Biochemical toxicology of argemone oil. I. Effect on hepatic cytochrome P-450 and xenobiotic metabolizing enzymes

The in vivo effect of argemone oil on hepatic xenobiotic metabolizing enzymes was investigated in albino rats following either a single (10 ml kg-1 body wt.) or multiple intraparenteral doses (5 ml kg-1 body wt.) for three days. Animals sacrificed 72 h after a single intraparenteral dose of argemone oil exhibited a significant loss of hepatic cytochrome P-450 (35%) and cytochrome b5 (34%) contents and inhibition of aminopyrine-N-demethylase (APD), aryl hydrocarbon hydroxylase (AHH) and ethoxycoumarin-O-deethylase (ECD) activities (21-39%). Three successive 24-hourly intraparenteral injections of argemone oil followed by sacrificing the animals after 24 h of the last injection, showed a greater degree of inhibition of the content of cytochrome P-450 (58%) and its dependent mixed-function oxidases (35-63%). Also, multiple treatment of argemone oil caused a depletion of endogenous hepatic glutathione (GSH) content (72%) with a concomitant increase in lipid peroxidation (177%) and decrease in glutathione-S-transferase (GST) activity (30%). A significant decrease in relative liver weight (39%) was observed in animals treated with multiple treatment of argemone oil. These results suggest that argemone oil can alter both membrane and cytosolic defences and destabilizes the hepatic cytochrome P-450 dependent mixed-function oxidase system, so that it tips in the direction of autooxidative peroxidation of lipids.     

Clinicoepidemiological,Toxicological, and Safety Evaluation Studies on Argemone Oil

Abstract

Consumption of oil extracted from accidental or deliberate contamination of argemone seed to mustard seed is known to pose a clinical condition popularly referred to as Epidemic Dropsy. Several outbreaks of Epidemic Dropsy have occurred in the past in India as well as in Mauritius, Fiji Island, and South Africa. Clinico-epidemiological manifestations of argemone oil poisoning include vomiting, diarrhea, nausea, swelling of limbs, erythema, pitting edema, breathlessness, etc. In extreme cases, glaucoma and even death due to cardiac arrest have been encountered. The toxicity of argemone oil has been attributed to two of its physiologically active benzophenanthridine alkaloids, sanguinarine and dihydrosanguinarine. Histopathological studies suggest that liver, lungs, kidney, and heart are the target sites for argemone oil intoxication. Studies have shown to elucidate the cocarcinogenic potential of argemone oil that can be correlated with the binding of sanguinarine with a DNA template. Pharmacological response in intestine revealed immediate stimulation of tone and peristaltic movements of the gut in the sanguinarine-treated animals. Argemone oil/Sanguinarine caused a decrease in hepatic glycogen levels which may be due to the activation of glycogenosis leading to an accumulation of pyruvate in the blood of Epidemic Dropsy cases. The increase in pyruvate levels causes uncoupling of oxidative phosphorylation leading to breathlessness, as observed in patients. Sanguinarine has been shown to inhibit Na⁺, K⁺-ATPase activity of different organs such as brain, heart, liver, intestine, and skeletal muscle, which may be due to the interaction with the glycoside receptor site on ATPase enzyme, thereby causing a decrease in the active transport of glucose. Argemone oil/alkaloid showed a Type II binding spectra with hepatic cytochrome P-450 (P-450) protein, thereby causing loss of P-450 content and an impairment of phase I and phase II enzymes. A green fluorescent metabolite of sanguinarine, benzacridine was detected in the milk of grazing animals. The delayed appearance of this metabolite in urine and feces of experimental animals suggests the slow elimination of the alkaloid. Argemone oil enhances hepatic microsomal and mitochondrial lipid peroxidation, indicating that these two organelles are the sites of membrane damage. Furthermore, studies suggest that singlet oxygen and hydroxyl radical are involved in argemone oil toxicity. Several bioantioxidants show protective effect in argemone oil-induced toxicity in experimental animals. The line of treatment in argemone-intoxicated epidemics has so far been only symptomatic, and specific therapeutic measures are still lacking, although it has been suggested that diuretics, bioantioxidants, steroids, vitamins, calcium- and protein-rich diet had some beneficial effects on Epidemic Dropsy cases.     

