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Gallic acid (GA) is a powerful antioxidant extracted from plants of the Brazilian Cerrado. Oxidative stress plays an important role in the occurrence of radiation-induced osteonecrosis in patients treated for head and neck cancer. There is a need to develop research aimed at developing complementary therapies to prevent or reverse bone damage. The aim of the present study was to investigate the effect of GA in preosteoblasts exposed to therapeutic ionizing radiation. MC3T3-E1 preosteoblast cells were treated with 10 µM GA and exposed to 6 Gy ionizing radiation. We performed in vitro assays of cell proliferation, oxidative stress analysis by detection of reactive oxygen species, and alkaline phosphatase assay. GA at lower concentrations was able to significantly increase proliferation and inhibit radiation-induced generation of reactive oxygen species in osteoblast precursor cells, despite ionizing radiation-induced injury. Furthermore, GA significantly increased alkaline phosphatase at a dose of 6 Gy. The findings suggested that GA could attenuate ionizing radiation-induced injuries in osteoblast precursor cells. Moreover, in vivo studies are needed to better investigate the role of GA in osteonecrosis, especially in cancer patients undergoing radiotherapy or taking antiresorptive drugs.
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The present work reports the inhibitory effect of amides derived from gallic acid (gallamides) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro), along with cytotoxicity evaluation and molecular docking studies. In addition to gallamides, other relevant compounds were also synthesized and evaluated against Mpro, making a total of 25 compounds. Eight compounds presented solubility issues during the inhibitory assay and one showed no inhibitory activity. Compounds 3a, 3b, and 3f showed the highest enzymatic inhibition with IC50 = 0.26 ± 0.19 µM, 0.80 ± 0.38 µM, and 2.87 ± 1.17 µM, respectively. Selenogallamide 6a exhibited IC50 values of 5.42 ± 2.89 µM and a comparison with its nonselenylated congener 3c shows that the insertion of the chalcogen moiety improved the inhibitory capacity of the compound by approximately 10 times. Regarding the cellular toxicity in THP-1 and Vero cells, compounds 3e and 3g, showed moderate cytotoxicity in Vero cells, while for THP-1 both were nontoxic, with CC50 > 150 µM. Derivative 3d showed moderate cytotoxicity against both cell lines, whereas 6d was moderatly toxic to THP-1. Other compounds analyzed do not induce substantial cellular toxicity at the concentrations tested. The molecular docking results for compounds 3a, 3b, and 3f show that hydrogen bonding interactions involving the hydroxyl groups (OH) of the gallate moiety are relevant, as well as the carbonyl group.
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Glycosyltransferases catalyze the transfer of a glycoside group to a wide range of acceptor compounds to produce glycoconjugates with diverse biological and pharmacological activities. The present work reports the identification and biochemical characterization of Nicotiana tabacum UGT89A2 glycosyltransferase (NtUGT89A2). The enzyme is a monomer in solution that catalyzes the O-ß-glucosylation of di- and tri-hydroxylated and chlorinated derivatives of benzoic acid. NtUGT89A2 has a preference for 2,5-dihydroxybenzoic acid (2,5-DHBA) over 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,4-dihydroxybenzoic acid (2,4-DHBA). Other substrates that can be used by NtUGT89A2 include 3,4,5-trihydroxybenzoic acid and chlorinated derivatives such as 2-chloro-5-hydroxybenzoic acid (2-Cl-5-HBA). The substrates of NtUGT89A2 were identified by thermal stability experiments, where we observed a maximum increase of the thermal denaturation midpoint (Tm) of 10 °C in the presence of 2,5-DHBA and UDP-glucose. On the other hand, the highest specific activity was obtained with 2,5-DHBA (225 ± 1.7 nkat/mg). Further characterization revealed that the enzyme has a micromolar affinity for its substrates. Notably, the enzyme retains full activity after incubation at 70 °C for 1 h. These results provide a basis for future functional and structural studies of NtUGT89A2.
