Changes of RAGE/p38MAPK/NF-κB signaling pathway in brain tissue of subchronic fluorosis rats and protective effects of Ginkgo biloba extract and RAGE antagonist / 环境与职业医学

Background Fluorine accumulates in the brain tissue after long-term excessive intake and subsequently cause nerve damage and decline of learning and memory ability. Receptor of advanced glycation end-products (RAGE)/p38 mitogen-activated protein kinase (p38MAPK)/nuclear factor kappa-B (NF-κB) signaling pathway is considered to be involved in the associated mechanism. Objective To study the changes of RAGE/ p38MAPK/ NF-κB signaling pathway in rats with subchronic fluorosis, and to explore the protective effects of extract of Ginkgo biloba 761 (EGb761) and RAGE antagonist (FPS-ZM1) on neuromemory ability. Methods Ninety male clean SD rats were divided into 9 groups with 10 rats in each group. The modeling period was 6 months. Control group (C group): free drinking tap water (fluoride content <0.5 mg·L−1), low- and high-dose fluoride groups (LF group, HF group): free drinking tap water with 10 or 50 mg·L−1 fluoride; intervention group of Ginkgo biloba extract (CE, LFE, and HFE groups): on the basis of the C group, LF group, and HF group, 100 mg·kg−1·d−1 EGb761 was given daily via intragastric administration; FPS-ZM1 intervention groups (CF, LFF, and HFF groups): 7 d before the end of modeling, 1 mg·kg−1·d−1 FPS-ZM1 was injected intraperitoneally daily on the basis of the C group, LF group, and HF group. The contents of fluoride in brain and blood of each group were detected. The learning and memory ability was tested by water maze experiment. The histopathologic changes of the hippocampus were detected by Nissl staining. The protein expression levels of RAGE and its ligand high mobility group protein B1 (HMGB1), NF-κB, p38MAPK, phospho-p38MAPK (p-p38MAPK), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) in brain tissue were detected by Western blotting. The mRNA expression levels of RAGE, HMGB1, and p38MAPK were detected by quantitative real-time PCR. Results Compared with the C group, the contents of blood fluoride and brain fluoride in the LF and the HF groups were increased (P<0.05). The results of the water maze experiment showed that, compared with the C group, the escape latency time of the LF group and the HF group was longer and the crossing times were reduced; compared with the HF group, the escape latency time of the HFE group and the HFF group was shortened, and the crossing times were increased (P<0.05). The Nissl staining results showed that the number of Nissl body in the HF group decreased compared with the C group; compared with the HF group, the number of Nissl body in the HFE group and the HFF group increased. The Western blotting results showed that compared with the relative protein expression levels of RAGE, HMGB1, NF-κB, p38MAPK, p-p38MAPK, IL-6, and TNF-α in the C group , the levels of above indicators in the HF group and the levels of RAGE, HMGB1, NF-κB, p-p38MAPK, and IL-6 in the LF group were up-regulated (P<0.05); compared with the HF group, the levels of above indicators in the HFE group and the HFF group were all down-regulated (P<0.05); compared with the relative protein expression levels of RAGE and HMGB1 in the LF group, the levels in the LFE group and the LFF group were all down-regulated (P<0.05). The quantitative real-time PCR results showed that compared with the C group, the mRNA expression levels of RAGE and HMGB1 in the LF group and the HF group were up-regulated; compared with the LF group, the mRNA expression levels of RAGE in the LFE group and the LFF group were down-regulated ; compared with the HF group, the mRNA expression levels of RAGE and HMGB1 in the HFE group and the HFF group were down-regulated (P<0.05). Conclusion The central nervous system injury caused by subchronic fluorosis may be related to the activation of RAGE/p38-MAPK/NF-κB signaling pathway, which can impair the learning and memory ability of rats, while EGb761 and FPS-ZM1 may have certain protective effects on the nerve injury.

Acute and Subchronic Toxicities of the Aqueous Extract of the Hymenocardia acida (Euphorbiaceae) Roots in Rodents

The roots of Hymenocardia acida are used in traditional African medicine to treat mainly erectile dysfunction. This study aims to evaluate the lethal and sub-lethal toxicities of the aqueous extract of Hymenocardia acida roots in in two rodents species, namely Mus musculus and Rattus norvegicus. The acute intraperitoneal and oral toxicities of the extract were determined by the method of Miller and Tainter. Subchronic oral toxicity with doses of 500 and 1000 mg/kg body weight was assessed according to the slightly modified OECD 408 method. The results showed that the 50% intraperitoneal lethal dose was 223.87 mg/kg body weight in mice. In addition, the 50% oral lethal dose in mice was greater than 12,000 mg/kg body weight. In the subchronic study, the extract induced a significant (P < .001) increase in white blood cell count at 1000 mg/kg body weight after 60 days of treatment. From the thirtieth day of treatment onwards, the extract induced a significant (P < .05) reduction in blood glucose levels at the 500 mg/kg body weight dose and a significant (P < .05) increase in blood glucose levels at the 1000 mg/kg body weight dose. Aqueous extract of Hymenocardia acida roots is toxic by the intraperitoneal route and exerts a non-specific immunity action at high doses. It was harmless to rats at doses of 500 and 1000 mg/Kg of body weight.