Biochemical toxicology of argemone alkaloids. III. Effect on lipid peroxidation in different subcellular fractions of the liver

Consumption of edible oils contaminated with Argemone mexicana seed oil causes various toxic manifestations. In this investigation the in vivo effect of argemone oil on NADPH-dependent enzymatic and Fe2+-, Fe2+/ADP- or ascorbic acid-dependent non-enzymatic hepato-subcellular lipid peroxidation was studied. Parenteral administration of argemone oil (5 ml/kg body weight) daily for 3 days produced a significant increase in both non-enzymatic and NADPH-supported enzymatic lipid peroxidation in whole homogenate, mitochondria, and microsomes. Lipid peroxidation aided by various pro-oxidants, namely Fe2+, Fe2+/ADP and ascorbic acid also revealed a significant enhancement in the whole homogenate, mitochondria and microsomes of argemone oil-treated rats. Further, when compared with whole homogenate, the hepatic mitochondria and microsomes of either control or argemone oil-treated rats showed a 4- and 6-fold increase in non-enzymatic, and a 5- and 18-fold increase in NADPH-dependent enzymatic lipid peroxidation, respectively. Similarly, both mitochondrial and microsomal fractions showed a 5- and 7-fold increase in Fe2+-, and a 12- and 15-fold increase in either Fe2+/ADP- or ascorbic acid-aided lipid peroxidation, respectively. These results suggest that the hepatic microsomal as well as the mitochondrial membrane is vulnerable to the peroxidative attack of argemone oil and may be instrumental in leading to the hepatotoxicity symptoms noted in argemone poisoning victims.     

Safety evaluation studies on argemone oil through dietary exposure for 90days in rats.

Epidemic dropsy is a disease caused by the consumption of mustard oil contaminated with argemone oil (AO). During 1998 dropsy in New Delhi, which is so far the largest with more than 3000 victims and over 60 deaths, it was enquired at various scientific and regulatory meetings about the maximum tolerated dose of AO. Hence, the present study was aimed to investigate the safety levels of AO in rats. Animals were given AO in diet at a dose of 0.001%, 0.01%, 0.1%, 0.5% and 1% daily for 90 days and the two control groups received the standard diet with and without 1% mustard oil. A decrease in body weight gain (28-31%) was observed in 0.5% and 1% AO groups; while significant increases in relative lungs and liver weight was noticed in respective doses of 0.01% and 0.1% AO groups as well as in higher dosage animals. Reduction in RBC count and hemoglobin content (p<0.05) was noticed in 0.01% and 0.1% AO exposed animals. This effect was more pronounced in higher AO doses. Serum marker enzymes including alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were found to be significantly elevated in 0.01-1% AO groups. Further, a decrease in albumin/globulin ratio (42-78%) was observed in the serum of 0.01% to higher AO dose groups. The levels of serum triglycerides and VLDL cholesterol were found to be enhanced (p<0.05) in AO treated (0.01-1.0%) animals. Histopathological changes in lung were observed at 0.01% dose of AO while liver, kidney and heart produced changes at 0.1% AO and above doses. None of the parameters were found to be affected in 0.001% AO treated animals. These results suggest that the no observed adverse effect level (NOAEL) dose of AO is 0.001% in rats and considering a factor of 100 for humans for highly toxic compound, the safe limit of 0.00001% (100 ppb or 100 ng AO/g oil) AO can be implicated which shall contain only 0.55% of sanguinarine equivalent to 0.6 ng sanguinarine per gram oil. However, the minimum detectable limit of AO is 5 ppm (equivalent to 5 microg sanguinarine per gram oil) with the present existing HPLC method, thereby suggesting that mustard oil should be absolutely free from AO contamination.     

Toxicity of sodium pentafluorostannite. A new anticariogenic agent. III. 30-Day toxicity study in rats.

For 30 days, groups of 12–19 Wistar rats (divided according to sex) were dosed daily by gavage with distilled water or with 20, 100, or 175 mg/kg sodium pentafluorostannite. On Days 14 and 29, blood was collected from five rats in each group to determine hemoglobin concentration and packed cell volume. On Days 15 and 30, rats were sacrificed, blood collected, and serum urea nitrogen (BUN), direct and total bilirubin, SGOT activity, inorganic phosphorus, calcium and glucose concentrations were determined. A necropsy was performed on each rat, its organs weighed, and sections prepared for microscopic examination. After 15 and 30 days, growth was depressed in a dose-related manner. Serum glucose concentration was also lowered. Microscopic findings in organs were generally unremarkable except for degenerative changes of the proximal tubular epithelium of the kidneys in 15–20% of the animals in the 175-mg/kg groups. Animals that died spontaneously displayed signs suggestive of cardiac failure, including congestion of the liver, spleen, lungs and/or kidneys. In addition, most had moderate to severe renal tubular necrosis.     

