Variation in response to selenium folic acid and vitamin E in arsenic exposed aerobic flora in rats.

Gut bacteria are considered to be body's first line of defense against ingested xenobiotics. Various nutritional and enviormental factors play a role in bacterial growth and multiplication. Bacteria exposed to arsenic in high concentration for a long period showed growth inhibition. Influence of nutrition on bacterial growth and multiplication was observed by giving selenium (0.4 μg/day), vitamin E (1 mg/day), folic acid (200 μg/day) supplementation. Selenium and vitamin E were able to overcome the inhibitory effect of arsenic on gut flora. Selenium not only increased gut bacterial count, it also increased arsenic excretion in stool. Folic acid could not overcome the inhibitory effect of arsenic on gut flora but there was significant decrease in liver arsenic level suggestive of hepatic mehylation of arsenic.

Zinc supplement on tissue arsenic concentration in rats.

To examine the effect of zinc in the removal of accumulated arsenic from different tissues (liver, kidneys, spleen and lungs), rats were initially allowed to drink high concentration (400 microg/kg/day) of arsenic for two months followed by a period of cessation (one month). Administration of zinc (2 mg/kg/day) during the third month in arsenic-treated and non-treated groups were compared. In arsenic-treated rats, the mean (+/- SD) amounts of total arsenic in liver, kidneys, spleen and lungs were 12.3 +/- 0.7, 20.5 +/- 1.0, 31.4 +/- 1.0 and 25.6 +/- 1.1 microg/g of tissues respectively. Administration of zinc to arsenic-treated rats reduced the arsenic concentrations of those tissues to 7.8, 10.7, 23.0 and 14.0 microg/g of tissues. This in vivo study suggests that zinc removes the accumulated arsenic from different tissues significantly (p < 0.001).

Absorption and metabolism of paracetamol in rats drinking high concentration of arsenic.

The effect of chronic intake of arsenic on the plasma concentration of paracetamol in rat was investigated. Rats received saline water with or without arsenic trioxide (10 mg/kg body weight/day) by gastric gavage on every alternate day for 29 days. A single dose of paracetamol (range 10 infinity 40 mg/kg body weight) was administered by gastric gavage to both arsenic-untreated and -treated rats on 30(th) day. Rats were sacrificed after 30 min and the amounts of free paracetamol and its metabolites in plasma were estimated using isocratic reverse-phase High Performance Liquid Chromatography (HPLC). Arsenic toxicity reduced the plasma concentration of paracetamol to 53 - 65% when compared with the rats received no added arsenic. There were maximum 67.4 and 76.9% inhibitions of sulfate and cysteine conjugations of paracetamol respectively. But arsenic had no effect on glucuronide and mercapturate conjugations. Both liver and small intestine showed increased accumulation of arsenic and decreased amount of glutathione in arsenic-treated rats. This study suggests that chronic ingestion of arsenic inhibit the absorption and metabolism of paracetamol.

Effect of hexane extract of spirulina in the removal of arsenic from isolated liver tissues of rat.

The present study was conducted to investigate whether the active compound(s) of spirulina is present in its -- alcohol extract, hexane extract, DCM extract or in their residues. In phase I the accumulation of arsenic in isolated liver tissues of rat at different incubation period (15, 30, 45 minutes) was seen. In phase II arsenic-loaded liver tissues were incubated in presence and absence of alcohol extract, alcohol extraction residues, hexane extract, hexane extraction residues, DCM extract and DCM extraction residues of spirulina respectively. The percentage removal of arsenic from liver tissues by different extracts and residues of spirulina was estimated by Atomic Absorption Spectrophotometer. In phase III arsenic-loaded liver tissues were incubated in presence and absence of different concentration of hexane extract of spirulina and the percentage removal of arsenic from liver tissues was estimated. This study showed that the accumulation of arsenic in isolated liver tissue was time dependent and highest accumulation found was 0.69 microg/g tissues after 45 minutes incubation, which was highly significant. The percentage removal of arsenic from arsenic loaded liver tissues by alcohol extract, alcohol extraction residues, hexane extract, hexane extraction residues, DCM extract, DCM extraction residues were 33.8%,4.4%,83.0%,10.2%,7.3% and 2.9%, respectively. The percentage removal of arsenic by hexane extract at the concentration of 1, 10, 100 microg were 13.2%, 29.4% and 89.7%, respectively. Among the different extracts and residues of spirulina the hexane extract causes highly significant (p<0.001) removal. In conclusion the present study suggests that the active compound(s) of spirulina is present mostly in its hexane extract.