Skin damage caused by sunlight ultraviolet in mice / 预防医学

Objective @#To study the damage effect of sunlight ultraviolet exposure on skin.@*Methods @#No exposure group, low exposure group and high exposure group were set up with 10 mice in each. The exposure doses of sunlight ultraviolet were 0, 10 J/cm2 and 20 J/cm2, respectively. The skin of mice was irradiated by a sunlight ultraviolet simulator for 5 days a week, 13 weeks. At the end of the experiment, the skin appearance of mice was examined; the skin moisture, oil content, texture density, hydroxyproline ( HYP ), hyaluronic acid (HA), malondialdehyde ( MDA ), glutathione ( GSH ) and superoxide dismutase ( SOD ) activities were detected; and the skin tissue morphology, collagen fiber morphology and elastic fiber morphology were observed. @*Results @#The skin appearance of mice in the no exposure group was normal; in the low exposure group, only one mouse had mild skin desquamation; in the high exposure group, the skin was loose and wrinkled, dry and desquamated, local thickening and erythema formation. Compared with the no exposure group, the contents of skin moisture, HYP, HA and SOD activity were lower, texture density, MDA content, morphological scores of skin tissue, collagen fiber tissue and elastic fiber tissue were higher in the high exposure group ( all P<0.05 ). Compared with the low exposure group, the HA content and SOD activity were lower, the skin texture density, MDA content, and histomorphological scores of skin tissue and collagen fibers were higher in the high exposure group ( all P<0.05 ).@*Conclusion @#Exposure to 20 J/cm2 sunlight ultraviolet can significantly lead to abnormal skin appearance and function in mice.

Effects of subchronic fluoride exposure through drinking water on renal toxicity and the expressions of STIM1 and ORAI1 in renal tissues in mice / 环境与职业医学

Background It has been found that fluoride may cause cell damage by inducing intracellular calcium overload. Store-operated calcium entry (SOCE) plays an important role in maintaining intracellular calcium homeostasis, but the effect of fluoride on renal SOCE is unknown. Objective To explore the renal toxicity and the expression levels of the key proteins of SOCE, stromal interaction molecule 1 (STIM1) and calcium release-activated calcium modulator 1 (ORAI1) in the kidney tissues of mice exposed to fluoride subchronically. Methods Twenty male ICR mice were randomly divided into four groups with five mice in each group, including 0 (control group), 0.3, 3, and 30 mg·L−1 fluoride groups. The mice were given drinking water containing designed fluoride for 12 weeks. Body weight and liver and kidney organ coefficients of the mice were measured after the exposure; histopathological changes of the mouse kidney were observed; 24 h urine was collected at the end of 12 weeks of exposure to determine the levels of urine creatinine (UCr), urine calcium (UCa), albumin (ALB), and β2-microglobulin (β2-MG); the protein expression levels of STIM1 and ORAI1 in the kidney were detected by Western blotting; the fluorescence co-localization of STIM1 and ORAI1 was used to further verify the expression levels of STIM1 and ORAI1. Results After the exposure, there were no differences in body weight as well as liver and kidney organ coefficients among the groups (P > 0.05). Under optical microscope, the renal tubular cell showed degeneration, apical protrusion, shedding, and dilation in the 3 and 30 mg·L−1 fluoride groups. There was no statistical difference in UCr among the mice in each group (P > 0.05). Compared with the control group, the levels of UCa adjusted by UCr in the 3 and 30 mg·L−1 fluoride groups were (0.075±0.014) and (0.081±0.012) mol·mol−1 (represent by UCr per mol), which had a rising trend but showed no statistical difference. No difference was identified in the level of ALB among the groups (P > 0.05). The levels of β2-MG showed difference in different exposure groups, and the level of urine β2-MG in the 30 mg·L−1 fluoride group was (0.077±0.014) g·mol−1, higher than that in the control group (P<0.05). Based on the results of Western blotting, the protein expression levels of STIM1 and ORAI1 showed significant differences among the groups (F=18.411, 6.853; P=0.001, 0.013); compared with the control group, the expression levels of STIM1 protein increased in the 3 and 30 mg·L−1 fluoride groups (P < 0.05), and the protein expression level of ORAI1 in the 30 mg·L−1 fluoride group was increased (P < 0.05). The fluorescence co-localization results of STIM1 and ORAI1 showed that the expressions of STIM1 and ORAI1 were up-regulated in the 3 and 30 mg·L−1 fluoride groups. Conclusion Subchronic exposure to fluoride through drinking water can up-regulate the expression levels of STIM1 and ORAI1 in renal tissues and induce renal injury.

