Richard Pereira Dutra

The potential use of propolis as a cariostatic agent and its actions on mutans group streptococci

Propolis is a resinous substance made by bees. It possesses many biological activities, and many studies have reported its potential application in the control of dental caries. However, variability in the chemical composition of propolis is a potential problem in its quality control, especially since propolis has already been incorporated into products for oral use. Therefore, a critical analysis of the available data on propolis is warranted. The present review discusses the in vitro and in vivo studies published in the period between 1978 and 2008 regarding the effects of propolis on Streptococcus mutans growth, bacterial adherence, glucosyltransferase activity, and caries indicators. Several investigations carried out with crude propolis extracts, isolated fractions, and purified compounds showed reductions in Streptococcus mutans counts and interference with their adhesion capacity and glucosyltransferase activity, which are considered major properties in the establishment of the cariogenic process. Data from in vivo studies have demonstrated reductions in Streptococcus mutans counts in saliva, the plaque index, and insoluble polysaccharide formation. These findings indicate that propolis and/or its compounds are promising cariostatic agents. However, the variation in the chemical composition of propolis due to its geographical distribution is a significant drawback to its routine clinical use. Thus, further studies are needed to establish the quality and safety control criteria for propolis in order for it to be used in accordance with its proposed activity.

Antimicrobial activity against oral pathogens and immunomodulatory effects and toxicity of geopropolis produced by the stingless bee Melipona fasciculata Smith

BackgroundNative bees of the tribe Meliponini produce a distinct kind of propolis called geopropolis. Although many pharmacological activities of propolis have already been demonstrated, little is known about geopropolis, particularly regarding its antimicrobial activity against oral pathogens. The present study aimed at investigating the antimicrobial activity of M. fasciculata geopropolis against oral pathogens, its effects on S. mutans biofilms, and the chemical contents of the extracts. A gel prepared with a geopropolis extract was also analyzed for its activity on S. mutans and its immunotoxicological potential.MethodsAntimicrobial activities of three hydroalcoholic extracts (HAEs) of geopropolis, and hexane and chloroform fractions of one extract, were evaluated using the agar diffusion method and the broth dilution technique. Ethanol (70%, v/v) and chlorhexidine (0.12%, w/w) were used as negative and positive controls, respectively. Total phenol and flavonoid concentrations were assayed by spectrophotometry. Immunotoxicity was evaluated in mice by topical application in the oral cavity followed by quantification of biochemical and immunological parameters, and macro-microscopic analysis of animal organs.ResultsTwo extracts, HAE-2 and HAE-3, showed inhibition zones ranging from 9 to 13 mm in diameter for S. mutans and C. albicans, but presented no activity against L. acidophilus. The MBCs for HAE-2 and HAE-3 against S. mutans were 6.25 mg/mL and 12.5 mg/mL, respectively. HAE-2 was fractionated, and its chloroform fraction had an MBC of 14.57 mg/mL. HAE-2 also exhibited bactericidal effects on S. mutans biofilms after 3 h of treatment. Significant differences (p < 0.05) in total phenol and flavonoid concentrations were observed among the samples. Signs toxic effects were not observed after application of the geopropolis-based gel, but an increase in the production of IL-4 and IL-10, anti-inflammatory cytokines, was detected.ConclusionsIn summary, geopropolis produced by M. fasciculata can exert antimicrobial action against S. mutans and C. albicans, with significant inhibitory activity against S. mutans biofilms. The extract with the highest flavonoid concentration, HAE-2, presented the highest antimicrobial activity. In addition, a geopropolis-based gel is not toxic in an animal model and displays anti-inflammatory effect.

Avaliação farmacognóstica de geoprópolis de Melipona fasciculata Smith da Baixada maranhense, Brasil

Melipona fasciculata Smith is a native, social, stingless bee species that produces wax, honey and geopropolis. This work aimed to do a pharmacological evaluation of Melipona fasciculata geopropolis, collected in beehives in the municipal districts of Arari, Sao Bento and Sao Joao Batista, in Baixada maranhense, in the state of Maranhao, Brazil, seeking to obtain basis for the quality control and standardization of the product. The methodology used included the accomplishment of sensorial analyses, chemical approach, chromatographic profiles and determination of the flavonoids contents. The results demonstrate that the geopropolis have organoleptic characteristics similar to the ones found for the propolis of Apis mellifera, presence of phenolic compounds in larger concentration, besides substances of the class of the terpenes and saponins and absence of alkaloids. The chromatographic profiles indicated that the composition and concentration of the chemical substances are different among the samples. The flavonoids contents ranged between 0.17 - 2.6%. The content for most of the samples presented values above the minimum demanded by the Brazilian legislation for propolis of Apis mellifera. The found data suggest that the qualitative and quantitative variations of flavonoids and other chemical substances in geopropolis are strongly affected for the flora visited by the bees, geographical area and environmental factors.