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Glicosiltransferases , Nicotiana , Nicotiana/enzimologia , Glicosilação , Glicosiltransferases/metabolismo , Glicosiltransferases/química , Estrutura Molecular , Ácido Benzoico/química , Ácido Benzoico/metabolismo , Benzoatos/química , Benzoatos/metabolismo , BiocatáliseRESUMO
Obesity and overweight are multifactorial diseases affecting more than one-third of the world's population. Physical inactivity contributes to a positive energy balance and the onset of obesity. Exercise combined with a balanced diet is an effective non-pharmacological strategy to improve obesity-related disorders. Gallic acid (GA), is a natural endogenous polyphenol found in a variety of fruits, vegetables, and wines, with beneficial effects on energetic homeostasis. The present study aims to investigate the effects of exercise training on obese mice supplemented with GA. Animal experimentation was performed with male Swiss mice divided into five groups: ST (standard control), HFD (obese control), HFD + GA (GA supplement), HFD + Trained (training), and HFD + GA + Trained (GA and training). The groups are treated for eight weeks with 200 mg/kg/body weight of the feed compound and, if applicable, physical training. The main findings of the present study show that GA supplementation improves liver fat, body weight, adiposity, and plasma insulin levels. In addition, animals treated with the GA and a physical training program demonstrate reduced levels of anxiety. Gene expression analyses show that Sesn2 is activated via PGC-1α independent of the GATOR2 protein, which is activated by GA in the context of physical activity. These data are corroborated by molecular docking analysis, demonstrating the interaction of GA with GATOR2. The present study contributes to understanding the metabolic effects of GA and physical training and demonstrates a new hepatic mechanism of action via Sestrin 2 and PGC-1α.
Assuntos
Ácido Gálico , Fígado , Camundongos Obesos , Obesidade , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Condicionamento Físico Animal , Animais , Camundongos , Ácido Gálico/farmacologia , Masculino , Fígado/metabolismo , Fígado/efeitos dos fármacos , Obesidade/metabolismo , Obesidade/genética , Obesidade/tratamento farmacológico , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Ansiedade/tratamento farmacológico , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Dieta Hiperlipídica/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , SestrinasRESUMO
The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.
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Adenocarcinoma , Antineoplásicos , Neoplasias do Colo , Humanos , Camundongos , Animais , Extratos Vegetais/química , Casca de Planta/química , Dano ao DNA , Água , Mutagênicos , Células MCF-7RESUMO
BACKGROUND/AIM: Enzyme-mediated grafting of poly (gallic acid) (PGAL) and L-arginine and a-L-lysine onto PGAL produces reactive oxygen species (ROS)-suppressor multiradical molecules with low cytotoxicity, high thermostability and water solubility with cancer treatment potential. This study examined the anticancer effects of these molecules in hepatic (HepG2, ATCC HB-8065), breast (MCF7, ATCC HTB-22), and prostate (PC-3, ATCC CRL-1435 and DU 145, ATCC HTB-81) cancer cell lines, as well as in fibroblasts from healthy human skin as control cells. MATERIALS AND METHODS: PGAL was synthesized by the oxidative polymerization of the naturally abundant GA using laccase from Trametes versicolor. Insertions of amino acids L-arginine and α-L-lysine on the PGAL chain were carried out by microwave. The cells of dermal fibroblast (Fb) were obtained from primary skin cultures and isolated from skin biopsies. The cancer cells lines of hepatic (HepG2), breast (MCF7), and prostate (PC-3, DU 145) were obtained from ATCC. The viability of the cancer cells and the primary culture was obtained by the MTT assay. Proliferation was demonstrated by crystal violet assay. Cell migration was determined by Wound healing assay. Finally, cell cycle analysis was carried out with cells. RESULTS: The results show that 200 µg/ml of PGAL cultured in vitro with prostate cancer cells decreased viability, proliferation, and migration, as well as arrested cells in the G1 and S phases of the cell cycle. In contrast, the dermal fibroblasts and the hepatic line remained unaffected. The random grafting of L-Arg and a-L-Lys onto the PGAL chain also decreased the viability of prostate cancer cells. CONCLUSION: PGAL and PGAL-grafted amino acids are potential adjuvants for prostate cancer treatment, with improved physicochemical characteristics compared to GA.