Liver lipid peroxidation-related parameters after short-term administration of hexachlorocyclohexane isomers to rats.

Rats treated with diets containing 20 ppm of alpha- or gamma-hexachlorocyclohexane (HCH) for 15 or 30 days showed increased levels of liver cytochrome P-450 followed by increased production of both thiobarbituric acid reactants by liver homogenates and microsomes and superoxide anion production by liver microsomes. In these animals superoxide dismutase (SOD) activity was also increased. In consequence, the ratio between SOD activity and microsomal superoxide radical (O2-.) production showed a slight increase after 15 days of treatment. However, after 30 days, there was a tendency for this ratio to decrease. Other parameters studied were liver glucose-6-phosphate dehydrogenase, glutathione peroxidase, glutathione reductase and catalase (CAT) activities. Among them, only CAT activity showed a 26% and 38% increase after 15 or 30 days of treatment with the alpha-isomer. It is suggested that when lipid peroxidation is involved in the mechanism of toxicity of a xenobiotic, this parameter can be used to determine the no-observed-effect level.     

Antioxidant status of erythrocytes and their response to oxidative challenge in humans with argemone oil poisoning

Oxidative damage of biomolecules and antioxidant status in erythrocytes of humans from an outbreak of argemone oil (AO) poisoning in Kannauj (India) and AO intoxicated experimental animals was investigated. Erythrocytes of the dropsy patients and AO treated rats were found to be more susceptible to 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) induced peroxidative stress. Significant decrease in RBC glutathione (GSH) levels (46, 63%) with concomitant enhancement in oxidized glutathione (172, 154%) levels was noticed in patients and AO intoxicated animals. Further, depletion of glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G-6-PDH) and glutathione-S-transferase (GST) (42-52%) was observed in dropsy patients. Oxidation of erythrocyte membrane lipids and proteins was increased (120-144%) in patients and AO treated animals (112-137%) along with 8-OHdG levels in whole blood (180%) of dropsy patients. A significant reduction in alpha-tocopherol content (68%) was noticed in erythrocytes of dropsy patients and hepatic, plasma and RBCs of AO treated rats (59-70%) thereby indicating the diminished antioxidant potential to scavenge free radicals or the limited transport of alpha-tocopherol from liver to RBCs leading to enhanced oxidation of lipids and proteins in erythrocytes. These studies implicate an important role of erythrocyte degradation in production of anemia and breathlessness in epidemic dropsy.     

Histopathological and biochemical changes in guinea pigs after repeated dermal exposure to benzene hexachloride.

Dermal application of benzene hexachloride in daily doses of 100, 200 and 500 mg/kg for a total period of 30 days caused significant changes in male guinea pigs. The animals exposed to high doses of benzene hexachloride (1,2,3,4,5,6-hexachlorocyclohexane) (BHC) (BHC) died within 5--12 days. There was no mortality in 100 mg/kg/day but significant pathologic and biochemical changes were observed in the vital organs of the experimental animals. Massive congestion and thickened blood vessels were seen in liver of the BHC treated animals in comparison to the normal picture of the controls. Similarly, testicular changes included mild to severe pathologic lesions. There was no change in the epididymis, kidney, spleen, brain and lungs. The changes in the skin were mild and no signs of dermatitis were observed in the BHC painted areas. The activity of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and alkaline phosphatase in liver and serum revealed significant changes from that of the controls. The significance of biochemical changes with the tissue damage of the insecticide exposed animals are discussed.     

Alterations in redox potential of glutathione/glutathione disulfide and cysteine/cysteine disulfide couples in plasma of dropsy patients with argemone oil poisoning

