Gerardo Cristino Filho

Lectins from the Red Marine Algal Species Bryothamnion seaforthii and Bryothamnion triquetrum as Tools to Differentiate Human Colon Carcinoma Cells

The carbohydrate-binding activity of the algal lectins from the closely related red marine algal species Bryothamnion triquetrum (BTL) and Bryothamnion seaforthii (BSL) was used to differentiate human colon carcinoma cell variants with respect to their cell membrane glyco-receptors. These lectins interacted with the cells tested in a dose-dependent manner. Moreover, the fluorescence spectra of both lectins clearly differentiated the cells used as shown by FACS profiles. Furthermore, as observed by confocal microscopy, BTL and BSL bound to cell surface glycoproteins underwent intense internalization, which makes them possible tools in targeting strategies.

Neuroprotective Effects of Sulphated Agaran from Marine Alga Gracilaria cornea in Rat 6-Hydroxydopamine Parkinson's Disease Model: Behavioural, Neurochemical and Transcriptional Alterations.

Parkinsons disease (PD) is a multifactorial disease associated with the degeneration of dopaminergic neurons and behavioural alterations. Natural bioactive compounds may provide new therapeutic alternatives for neurodegenerative disorders, such as PD. The sulphated polysaccharides isolated from marine algae are heterogenic molecules that show different biological activities. The red marine alga Gracilaria cornea has a sulphated polysaccharide (SA‐Gc) with structure and anti‐inflammatory and antinociceptive activities reported in the literature. Therefore, this study aimed to evaluate the neuroprotective effects of SA‐Gc in rat model PD induced by 6‐hydroxydopamine (6‐OHDA). Firstly, we established the PD model in rats, induced by an intrastriatal injection (int.) of 6‐OHDA, followed by a single administration of SA‐Gc (15, 30 or 60 μg; int.). On the 14th day, behavioural tests were performed. After killing, brain areas were dissected and used for neurochemical and/or transcriptional analyses. The results showed that SA‐Gc (60 μg, int.) promoted neuroprotective effects in vivo through reducing the oxidative/nitroactive stress and through alterations in the monoamine contents induced by 6‐OHDA. Furthermore, SA‐Gc modulated the transcription of neuroprotective and inflammatory genes, as well as returning behavioural activities and weight gain to normal conditions. Thus, this study reports the neuroprotective effects of SA‐Gc against 6‐OHDA in rats.

Αlpha-2 Adrenergic and Opioids Receptors Participation in Mice Gastroprotection of Abelmoschus esculentus Lectin

Lectins are a heterogeneous group of proteins and glycoproteins with potential role as therapeutic and diagnostic tools to combat various diseases, besides some functions on human organism. Abelmoschus esculentus (Okra), a horticultural plant of African origin, is cultivated in northeastern Brazil, and used for different medicinal purposes. This work is aimed to elucidate the action mechanisms of Abelmoschus esculentus lectin (AEL) gastro protective effect on gastropathy induced by ethanol. Fasted mice treated with Ethanol 99.9% (0.2 ml/animal, p.o.) received previously AEL (0.01, 0.1, 1.0, 10 or 50 mg/kg, i.v.), saline (5 ml/kg; i.v.) or ranitidine (80 mg/kg, p.o.) in four experimental series, in which pharmacological tools (yohimbine, naloxone, L-NAME or indomethacin), were administered with the purpose of make clear possible molecular action mechanisms. Mice were euthanized 30 min after ethanol challenge to verify the stomach damages. Establishment of gastric oxidative stress, tissue hemoglobin (Hb) content and microscopic features (H&E) were taken in order to characterize the AEL gastro protective effect. AEL (1 mg/kg) was capable of protect mucosa against ethanol damages in presence of two (L-NAME and indomethacin) of four antagonists/inhibitors used. The AEL effect was reversed by naloxone and yohimbine, showing the involvement of opioids and Αlpha-2 adrenergic receptors on gastric protective effect of this lectin. Evaluation of microscopic features, oxidative stress, and Hb levels pointed the protective effects of AEL. This activity seems to be mediated by alpha-2 adrenergic and opioid receptors activation. Nitric oxide or prostaglandins were not involved. AEL simultaneously showed antioxidant effect that is probably implicated in its intricate defensive mechanism of action.

