Chronic study of arsenic trioxide-induced hepatotoxicity in relation to arsenic liver accumulation in rats

This study measured activities of serum enzymes alkaline phosphatase, acid phosphatase, glutamic oxaloacetic transaminase (SGOT), and glutamic pyruvic transaminase (SGPT), markers of liver function in albino rats after continuous ingestion of arsenic trioxide (As₂0₃). For the study, treated animals were given AS₂O₃ (0.2 mg/100 g/day) orally for 180 days. After the completion of treatment, the blood was collected for the estimation of serum biochemical markers. The results obtained were compared with control group. Data showed a significant increase in SGOT and SGPT activity after 60 days of As₂0₃ administration. The level of alkaline phosphatase and acid phosphatase increased significantly after 90 and 120 days, respectively. Since the elevation of these serum enzymes is an indicator of hepatic damage, data indicate that As₂O₃ produces hepatotoxicity. When taken continuously, arsenic was also deposited in liver and blood and affected the enzymatic pathways. Total accumulated arsenic was determined by HG-AAS at 193.7 nm.     

Endosulfan reduces fertilization success and causes abnormal embryo development to zebrafish

Abstract

Reproductive and teratogenic effects of endosulfan were investigated by exposure of mature breeding zebrafish (Danio rerio) to environmentally relevant concentrations of 0.01–1.2?μg L^?1 and monitoring their spawning, fertilization success, and gonad histology. Fertilization success was negatively correlated to duration of exposure at endosulfan concentration of 1.2?μg L^?1. No apparent effect was observed on fish gonads after histological examination. Teratogenic effects were assayed by exposing newly spawned embryos to endosulfan at 1.0–200?μg L^?1 and determining coagulation, tail development, eye formation, and spontaneous movements 24?h after fertilization; pigmentation, heart rate, edema, and mortality after 48?h and hatch time, mortality, and spinal deformations after 144?h. At 50–100?μg L^?1, endosulfan caused impaired tail development and differentiation, and at 10–200?μg L^?1 spinal deformation and increased mortality, depending upon the timing of exposure.     

Carboxymethyl‐β‐cyclodextrin influence on the solubility and toxicity of substituted indole compounds

The solubilization of eight selected substituted indole compounds (SICs) by carboxymethyl‐β‐cyclodextrin (CMCD) in water is reported. The results show that their solubility was well improved in CMCD aqueous solution, and the stoichiometry of inclusion complex of the studied SICs with CMCD was 1: 1. The acute toxicity to Photobacterium phosphoreum of the investigated SICs in CMCD aqueous solutions was also investigated and was compared with that in water. The results show that the toxicity of five studied SICs decreased while the toxicity of the rest three SICs increased in CMCD aqueous solutions, but neither the increase nor the decrease was significant.     

PCB disposition and different biological effects in rats following direct soil exposure vs. PCBs off-gassed from the soil

A comparison of PCB congener profiles and limited biological effects was made between direct exposure to PCB-contaminated soil and vapor phase PCBs from that soil to determine congener patterns useful for identifying exposure sources in humans and wildlife. Weanling female Sprague–Dawley rats were exposed to either control or PCB-contaminated soil (from a landfill in Southern Illinois) for 1 and 2 weeks. The exposures were via direct contact with the soil or via airborne exposure with the rats isolated from the soil by a wire screen. Total PCB of 25% contaminated soil used in the study was 13?500?ppm. No PCBs were detectable in control rats. In direct-exposed rats, total PCB residues in fat pad, ear skin, serum, liver, and inguinal lymph nodes after the 1-week exposure were 6256, 185, 3.2, 149, and 41?ppm, respectively, but decreased to 465, 72, 1.7, 106, and 32.4?ppm after the 2-week exposure. In airborne-exposed rats, total PCB residues were 7.8, 1.6, 0.03, 0.2, and 0.6 in the same manner and slightly increased in fat pad and ear skin to 11.6 and 2.14, respectively. Decreases in both the concentrations and percentages of “episodic” PCBs (those congeners rapidly metabolized) in the fat pad were apparent following the 2-week exposure compared to the 1-week exposure by both routes. Both EROD and BROD activities were significantly increased in the direct-exposed rats, whereas only BROD activity increased in airborne-exposed rats. Serum T ₄ levels were depleted in the direct-exposed rats regardless of time of exposure but were increased insignificantly after 1-week and significantly after 2 weeks in the airborne-exposed rats. No significant changes in serum insulin levels were apparent in any of the treated groups. The results suggested that exposure of animals to PCBs via different routes could result in different PCB profiles, which could cause different biological effects.     

