia

Personalised recommendations