Subchronic Oral Toxicity Evaluation of Sodium Dehydroacetate: A 90-day Repeated Dose Study in Rats / 生物医学与环境科学（英文）

Objective@#The present study was undertaken to evaluate the subchronic oral toxicity of sodium dehydroacetate (DHA-Na) and to determine the point of departure (POD), which is a critical factor in the establishment of an acceptable dietary intake.@*Methods@#DHA-Na was administered once daily by gavage to Sprague-Dawley rats at dose levels of 0.0, 31.0, 62.0, and 124.0 mg/kg BW per day for 90 days, followed by a recovery period of 4 weeks in the control and 124.0 mg/kg BW per day groups. The outcome parameters were mortality, clinical observations, body weights, food consumption, hematology and clinical biochemistry, endocrine hormone levels, and ophthalmic, urinary, and histopathologic indicators. The benchmark dose (BMD) approach was applied to estimate the POD.@*Results@#Significant decreases were found in the 62.0 and 124.0 mg/kg BW groups in terms of the body weight and food utilization rate, whereas a significant increase was found in the thyroid stimulating hormone levels of the 124.0 mg/kg BW group. Importantly, the 95% lower confidence limit on the BMD of 51.7 mg/kg BW was modeled for a reduction in body weight.@*Conclusion@#The repeated-dose study indicated the slight systemic toxicity of DHA-Na at certain levels (62.0 and 124.0 mg/kg BW) after a 90-day oral exposure.

Evaluación de la toxicidad de chalconas sintéticas con potencial anti-Leishmania en ratones BALB/c / Toxicity assessment of synthetic chalcones with antileishmanial potential in BALB/c mice

RESUMEN Objetivo: Evaluar la toxicidad de tres chalconas sintéticas administradas por vía intraperitoneal en ratones BALB/c. Materiales y métodos: La dosis letal media (DL50) se estimó por el método Up-and-Down de Dixon. La toxicidad subcrónica de las chalconas se evaluó a 20 y 40 mg/kg por 21 días. Se evaluó el efecto tóxico a nivel de comportamiento, fisiológico, bioquímico e histológico. Resultados: La chalcona 43 generó moco en las heces, daño visceral (hígado) y alteración en el coeficiente de órganos (riñón, p = 0,037 y cerebro, p = 0,008) en comparación con el grupo control. Además, en el análisis histológico se observó que esta chalcona produjo edema, inflamación y necrosis en los órganos evaluados, aunque no hubo diferencia significativa con el control. Todos los parámetros bioquímicos no difirieron significativamente entre los grupos de tratamiento a dosis de 40 mg/kg y el control. Conclusiones: La DL50 para las tres chalconas fue superior a 550 mg/kg de peso corporal. Las chalconas 40 y 42 son relativamente no tóxicas. Ambas pueden considerarse seguras para la aplicación vía intraperitoneal en ratones BALB/c y, en consecuencia, son posibles candidatas para ser usadas en el tratamiento contra las leishmaniosis.

ABSTRACT Objective: To evaluate the toxicity of three synthetic chalcones administered intraperitoneally to BALB/c mice. Materials and methods: The median lethal dose (LD50) was estimated by Dixon's Up-and-Down method. Subchronic toxicity of chalcones was evaluated at 20 and 40 mg/kg for 21 days. Behavioral, physiological, biochemical, and histological toxic effects were evaluated. Results: Chalcone 43 produced mucus in feces, visceral damage (liver) and alterations in organ coefficient (kidney, p = 0.037 and brain, p = 0.008) when compared to the control group. In addition, histological analysis showed that this chalcone produced edema, inflammation and necrosis in the evaluated organs, although there was no significant difference with the control. None of the biochemical parameters differed significantly between the treatment groups at 40 mg/kg dose and the control. Conclusions: The LD50 for all three chalcones was greater than 550 mg/kg of body weight. Chalcones 40 and 42 were found to be relatively non-toxic. Both can be considered safe for intraperitoneal application in BALB/c mice and, consequently, are potential candidates for use in the treatment of leishmaniasis.