Several incidences of adverse effects on human health have been reported in many countries, due to consumption of edible oil adulterated with argemone oil (AO). The clinical manifestation of the disease is commonly referred to as epidemic dropsy. In the present study, we determined the relationship between redox potentials (E(h)) of glutathione/glutathione disulfide (GSH/GSSG), cysteine/cysteine disulfide (Cys/CySS) couples and non-enzymatic antioxidants such as alpha-tocopherol and ascorbic acid status in plasma of dropsy patients (n=14) from an outbreak of argemone oil poisoning in Lucknow (March, 2005), India. Depleted GSH (55%) and concomitant enhancement (163%) of plasma GSSG content was observed in patients (P<0.05). Furthermore, lower content of Cys (42%) and CySS (25%) was noticed in patients (P<0.05) when compared to control subjects. Eh GSH and Eh Cys values were shifted by +46 mV and +12 mV towards more oxidizing environment in patients (P<0.05). In addition, alpha-tocopherol and ascorbic acid contents were found to be depleted significantly (P<0.05) in plasma of patients (59-58%). The alterations in redox potentials and antioxidants in plasma, which are synthesized in liver, may be responsible for histopathological changes in hepatic tissue of patients showing swelling of hepatocytes, fluid accumulation in spaces of Desci along with mild kupfur cell hyperplasia. Over all the present study shows that redox state of GSH/GSSG and Cys/CySS pools become oxidized which inturn causes depletion of alpha-tocopherol and ascorbic acid, thus providing a strategy to distinguish pro-oxidant and antioxidant events in patients.     

Toxicological study of pyridoxal isonicotinoyl hydrazone: acute and subchronic toxicity.

Pyridoxal isonicotinoyl hydrazone (PIH) is a highly effective iron chelator. Acute toxicity testing was performed in mice and rats of both sexes, with 10 mice or rats/sex/group. The LD50 values of PIH in both species were 5 and 1 g/kg given orally and intraperitoneally, respectively. Microscopic examination of tissues from the highest oral dose (6 g/kg) animals that survived 7 days revealed fatty degeneration in the liver. Subchronic toxicity was tested in rats of both sexes, with 8 males and 8 females/group. PIH doses of 100, 400 and 800 mg/kg were given orally for 90 consecutive days. Water was given to the control group. Hematocrit and blood chemistries were analysed at weeks 3, 6, 10 and 13. There were no changes in hematocrit and BUN. PIH at doses of 800 mg/kg caused a significant increase in serum alkaline phosphatase and transaminase levels at week 13. Microscopic examination showed hepatic degeneration in a dose-related fashion. Vascular congestion of the kidney and spleen was also found. No histopathological changes were detected in sections from the stomach and intestine.     

The effects of alpha-tocopherol on the toxicity, disposition, and metabolism of adriamycin in mice.

Fourteen days after adriamycin treatment, 15 mg/kg ip, there was greater than 50% mortality in CDF₁ mice pretreated with either olive oil or saline ip, but only 5% mortality in animals pretreated with a single dose of α-tocopherol. However, 60 days after adriamycin, mortality was 80±5% in all three groups. A single dose of α-tocopherol alone caused no deaths. Blood concentrations of [¹⁴C]adriamycin-derived radioactivity in mice pretreated with α-tocopherol of olive oil were significantly higher than those of saline controls between 3 and 15 min after injection. At 30 and 60 min blood concentrations of radioactivity did not differ in the three groups. Sixty minutes after adriamycin administration, concentrations of radioactivity in heart, kidney, muscle, and lung were significantly higher in the α-tocopherol and olive oil groups than in the saline controls. No differences in the metabolic profile of adriamycin were found in heart or liver, but renal concentration of adriamycin and several metabolites were higher in both the α-tocopherol and olive oil groups. In general, α-tocopherol pretreatment had only slight effect on the metabolism of adriamycin in vivo. Thus, the time-dependent efficacy of α-tocopherol in ameliorating the lethal toxicity of adriamycin in mice does not appear to result from acute changes in the distribution or metabolism of adriamycin. It appears that the effect of α-tocopherol is to delay rather than prevent the lethal toxicity of adriamycin.     

Increased acetaminophen-induced hepatotoxicity after chronic ethanol consumption in mice

The effect of chronic ethanol consumption on acetaminophen (200, 400, and 600 mg/kg) toxicity was determined by maintaining mice for 10 days on diets consisting of chow and one of the following drinking solutions: 10% ethanol + 10% sucrose, 8% sucrose, or tap water. Toxicity as manifested by mortality, liver enlargement, and liver congestion was greatest in the ethanol-treated group. We suggest that the greater mortality was a result of the increased liver congestion and consequent hypovolemia. Despite the increased levels of cytochrome(s) P-450, covalent binding of [³H]acetaminophen reactive metabolite(s) to liver protein was not higher in ethanol-treated animals. This can be explained by the higher initial glutathione concentration and/or ability to replenish glutathione in the ethanol-treated group. We suggest that the enhancement of acetaminophen toxicity by ethanol is the result of an effect of ethanol on hepatocyte membranes which renders the cells more susceptible to toxic injury.     

