Effect of the isoflavone genistein against galactose-induced cataracts in rats.
Worldwide, ocular cataracts are a major cause of human blindness. A key goal of cataract-related research is to identify simple, cost-efficient but effective ways to prevent cataract formation or progression. Genistein is a naturally occurring dietary isoflavone with well-documented estrogenic, antioxidant, and protein tyrosine kinase inhibitor activity, which in turn modulates the activity of several enzymes involved in cell signaling and proliferation. Furthermore, many isoflavones have been shown to be potent inhibitors of aldose reductase, which is an important rate-limiting enzyme in the process of cataract induction in the metabolic disease galactosemia. In order to assess the potential for genistein to mitigate cataract formation, we have studied its effects in the animal model of dietary galactose-induced cataracts in adult male rats. Our experimental hypothesis was that dietary genistein would prevent or delay the progression of cataracts induced by high dietary intake of galactose. Our results show that the isoflavone genistein was not able to completely prevent galactose-induced cataract formation, but genistein did delay the progression of cataracts induced by dietary galactose. In addition, we found that dietary galactose decreased concentrations of serum somatostatin, while adding genistein decreased the serum glucose level but increased the serum testosterone level. As an initial inquiry into the mechanisms by which the partial protective effect of genistein could be mediated, we found that genistein increased the expression of connexin (Cx) 43 in the lens but did not affect the expression of soluble guanylyl cyclase (sGC) subunits. This finding suggests that the partial protective effect of genistein on cataract induction appears to be unrelated to sGC but may be mediated by enhanced expression of Cx43 and changed metabolic state.
Huang
Ruihua
R
The College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
Shi
Fangxiong
F
Lei
Tietao
T
Song
Yajun
Y
Hughes
Claude L
CL
Liu
Gentao
G
D000818:Animals; D001786:Blood Glucose; D002386:Cataract / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000517:prevention & control*; D018031:Connexin 43 / Q000096:biosynthesis; D004032:Diet / Q000379:methods; D004195:Disease Models, Animal; D018450:Disease Progression; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D005690:Galactose / Q000008:administration & dosage; D019833:Genistein / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006162:Guanylate Cyclase / Q000096:biosynthesis; D007150:Immunohistochemistry; D007908:Lens, Crystalline / Q000737:chemistry / Q000473:pathology; D008297:Male; D008853:Microscopy; D051381:Rats; D020318:Rats, Long-Evans; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis; D000071756:Soluble Guanylyl Cyclase; D013004:Somatostatin / Q000097:blood; D013739:Testosterone / Q000097:blood
D001786:Blood Glucose; D018031:Connexin 43; D004791:Enzyme Inhibitors; D018160:Receptors, Cytoplasmic and Nuclear; D013739:Testosterone; D013004:Somatostatin; D019833:Genistein; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D005690:Galactose