Safety evaluation of chromium picolinate in experimental rats

Background: Chromium, an essential trace mineral plays an important role in the metabolism of carbohydrate, fat and proteins. Chromium picolinate (Cr.Pic) is used in alternative medicine to treat chromium deficiency. Though Cr.Pic is increasingly used to treat diabetes and obesity, studies on its safety profile is limited.Methods: Acute toxicity study was conducted by oral administration of Cr.Pic (2000 mg/kg body weight). The animals were maintained another 14 days with once a day observation. For sub-chronic studies, test groups were treated with Cr.Pic 10 mg/kg/day for 90 days. Tests for hepatic and renal function were conducted. Effect of Cr.Pic on behavioural changes and motor co-ordination was done on every week. Histopathological studies were conducted on day 90 at the end of the experiment.Results: Acute toxicity study of Cr.Pic showed no signs of toxicity and mortality. Absence of any behavioural alteration or mortality during the period of 14 days indicates that Cr.Pic has no latent effect. Similar results were obtained with sub-chronic studies suggesting safety of Cr.Pic. Cr.Pic treated groups showed no changes in learning and motor co-ordination compared to the untreated group. No gross histopathological changes were seen in any group indicating safety of Cr.Pic.Conclusions: The present study conferred safety profile of Cr.Pic from normal results obtained in hepatic function, renal function, behavioural and histopathological studies, suggesting its safety.

Impact of subchronic exposure to low-dose nano-nickel oxide on the reproductive function and offspring of male rats / 中华男科学杂志

Objective@#To investigate the influence of subchronic exposure to low-dose subchronic nano-nickel oxide (NNO) on the reproductive function of male rats and embryonic development of the pregnant rats.@*METHODS@#Fifty normal healthy male SD rats weighing 180－220 g were randomly divided into five groups of equal number, negative control, 4 mg/ml micro-nickel oxide (MNO), and 0.16, 0.8 and 4 mg/ml NNO, those of the latter four groups exposed to MNO or NNO by non-contact intratracheal instillation once every 3 days for 60 days, and then all mated with normal adult female rats in the ratio of 1∶2. After the female animals were confirmed to be pregnant, the males were sacrificed and the weights of the body, testis and epididymis obtained, followed by calculation of the visceral coefficients, determination of epididymal sperm concentration and viability and the nickel contents in the blood and semen by atomic fluorescence spectrometry. The female rats were killed on the 20th day of gestation for counting of the implanted fertilized eggs and live, dead and resorbed fetuses.@*RESULTS@#After 60 days of exposure, the rats of the NNO groups showed no statistically significant differences from those of the negative control and MNO groups in the weights of the body, testis and epididymis or visceral coefficients. Compared with the negative control group, the animals of the 0.8 and 4 mg/ml NNO groups exhibited markedly decreased sperm concentration (［9.36 ± 0.98］ vs ［7.49 ± 1.46］ and ［6.30 ± 1.36］ ×10⁶/ml, P < 0.05) and viable sperm (［85.35 ± 9.16］% vs ［68.26 ± 16.63］% and ［65.88 ± 14.68］ %, P < 0.05), increased morphologically abnormal sperm (［8.30 ± 2.47］% vs ［13.99 ± 4.87］% and ［15.38 ± 8.86］ %, P < 0.05), and elevated rate of dead and resorbed fetuses (1.18% vs 6.89% and 7.37%, P < 0.05), blood nickel content (［0.13 ± 0.16］ vs ［0.52 ± 0.34］ and ［0.82 ± 0.44］ mg/L, P < 0.05) and semen nickel content (［0.08 ± 0.13］ vs ［0.35 ± 0.23］ and ［0.63 ± 0.61］ mg/L, P < 0.05). The nickel level in the semen was correlated significantly with that in the blood (r = 0.912, P <0.01), negatively with the rate of viable sperm (r = －0.879, P <0.01) and positively with the percentage of morphologically abnormal sperm (r = －0.898, P <0.01).@*CONCLUSIONS@#Sixty-day exposure to nano-nickel oxide at 0.8 and 4 mg/ml can produce reproductive toxicity in male rats and result in fetal abnormality in the females, while that at 0.16 mg/ml has no significant toxic effect on the reproductive function of the males.