Lectin from seeds of a Brazilian lima bean variety (Phaseolus lunatus L. var. cascavel) presents antioxidant, antitumour and gastroprotective activities.

Lectins are proteins able to interact specifically and reversibly with carbohydrates. They are present in all living beings, particularly in legume seeds, which have many biological functions. The aim of this study was to isolate, characterize and verify antioxidant, anti-hemolytic, antitumor and gastroprotective activities in a lectin present in seeds of Phaseolus lunatus L. var. cascavel (PLUN). The isolation of lectin was performed by size exclusion chromatography on Sephadex G-100, which was isolated from a protein capable of agglutinating only human erythrocytes type A, being this the only inhibited haemagglutination n-acetyl-d-galactosamine. Its weight was estimated by PAGE is 128kDa. The lectin is thermostable up to 80°C and is active between pH 2-11. As 8M urea was able to denature the lectin. PLUN is a glycoprotein consisting of 2% carbohydrate and has antioxidant action with ascorbic acid equivalent antioxidant capacity (μMAA/g) of 418.20, 326 and 82.9 for total antioxidant activity, ABTS radical capture and capture of DPPH radical, respectively. The lectin has antitumor activity against melanoma derived cells at doses of 100 and 50mg/ml, reducing up to 83% tumor cells, and gastroprotective action, reducing up to 63% damaged area of ​​the stomach induced by ethanol.

Impact of the Chronic Omega‐3 Fatty Acids Supplementation in Hemiparkinsonism Model Induced by 6‐Hydroxydopamine in Rats

Parkinsons disease (PD) is characterized by a progressive degeneration of dopaminergic neurons in the substantia nigra. The neuronal degeneration may result from the convergence of a number of different pathogenic factors, including apoptosis, excitotoxicity and oxidative stress. Many studies emphasize the importance of omega‐3 polyunsaturated fatty acids (ω‐3 PUFAs) in vital processes such as maintenance of the properties of cell membranes and the participation in signal transduction and biodynamic activity of neuronal membranes. In this study, the protective effect of ω‐3 PUFA administration on the 6‐hydroxydopamine (6‐OHDA) model of PD in rats was investigated. ω‐3 PUFA (1.5 and 3.0 g/kg) was orally administered by gavage during 28 consecutive days to male Wistar rats. On the 4th day, hemiparkinsonism was induced through intrastriatal injection of 6‐OHDA. On the 25th day, the animals were submitted to behavioural analysis. On the 28th day, after euthanasia, the brain areas were collected for neurochemical evaluation. ω‐3 PUFAs (1.5 and 3.0 g/kg) restored monoamine and amino acid levels on the striatum from hemiparkinsonian rats, followed by reduction in the number of apomorphine‐induced rotations and promotion of a partial locomotor recovery. In addition, ω‐3 PUFAs (1.5 and 3.0 g/kg) decreased the lipid peroxidation levels and nitrite levels in the brain areas from hemiparkinsonian rats. Thus, this study suggests that supplementation with ω‐3 PUFAs prevents behavioural and neurochemical disturbances induced by 6‐OHDA, presenting a potential neuroprotective action.

Aneurisma gigante do segmento intracavernoso da carótida interna associado a doença renal policística autossômica dominante: relato de caso

We report the case of a 60 years-old woman with autosomal dominant polycystic kidney disease (ADPKD) that presented with headache and right complete ophthalmoplegia. The CT scan raised the possibility of a giant aneurysm of the right intracavernous internal carotid artery, confirmed by angiography. The patient underwent endovascular occlusion of parent vessel with detachable coils, then she presented interruption of headache and partial recovery of ptosis and ophthalmoplegia. We emphasize the relationship between ADPKD and intracranial aneurysms. We also discuss the natural history and compare the therapeutic options for the management of giant aneurysms of the cavernous portion of the carotid artery.