Phenolic Acids, Hydrolyzable Tannins, and Antioxidant Activity of Geopropolis from the Stingless Bee Melipona fasciculata Smith

Geopropolis is a mixture of plant resins, waxes, and soil produced by the stingless bee Melipona fasciculata Smith. This paper describes the antioxidant activity and chemical composition of geopropolis produced by M. fasciculata. The total phenolic content determined with the Folin-Ciocalteu reagent was highest in the ethyl acetate fraction and hydroalcoholic extract. Antioxidant activity was assayed by the in vitro DPPH, ABTS, and FRAP assays. The hydroalcoholic extract and fractions of geopropolis, except for the hexane fraction, exhibited antioxidant activity against DPPH, ABTS, and FRAP. The phenolic compounds were identified by HPLC-DAD-MS on the basis of the evaluation of their UV-vis absorption maxima (λmax) and mass spectral analysis. Eleven compounds belonging to the classes of phenolic acids and hydrolyzable tannins (gallotannins and ellagitannins) were tentatively identified. These compounds are responsible for the antioxidant activity and high phenolic content of geopropolis produced by M. fasciculata.

Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats

Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10–1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated with improvements in metabolic outcomes in MSG-induced obese rats.

Efeito do tratamento com própolis de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich em camundongos

Neste trabalho foi investigado o efeito do extrato hidroalcoolico de propolis (EHP) de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich na forma solida, sobre a celularidade dos orgaos linfoides dos animais portadores de tumor, bem como, sobre a producao de oxido nitrico (NO) pelos macrofagos destes animais. Camundongos Swiss foram divididos em quatro grupos: controle, EHP 0,5; EHP 5 e EHP 50, os quais foram tratados por via intraperitoneal com dose unica de solucao salina (NaCl 0,9%); 0,5; 5 ou 50 mg de EHP/kg de animal, respectivamente. Depois de 48 h do tratamento, os animais foram inoculados com 105 celulas do tumor de Ehrlich nas patas. Os resultados mostraram que o tratamento com EHP nas doses de 5 e 50 mg/kg inibiu de forma significativa o desenvolvimento do tumor a partir do 6o dia pos-inoculo quando comparado ao controle e ao EHP 0,5. Alem disso, houve aumento significativo da celularidade do baco e da medula ossea nos grupos EHP 0,5 e EHP 5 em relacao ao controle. A producao de NO estimulada com concanavalina A (ConA) apresentou uma significante diminuicao nos grupos tratados com EHP em relacao ao controle. Pode-se concluir que o tratamento com EHP apresentou efeito antitumoral quando administrado nas doses de 5 e 50 mg/kg, o que pode estar relacionado com a sua composicao quimica e com a inibicao da producao de NO.

Pharmacognostic and acute toxicological evaluation of Scaptotrigona aff. postica propolis extract in pre-clinical assays

The propolis of Scaptotrigona aff. postica is popularly used in Maranhão State, Brazil, for treating wounds and respiratory illnesses. Nevertheless, little is known about the chemical composition of this propolis and the adverse effects of its use. Hence, this study is a pharmacognostic characterisation of the propolis hydroalcoholic extract (PHE) from S. aff. postica. The methodology consisted of an evaluation of the sensory and chemical parameters. Chemical analysis of PHE indicated high concentrations of phenolic and triterpens substances, and the absence of steroids. Additionally, we evaluated the acute toxicity of propolis using 48 Swiss male and female mice. The animals received single doses of PHE (1000, 2000 or 4000 mg kg−1) orally and were observed for 14 days. After this period, the mice were sacrificed and the blood was used for biochemical and haematological evaluation. PHE did not induce any death, and the acute treatment significantly reduced serum concentrations of alanine aminotransferase and alkaline phosphatase. The resultant data indicate that PHE from S. aff. postica has low toxicity when used orally, even in high doses.

