Exposure to strontium isotopes remains a widespread problem in most industrialized countries. Modern agents purposed for prevention of the radioisotope absorption as well as for therapy of chronic poisoning with these substances generally exert toxic effects causing mineral misbalance. Dietary non-starch polysaccharides were suggested as substances effectively binding bivalent ions. The present study was carried out to estimate strontium binding capacity of low and high esterified pectin compounds and their influence on strontium absorption, distribution, and removal in laboratory rats. Under in vitro conditions, pectin with low degree of esterification was the most effective and bound 2.2 mmol of strontium ions per gram. Administration of low esterified pectin and its calcium salt in rats resulted in significantly reduced amount of strontium accumulated in liver, heart, kidney, and femur. After advance administration of the strontium chloride solution the low esterified pectin and calcium pectate contributed to the removal of the strontium ions from organs and femur in rats. All their effects were more pronounced than those of high esterified pectin. These effects were also proved by 45.7% and 21.0% increased amount of strontium being eliminated with feces of the animals given respectively calcium pectate and low esterified pectin. The results obtained show that the low esterified pectin and calcium pectate may be considered as the perspective dietary components protecting humans from environmental strontium.

In this study, we determined the parameters of sorption of strontium ions by pectins that were isolated from the sea grasses Zostera marina and Phyllospadix iwatensis collected in the Peter the Great Bay of the Sea of Japan. The maximum strontium binding capacity and the coefficient of affinity with respect to strontium ions were significantly higher in sea grass pectins than in commercial pectin. These parameters were correlated with the etherification degree of pectins. The sea grasses studied here can be considered as a promising source of pectins for the binding and removal of strontium radioisotopes from the human body.

The efficacy of an enterosorbent based on low-esterified pectin, activated charcoal, and polyphepan was evaluated in rats with experimental renal failure. Pectin was shown to be most effective. Its use causes increased daily diuresis and lower blood urine and creatinine levels in experimental animals. The findings have led to the conclusion that low-esterified pectin may be used to design drugs for the complex treatment in patients with chronic renal failure.

Efficacy of such oral sorbents as activated charcoal, polyphepan and calcium alginate in rats with mercury induced renal failure was studied. Calcium alginate exerted the most pronounced effects manifested with enlarged daily diuresis, and reduced blood levels of creatinine and urea.

Mercury (II) binding capacity of calcium alginate and oral sorbents was studied in vitro conditions. Calcium alginate was found to rapidly bind mercury ions in the media pH from 4 to 6. Parameters of sorption activity of calcium alginate are 2 points higher than that of drugs such as activated charcoal, microcrystalline cellulose and lignin.

Study of the effects of low-esterified pectin in toxic damage to the liver caused by enteral treatment with lead acetate showed that pectin treatment promoted the decrease in lead content in the liver, reduction of LPO activity, and recovery of parameters of lipid metabolism.

A comparative study of antioxidant activities of low-etherified pectin extracted from the eelgrass Zostera marina and of two antioxidative medicines, mildronat and emoxipin, was carried out using two in vitro methods allowing us to estimate the reducing activities of the compounds (FRAP assay), and their ability to impede iron- and ascorbate-induced oxidation of Tween 80 to malondialdehyde. It was found that zosterin pectin manifested higher reducing activity compared to the medicines. The inhibitory capacity of zosterin was lower than that of mildronat.

In experiments on male white mice we initiated the induction of peroxidation of lipids by lead acetate, tetrachloromethane, sodium nitrite, or SOVOL (a mixture of polychlorinated biphenyls). Then the animals received intragastral injections of pectin isolated from the seagrass Zostera marina , in the form of a 1% gel, at 100 mg/kg for 2 weeks. It has been found that the low etherified pectin normalizes the level of malonic dialdehyde and the activity of glutathione reductase and glutathione peroxidase in the liver.