Pablo Silva

Dr. Pablo Silva

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 January 2023 in Pharmaceuticals
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SASonaly Albino
Sonaly Albino
WMWillian Charles da Silva Moura
Willian Charles da Silva Moura
MRMalu Maria Lucas dos Reis
Malu Maria Lucas dos Reis
Gleyton Leonel Silva SousaGleyton Leonel Silva Sousa
Gleyton Leonel Silva Sousa
Pablo SilvaPablo Silva
Pablo Silva
RMRicardo Olímpio de Moura
Ricardo Olímpio de Moura
The present study proposed the synthesis of a novel acridine derivative not yet described in the literature, chemical characterization by NMR, MS, and IR, followed by investigations of its antileishmanial potential. In vitro assays were performed to assess its antileishmanial activity against L. amazonensis strains and cytotoxicity against macrophages through MTT assay and annexin V-FITC/PI, and the ability to perform an immunomodulatory action using CBA. To investigate possible molecular targets, its interaction with DNA in vitro and in silico targets were evaluated. As results, the compound showed good antileishmanial activity, with IC50 of 6.57 (amastigotes) and 94.97 (promastigotes) µg mL−1, associated with non-cytotoxicity to macrophages (CC50 > 256.00 µg mL−1). When assessed by flow cytometry, 99.8% of macrophages remained viable. The compound induced an antileishmanial effect in infected macrophages and altered TNF-α, IL-10 and IL-6 expression, suggesting a slight immunomodulatory activity. DNA assay showed an interaction with the minor grooves due to the hyperchromic effect of 47.53% and Kb 1.17 × 106 M−1, and was sustained by docking studies. Molecular dynamics simulations and MM-PBSA calculations propose cysteine protease B as a possible target. Therefore, this study demonstrates that the new compound is a promising molecule and contributes as a model for future works.

1 January 2021 in BioMed Research International
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JAJéssica C. Andrade
Jéssica C. Andrade
ÁMÁlefe B. Monteiro
Álefe B. Monteiro
HAHumberto H. N. Andrade
Humberto H. N. Andrade
TGThallita K. S. N. Gonzaga
Thallita K. S. N. Gonzaga
Pablo SilvaPablo Silva
Pablo Silva
RAReinaldo N. Almeida
Reinaldo N. Almeida
Hydroxycitronellal (HC) is a monoterpene present in essential oils of aromatic plants of different species, obtained from semisynthesis of citronellal, and is widely used as a fragrance in cosmetics. The objective of this work was to evaluate the possible anxiolytic‐like activity of HC and its possible mechanism of action using in vivo and in silico methodologies. Swiss male mice (Mus musculus) were treated with HC (12.5, 25, and 50 mg/kg, i.p.) and subjected to the rota rod, elevated plus maze, and open field tests. No significant impairments were observed in the rota rod tests for the motor activity of the animals treated with HC at 12.5, 25, and 50 mg/kg, i.p., indicating no myo‐relaxing or sedative effects. In the elevated plus maze, HC (in the three doses) induced significant increases in the percentage of entries (respectively, 34.8%, 33.8%, and 38.6%) and in the length of stay (respectively, 49.9%, 56.1%, and 57.0%) in the open arms of the EPM, as well as the number of crossings in the open field tests. The mechanism of action of the compound’s anxiolytic‐like activity can be attributed to the involvement of GABAA receptors, and this interaction was observed in in vivo and in silico studies. For HC, the results suggest anxiolytic‐like effects, possibly via modulation of the GABAergic system. The use of natural products to treat anxiety can become an alternative to existing synthetic products.

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Pablo SilvaPablo Silva
Pablo Silva
MAMaria de Almeida
Maria de Almeida
JSJamire Muriel Silva
Jamire Muriel Silva
SASonaly Albino
Sonaly Albino
RSRenan F. do Espírito Santo
Renan F. do Espírito Santo
ESEunice Lucia Maria dos Santos
Eunice Lucia Maria dos Santos
The compound (E)-2-cyano-3-(1H-indol-3-yl)-N-phenylacrylamide (ICMD-01) was designed and developed based on the structures of clinically relevant drugs indomethacin and paracetamol through the molecular hybridization strategy. This derivative was obtained by an amidation reaction between substituted anilines and ethyl 2-cyanoacetate followed by a Knoevenagel-type condensation reaction with indole aldehyde that resulted in both a viable synthesis and satisfactory yield. In order to assess the immunomodulatory and anti-inflammatory activity, in vitro assays were performed in J774 macrophages, and significant inhibitions (p < 0.05) of the production of nitrite and the production of cytokines (IL-1β and TNFα) in noncytotoxic concentrations were observed. The anti-inflammatory effect was also studied via CFA-induced paw edema in vivo tests and zymosan-induced peritonitis. In the paw edema assay, ICMD01 (50 mg kg−1) showed satisfactory activity, as did the group treated with dexamethasone, reducing edema in 2–6 h. In addition, there was no significant inhibition of PGE2, IL-1β or TNFα in vivo. Moreover, in the peritonitis assay that assesses leukocyte migration, ICMD-01 exhibited promising results. Therefore, these preliminary studies demonstrate this compound to be a strong candidate for an anti-inflammatory drug together with an improved gastrointestinal safety profile when compared to the conventional anti-inflammatory drugs.

