Role of ascorbic acid versus silymarin in amelioration of hepatotoxicity induced by acrylamide in adult male albino rats: histological and immunohistochemical study / Rol del ácido ascórbico frente a la silimarina en la mejoría de la hepatotoxicidad inducida por acrilamida en ratas albinas macho adultas: estudio histológico e inmunohistoquímico

SUMMARY: Acrylamide (ACR) is a cytotoxic and carcinogenic material. It is a product of a Maillard reaction during the cooking of many types of fried fast food, e.g. potato chip fries, and chicken nuggets. ACR has a severe toxic effect on different body organs. This study investigates the hepatotoxic effect of ACR, and the protective effect of ascorbic acid and silymarin. For this purpose, forty adult, male, albino rats were divided into four groups and received the following treatments for fourteen days: Group I: (the control) normal saline; Group II: ACR only; Group III: ACR and ascorbic acid; and Group IV: ACR and silymarin. Under a light microscope, the liver from rats treated with ACR only presented disturbed liver architecture, degenerated hepatocytes, reduced glycogen contents, congested central vein, and increased collagen fibres with areas of fibrosis. Immunohistochemical examination revealed an increased mean number of CD68-, and α-SMA-positive cells. This indicates the presence of large numbers of stellate macrophages (Kupffer cells) and Hepatic stellate cells (HSCs). The combination of ACR with either ascorbic acid or silymarin resulted in less hepatic degeneration, less fibrosis and fewer CD68 and α-SMA positive cells compared to the ACR only group. In conclusion, treatment with silymarin or ascorbic acid along with ACR appears to alleviate ACR-induced hepatotoxicity with more protection in silymarin treated rats.

RESUMEN: La acrilamida (ACR) es un material citotóxico y cancerígeno. Es producto de la reacción de Maillard durante la cocción de muchos tipos de comida rápida y frita, por ejemplo: papas fritas y nuggets de pollo. ACR tiene un efecto tóxico severo en diferentes órganos del cuerpo. Este estudio investigó el efecto hepatotóxico del ACR y el efecto protector del ácido ascórbico y la silimarina. Con este fin, cuarenta ratas albinas machos adultas se dividieron en cuatro grupos y recibieron los siguientes tratamientos durante catorce días: Grupo I (control), solución salina normal; Grupo II, solo ACR; Grupo III, ACR y ácido ascórbico; y Grupo IV, ACR y silimarina. Bajo microscopio óptico, el hígado de ratas tratadas con ACR solo presentó alteración de su arquitectura, entre ellos hepatocitos degenerados, contenido reducido de glucógeno, vena central congestionada y aumento de fibras de colágeno con áreas de fibrosis. El examen inmunohistoquímico reveló un aumento del número medio de células CD68 y α-SMA positivas. Esto indica la presencia de un gran número de macrófagos estrellados (células de Kupffer) y células estrelladas hepáticas (HSC). La combinación de ACR con ácido ascórbico o silimarina resultó en menos degeneración hepática, menos fibrosis y menos células positivas para CD68 y α-SMA en comparación con el grupo de ACR solo. En conclusión, el tratamiento con silimarina o ácido ascórbico junto con ACR parece aliviar la hepatotoxicidad inducida por ACR.

Atomoxetine improves hippocampal cell proliferation but not memory in Doxorubicin-treated adult male rats.