Acute and subchronic mammalian toxicity of naphthenic acids from oil sands tailings.

Naphthenic acids are the most significant environmental contaminants resulting from petroleum extraction from oil sands deposits. In this study, a mixture of naphthenic acids isolated from Athabasca oil sands (AOS) tailings pond water was used in acute and subchronic toxicity tests with rodents, in order to assess potential risks posed to terrestrial wildlife. Dosages were chosen to bracket worst-case environmental exposure scenarios. In acute tests, adult female Wistar rats were given single po dosages of naphthenic acids at either 3, 30, or 300 mg per kg body weight (mg/kg), while adult male rats received 300 mg/kg. Food consumption was temporarily suppressed in the high-dose groups of both sexes. Following euthanasia 14 days later, histopathology revealed a significant incidence of pericholangitis in the high-dose group of both sexes, suggesting hepatotoxicity as an acute effect. Other histological lesions included brain hemorrhage in high-dose males, and cardiac periarteriolar necrosis and fibrosis in female rats. In subchronic tests, naphthenic acids were po administered to female Wistar rats at 0.6, 6, or 60 mg/kg, 5 days per week for 90 days. Results again suggested the liver as a potential target organ. The relative liver weight in the high-dose group was 35% higher than in controls. Biochemical analysis revealed elevated blood amylase (30% above controls) and hypocholesterolemia (43% below controls) in high-dose rats. Excessive hepatic glycogen accumulation was observed in 42% of animals in this group. These results indicate that, under worst-case exposure conditions, acute toxicity is unlikely in wild mammals exposed to naphthenic acids in AOS tailings pond water, but repeated exposure may have adverse health effects.     

Maximal Tolerated Daily Doses of Dicophane

Dicophane was given by intragastric cannula to young male albino rats in daily doses of from 43 to 250 mg/kg for 100 days or until 90 % of the animals had died. The LDO (100 days) or maximal dose which killed no animals when given daily for 100 days was 42.8 ± 1.6 mg/kg/day, the LD50 (100 days) was 64.8 ± 1.4 mg/kg/day and the minimal LD100 (100 days) was 97.1 ± 2.8 mg/kg/day. The 100-day LD50 index, or the LD50 (100 days) expressed as a percentage of the acute, oral LD50 (1 dose) was 17.6 ± 0.4. During the first 21 days of administration, the clinical signs of intoxication were similar to those recorded in studies on acute toxicity with single lethal doses. Clinical signs in 21 day-survivors were limited to polydipsia, diuresis, aciduria, and some loss of body weight. Autopsy at 100 days revealed degenerative changes in the kidneys, liver and testes, a stress reaction, hypertrophy of the liver and gastrointestinal organs, and capillary congestion and loss of weight (with variable changes in water content) of many body organs. The 100-day multiposal (subacute, chronic) toxicity of dicophane was similar to that of non-narcotic analgesics such as aspirin, phenacetin and paracetamol.     

小花清风藤胶囊的保肝作用研究及其急毒实验

目的 研究小花清风藤胶囊对CCl4和D-半乳糖致小鼠急性肝损伤的保护作用及其急性毒性的测定。方法 将小鼠分成正常对照组、阳性联苯双脂组、模型组及高中低三个给药剂量组,采用腹腔注射CCl4和D-半乳糖建立小鼠急性肝损伤模型,经眼球取血,测定血清中的谷丙转氨酶（ALT）、谷草转氨酶（AST）、超氧化物歧化酶（SOD）和丙二醛（MDA）的水平,同时测定肝脏指数,部分肝脏作常规HE切片观察。将小鼠随机分成给药组和空白对照组,并观察记录14d内小鼠是否死亡、体质量和摄食量等,14d后处死做大体解剖,观察其各主要脏器是否异常。结果 小花清风藤胶囊各个剂量组均能降低肝损伤小鼠血清中的ALT、AST、MDA水平和肝脏指数,升高血清中SOD含量（P〈0.05或P〈0.01）,肝脏病理切片结果显示小花清风藤胶囊各组对肝损伤均有明显改善作用;实验给药组无一例小鼠死亡,与空白对照组比较,体质量略有降低,但进食量和行为活动均无异常,大体解剖后未见给药组动物的脏器异常。结论 小花清风藤胶囊对小鼠急性肝损伤具有一定保护作用;以最大剂量给药未见急性毒性反应。     