12 March 2021 in Molecules
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MAMaria Elaine Araruna
Maria Elaine Araruna
Pablo SilvaPablo Silva
Pablo Silva
MAMaria Almeida
Maria Almeida
RRRenaly Rêgo
Renaly Rêgo
RDRaiff Dantas
Raiff Dantas
ESEunice Lucia Maria dos Santos
Eunice Lucia Maria dos Santos
Spondias mombin L. (Anacardiaceae) has a worldwide distribution and is present in all regions of Brazil. Its leaves, flowers and bark are used as teas in folk medicine to treat diseases of the digestive system. This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity, and the related mechanisms of action of nebulized extract and tablets based on dried Spondias mombin (SmNE). SmNE screening showed the presence of flavonoids (0.65%), polyphenols (25.50%), where the major compound is gallic acid. In the acute oral toxicity assay, a dose of 2000 mg/kg of SmNE administered orally in Swiss mice did not induce any behavioral changes. SmNE (250 or 500 mg/kg p.o) significantly reduced the ulcerative lesion area when compared to the control group in ethanol and non-steroidal anti-inflammatory drug (NSAIDs) models. Results showed that treatment with SmNE (250 mg/kg) reduced acid secretion and gastric content, accompanied with an increase in pH. Previous administration of indomethacin and glibenclamide reversed the protection provided by SmNE, confirming the participation of prostaglandins (PGs) and ATP-sensitive potassium channels (KATP) in its gastroprotective effect. The SmNE tablets met the pharmacopeial quality requirements with gastroprotective activity and similar protection in comparison to the isolated extract administrated. In conclusion, SmNe has a gastroprotective activity related to cytoprotective mechanisms, such as the participation of endogenous prostaglandins and KATP channels, having an anti-secretory effect with systemic action. The formulation obtained presented gastroprotective effects similar to the administration of the extract, the tablets showed favorable compression characteristics by the direct route and met the pharmacopeial quality requirements.

13 January 2022 in Pharmaceutics
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Pablo SilvaPablo Silva
Pablo Silva
RSRenan F. do Espírito Santo
Renan F. do Espírito Santo
CMCamila de Oliveira Melo
Camila de Oliveira Melo
Fábio Emanuel Pachú CavalcanteFábio Emanuel Pachú Cavalcante
Fábio Emanuel Pachú Cavalcante
TCThássia Costa
Thássia Costa
ESEunice Lucia Maria dos Santos
Eunice Lucia Maria dos Santos
The compound (E)-2-cyano-N,3-diphenylacrylamide (JMPR-01) was structurally developed using bioisosteric modifications of a hybrid prototype as formed from fragments of indomethacin and paracetamol. Initially, in vitro assays were performed to determine cell viability (in macrophage cultures), and its ability to modulate the synthesis of nitrite and cytokines (IL-1β and TNFα) in non-cytotoxic concentrations. In vivo, anti-inflammatory activity was explored using the CFA-induced paw edema and zymosan-induced peritonitis models. To investigate possible molecular targets, molecular docking was performed with the following crystallographic structures: LT-A4-H, PDE4B, COX-2, 5-LOX, and iNOS. As results, we observed a significant reduction in the production of nitrite and IL-1β at all concentrations used, and also for TNFα with JMPR-01 at 50 and 25 μM. The anti-edematogenic activity of JMPR-01 (100 mg/kg) was significant, reducing edema at 2–6 h, similar to the dexamethasone control. In induced peritonitis, JMPR-01 reduced leukocyte migration by 61.8, 68.5, and 90.5% at respective doses of 5, 10, and 50 mg/kg. In silico, JMPR-01 presented satisfactory coupling; mainly with LT-A4-H, PDE4B, and iNOS. These preliminary results demonstrate the strong potential of JMPR-01 to become a drug for the treatment of inflammatory diseases.

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DFDiogo Vilar Da Fonsêca
Diogo Vilar Da Fonsêca
JRJuliana Sousa Rocha
Juliana Sousa Rocha
Pablo SilvaPablo Silva
Pablo Silva
HPHugo Natan de Sá Novaes Pereira
Hugo Natan de Sá Novaes Pereira
LSLucas SANTOS
Lucas SANTOS
LUCIANA SCOTTILUCIANA SCOTTI
LUCIANA SCOTTI
Chronic pain significantly impacts quality of life and is often accompanied by inflammation, a natural bodily response that can become harmful when excessive. The orofacial region is commonly affected, making effective treatment crucial. However, current drugs often cause undesirable side effects, highlighting the need for new pharmacological alternatives. 4-hydroxycoumarin (4-HC), a natural compound, has shown promising antinociceptive and anti-inflammatory effects, but studies confirming its specific properties are limited. In silico analyses suggest that 4-HC exhibits favorable pharmacokinetic characteristics, not interacting with P-glycoprotein and successfully crossing the blood–brain barrier. Molecular docking studies indicate that its effects may be mediated through NMDAR or by inhibiting iNOS. Our study assessed the antinociceptive and anti-inflammatory effects of 4-HC in animal models at doses of 25, 50, and 75 mg/kg. 4-HC significantly reduced abdominal contortions induced by acetic acid and decreased nociceptive rubbing in orofacial pain models induced by formalin, glutamate, and capsaicin. Interactions with opioid receptors were not observed, suggesting that 4-HC’s antinociceptive effect does not involve this pathway. Additionally, 4-HC reduced paw edema induced by carrageenan and significantly decreased leukocyte migration and TNF-α levels. These findings highlight the therapeutic potential of 4-HC and warrant further investigation into its mechanisms.