Effect of propolis of Scaptotrigona aff. postica on the development of the tumor of Ehrlich in mice

Neste trabalho foi investigado o efeito do extrato hidroalcoolico de propolis (EHP) de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich na forma solida, sobre a celularidade dos orgaos linfoides dos animais portadores de tumor, bem como, sobre a producao de oxido nitrico (NO) pelos macrofagos destes animais. Camundongos Swiss foram divididos em quatro grupos: controle, EHP 0,5; EHP 5 e EHP 50, os quais foram tratados por via intraperitoneal com dose unica de solucao salina (NaCl 0,9%); 0,5; 5 ou 50 mg de EHP/kg de animal, respectivamente. Depois de 48 h do tratamento, os animais foram inoculados com 105 celulas do tumor de Ehrlich nas patas. Os resultados mostraram que o tratamento com EHP nas doses de 5 e 50 mg/kg inibiu de forma significativa o desenvolvimento do tumor a partir do 6o dia pos-inoculo quando comparado ao controle e ao EHP 0,5. Alem disso, houve aumento significativo da celularidade do baco e da medula ossea nos grupos EHP 0,5 e EHP 5 em relacao ao controle. A producao de NO estimulada com concanavalina A (ConA) apresentou uma significante diminuicao nos grupos tratados com EHP em relacao ao controle. Pode-se concluir que o tratamento com EHP apresentou efeito antitumoral quando administrado nas doses de 5 e 50 mg/kg, o que pode estar relacionado com a sua composicao quimica e com a inibicao da producao de NO.

Chemical composition and antioxidant activity of geopropolis produced by Melipona fasciculata (Meliponinae) in flooded fields and cerrado areas of Maranhão State, northeastern Brazil

Geopropolis, uma mistura de resinas vegetais, cera, terra e secrecao salivar, produzida pela abelha sem ferrao Melipona fasciculata. Este estudo investigou a composicao quimica e a atividade antioxidante da geopropolis coletada em colmeias em duas regioes fitogeograficas de campos alagados e de cerrado, nos municipios de Palmeirândia e Fernando Falcao, no Estado do Maranhao, Nordeste do Brasil. Os compostos da geopropolis foram identificados por cromatografia gasosa acoplada a espectrometria de massas (CG/EM). Foram determinados os teores de fenolicos totais pelo reagente de Folin−Ciocalteu, e atividade antioxidante utilizando o ensaio in vitro com 2,2-difenil-1-picrilhidrazil (DPPH) e capacidade redutora do ferro (FRAP). As quatro amostras de geopropolis apresentaram variacoes no teor de fenolicos totais e atividade antioxidante, as geopropolis de Fernando Falcao, apresentaram maiores teores. Nas geopropolis do municipio de Palmeirândia foram identificados, triterpenos do tipo cicloartano, ursano e oleanano e acidos fenolicos (acido protocatecuico e acido galico), enquanto que na geopropolis de Fernando Falcao, acidos fenolicos, acido galico e elagico foram os principais constituintes. A propriedade antioxidante da geopropolis pode ser atribuida aos altos teores de fenolicos totais e de acido galico e elagico. Os resultados demonstram que as fontes vegetais das duas regioes fitogeograficas do Maranhao, Brasil, utilizadas pelas abelhas para a producao da geopropolis contribuem para a composicao quimica e bioatividade deste produto.

Effect of propolis of Scaptotrigona aff. postica on the development of Ehrlich's tumour in mice.

Neste trabalho foi investigado o efeito do extrato hidroalcoolico de propolis (EHP) de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich na forma solida, sobre a celularidade dos orgaos linfoides dos animais portadores de tumor, bem como, sobre a producao de oxido nitrico (NO) pelos macrofagos destes animais. Camundongos Swiss foram divididos em quatro grupos: controle, EHP 0,5; EHP 5 e EHP 50, os quais foram tratados por via intraperitoneal com dose unica de solucao salina (NaCl 0,9%); 0,5; 5 ou 50 mg de EHP/kg de animal, respectivamente. Depois de 48 h do tratamento, os animais foram inoculados com 105 celulas do tumor de Ehrlich nas patas. Os resultados mostraram que o tratamento com EHP nas doses de 5 e 50 mg/kg inibiu de forma significativa o desenvolvimento do tumor a partir do 6o dia pos-inoculo quando comparado ao controle e ao EHP 0,5. Alem disso, houve aumento significativo da celularidade do baco e da medula ossea nos grupos EHP 0,5 e EHP 5 em relacao ao controle. A producao de NO estimulada com concanavalina A (ConA) apresentou uma significante diminuicao nos grupos tratados com EHP em relacao ao controle. Pode-se concluir que o tratamento com EHP apresentou efeito antitumoral quando administrado nas doses de 5 e 50 mg/kg, o que pode estar relacionado com a sua composicao quimica e com a inibicao da producao de NO.