oxalates and betulin

Naturally occurring pentacyclic triterpenes of plant origin have been identified as possessing a wide range of pharmacological effects. Lupeol (Lupa-21,20(29) dien, 3beta-ol) has been found to be efficient in reducing the risk of stone formation in animals by way of preventing crystal-induced tissue damage and dilution of urinary stone-forming constituents. In the present study, two structurally related triterpenes, lupeol and betulin (Lupa-20(29)ene-3,28 diol) were assessed for their antilithiatic effect. Foreign body implantation method followed by supplementation of ammonium oxalate was adapted to induce stone formation in the bladder. This led to elevated lipid peroxidation and depleted antioxidant status in the renal tissues. Both the triterpenes were equally efficient in minimizing crystal-induced renal peroxidative changes measured in terms of malondialdehyde and subsequent tissue damage. The antioxidant status, comprising of the enzymatic and non-enzymatic components, was found to be significantly depleted in the kidney and bladder of stone-forming animals. Both lupeol and betulin were comparable in their ability to restore the thiol status and the antioxidant enzymes like superoxide dismutase, catalase and glutathione peroxidase. The mechanism by which the two compounds render protection against oxalate-induced toxic manifestations and free radical production may involve the inhibition of calcium oxalate crystal aggregation and enhancement of the body defence systems. 2000 Academic Press.

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Catalase; Crystallization; Free Radicals; Glutathione; Glutathione Transferase; In Vitro Techniques; Lipid Peroxidation; Malondialdehyde; Oxalates; Pentacyclic Triterpenes; Plants, Medicinal; Rats; Thiobarbituric Acid Reactive Substances; Triterpenes; Urinary Bladder; Urinary Calculi

Investigations were carried out to evaluate the effect of two, structurally related, triterpenes-betulin and lupeol-on the membrane peroxidation and antioxidant systems in red blood cells, during pyridoxine-deficient condition in rats. Increased lipid peroxidation levels in the absence and presence of ferrous sulphate, an inducer of lipid peroxidation, indicated peroxidative damage to the red-cell membrane. Na(+), K(+)-ATPase activity was decreased while that of other ion-specific ATPases were increased in the red cells of pyridoxine-deficient rats. Antioxidants, such as reduced glutathione, glutathione peroxidase, catalase, glutathione reductase and glutathione S-transferase were decreased, while superoxide dismutase alone was increased in the pyridoxine-deficient rat red blood cells. The red-cell osmotic fragility was found to be reduced. Treatment with the triterpenes proved effective in restoring the normal condition.

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Erythrocytes; Hyperoxaluria; Lipid Peroxidation; Male; Oxalates; Pentacyclic Triterpenes; Pyridoxine; Rats; Rats, Wistar; Triterpenes