Reproductive effects in male rats exposed to diuron

Diuron is a ureic herbicide considered to have very low toxicity. The present study evaluated several aspects of reproductive toxicity of diuron in adult male rats. Diuron was diluted in corn oil and administered by oral gavage to groups of 18-20 rats at doses of 0, 125 or 250 mg/kg per day for 30 days; the control group received only the corn oil vehicle. At the end of the treatment period, approximately half the animals from each group were assigned to one of two terminal assessment lines: (1) reproductive organ, liver and kidney weights; measurement of diuron concentrations in liver and kidney; plasma testosterone determinations; evaluation of daily sperm production per testis; sperm number and sperm transit time in the epididymis; or (2) sexual behavior assessment during cohabitation with a receptive female; fertility and pregnancy outcome after natural mating; testicular, epididymal, kidney and liver histopathology; sperm morphology. After 30 days of oral diuron treatment, there were no treatment-related changes in body weights, but dose-related diuron residues were detected in the liver of all treated rats and absolute and relative liver weights were increased in both groups. There were no statistically significant differences between the treated and control groups obtained in plasma testosterone concentrations, or in parameters of daily sperm production, sperm reserves in the epididymis, sperm morphology or measured components of male sexual behavior. On the other hand, the number of fetuses in the litters from diuron-treated rats was slightly smaller than litters from control rats. Therefore, although the results did not indicate that diuron exposure resulted in direct male reproductive toxicity in the rat, they suggest that additional studies should be undertaken to investigate the possible effects on fertility and reproductive performance.     

Toxicity of short-term administration of cannabinoids to rhesus monkeys

Because of potential use as therapeutic agents, additional toxicologic studies on pure cannabinoids and cannabis extracts were conducted. Monkeys received a single iv dose of cannabidiol (CBD) or cannabichromene (CBCH) as an aqueous emulsion and LD50s were 212 and 270 mg/kg, respectively. The larger doses of CBD elicited tremors, convulsions, hypopnea, bradycardia, and cardiac failure. Survivors from smaller doses recovered in 1–3 days and liver weights increased 19–142%. CBCH evoked a dose-related hyperpnea and salivation initially but subsequent CNS inhibition resulted in apnea and bradycardia. Liver weights were elevated 8–71% and kidney weights 10–155% and pulmonary irritation, nephritis, increased BUN, and decreased serum electrolytes, hemoglobin, and RBC were found. Hashish oil containing 11.6 or 31.1% Δ⁹-THC caused muscle spasms, salivation, dyspnea, arrhythmia, and hypothermia and the LD50s were 326 and 435 mg/kg, respectively. Survivors recovered in a few days; lung and spleen congestion were common. Five day iv treatment with hashish oil 65–260 mg/kg) initiated similar toxicity and tolerance developed by Day 4. Growth rates were inhibited 7–20% and liver, kidney, and heart weights increased 20–100%. Delayed lethality occurred in two monkeys; histopathology included injection site necrosis, hemorrhagic foci in lungs, heart, intestines, and endocrines. Ninetyday oral treatment with CBD (30–300 mg/kg) had little effect but liver and kidney weights rose 13–56% above controls without morphologic changes. Decreased testicular size and inhibition of spermatogenesis occurred. The temporal pattern of adverse responses differentiated CBD, CBCH, and hashish oil.     

Neuroprotective effect of vitamin e supplementation in wistar rat treated with acrylamide

Male wistar rats (weighting 160-180 g) were divided into six groups of six animals per group. Groups A and F served as control. Groups B, C, D, and E received acrylamide at 20 mg/kg body weight for 28 days and groups C and E received additionally vitamin E (50 IU/kg body weight) for 1 to 28 days and 29 to 42 days of experiment, respectively. The animals from groups A, B, and C were sacrificed on day 28 of experiment and from groups D, E, and F on day 42 of experiment, respectively. The FOB (Functional Observational Battery) and histopathological changes were investigated at the end of 4(th) week and 6(th) week. FOB at the end of 4(th) week, of rats given acrylamide alone, or in combination with vitamin E, revealed a significant change in CNS, neuromuscular, and autonomic domains. A marked decrease in grip strength was recorded. A significant increase in foot splay, reduction in width and angle of sequential stride was noticed. Degenerative changes, necrosis, congestion, and kupffer cell proliferation in liver while vacuolar degenerative changes in tubular epithelium, coagulative necrosis, and hemorrhages in kidney were constant findings in acrylamide intoxicated rats. Neuronal degeneration, severe gliosis, congestion were found in brain. Spinal cord revealed demyelination. Acute microscopic softening of lumbar cord, bilateral necrosis with malacia and liquefaction of white matter, and loss of myelin from grey matter were seen. In the recovery period, vitamin E-treated rats revealed improvement in remyelination of spinal cord. In brain mild gliosis was seen. Thus, it appears that vitamin E is not able to protect them from acrylamide toxicity during active feeding, but after cessation of acrylamide feeding treatment with vitamin E revealed faster recovery as compared to the non-treated group.     