Sub-chronic toxicity evaluation of Dryopteris filix-mas (L. ) schott, leaf extract in albino rats

This study evaluated the acute and sub-chronic toxicities of ethanol leaf extract of Dryopteris filix-mas. Acute toxicity and phytochemical tests on ethanol leaf extract were determined. In sub-chronic toxicity test, animals were treated with 62.5, 125, 250 and 500 mg/kg of extract every day for 90 days. Blood samples were collected via retro-orbital puncture for baseline studies and at 31, 61 and 91st days for determination of hematological, kidney and liver function parameters. Liver and kidneys were harvested for histopathology analyses on 91st day. Also, a 28 day recovery study was carried out to determine reversibility in toxicological effects. Phytochemical screening revealed the presence of tannins, phenols, flavonoids, saponins, steroids, alkaloids, terpenoids, reducing sugar and cardiac glycosides. Acute toxicity test did not show toxicity or death at 5000 mg/kg. There was significant (p<0.005) reduction in white blood cell and lymphocyte counts, significant (p<0.05) increase in some liver and kidney biomarkers as well as alterations in liver and kidney histo-architecture on 91st days in animals that were treated with 250 and 500 mg/kg extract. However, toxicities observed on 91st day were reversible in recovery studies. The leaf extract of Dryopteris filix-mas may be hepatotoxic and nephrotoxic when used for long periods

Sub-chronic Toxicity of Defoamer Used in Seawater Desalination / 生物医学与环境科学（英文）

OBJECTIVE@#To explore the possible long-term health effects of the defoamer used in seawater desalination by sub-chronic toxicity testing.@*METHODS@#Blood analysis, internal organ assessment, and histopathological examination were carried out in rats exposed to low, medium, and high (0.5, 1.0, and 2.0 g/kg BW, respectively) doses of defoamer for 90 days through oral administration.@*RESULTS@#The high dose group showed decreased blood alanine aminotransferase and aspartate aminotransferase (P < 0.05). All doses resulted in a significant increase in albumin and decrease in globulin (P < 0.05). The direct bilirubin and indirect bilirubin were decreased in the medium and high dose groups (P < 0.05). All dose groups showed significant induction of alkaline phosphatase (P < 0.05). Pathological examination revealed a case of liver mononuclear cell infiltration in the medium dose group and three cases of liver congestion, steatosis of hepatic cells around the central vein, and punctate necrosis with multiple focal mononuclear cell infiltration in male rats administered the high dose. The No Observed Adverse Effect Level was 0.5 g/kg BW in rats, with albumin and total bilirubin as health effect indices.@*CONCLUSION@#Long-term defoamer exposure may cause liver injury but has no significant impact on renal function in rats. The effect on blood cells in female rats was more prominent than that in male rats.

Subchronic Toxicity Study of the Extract of Sacoglottis gabonensis (Baille) Urban (Humiriaceae) in Wistar Rats

Introduction:Sacoglottis gabonensis (Baille) Urban (Humiriaceae) is a medicinal plant used in the treatment of Buruli ulcer in Ivory Coast. To ensure its effect over along period of use, the subchronic toxicity of the total aqueous extract of S. gabonensisstem bark (ETASg) in rats was evaluated.Methods:80 rats were homogeneously distributed in 4 lots of 20 rats each, including 10 males and 10 females. ETASg was administered daily orally for 90 days for 2 mL/100 g body weight (b.w.) rats at doses of 3.5; 35 and 350 mg/kg b.w. The control group received distilled water. A venous blood sample is taken every 30 days for 90 days to determine serum biochemical parameters Results:The study showed that ETASg did not influence serum biochemical markers at the therapeutic dose of 3.5 mg/kg b. w. significant increases in ASAT serum activity, ALT, PAL, and LDH in rats tested at 35 and 350 mg/kg b. w. was found on the 60th and 90th days. Administration of ETASg did not affect most of the metabolites and electrolytes studied at doses of 3.5; 35 and 350 mg/kg b. w. After 30 days of discontinuing oral administration of ETASg, the increase observed at the 350 mg/kg b. w. is moderate and reversible.Conclusion:This study revealed that ETASg is nontoxic for biochemical parameters, at doses of 3.5; 35 and 350 mg/kg b. w. during 90 days of administration in rats

Hepatic and Renal Biochemical Profile of Albino Rats Exposed to Chloroform and Methanol Leaf Extracts of Portulaca oleracea Linn.