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Ácido Gálico , Neoplasias da Próstata , Salicilatos , Masculino , Humanos , Ácido Gálico/farmacologia , Lisina , Trametes , Neoplasias da Próstata/patologia , Células MCF-7 , Arginina/farmacologia , Proliferação de CélulasRESUMO
ABSTRACT Cutaneous leishmaniasis, caused by protozoa of the genus Leishmania, presents diverse clinical manifestations, and current therapeutic options have limitations, including long treatment periods, potential hospitalization, and excessive pain during treatment. Methyl gallate, a phenolic compound found in plants such as Libidibia ferrea, presents promising antileishmanial activity. Combining this compound with existing leishmaniasis medications could lead to reduced dosages and the minimization of side effects. This study aimed to assess the efficacy of a microemulsion containing methyl gallate, either on its own or in combination with Glucantime®, for the experimental treatment of cutaneous leishmaniasis in a 30-day in vivo assay using golden hamsters infected with Leishmania (Leishmania) amazonensis. The control groups included an untreated positive control and an uninfected, untreated negative control. After treatment, we evaluated clinical, parasitological, and biochemical parameters. While none of the treatments achieved clinical or parasitological cure, notable improvements were observed in the combined group, with significant reductions in snout skin lesions and parasite load when compared to the control. Biochemical parameters such as creatinine, CK-MB, GOT, and GPT remained unchanged, but urea and CPK levels significantly increased in all the experimental groups relative to the control. In conclusion, the integration of a topical methyl gallate microemulsion with intralesional Glucantime® showed potential as an effective treatment for cutaneous leishmaniasis. Further investigations into optimal dosages and therapeutic schemes are warranted in order to enhance treatment outcomes.
RESUMO A leishmaniose cutânea, causada por protozoários do gênero Leishmania, apresenta diversas manifestações clínicas e as opções terapêuticas atuais têm limitações, incluindo longos períodos de tratamento, possível hospitalização e dor excessiva durante o tratamento. O galato de metila, um composto fenólico encontrado em plantas como Libidibia ferrea, mostra atividade antileishmania promissora. A combinação deste composto com os medicamentos existentes para leishmaniose pode levar a dosagens reduzidas e à minimização dos efeitos colaterais. Este estudo teve como objetivo avaliar a eficácia de uma microemulsão contendo galato de metila, isoladamente ou em combinação com Glucantime®, no tratamento experimental da leishmaniose cutânea em um ensaio in vivo de 30 dias em hamsters sírios infectados com Leishmania (Leishmania) amazonensis. Os grupos de controle incluíram um controle positivo não tratado e um controle negativo não infectado e não tratado. Após o tratamento, avaliamos parâmetros clínicos, parasitológicos e bioquímicos. Embora nenhum dos tratamentos tenha alcançado cura clínica ou parasitológica, melhorias notáveis foram observadas no grupo combinado, com redução significativa nas lesões cutâneas do focinho e na carga parasitária em comparação com o controle. Parâmetros bioquímicos como creatinina, CK-MB, TGO e TGP permaneceram inalterados, os níveis de ureia e CPK aumentaram significativamente em todos os grupos experimentais em relação ao controle. Em conclusão, a integração da microemulsão tópica de galato de metila com Glucantime® intralesional mostrou potencial como um tratamento eficaz para a leishmaniose cutânea. Mais investigações sobre dosagens ideais e esquemas terapêuticos são necessárias para melhorar os resultados do tratamento.
