Preclinical safety assessment of the crude extract from Sida rhombifolia L. aerial parts in experimental models of acute and repeated-dose 28 days toxicity in rats.

Sida rhombifolia (Malvaceae) is popularly used as a treatment for several pathological conditions; however, there is a lack of studies that identify its compounds and that evaluate comprehensively the safety of its consumption. Therefore, the aim of this study was to determinate the phytochemical constitution of the crude extract of Sida rhombifolia (CESR), and its safety in models of acute and repeated doses (28 days) toxicity. The tested dose for the model of acute toxicity was 2000 mg/kg doses for the repeated dose model were 150, 300 e 600 mg/kg. Hematological, biochemical, histopathological and oxidative markers were investigated. HPLC-DAD-MS analysis evidenced the presence of caffeic acid, coumarin, and rutin. In the acute toxicity model the only altered parameters were tissue ROS, and AST and BUN in serum. As for the repeated dose experiment both hematological and biochemical markers remained within the values of reference for the species. Obtained results demonstrate that the CESR did not present significant toxic effects when administrated orally to male and female rats in acute and repeated doses.

Tucumã (Astrocaryum aculeatum) prevents memory loss and oxidative imbalance in the brain of rats with hyperlipidemia.

Hyperlipidemia generates deposition of lipids, inflammation, and oxidative damage in cells and tissues, including those of the brain. Tucumã (Astrocaryum aculeatum) fruits contain bioactive compounds with antioxidant and anti-inflammatory effects. We evaluated the action of Tucumã extract on memory and brain cortex redox balance in hyperlipidemic rats. For 30 days, Wistar rats received Tucumã extract (250 mg/kg). Then, hyperlipidemia was induced by intraperitoneal administration of Poloxamer-407. Twenty-four hours later, the object recognition index was measured. The animals were euthanized for sample collection 36 hr postinduction. Hyperlipidemic animals showed memory loss and an imbalance between reactive species and intrinsic antioxidants. We found that Tucumã prevented memory loss and protein and lipid oxidative damage and prompted a better antioxidant response in the cerebral cortex of rats with hyperlipidemia. These findings suggest a neuroprotective effect and nutraceutical potential of Tucumã. PRACTICAL APPLICATIONS: In the present work, we demonstrated that induced hyperlipidemia in rats caused memory loss and redox unbalance, both factors prevented by the administration of Tucumã (Astrocaryum aculeatum) extract. Two aims were fulfilled with these results. The first was to show that hyperlipidemia affected brain function through oxidative damage and concerned basic research. The second was to offer a therapy that prevented this harm and could be applied in the clinic. Tucumã has ethnopharmacological importance through the consumption of fruits or the administration of extracts and oils by a population that was shown to enjoy improved health and longevity. Here, we show evidence that Tucumã contributes to the maintenance of brain health by preventing memory loss and oxidative damage, a nutraceutical supplement that may aid the prevention of vascular, inflammatory, and brain diseases.

Antioxidant, hepatoprotective, genoprotective, and cytoprotective effects of quercetin in a murine model of arthritis.

Rheumatoid arthritis is a highly debilitating inflammatory autoimmune disease which is characterized by joint destruction. The present study sought to investigate the effect of quercetin in rats with complete Freund's adjuvant-induced arthritis. Animals were divided into control/saline, control/quercetin (5 mg/kg, 25 mg/kg, and 50 mg/kg) arthritis/saline, and arthritis/quercetin (5 mg/kg, 25 mg/kg, and 50 mg/kg); the treatments were administered for 45 days. Biochemical, oxidative stress, genotoxicity, and cytotoxicity parameters were evaluated. All doses of quercetin reduced the levels of aspartate aminotransferase, thiobarbituric acid-reactive substances, and reactive oxygen species; however, only treatment with 25 or 50 mg/kg increased catalase activity. Total thiol and reduced glutathione levels were not significantly affected by the induction nor by the treatments. Genotoxicity assessed by DNA damage, and cytotoxicity through picogreen assay, decreased after treatments with quercetin. Our results present evidence of the antioxidant, cytoprotective, genoprotective and hepatoprotective, and effects of quercetin, demonstrating its potential as a candidate for coadjuvant therapy.

Berberine protects against memory impairment and anxiogenic-like behavior in rats submitted to sporadic Alzheimer's-like dementia: Involvement of acetylcholinesterase and cell death.

The present study aimed to investigate the effects of berberine (BRB) on spatial and learning memory, anxiety, acetylcholinesterase activity and cell death in an experimental model of intracerebroventricular streptozotocin (ICV-STZ) induced sporadic Alzheimer's-like dementia. Sixty male Wistar rats were randomly divided into six groups: control (CTR), BRB 50mg/kg (BRB 50), BRB 100mg/kg (BRB 100), streptozotocin (STZ), streptozotocin plus BRB 50mg/kg (STZ+BRB 50), and streptozotocin plus BRB 100mg/kg (STZ+BRB 100). Rats were injected with ICV-STZ (3mg/kg) or saline, and daily oral BRB treatment began on day 4 for a period of 21days. Behavioral tests were carried out on day 17, and rats were euthanized on day 24. Cell death analysis and determination of acetylcholinesterase activity was performed on the cerebral cortex and hippocampus of the brain. Administration of BRB prevented the memory loss, anxiogenic behavior, increased acetylcholinesterase activity and cell death induced by ICV-STZ. This may be explained, in part, by a protective effect of BRB on ameliorating the progression of neurodegenerative diseases, including Alzheimer's disease, and the results of this study provide a better understanding of the effect of BRB on the brain. Thus, BRB may act as a potential neuroprotective agent.