Model of vitamin and mineral deficiency for toxicological research: Apoptosis activity under conditions of CCL4 intoxication

Detrimental effects of 6 months exposure to very low doses of a mixture of six pesticides associated with chronic vitamin deficiency on rats

This study aimed to evaluate the long-term low-dose effects of exposure to a mixture of 6 pesticide active substances (diquat, imazamox, imazethapyr, tepraloxydin, bentazone, acifluorfen) and to elucidate if chronic vitamin deficiency can influence their toxicity. Two hundred Wistar rats were divided in 4 groups: a vitamin-sufficiency control group, a vitamin-deficiency control group, a vitamin sufficiency test group and a vitamin-deficiency test group. The test groups were treated with the aforementioned pesticides at doses 100 times lower than the corresponding NOAEL. After 6 months, ten rats from each group were sacrificed and a complete evaluation of blood and urine biochemistry, biomarkers of oxidative stress, xenobiotic detoxification enzymes and lysosomal enzymes and organ histopathology was performed. The pesticides mixture and vitamin deficiency determined an increase in alkaline phosphatase levels and urinary calcium levels, abnormal serum lipid profile, and a decrease of total blood proteins levels, red blood cells, haematocrit and haemoglobin. The combination of the two stressors up-regulated CYP1A1, CYP1A2, CYP2B1 and GST levels. This study provides a new proof for the need to move forward from single chemical testing to a more complex approach to account for the multitude of stressors that can challenge the setting of real safety levels.

The Use of the Adaptation Potential Reduction Model for Reproductive Toxicity Research In Vivo

The modeling of adaptation potential decrease in rats due to modification of the diet's vitamin–mineral composition allows to increase animals' sensitivity to toxic load in reprotoxicological experiments. The threshold values of vitamins B1, B2, B3, and B6 and mineral substances Fe³⁺ and Mg²⁺ in the diet, which lead to a considerable reduction of laboratory animals' adaptation potential, have been determined as 19% (from the basic level in the diet) for males and 18% for females. The efficiency of this model has been confirmed in a reprotoxicological experiment with glyphosate as a toxic factor: the action of the toxic factor against the background of reduced availability of B vitamins and salts Fe³⁺ and Mg²⁺ led to significant changes in such indicators of reproductive function as mating efficiency, postimplantation loss, and the total number of alive pups, while the toxic effect of glyphosate was not so pronounced against the normal level of essential substances. The obtained results prove that this adaptation potential reduction model can be recommended for the research of the low-toxicity objects reproductive toxicity in rats and for the safety assessment of novel food, in particular.

Toxicological evaluation of Sargassum Wightii greville derived fucoidan in wistar rats: Haematological, biochemical and histopathological evidences

Objective

The present study aimed to investigate the acute and subacute toxicity profile of fucoidan obtained from Sargassum wightii Greville, a brown marine algae in order to assess its safety.

Methods

Fucoidan was isolated from Sargassum wightii Greviile and subjected to FTIR analysis to confirm the functional groups. In acute toxicity study, a single dose of fucoidan (2000 mg/kg) was orally administered to three female rats as per OECD guideline 423. OECD guidelines 407 was adopted for subacute toxicity study. Fucoidan was orally administered to male and female rats at doses of 100, 200 and 400 mg/kg. Hematological, biochemical and histopathological analyses were carried out.

Results

FTIR analysis confirmed the presence of major functional groups. The animals did not show any remarkable toxic signs or mortality in acute toxicity study at single oral administration of fucoidan at the dose of 2000 mg/kg bodyweight. In subacute toxicity, no statistically significant difference in body weight, relative weight of vital organs, food and water intake compared to the control group was observed. Serum glucose and cholesterol showed a statistically significant reduction at all the doses when compared to normal control and the reduction was in a dose dependent manner. There were no other changes observed in biochemical or haematological parameters. Histopathological analysis showed no significant toxic signs at organ levels in treated groups when compared to normal control.

Conclusions

Based on the results obtained from acute and subacute toxicity study, fucoidan is considered to be safe in the models tested, which encourages its long term administration for medicinal uses. This study supports the application of fucoidan as a traditional medicine.

Zingiber officinale (Roscoe) mitigates CCl4-induced liver histopathology and biochemical derangements through antioxidant, membrane-stabilizing and tissue-regenerating potentials

The world-wide increasing incidence of liver injury has attracted scientific interest in the exploration of better treatment or adjuvant treatment therapies. This study investigated the effects of methanol extract of Zingiber officinale (Roscoe) rhizome (MEZOR) in a Wistar rat model of carbon tetrachloride (CCl4)-induced liver injury. The study recruited thirty female Wistar rats that received graded doses of MEZOR (determined by its LD50) by oral gavage through an oral canula, for 4 consecutive weeks following 1 week oral administration of CCl4 (0.7 ml/kg in olive oil; 1:1, v/v) while livolin forte® (5.2 mg/kg p.o.) was used as a standard. CCl4 induced deleterious hepatic effects as revealed by the liver function biomarkers (AST, ALT, ALP and total protein), antioxidant indicators (GSH and CAT) and histopathological effects, demonstrated by H & E, Gordon and Sweet, Masson's trichrome, PAS staining techniques as well as by quantificational analyses of the liver micrographs, using image-J. MEZOR treatment was associated with a dose-dependent and significant mitigation of the aforementioned parameters (p < 0.05). This study concluded that MEZOR is a potential therapeutic choice in the adjuvant treatment of subjects with chemically-induced liver injury.