Oxidative stress and changes in locomotor behavior and gill morphology of Gambusia affinis exposed to chromium

Sublethal effects of chromium trioxide on mosquito fish, Gambusia affinis, were carried out for 28 days on day 4, 8, 12, 16, 20, 24, and 28. The sublethal effects of chromium (LC₁₀, 77.62?mg?L^?1) on antioxidant enzymes, thiobarbituric acid reactive substance (TBARS), locomotor behavior, and gill morphology were studied. The antioxidant enzymes like superoxide dismutase (SOD) and catalase were induced throughout the exposure span of 28 days. Percent induction was also increase with the days of exposure. Lipid peroxidation product, malondialdehyde was enhanced in the viscera tissue of chromium-exposed fish. Perturbation of locomotor behavior like decrease in distance travelled (m?min^?1) and in swimming speed (cm?s^?1) was observed in exposed fish. Chromium toxicity caused alterations in gill morphology like hypertrophy and hyperplasia in secondary lamellae followed by detached epithelium with severe necrosis. It can be concluded from the results that Cr intoxication in Gambusia fish, caused induction in antioxidant enzymes and lipid peroxidation, plus changes in gill morphology and locomotor behavior.     

Comparative sensitivities of the tropical cladoceran,Ceriodaphnia rigaudii and the temperate species Daphnia magna to seven toxicants

The toxicities of seven chemicals [cadmium (Cd) chloride, potassium dichromate, sodium dodecyl sulfate, potassium chloride (KCl), Triton X-100, zinc (Zn) chloride and copper (Cu) (II) sulfate] were determined using the tropical freshwater cladoceran, Ceriodaphnia rigaudii and the temperate species, Daphnia magna. Data generated was subsequently used to determine the relative sensitivities of both species, using interspecies correlation to compare the 48?h LC50 values for both species. The 48?h LC50 values for C. rigaudii ranged from 0.002?mg?L^?1 (potassium dichromate) to 21.1?mg?L^?1 (KCl), whereas those for D. magna ranged from 0.3?mg?L^?1 for Cu to 418.87?mg?L^?1 for KCl. The LC50 values for C. rigaudii were significantly less than that for D. magna for six of the compounds tested. The interspecies correlation also showed a low, positive correlation suggesting that the sensitivities of both species were not similar for the compounds tested. The sensitivity factors for C. rigaudii and D. magna ranged between 0.01 and 12.3. These values further suggested that for six of the compounds tested, C. rigaudii appeared to be more sensitive than D. magna. It is therefore possible that because of these differences in relative sensitivities, toxicity data generated with D. magna may not be appropriate for Trinidad.     

Effects of coconut product–caffeine interactions on liver cells in Wistar albino rats

The effects of interactions between coconut products and caffeine on the induction of drug-metabolizing enzyme in Wistar albino rats were studied. Twenty rats were randomly divided into four groups: (Group 1) control received via oral route a placebo (4 mL distilled water). Groups 2–4 were treated for a 14-day period, respectively, with 50 mg caffeine/kg body weight (BW), 50 mg caffeine/kg plus 50 mg coconut water/kg, or 50 mg caffeine/kg plus 50 mg coconut milk/kg in a 4 mL volume via gastric intubation. One day after the after the final exposure, the animals were euthanized by inhalation of an overdose of chloroform. The blood of each rat was collected by cardiac puncture, and the liver of each was harvested and processed to examine several biochemical parameters, including total protein and RNA levels, protein/RNA ratios, and the activities of alanine and aspartate aminotransferases (ALT and AST, respectively). Results showed that while ingestion of coconut milk and coconut water increased the values of protein and protein/RNA ratios, there was a decrease in ALT and AST activities. These effects were opposite to those produced by caffeine alone and may prevent the adverse effects attributed to caffeine.     

