RESUMO
Objective: The study was designed to assess the beneficial role of mangiferin (MGN) in lead (Pb)-induced neurological damages in the activation of Nrf2-governed enzymes, genes and proteins. Methods: A total of 96 weaned Wistar rats (48 males and 48 females, 26- to 27-day-old), weighing 50-80 g were used. The experiment was performed in six groups: normal group (control, n = 16), model group (chronic Pb exposed, n = 16), Dimercaptosuccinic acid (DMSA)-treated group (positive control, Pb + DMSA, n = 16), three MGN-treated groups with different doses (Pb + MGN, n = 48). Normal group freely had access to purified water. DMSA-treated group was given DMSA, which was clinically used as the standard treatment for moderate Pb poisoning, at 50 mg/kg (2 mL suspension with purified water) by intragastric gavage (ig) 4 continual days a week for 4 weeks, MGN-treated groups were given MGN at 50, 100, or 200 mg/kg (2 mL suspension with purified water) by ig daily for 4 weeks. At the end of the treatment, all rats were sacrificed and the brain samples were collected. The haematoxylin and eosin (H&E) staining was used for observation of histopathology. Commercial kit, real-time quantitative polymerase chain reaction (RT-qPCR), Western-blot and immunohistochemistry (IHC) detection were used to detect the mRNA and protein expression. Results: Eight weeks exposure to Pb-containing water resulted in pathological alterations, anti-oxidative system disorder in the brain, all of which were blocked by MGN in a Nrf2-dependent manner. Nrf2 downstream enzymes such as HO-1, NQO1, γ-GCS were activated. Nrf2, GCLC, GCLM, HO-1 mRNA and total Nrf2, Nuclear Nrf2, γ-GCS, HO-1 protein expression were affected too. Conclusion: MGN ameliorated morphological damage in the hippocampus. Its neuroprotective effects were achieved by the activation of the Nrf2 downstream genes. The data from this in vitro study indicates that MGN targeting Nrf2 activation is a feasible approach to reduce adverse health effects associated with Pb exposure. Thus, MGN could be an effective candidate agent for the Pb-induced oxidative stress and neurotoxicity in the human body.
RESUMO
OBJECTIVE: To explore the effect of extracts from the leaves of Phyllanthus emblica (PLFs) on the immune function of mice. METHODS: 70 Kunming mice were choosed to conduct the acute toxicity test of PLFs. The mice were randomly divided into four groups: PLFs high-dosage group, mid-dosage group, low-dosage group and control group. The high,mid,low-dosage groups were treated with PLFs 1.982, 0.991 and 0.496 g/kg respectively per day. The same volume of double distilled water was given to the control group. All by intragastric administration for 7 d. The animals were killed and indexes of thymus and spleen were calculated. The expurgation index K and phagocyte index a were detected after the mice being injected with a dilute India ink through caudal vein. In addition, prepared spleen cells conventionally,the activity of Natural Killer cells was measured and the proliferation of T and B cells were detected. The effect of the extracts on serum hemolysin was detected after the SRBC was injected into the enterocoelia. RESULTS: The LD50 of PLFs was 9. 911 g/kg. Compared with the control group, the indexes of thymus and spleen in the treatment groups had no markedly difference (P > 0.05). The high- and mid-dosage groups could obviously improve the expurgation index K (P < 0.05), phagocyte index alpha (P < 0.05) and NK cell activity (P < 0.05). CONCLUSION: The extracts from Phyllanthus emblica leaves can promote nonspecific immunity immune function in mice.
