Histomorphological and Histochemical Alterations Following Short-term Inhalation Exposure to Sulfur Mustard on Visceral Organs of Mice

Toxic effects of inhaled sulfur mustard (SM) on the histology of visceral organs was investigaed by exposing mice to 84. 6mg/m3 for 1h duration, using controlled single exposure conditions. A progressive fall in body weight from third day onwards was noticed. Light microscopic examination of the pulmonary tissue of these animals at 6 h post exposure revealed that the tracheobronchial epithelium remained intact, but was infiltrated by inflammatory cells. By 24 h post exposure, the mucosecretory cells were destroyed. The indanunatory reaction was maximum at 48 h. By 7th day post exposure there was swelling and vacuolation of lung parenchymal cells and thrombi formation. In addition SM caused congestion and hemorrhage at alveolar level. SM also caused granulovacuolar degeneration with perinuclear clumping of the cytopasm of hepatocytes and renal parenchymal cells. Renallesions were chazacterized by congestion and hemorrhage. Among visceral tissues, maximum atrophywas observed in spleen. Distribution of lesions increased with post exposure period. The maximum lesions were observed at 7th day post-exposure.

Sulphur Mustard Induced Oxidative Stress and Its Prevention by Sodium 2, 3-Dimercapto Propane Sulphonic Acid (DMPS) in Mice

Sulphur mustard [bis(2 chloro ethyl) sulfide] (SM), a bifunctional alkylating agent has been frequently used as a chemical warfare agent. In the present study, the effects of sodium 2 3 dimercaptopropane sulphonic acid (DMPS) on some biochemical and histological parameters in mice, exposed to 1/4LC 50 concentration of SM vapor (10.5 mg/m\+3) were examined over a period of seven days. Exposure of SM resulted in a significant loss of blood, hepatic and pulmonary glutathione (GSH) and an elevation of hepatic and pulmonary oxidized glutathione (GSSG). These biochemical changes were accompanied by a number of histopathological alterations. The most prominent was congestion and degeneration in viscera and obliteration of chromatin material. These biochemical and histopathological changes were less marked in animals pre administered with DMPS followed by DMPS exposure indicating some protective value of the thiol (DMPS) against SM induced oxidative injury in mice.

Toxicity Evaluation of in vitro Cultures of Freshwater Cyanobacterium Microcystis aeruginosa:Ⅰ.Hepatotoxic and Histopathological Effects in Rats

Laboratory cultures of freshwater cyanobacterium (blue-green alga) Microcystis aeruginosa PCC 7806 was cvaluated for its hepatotoxic effects in rats. The lyophilized cell extract injected intraperitoneally at 1 and 2 LD50 (15.8 and 31.6 mg/kg, respectively) produced significant increase in liver-specific enzymes viz. plasma alkaline phosphatase,γ-glutamyl transferase, lactate dehydrogenase with a concomitant decrease in hepatic glutamic pyruvic transaminase. A corresponding increase in liver body weight index and histopathological changes in liver (degeneration of hepatocytes, congestion and hemorrhage etc.) are indicative of a dose and time dependent hepatotoxic nature of the algal extract

Acute Inhalation Toxicity Study of 2-Fluoroaceta mide in Rats

One of the most potent rodenticides is 2_fluoroacetamide (2_FA). Toxicity of this chemical is well documented. However, its inhalation toxicity data is not available in the literature. Hence, \{acute\} inhalation toxicity study was carried out by exposing male and female rats to aerosols of 2_FA at different concentrations for 4 h in a dynamically operated whole body inhalation exposure chamber. During and after the inhalation exposure the rats were less active, and showed mild tremors and convulsions. At higher concentrations the rats died after 2_3 days. The estimated 4_h LC 50 for male and female rats was 136.6 and 144.5 mg·m -3 respectively. Exposure to 0.7 LC 50 for 4 h duration showed an increase in the liver weight of male and female rats 7 days after exposure. Various haematological and biochemical variables determined were within the normal limits. However, histological findings showed injured lung as indicated by desquamation and necrosis of the epithelium of the respiratory tract. Marked hypertrophy of hepatocytes displaying strong acidophilic granulated cytoplasm was observed. Focal dilatation of renal proximal tubules in kidney with cytoplasmic vacuolation, and irregularly placed pyknotic nuclei were seen. The present study shows that 2_FA is a highly toxic chemical through the inhalation route based on the LC 50 value. Consequently necessary precautions should be taken during its handling.