Portulaca oleracea Linn. is among the medicinal plants used globally in the treatment of diseases and management of health challenges. The dearth of information on the long term effect of Portulaca oleracea on hepatic and renal toxicity prompted this study. The study investigated the subchronic effect of the oral administration of chloroform leaf extracts of Portulaca oleracea (CLEPO) and methanol leaf extracts of Portulaca oleracea (MLEPO) on plasma activity of some enzymes (ALT, ALP & AST) and levels of other biochemical parameters such as blood electrolytes, total protein, albumin, bilirubin, urea and creatinine in male albino rats. One hundred and twelve (112) animals were randomly divided into seven (7) groups of sixteen (16) rats each. Group A (Control) received 0.5ml/kg of 20% Tween 80 (vehicle), Groups B, C & D received 125, 250 & 500 mg/kg of CLEPO respectively and Groups E, F & G received 125, 250 & 500 mg/kg of MLEPO respectively for 60 days. On days 14, 28, 42 and 60; four rats from each group were anaesthetized and blood samples were collected for plasma biochemical assay. MLEPO caused a significant (p<0.05) decrease in plasma AST and ALP level while CLEPO significantly (p<0.05) decreased the plasma AST level. MLEPO produced a highly significant (p<0.01) reduction in both total bilirubin and conjugated bilirubin levels as well as significant (p<0.05) decline in urea level. CLEPO produced a significant (p<0.05) decrease on conjugated bilirubin. Both extracts significantly (p<0.05) reduced the chloride level. Oral administration of CLEPO and MLEPO over a 60 day period is neither hepatotoxic nor nephrotoxic.

Subchronic Oral Toxicity of Silica Nanoparticles and Silica Microparticles in Rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the subchronic oral toxicity of silica nanoparticles (NPs) and silica microparticles (MPs) in rats and to compare the difference in toxicity between two particle sizes.</p><p><b>METHODS</b>Sprague-Dawley rats were randomly divided into seven groups: the control group; the silica NPs low-, middle-, and high-dose groups; and the silica MPs low-, middle-, and high-dose groups [166.7, 500, and 1,500 mg/(kg•bw•day)]. All rats were gavaged daily for 90 days, and deionized water was administered to the control group. Clinical observations were made daily, and body weights and food consumption were determined weekly. Blood samples were collected on day 91 for measurement of hematology and clinical biochemistry. Animals were euthanized for necropsy, and selected organs were weighed and fixed for histological examination. The tissue distribution of silicon in the blood, liver, kidneys, and testis were determined.</p><p><b>RESULTS</b>There were no toxicologically significant changes in mortality, clinical signs, body weight, food consumption, necropsy findings, and organ weights. Differences between the silica groups and the control group in some hematological and clinical biochemical values and histopathological findings were not considered treatment related. The tissue distribution of silicon was comparable across all groups.</p><p><b>CONCLUSION</b>Our study demonstrated that neither silica NPs nor silica MPs induced toxicological effects after subchronic oral exposure in rats.</p>

Subchronic Oral Toxicity Evaluation of Lanthanum: A 90-day, Repeated Dose Study in Rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The present study was undertaken to evaluate the subchronic toxicity of lanthanum and to determine the no observed adverse effect level (NOAEL), which is a critical factor in the establishment of an acceptable dietary intake (ADI).</p><p><b>METHODS</b>In accordance with the Organization for Economic Co-operation and Development (OECD) testing guidelines, lanthanum nitrate was administered once daily by gavage to Sprague-Dawley (SD) rats at dose levels of 0, 1.5, 6.0, 24.0, and 144.0 mg/kg body weight (BW) per day for 90 days, followed by a recovery period of 4 weeks in the 144.0 mg/kg BW per day and normal control groups. Outcome parameters were mortality, clinical symptoms, body and organ weights, serum chemistry, and food consumption, as well as ophthalmic, urinary, hematologic, and histopathologic indicators. The benchmark dose (BMD) approach was applied to estimate a point of departure for the hazard risk assessment of lanthanum.</p><p><b>RESULTS</b>Significant decreases were found in the 144.0 mg/kg BW group in the growth index, including body weight, organ weights, and food consumption. This study suggests that the NOAEL of lanthanum nitrate is 24.0 mg/kg BW per day. Importantly, the 95% lower confidence value of the benchmark dose (BMDL) was estimated as 9.4 mg/kg BW per day in females and 19.3 mg/kg BW per day in males.</p><p><b>CONCLUSION</b>The present subchronic oral exposure toxicity study may provide scientific data for the risk assessment of lanthanum and other rare earth elements (REEs).</p>

Evaluación de la toxicidad subcrónica de la variedad colombiana de Smallanthus sonchifolius (Yacón) en ratas hembra / Subchronic toxicity evaluation of colombian variety of Smallanthus sonchifolius (Yacón) in female rats