Short-term dietary restriction modulates liver lipid peroxidation in carbon tetrachloride-intoxicated rats

We investigated whether dietary restriction (DR) can protect the liver against the acute toxicity of carbon tetrachloride (CCl4). Adult female Wistar rats received a quantum of diet representing 75 and 50 percent of the food intake of control rats fed ad libitum (25% and 50% daily regimen, respectively) for 30 days. A single dose of CCl4 (3 mL kg(-1) b.w.) was administered subcutaneously at the end of the feeding period. Lipid peroxidation, as thiobarbituric acid reactive substance, conjugated dienes, lipid hydroperoxides and the hepatic markers alanine transaminase, aspartic transaminase, and alkaline phosphatase were significantly decreased in food-restricted rats. The enzymic antioxidants superoxide dismutase, catalase, glutathione peroxidase and the non-enzymic antioxidant glutathione were significantly increased in both groups. The magnitude of liver damage after CCl4 treatment was lower in food-restricted animals than in ad libitum-fed animals. The results suggest that dietary restriction increases the resistance of the liver and protects against oxidative insult produced by an acute dose of CCl4.     

Short-term oral toxicity of gasohol in female rats.

The systemic toxicity of gasohol (10% ethanol in gasoline by volume) in female rats following 4-week oral administration was studied. Female Sprague-Dawley rats (198+/-14 g) were divided into four groups of ten animals each. The low- and medium-dose groups received by gavage corn oil containing gasoline/ethanol at 16/1.8 and 160/18 (mg kg(-1) body weight), respectively, for 28 consecutive days. The high-dose animals were administered gasoline/ethanol at 1600/180 mg kg(-1) on the first day and the dose was reduced to 800/90 mg kg(-1) for the rest of the study period. Control animals received corn oil only. Urine was obtained from all rats after weeks 1, 2 and 4 for biochemical analysis. At termination of the study, kidneys of four rats from each group were examined by electron microscopy. Body weight gains, organ weights, tissue and organ histopathology, serum biochemistry, hematology, liver enzymes and biochemistry were determined in the remaining six animals of each group. No treatment-related changes were observed in the following endpoints: body weight gain or relative weights of the brain, lungs, liver, kidneys, spleen and thymus. A significant increase in pentoxyresorufin O-deethylase (PROD) and benzoylresorufin O-dealkylase (BROD) activities was detected in the high-dose animals, whereas ethoxyresorufin O-deethylase (EROD) activity was unchanged. Treatment with gasohol did not produce any significant changes in hematology and serum clinical chemistry parameters. Biomarkers of oxidative stress such as serum and liver thiobarbituric acid reactive substances (TBARS) and liver glutathione also were unaffected by treatments. Urinary ascorbic acid was elevated markedly in the medium- and high-dose groups following the first, second and fourth weeks of treatment. Urine hippuric acid was increased significantly in the high-dose groups. A dose-related increase in urinary aldehydes also was observed in animals after the first, second and fourth week of treatment. Interestingly, a separate 1-week dosing study revealed that the increase in urinary aldehydes was associated with gasoline and not with ethanol treatment. In the high-dose animals slight increases in urinary protein and N-acetylglucosaminidase activity were observed after week 1 but not after week 2 or week 4. No histopathological changes were detected in the liver, kidneys, stomach, brain, lungs or other tissues examined. Electron microscopic examination of the kidneys also did not reveal any abnormalities. It was concluded that short-term oral administration of gasoline/ethanol at 800/90 mg kg(-1) produced a biochemical response in the liver but no adverse effects in the kidneys and lungs. The biological significance of elevated urinary aldehydes at gasoline/ethanol concentrations of 160/18 mg kg(-1) and higher remains to be studied.