Influence of Combined Therapeutic Potential of Meso 2, 3-dimercaptosuccinic Acid and Calcium Disodium Edetate on Lead-induced Testicular Alterations in Rats

The therapeutic efficacy of a combinaion of meso 2,3-dimeroaptosuccinic acid (DMSA) and calcium disodium EDTA in protecting testicular disorders in chronic lead intoxication was investigated. The results indicate that two five-days courses of the combined therapy produced a more effective recovery in the lead induced biochemical and histopahological disorders compared to conventional single 5 days therapy. No adverse effect of the chelators, when administered individually or in combination, was noticed in the testes of control (without lead exposure) animals.

Subacute (90 Days) Oral Toxicity Studies of Kombucha Tea

Kombucha tea (KT) is a popular health beverage and is used as an alternative therapy. KT is prepared by placing the kombucha culture in solution of tea and sugar and allowing to ferment. The inoculum is a fungus consisting of symbiotic colony of yeast and bacteria. KT is consumed in several countries and is believed to have prophylactic and therapeutic benefits in a wide variety of ailments, viz., intestinal disorders, arthritis, ageing and stimulation of immunological system. Though KT is used in several parts of the world its beneficial effects and adverse effects have not been scientifically evaluated. Since there are no animal toxicological data on KT, subacute oral toxicity study was carried out. Five groups of rats were maintained: (a) control group given tap water orally, (b) KT given 2 ml/kg orally, (c) plain tea (PT) given 2 ml/kg orally, (d) KT given in drinking water, 1% (v/v) and (e) PT given in drinking water, 1% (v/v). The rats were given this treatment daily for a period of 90 days. Weekly records of weight, feed intake, water intake and general behaviour were monitored. There was no significant difference in the growth of the animals as evidenced by the progressive body weight change. The organ to body weight ratio and histological evaluation did not show any toxic signs. The haematological and biochemical variables were within the clinical limits. The study indicates that rats fed KT for 90 days showed no toxic effects.

Effects of Some Thiol Chelators on Enzymatic Activities in Blood, Liver and Kidneys ofAcute Arsenic (Ⅲ) Exposed Mice

The effects of meso 2, 3-dimercaptosuccinic acid (DMSA), sodium 2, 3 dimercaptopropane 1-sulfonate (DMPS) and S-adenosyl L-methionine (SAM) on the enzymatic activities of mice were studied. The mice were given intraperitoneal (i. p. ) injections of these chelating agents (1 mmol/kg) and 3 h later the activity of 8-aminolevulinic acid dehydratase (ALAD) in the blood, and aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyltranspeptidase (γ-GT), alkaline phosphatase (ALP) in the liver and kidney were determined. The activity of blood ALAD was significantly increased by the administration of DMSA and SAM while DMPS had only a moderate effect. The activities of other hepatic enzymes changed little when the mice were treated with these chelating agents, except for a significant reduction in hepatic ALP activlty following DMPS administration. Arsenic (Ⅲ) administration markedly increased the activities of ALT and ALP in the liver and kidneys. The changes in the enzymatic activities by treatment with arsenic were prevented by injection of DMSA,DMPS and SAM, DMSA being the most effective. These results indicate that DMSA, DMPS and SAM were not toxic to the liver or kidneys of mice and that treatment with DMSA is more effective than DMPS or SAM in protecting mice from acute hepatic or renal toxicity caused by arsenic.