Smallanthus sonchifolius (Yacón) es una planta usada comúnmente por largos periodos de tiempo con el fin de ayudar en el control de la diabetes y otros desordenes metabólicos, por lo que con el propósito de evaluar la toxicidad subcrónica de la variedad colombiana de esta planta, fueron tratadas 30 ratas hembra de 8 semanas de edad dividas en 6 grupos. A cada uno de ellos se administró durante 28 días una de las siguientes dosis de infusión acuosa liofilizada (500, 250 y 125 mg/kg de peso), evaluando paralelamente grupos control (positivo y negativo) e incluyendo entre ellos grupos con y sin dieta hipercalórica. Para el seguimiento del perfil metabólico de los animales, se tomaron muestras de sangre periódicamente durante el ensayo y se evaluaron los niveles séricos de: glucemia, triglicéridos, colesterol total y HDL. Además, también se realizó el control del peso, así como estudios comportamentales que incluyeron el Test de Irwin y el Test Hipocrático. Al final de estudio (28 días), se realizó el análisis anatomopatológico e histológico comparativo con el fin de detectar posibles daños tisulares. Como resultado pudo observase que el liofilizado, si bien puede tener un efecto antihiperglucemiante, no modificó significativamente el perfil lipídico. Además, a pesar de que la administración se hizo durante 28 días, no se observaron cambios comportamentales que evidencien toxicidad, pero sí pudieron observarse cambios histológicos en el tejido cardiaco como hialinización, separación y redondeo de fibras.

Abstract. Smallanthus sonchifolius (Yacón) is a plant commonly used over long periods of time to help control diabetes and other metabolic disorders. To assess the sub-chronic toxicity of the Colombia variety of this plant, it was tested on 30 eight-week-old female rats, divided into six groups. For 28 days each group was administered with the following doses: three groups with lyophi­lized aqueous infusion (500 mg, 250 mg and 125 mg per kg of weight), two control groups (positive and negative) being assessed in parallel; this groups receiving hyper-caloric diet, and the last group was the general control or normal control. To monitor the animals' metabolic profile, blood samples were taken from time to time during the test period, and the serum levels of glycemia, triglycerides, total cholesterol and HDL were measured. Weight tracking was also carried out, as well as behavioral studies, including the Irwin Test and the Hippocratic Test. At the end of the study (28 days), comparative anatomo-pathological and histological analyses were performed to detect possible tissue damage. The results showed that, although the lyophilized infusion could have an antihyperglycemic effect, it did not significantly change the lipid profile. Moreover, though the infusion was administered during 28 days, it was found that it did not lead to any behavioral changes indicating toxicity, but did produce in heart tissue histological changes such as hyalinization, separation and rounding of fibers.

Evaluating the safety of forsythin from Forsythia suspensa leaves by acute and sub-chronic oral administration in rodent models

OBJECTIVE@#To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety.@*METHODS@#Acute toxicity was determined by oral administration of a single dose of 18100 mg/kg forsythin in NIH mice. Sub-chronic toxicity was evaluated by oral administration of several doses of forsythin for 30 days at does of 0, 540, 1620, and 6480 mg/kg in SD rats.@*RESULTS@#In the acute toxicity study, mortality was not observed after 14 days. In addition, clinically relevant adverse effects, or variations in body weight or food consumption were not observed. Similarly, after 30 days in the sub-chronic toxicity study, no mortality or significant toxicological effects such as decreased food consumption, body weight, biochemical parameters and vital organs etc. were noticed.@*CONCLUSION@#The results revealed that the forsythin from Forsythia suspensa leaves has low or no toxicity via oral administration, and therefore is suitable for further development and applications.

Sub-chronic oral toxicity of 1,1-diamino-2,2-dinitroethene in rats / 中国职业医学

OBJECTIVE: To explore the sub-chronic oral toxicity of 1,1-diamino-2,2-dinitroethene( FOX-7) in rats.METHODS: Ninety-six specific pathogen free healthy adult SD rats were randomly divided into control group,low-,medium-,and high-dose groups. Each group consisted of 24 rats,half of them were males and the other half were females.The low-,medium-,and high-dose groups of rats were exposed to 10,30,90 mg /( kg·d) body weigh of 1,1-diamino-2,2-dinitroethene by gavage for 90 days,once a day,6 days a week. The control group was given the same volume of 4%water starch solution. The toxic symptoms,the body weight,food utilization,routine blood,blood biochemical indicators,organ coefficients and histopathology changes of the rats were observed or tested. RESULTS: a) The body weights of male and female rats in the high-dose group in the 28 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). Food utilization in the male and female high-dose group in the 77 th and 90 th day after exposure were lower than those of the control group for the same time and same sex( P < 0. 05). b) Red blood cell counts,hemoglobin levels,hematocrit levels in the female rats of low-,medium-,and high-dose groups were lower than those of the female control group( P < 0. 05). Platelet counts in the female high-dose group was lower than that of the female control group( P < 0. 05). Red blood cell counts,hemoglobin level,hematocrit level and mean corpuscular hemoglobin concentration in the male high-dose group were lower than those of the male control group( P < 0. 05). The platelet counts in the male medium-,and high-dose group were lower than that of the male control group( P < 0. 05). c) Total cholesterol levels in female medium-,and high-dose group and blood urea nitrogen level in the female high-dose group were higher than those of the female control group( P < 0. 05). In high-dose group,the levels of total protein and uric acid were higher and lactate dehydrogenase level was lower than those of the control group( P < 0. 05). d) The spleen organ coefficients in the female high-dose group were higher and those in male medium- and high-dose groups were higher than those of the control group for same sex( P < 0. 05). The organ coefficients of liver and kidney in high-dose group were higher than those of the control group( P < 0. 05),the organ coefficients of testis and epididym in the male high-dose group were lower than those of the male control group( P < 0. 05). The testis convoluted tubule shrink and seminiferous cells decreased in the male high-dose group. e) The no observed adverse effect level of FOX-7 dinitroethene in female rats were less than10. 00 mg /( kg·d) and it was 10. 00 mg /( kg·d) in the male rats. CONCLUSION: FOX-7 could inhibit the growth of rats and damage the blood system and male reproductive system.

