Article

Effect of Conduritol A, a Polyol from Gymnema sylvestre, on the Development of Diabetic Cataracts in Streptozotocin-treated Rats and on Aldose Reductase

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Abstract

Streptozotocin-diabetic rats were maintained on a stock diet for 16 weeks and some were given conduritol A (10 mg/kg/day). The administration of conduritol A, having a hypoglycemic effect, markedly prevented the diabetic rats from getting cataracts. In practice, conduritol A inhibited aldose reductase (EC 1.1.1.21) that is capable of catalyzing the conversion of aldoses to sugar alcohols in the polyol pathway. In an in vitro assay, lens aldose reductase was most effectively inhibited by conduritol A when α,β-d-glucose was used as a substrate. Some enzymes from the rats were not inhibited by conduritol A. Neither an intraperitoneal injection nor oral dosage of conduritol A caused acute toxicity in the rats. These findings suggest that the inhibition of lens aldose reductase by conduritol A may be responsible for its cataract-suppressing effect.

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... The ethanol extract of Radix Purerariae inhibits glycosylation of rat lens protein (Hirakura et al., 1989) 7-(6-O-malonyl-b-D-glucopyranosyloxy)-3-(4-hydroxyphenyl)-4H-1benzopyran-4-one Discovery of a new key chemical constituent proven to be useful in DR by inhibiting aldose reductase (Duan et al., 2000) Gymnema sylvestre A polyol, conduritol A Beneficial effect on cataract by inhibiting lens aldose reductase (Miyatake et al., 1994) Astragalis radix Astragalosides Potentially useful for the prevention of clinical diabetic complications such as diabetic retinopathy by inhibiting AGE product (Motomura et al., 2009) Hachimi-Jio-gan (Trhmannia Eight Formula) ...
... Not known Controls the balance of sodium, potassium and calcium ions for maintenance of lens transparency. This finding may lead the possibility of prophylactic use in eye diseases such as diabetic cataract (Kamei et al., 1987) Trigonella foenum graecum (Fenugreek) Saponins, Flavanoids, 4-hydroxyisoleucine Beneficial effect for abnormal accumulation of sorbitol and fructose in the diabetic lens Restore disintegration of the inner nuclear layer cells with reduction in rough endoplasmic reticulum and swelling of mitochondria in the diabetic retina Cataract-suppressing effect by inhibiting lens aldose reductase (Miyatake et al., 1994) (Preet et al., 2006) Vaccinium myrtillus (billbery) ...
... A polyol, conduritol A from Gymnema sylvestre may be responsible for the cataract-suppressing effect by inhibiting lens aldose reductase (Miyatake et al., 1994). ...
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