Rats given ammonium metavanadate as their only drinking fluid for up to 90 days showed increased lipid peroxidation and antioxidant enzyme activity in the kidney and structural damage to the renal cortex. Rats that received the same vanadium dose in a common mallow (Malva sylvestris) decoction did not show these changes. Serum creatinine did not change, which the authors read as kidney damage that was not yet severe.
Key numbers
- Dose: ammonium metavanadate at 1.185 mmol/L as the sole beverage, stated to correspond to 60 mg ammonium metavanadate/kg body weight (Materials and methods, p. 6). The abstract instead gives 0.24 mmol/kg body weight (Abstract, p. 1); the two statements are not reconciled in the paper.
- At day 30, kidney lipid peroxidation (TBARS) in vanadium-treated rats was about 117.5% above controls (Results, p. 2; Fig. 1).
- At day 30, kidney superoxide dismutase, catalase and glutathione peroxidase activities rose by 74.5%, 31.5% and 82% in vanadium-treated rats (Results, p. 3; Fig. 4).
- Histology after vanadium: deterioration of renal cortical capsules, smaller Bowman’s space and hypertrophy of interstitial cells (Results, p. 2; Fig. 2).
- No significant difference in serum creatinine between groups (Results, pp. 2 to 3; Fig. 3).
- Mallow decoction (0.2 g dry plant/kg body weight/day) kept these measures at control values; in vitro IC50 values were 0.68 g/L (DPPH) and 1 g/L (superoxide) of dry plant (Tables 1 and 2, p. 2).
Methods (brief)
Eighty male Wistar rats were split into control, vanadium, mallow and mallow-plus-vanadium groups and followed for 15, 30, 60 and 90 days. Kidney TBARS, superoxide dismutase, catalase and glutathione peroxidase were measured by spectrophotometry, serum creatinine with a commercial kit and kidney structure by light microscopy. Means were compared by Student’s t-test (n = 5).
Evidence fitness
Supports statements that oral vanadium (as ammonium metavanadate) can cause oxidative stress and structural kidney changes in rats at high doses. It does not measure vanadium in tissues or food, does not give a dose-response, and does not support human toxicity thresholds or human dietary advice.
Limitations
Single high dose and small groups; dose description is inconsistent between abstract and methods. Vanadium exposure was not confirmed by tissue measurement. Results are reported as figures normalized to controls. The authors declare no competing interests.
Related evidence
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