Antinociceptive, anti-inflammatory and toxicological evaluation of semi-synthetic molecules obtained from a benzyl-isothiocyanate isolated from Moringa oleifera Lam. in a temporomandibular joint inflammatory hypernociception model in rats

Inflammation is a key component of many clinical conditions that affect the temporomandibular joint (TMJ) and Moringa oleifera Lam. has been used to treat inflammatory diseases. Here, we evaluated the toxicological effects on mice of a naturally-occurring isothiocyanate from M. oleifera and its seven analogue molecules. Further, the anti-nociceptive and anti-inflammatory effects on a rat model of TMJ inflammatory hypernociception were assessed. The systemic toxicological profile was determined in mice over a 14-day period: MC-1 1 μg/kg; MC-D1 1 μg/kg, MC-D3 100 μg/kg, MC-D6 1 μg/kg, MC-D7 1 μg/kg, MC-D8 1 μg/kg, MC-D9 10 μg/kg, and MC-H 1 μg/kg. The safest molecules were assayed for anti-nociceptive efficacy in the formalin (1.5%, 50 μL) and serotonin (255 mg) induced TMJ inflammatory hypernociception tests. The anti-inflammatory effect was evaluated through the vascular permeability assay using Evans blue. Further, the rota-rod test evaluated any motor impairment. Among the tested molecules, MC-D7, MC-D9, and MC-H were not toxic at the survival rate test, biochemical, and hystological analysis. They reduced the formalin-induced TMJ inflammatory hypernociception, but only MC-H decreased the serotonin-induced TMJ inflammation, suggesting an adrenergic receptor-dependent effect. They diminished the plasmatic extravasation, showing anti-inflammatory activity. At the rota-rod test, no difference was observed in comparison with control groups, reinforcing the hypothesis of anti-nociceptive effetc without motor impairment in animals. The analogues MC-D7, MC-D9, and MC-H were safe at the tested doses and efficient in reducing the formalin-induced TMJ hypernociception in rats. Our next steps include determining their mechanisms of anti-nociceptive action.

The efficacy of a lectin from Abelmoschus Esculentus depends on central opioid receptor activation to reduce temporomandibular joint hypernociception in rats

Abelmoschus esculentus is largely cultivated in Northeastern Brazil for medicinal purposes, e.g. inflammatory conditions. This study aimed to evaluate the efficacy of Abelmoschus esculentus lectin (AEL) in reducing formalin-induced temporomandibular joint inflammatory hypernociception in rats. The behavioral experiments were performed in male Wistar rats (180-240 g). Rats were pre-treated (i.v.) with AEL (0.001, 0.01 or 0.1 mg/kg) 30 min before formalin injection (i.art.). To analyze the possible effect of opioid pathways on AEL efficacy, animals were pre-treated with naloxone or CTOP (μ opioid receptor antagonist), naltrindole (δ opioid receptor antagonist) or nor-binaltorphimine (κ opioid receptor antagonist) (i.t.) 15 min before AEL administration followed by intra-TMJ injection of 1.5% formalin. Animals were monitored for a 45-min observation period. TMJ tissue, trigeminal ganglion, and subnucleus caudalis were collected for TNF-α dosage (ELISA). In addition, the vascular permeability was evaluated by Evans Blue extravasation. AEL significantly reduced formalin-induced TMJ inflammatory hypernociception and decreased Evans blue extravasation. It decreased TNF-α levels in the TMJ tissue, trigeminal ganglion, and subnucleus caudalis. AEL antinociceptive effects were not observed in the presence of naltrindole or nor-binaltorphimine, suggesting that AEL efficacy depends on TNF-α inhibition and the activation of δ and κ opioid receptors. AEL has provided prominent analgesic and anti-inflammatory effects in this pre-clinical model of TMJ, supporting its possible use as a pharmacological tool for the management of painful conditions.