Atomoxetine (ATX) is a noradrenaline reuptake inhibitor used to treat Attention deficit hyperactive disorder (ADHD), or improve cognition in normal subjects. Cancer patients treated with systemic adjuvant chemotherapy have described experiencing deterioration in cognition. Doxorubicin (DOX, Adriamycin) is one of the anthracycline families used in chemotherapy, which has a deteriorating effect on both cognition and proliferation. The cognitive effects of ATX require inputs from the hippocampus. The aim of this study was to examine spatial memory and proliferation in the subgranular zone (SGZ) of the DG in adult Lister Hooded rats treated either alone or with a combination of Atomoxetine (30 mg kg-1  day-1 , six i.p. doses, one injection every other day) and Doxorubicin (DOX) ( 2 mg kg-1  day-1 , six i.p. doses, one injection every other day). Spatial memory was tested using the Novel location recognition (NLR) test, and proliferation of hippocampal cells was quantified using immunohistochemistry for the proliferative marker Ki67. Results showed that ATX treatment has improved the NLR task and increased cell proliferation in the SGZ of the DG, compared with saline-treated controls. Animals treated with DOX only showed deficits in NLR task, and co-administration of ATX along with DOX did not improve their performance. DOX chemotherapy caused a significant reduction in the number of proliferating cells in the SGZ of the DG compared with saline-treated controls. This reduction was reversed by co-administration of ATX. The above findings suggest that DOX can negatively affect both cell proliferation and memory and ATX co-administration improves proliferation, but not memory in the adult male rat hippocampus.

Atomoxetine enhances memory and proliferation in adult male rat hippocampus

Atomoxetine (ATX) is a noradrenaline reuptake inhibitor used to treat Attention deficit hyperactive syndrome (ADHD), or improve cognition in normal subjects. The cognitive effects of ATX require inputs from the hippocampus. Moreover, proliferation is said to be located in the dentate gyrus (DG) of the hippocampus.In the present study, we hypothesised that ATX improves memory and proliferation of the adult rat hippocampus. To test this hypothesis, 5 intraperitoneal injections of ATX (30 mg/kg/day) over 5 consecutive days were delivered to rats. 30 minutes after the last injection, spatial memory was tested using the Novel location recognition (NLR) test. Proliferation of hippocampal cells was quantified using immunohistochemistry for the proliferative marker Ki67. ATX-treated rats showed cognitive enhancement in the NLR task and increase in cell proliferation in the Subgranular zone (SGZ) of the DG, compared to saline-treated controls. The results demonstrate that ATX is able to enhance cognition through increasing the levels of proliferation in the adult rat brains

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Effects of 5-FU.

5-fluorouracil (5-FU) is a chemotherapeutical agent used to treat cancers including breast and colorectal. Working as an antimetabolite to prevent cell proliferation, it primarily inhibits the enzyme thymidylate synthase blocking the thymidine formation required for DNA synthesis. Although having a relatively short half-life (< 30 mins) it readily enters the brain by passive diffusion. Clinically, it is used both as a single agent or in combination with other chemotherapies and has been associated with the long-term side effects of cognitive impairment, known as "chemo brain" or "chemo fog" These accounts have come primarily from patients undergoing treatment for breast cancer who report symptoms including confusion and memory impairment, which can last for months to years. Psychometric studies of patients have suffered from confounding variables, which has led to the use of rodent models to assess the cognitive effects of this drug. Researchers have used behavioral and physiological tests including the Morris water maze, novel object location/recognition tests, shock motivated T-maze, sensory gating and conditioning, to investigate the effect of this drug on cognition. The variety of cognitive tests and the difference in dosing and administration of 5-FU has led to varied results, possibly due to the different brain regions associated with each test and the subtlety of the drug's effect, but overall these studies indicates that 5-FU has a negative effect on memory, executive function and sensory gating. 5-FU has also been demonstrated to have biochemical and structural changes on specific regions of the brain. Evidence shows it can induce apoptosis and depress cell proliferation in the neurogenic regions of the adult brain including the sub granular zone (SGZ) within the hippocampus and in oligodendrocyte precursor populations within white matter tracts. Furthermore, investigations indicate levels ofdoublecortin, a marker for newly formed neurons and brain derived neurotrophic factor, a cell survival modulator, are also reduced by 5-FU in the SGZ. Thus, 5-FU appears to have a lasting negative impact on cognition and to affect cellular and biochemical markers in various brain regions. Further work is needed to understand the exact mechanisms involved and to devise strategies for the prevention or recovery from these symptoms.