Amelioration of fluoride toxicity by vitamins and calcium on reproductive organs of female rat

Normal female rats of Wistar strain (Rattus norvegicus) weighing between 150–200 g were treated with fluoride (Fl) contaminated drinking water (FW, 5.8 ppm), vitamin C (6 mg) and vitamin C (6 mg) + D (6 mg once a week) + calcium (6 mg) for 30 days. Fl water treatment to rats produced reduction in weights of ovaries, uterus, vagina, kidneys, and adrenal glands, circulating levels of estrogen, number of litters, fertility rate, and altered tissue and serum biochemistry compared to control rats. However, cholesterol concentrations of ovaries and adrenals increased significantly. The above altered parameters were restored partially/completely after exogenous feeding with vitamin C and vitamins (C + D) and calcium. The data suggest that Fl-induced adverse effects on reproductive and other organs in female rats, whereas vitamin C, vitamin D and calcium treatment ameliorated Fl toxicity. Therefore, vitamins (C and D) and calcium play an important role in prophylactic treatment of fluorosis.     

An approach for assessing the suitability of Ceriodaphnia rigaudii as an indigenous tropical toxicity test species

Although the selection criteria for toxicity test species are well-documented, they do not provide a clear approach for establishing the suitability of a species for regulatory testing. This study looks at the approach used to determine if Ceriodaphnia rigaudii, an indigenous tropical cladoceran species, may be designated as a suitable freshwater test species for regulatory testing in Trinidad and Tobago. The approach involved species identification, life cycle characterization, salinity tolerance, toxicological responses to standard chemicals, and comparative sensitivity evaluation with an established test species. The results showed that C. rigaudii (0.45 mm) was significantly smaller in size, had a shorter life cycle and matured faster than temperate cladoceran species such as Ceriodaphnia dubia and Daphnia magna (3–6 mm). Ceriodaphnia rigaudii has a life span of about 10–15 days and reached sexual maturity within 2 days, whereas D. magna had a life span of about 40–50 days and attained sexual maturity within 6–10 days. The LC₅₀ values for C. rigaudii were significantly less than D. magna for the six compounds tested. Interspecies correlation also showed a low positive correlation, suggesting that the sensitivities of both species were not similar for the compounds tested. The sensitivity factors of C. rigaudii and D. magna for the toxicants ranged 0.01–12.3, suggesting that C. rigaudii was more sensitive than D. magna. This study was useful in defining a stepwise approach to help establish C. rigaudii as an indigenous tropical toxicity test species in Trinidad.     

Histological and histochemical alterations induced by lead in the liver of the quail Coturnix coturnix

Adult males of the quail Coturnix coturnix were exposed to lead acetate trihydrate in drinking water (0.1, 0.25, 0.5, and 1% for one–six months) to investigate histological and histochemical alterations induced by lead intoxication in the liver. Chronic exposure to subtoxic concentrations of lead produced changes in hepatocytes, portal veins, Kupffer cells, and blood sinusoids. Alterations in hepatocytes mainly involved cytoplasmic vacuolation, necrosis, cytolysis, and glycogen accumulation. Kupffer cell hyperplasia, hemosiderosis, blood sinusoidal dilatation, portal vein congestion, and edema were also observed. No fibrosis or cirrhosis in the liver of any member of the dose groups over the entire period of the study was noted. The findings revealed that chronic exposure to lead produced mild histological and histochemical changes in the liver of the quail Coturnix coturnix.