Anxiolytic and Anticonvulsant Effects of Fisetin Isolated from Bauhinia pentandra on Adult Zebrafish (Danio rerio).

Anxiety and epilepsy are common worldwide and represent a primary global health concern. Fisetin, a flavonoid isolated from Bauhinia pentandra, has a wide range of biological activities may be a promising alternative to combat diseases related to the central nervous system (CNS). The present study aimed to investigate the anxiolytic and anticonvulsant effects of fisetin on adult zebrafish. Furthermore, molecular docking simulations were performed to improve the results. Fisetin did not present toxicity and caused anxiolytic behavior and delayed seizures in animals. This effect may occur through serotonin neurotransmission at 5-HT3A and/or 5-HT3B receptors. Molecular docking simulations showed that fisetin interacts with the orthosteric site of the 5-HT3A receptor with strong H-bond interactions with the Trp156 residue, with a strong contribution from the catechol ring, a behavior similar to that of the antagonist co-crystallized inhibitor granisetron (CWB). Fisetin may be a promising alternative to combat diseases related to the central nervous system. Keywords anxiety • Bauhinia pentandra • Danio rerio • epilepsy • fisetin.

Withaphysalin Derivatives from Iochroma arborescens Induce Antiproliferative and Antimigratory Activities in vitro.

Withanolides are steroidal lactones commonly found in plants of the Solanaceae family that have significant medicinal value. In this study, three withanolides extracted from Iochroma arborescens leaves were isolated and characterized. These included withaphysalin F (3: ) and two newly identified epimeric compounds: 18R- and 18S-O-methyl-withaphysalin F (1: and 2: ). Their structures were elucidated by NMR, IR, MS, CD, and X-ray diffraction analysis, and their potential against cell proliferation and migration was investigated. The cytotoxic assay revealed activity against different tumor and non-tumor cell lines. (18S)-O-methyl-withaphysalin F (2: ) presented cell death effects after at least 6 hours of exposure. MDA-MB-231 cells were exposed to 0.06 and 0.6 µM of (18S)-O-methyl-withaphysalin F (2: ), and reductions in cell adhesion, migration, and clonogenicity were observed. Morphological analysis revealed negative regulation in filopodia, salience, and roughness, as well as alterations in cellular microarchitecture. These results provide clues as to the effects of (18S)-O-methyl-withaphysalin F (2: ), allowing new molecular modifications to improve potency and selectivity and increase our antineoplastic arsenal.

Screening of alkaloids and withanolides isolated from Solanaceae plants for antifungal properties against non-wild type Sporothrix brasiliensis.

Antifungal resistance has often been found in animal sporotrichosis in Southern Brazil. The biological potential of compounds from plants of the Solanaceae family against infectious diseases is known, however, it is still unknown against Sporothrix brasiliensis. This study evaluated the anti-Sporothrix brasiliensis activity, synergism, cytotoxicity, and action mechanism of steroidal lactones (withanolides) and alkaloids isolated from these plants. Pure compounds of withanolide D (WNOD), physalin F (PHYF), withanicandin (WNIC), nicandin B (NICB), solasonine (SSON), and solamargine (SMAR) were tested against 12 Sporothrix brasiliensis isolated from cats (n = 11) and dogs (n = 2) through M38-A2 CLSI. For the compounds with the best activity, a checkerboard assay for synergism, sorbitol protection, and ergosterol effect for action mechanism; and MTT test for cytotoxicity were performed. The withanolides WNOD, PHYF, WNIC, and NICB were not antifungal, but SSON (MIC 0.125-1 mg/mL) and SMAR (MIC 0.5-1 mg/mL) were both fungistatic and fungicidal (MFC 0.5-1 mg/mL for both) against wild-type (WT) and non-WT isolates. The activity of SSON and SMAR was indifferent when combined with itraconazole. In the mechanism of action, cell wall and plasma membrane by complexation with ergosterol seemed to be two target structures of SSON and SMAR. SSON was selected for cytotoxicity, whose cell viability in MDBK cells ranged from 28.85 % to 101.75 %, and was higher than 87.49 % at concentrations ≤0.0015 mg/ml. Only the steroidal alkaloids SSON and SMAR were active against non-WT isolates, being promising antifungal candidates for the treatment of feline and canine sporotrichosis with low susceptibility to itraconazole.

Hypoglycemic and hepatoprotective effects in adult zebrafish (Danio rerio) of fisetinidol isolated from Bauhinia pentandra: In vivo and in silico assays.

Diabetes mellitus is a chronic metabolic disorder that has been increasing drastically around the worldwide. It is important to emphasize that although many drugs are commercially available to treat diabetes, many of them have shown a number of adverse effects. Therefore, search for new antidiabetic agents is of great interest, and natural products, especially those obtained from plants sources, may be an alternative to available drugs. This study reports the in vivo and in silico evaluation of the hypoglycemic activity of fisetinidol. The conformational analysis confirmed that the fisetinidol compound possesses two valleys in the potential energy curve, showing a stable conformer on the global minimum of the PES defined by the dihedral angle θ (C6-C7-O-H) at 179.9°, whose energy is equal to zero. In addition, fisetinidol has shown promise in glycemic control and oxidative stress caused by hyperglycemia induced by high sucrose concentration, causing hypoglycemic and hepatoprotective effects in adult zebrafish. ADMET studies showed that fisetinidol has high passive permeability, low clearance and low toxic risk by ingestion, and computational studies demonstrated that fisetinidol complexes in the same region as metformin and α-acarbose, which constitutes a strong indication that fisetinidol has the same inhibitory mechanisms of α-acarbose and metformin.Communicated by Ramaswamy H. Sarma.

Chromomycin A5 induces bona fide immunogenic cell death in melanoma.

Purpose: Some first-line cytotoxic chemotherapics, e.g. doxorubicin, paclitaxel and oxaliplatin, induce activation of the immune system through immunogenic cell death (ICD). Tumor cells undergoing ICD function as a vaccine, releasing damage-associated molecular patterns (DAMPs), which act as adjuvants, and neoantigens of the tumor are recognized as antigens. ICD induction is rare, however it yields better and long-lasting antitumor responses to chemotherapy. Advanced metastatic melanoma (AMM) is incurable for more than half of patients. The discovery of ICD inducers against AMM is an interesting drug discovery strategy with high translational potential. Here we evaluated ICD induction of four highly cytotoxic chromomycins A (CA5-8). Methods: ICD features and DAMPs were evaluated using several in vitro techniques with metastatic melanoma cell line (B16-F10) exposed to chromomcins A5-8 such as flow cytometry, western blot, RT-PCR and luminescence. Additionally in vivo vaccination assays with CA5-treated cells in a syngeneic murine model (C57Bl/6) were performed to confirm ICD evaluating the immune cells activation and their antitumor activity. Results: B16-F10 treated with CA5-8 and doxorubicin exhibited ICD features such as autophagy and apoptosis, externalization of calreticulin, and releasing of HMGB1. However, CA5-treated cells had the best profile, also inducing ATP release, ERp57 externalization, phosphorylation of eIF2α and altering expression of transcription of genes related to autophagy, endoplasmic reticulum stress, and apoptosis. Bona fide ICD induction by CA5 was confirmed by vaccination of C57BL/6 mice with CA5-treated cells which activated antigen-presenting cells and T lymphocytes and stimulated antitumor activity. Conclusion: CA5 induces bona fide immunogenic cell death on melanoma.

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.