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Sestrins (SESNs) are a family of evolutionarily conserved proteins among mammals. They have several body homeostatic functions such as antioxidant, metabolic, and anti-aging, and are required to regenerate hyperoxidized forms of peroxiredoxins and reactive oxygen species. Sestrin 2 has been studied as a therapeutic agent in obesity treatment. Gallic acid (GA) is a triphenolic compound with beneficial biological activities including anti-inflammatory, antidiabetic, antihypertensive, and antioxidant effects. Recent studies demonstrated the GA's ability to reduce body weight gain and improve glycemic parameters. In this sense, the present study aims to investigate the GA activating potential of Sestrin using the molecular docking method. The 3D structure of gallic acid was retrieved from the NCBI PubChem database and the chemical structure of the Sestrin2 protein from the RCSB Protein Data Bank (5DJ4). The docking calculus was performed via UCSF Chimera and AutoDock Vinaprograms. The results showed that amino acids Arg390, Glu451, Trp444, Thr386, Arg448, Thr374, Tyr375, Asn376, Thr377, Leu389, His454, Ser450, His86, and Val455 are very important for GA stabilization, resembling the interactions that permit Leucine to activate SESN2. In this context, the obesity therapeutic property of GA can be understood from a Sestrin activating process through amino acid metabolism.
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Ácido Gálico , Sestrinas , Animais , Simulação de Acoplamento Molecular , Ácido Gálico/farmacologia , Ácido Gálico/uso terapêutico , Obesidade/tratamento farmacológico , Antioxidantes , MamíferosRESUMO
Polygallic acid (PGAL) has been used in vitro to protect synoviocytes from monosodium urate (MSU) crystals due to its anti-inflammatory properties. However, MSU crystals can also activate other cells of the synovial fluid (SF). We studied the impact of PGAL on the phagocytosis of MSU crystals, inflammation, and oxidative stress using an in vitro model with SF leukocytes and THP-1 monocyte cells. SF leukocytes were stimulated with PGAL and MSU crystals, proinflammatory cytokines and phagocytosis were assessed. In THP-1 cells, the effect of PGAL on the phagocytosis of MSU crystals and the levels of IL-1ß, IL-6, TNF-α, and reactive oxygen species (ROS) was evaluated. PGAL was added to THP-1 cultures 24 h before MSU crystal addition as a pre-treatment, and IL-1ß was measured. One-way ANOVA with Tukey's post hoc test was performed, and a P value < 0.05 was considered statistically significant. PGAL (100 µg/mL) decreased phagocytosis in SF leukocytes by 14% compared to cells exposed to crystals without PGAL. In THP-1 cells, 100 and 200 µg/mL PGAL reduced phagocytosis by 17% and 15%, respectively. In SF cells, there was a tendency to decrease IL-1ß and IL-6. In THP-1 cells, decreases in IL-1ß and TNF-α, as well as a slight decrease in ROS, were identified. PGAL pre-treatment resulted in a reduction of IL-1ß. PGAL inhibits MSU phagocytosis by exerting an anti-inflammatory effect on cells exposed to crystals. The use of PGAL before an acute attack of gout suggests an important protective factor to control the inflammation.
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Gota , Fator de Necrose Tumoral alfa , Humanos , Espécies Reativas de Oxigênio , Interleucina-6 , Ácido Úrico/farmacologia , Inflamação , Anti-InflamatóriosRESUMO
Re-emerging arboviruses represent a serious health problem due to their rapid vector-mediated spread, mainly in urban tropical areas. The 2013-2015 Zika virus (ZIKV) outbreak in South and Central America has been associated with cases of microcephaly in newborns and Guillain-Barret syndrome. We previously showed that the conjugate gallic acid-Hecate (GA-FALALKALKKALKKLKKALKKAL-CONH2)-is an efficient inhibitor of the hepatitis C virus. Here, we show that the Hecate peptide is degraded in human blood serum into three major metabolites. These metabolites conjugated with gallic acid were synthesized and their effect on ZIKV replication in cultured cells was evaluated. The GA-metabolite 5 (GA-FALALKALKKALKKL-COOH) was the most efficient in inhibiting two ZIKV strains of African and Asian lineage at the stage of both virus entry (virucidal and protective) and replication (post-entry). We also demonstrate that GA-metabolite 5 does not affect cell growth after 7 days of continuous treatment. Thus, this study identifies a new synthetic antiviral compound targeting different steps of ZIKV replication in vitro and with the potential for broad reactivity against other flaviviruses. Our work highlights a promising strategy for the development of new antivirals based on peptide metabolism and bioconjugation.