Flavonoids: biological activities and therapeutic potential.

Flavonoids have aroused much interest in research, since they present a great diversity of biological activities observed in vitro, such as: antioxidant effect, modulation of the enzymatic activity and inhibition of cellular proliferation, exerting beneficial effects on the organism, as well as the use of its therapeutic potential. With wide distribution in the plant kingdom represent a class of phenolic compounds that differ in their chemical structure and particular characteristics. The objective of this review was to describe the relevant aspects of flavonoids, reporting the different known groups, the probable mechanisms by which they act, their pharmacological properties and to gain a better understanding of the reported beneficial health effects of these substances. This systematic review consisted of research using scientific databases such as Scopus, Science Direct, PubMed, SciVerse and SciELO, without time limitation. Some pharmacological properties of some flavonoids and their health benefits have been confirmed by previous studies.

Alpha-lipoic acid in the treatment of psychiatric and neurological disorders: a systematic review.

Despite the existence of many preclinical studies, scientific evidence is lacking on the clinical use of alpha-lipoic acid (ALA) for central nervous system disorders. Therefore, we aimed at revising the literature concerning the use of ALA for the treatment of psychiatric and neurological conditions and to point out what is missing for the introduction of this antioxidant to this purpose. For this systematic review we performed a search using PubMed and SCOPUS databases with the following keywords: "alpha-Lipoic Acid AND central nervous system OR psychiatric disorders OR neurological disorders OR mood disorders OR anxiety OR psychosis OR Alzheimer OR Parkinson OR stroke". The total number of references found after automatically and manually excluding duplicates was 1061. After primary and secondary screening 32 articles were selected. Regarding psychiatric disorders, the studies of ALA in schizophrenia are advanced being ALA administration related to the improvement of schizophrenia symptoms and side effects of antipsychotic medication. In neurological disorders, ALA as a supplement was effective in the prevention of Alzheimer disease progression. For stroke, the use of the supplement ALAnerv® (containing 300 mg ALA) presented important results, since it was observed a reversal of clinical parameters and oxidative imbalance in these patients. For other neurological conditions, such as encephalopathy, multiple sclerosis, traumatic brain injury, mitochondrial disorders and migraine, the results are still preliminary. Overall, there is a need of well-designed clinical trials to enhance the clinical evidences of ALA effects for the treatment of neurological and psychiatric conditions.

Standardized extract of Erythrina velutina Willd. attenuates schizophrenia-Like behaviours and oxidative parameters in experimental animal models.

OBJECTIVES: To study the effects of the standardized extract from the leaves of Erythrina velutina in behavioural and oxidative parameters in the ketamine-induced schizophrenia model. METHODS: Mice received ketamine (KET) or saline for 7 days. From 8th to 14th day, the animals received Erythrine (Eryt) (100, 200 or 400 mg/kg) or olanzapine (Olanz), 1 h after KET administration. At 14th day, 30 min after the last administration of KET, the open-field and pre-pulse inhibition (PPI) tests were performed. Then, the animals were sacrificed and the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) were dissected for the oxidative tests. KEY FINDINGS: Ketamine increased spontaneous locomotor activity and grooming. KET decreased the PPI, which was reversed by combining it with Eryt or olanzapine. KET decreased GSH concentration in PFC and ST this was reversed by Eryt. KET increased MDA concentration in PFC and HC this was reversed by Eryt. Eryt and Olanzapine reduced MDA concentration in ST when compared to KET group. Nitrite concentration was reduced by administration of KET in the PFC. CONCLUSIONS: These results demonstrate that the standardized extract of E. velutina can prevent behavioural symptoms and oxidative stress induced by repeated doses of KET.

Ivabradine possesses anticonvulsant and neuroprotective action in mice.

We analyzed whether ivabradine (IVA), a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker, clinically used for angina and arrhythmia, had anticonvulsant, antioxidant and neuroprotective properties against classical seizure models. Potential molecular targets to IVA anticonvulsant effects were evaluated by molecular docking. Mice were treated with IVA (1, 10 or 20 mg/kg, IP) for 3 days, and 30 min after the last administration were injected with pentylenetetrazole (PTZ - 85 mg/kg, IP), pilocarpine (PILO 400 mg/kg, SC), picrotoxin (PICRO 10 mg/kg, IP). The following measures were performed: presence of seizures, latency for the first seizure, latency for death, percentage of survival. Antioxidant activity was investigated by determination of lipid peroxidation (MDA), reduced glutathione (GSH) and nitrite levels in the prefrontal cortex (PFC), hippocampus and striatum (ST). Immunohistochemistry analysis for cleaved caspase-3, a pro-apoptotic and degenerative marker, in hippocampal subregions namely cornu ammonis (CA)1, CA3 and dentate gyrus (DG), were also performed. IVA attenuated PTZ- and PICRO-induced seizures while presented an antioxidant effect in all brain areas studied. IVA markedly reduced cleaved caspase-3 expression in the CA1 and DG region of PICRO- and PTZ-treated mice, respectively. Molecular docking demonstrated that IVA has high energetic affinity and binding compatibility for GABAA receptor without causing channel obstruction. However, no reproducibility in the binding of IVA to N-methyl-d-aspartate (NMDA) receptor was detected. In conclusion, IVA has anticonvulsant, antioxidant and neuroprotective effects against PTZ- and PICRO-induced seizures. Also, a high affinity of IVA to GABAA receptor was predicted, representing a potential underlying mechanism to these observable effects.