Evaluating the safety of forsythin from Forsythia suspensa leaves by acute and sub-chronic oral administration in rodent models

Objective To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety. Methods Acute toxicity was determined by oral administration of a single dose of 18 100 mg/kg forsythin in NIH mice. Sub-chronic toxicity was evaluated by oral administration of several doses of forsythin for 30 days at does of 0, 540, 1 620, and 6 480 mg/kg in SD rats. Results In the acute toxicity study, mortality was not observed after 14 days. In addition, clinically relevant adverse effects, or variations in body weight or food consumption were not observed. Similarly, after 30 days in the sub-chronic toxicity study, no mortality or significant toxicological effects such as decreased food consumption, body weight, biochemical parameters and vital organs etc. were noticed. Conclusion The results revealed that the forsythin from Forsythia suspensa leaves has low or no toxicity via oral administration, and therefore is suitable for further development and applications.

Assessment of the Toxicity of Sub-chronic Low and High Doses of the Bio-insecticide Spinosad on the Liver, Kidney and the Cerebellum in Male Albino Mice

ABSTRACT Spinosad (SPD) is a highly selective insect control product. However, it was reported that SPD has toxicity toward other non-target organisms. This study was conducted to address the toxic effect of two sub-chronic low and high doses; 35 and 350 mg/kg SPD on some biochemical, histological and immunohistochemical parameters of the liver, kidney and cerebellum. Thirty-six male Swiss mice were divided into three groups of 12 mice each; first group (G1) served as a control, second group (G2) received a low sub-chronic dose of SPD that is equal to 35 mg/kg, and third group (G3) received a high sub-chronic dose of SPD that is equal to 350 mg/kg. The results showed that mice which were received 350 mg/kg SPD showed a significant decrease in the body weight and a significant increase in their relative kidney and spleen weights. They also showed a significant increase in alanine aminotransferase (ALT), triglycerides and urea levels. Histopathological examination showed cytoplasmic degeneration and cell necrosis in the liver and kidney. Immunohistochemical examination showed that cerebellum illustrated several neurodegenerative changes and a down-regulation of synaptophysin-Syp. In conclusion, exposure to a high dose of SPD that is equal to 350 mg/kg could cause a marked toxicity on the liver, kidney and cerebellum in male albino mice.

Sub-chronic toxicity of MNT-016 by benchmark dose method in Sprague-Dawley rats / 军事医学

Objective To evaluate the repeated dose toxicity of MNT-016 in SD rats and to provide reference for toxicity evaluation.Methods MNT-016 was administered to rats at 5, 20 and 80 mg/kg for 90 days.The toxic effects on the animals were evaluated by observing the clinical signs and measuring the body weight, hematology and blood biochemistry as well as histopathological examination.NOAEL and benchmark dose lower confidence limit(BMDL) were observed by the end point of toxicity.Results Compared with the control group, the AST, TBIL, DBIL and Crea of male rats were increased in a dose-dependent manner, while TG and CHOL decreased.The body mass(before anatomy), heart, liver, thymus, epididymis of male rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of the heart and lung was increased.The body mass (before anatomy) and thymus of female rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of lungs was increased.Vacuolation of hepatocytes was observed in groups each dose, tubule atrophy was found in the kidneys of 20 and 5 mg/kg groups, and tubule basophilia was observed in 80 mg/kg group.The incidence of the above lesions was higher in male animals than in female ones.Conclusion The NOAEL of MNT-016 is lower than 5 mg/kg in male rats and 5 mg/kg in female rats.BMDL value is 2.65 mg/kg in male animals and more accurate than NOAEL, and is 9.04 mg/kg in female animals,which is slightly larger than the corresponding NOAEL.