Lucilene A. Silva

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.

Immune cells recruitment and activation by Tityus serrulatus scorpion venom

Despite several studies showed that the Tityus serrulatus scorpion venom (Tsv) induces an inflammatory response, just a few have investigated the effect of the venom on the immune response. Therefore, the aim of this study was to evaluate alterations of venom application on lymphoid organs and on the recruitment and activation of cells and also on the cytokine production. Swiss male mice (2-3 months, 20-25 g) received a non-lethal dose of crude Tsv (200 μg/kg), diluted in sterile PBS by subcutaneous route. Control animals received only sterile PBS. The animals were sacrificed after 30, 120 and 360 min. The inflammatory parameters studied were skin histology at the site of venom application, leukocyte count, and blood cytokine levels (IL-6, IL-10, and TNF-α). Inguinal lymph node, spleen and bone marrow cellularity was determined for evaluation of the Tsv effect on immune system organs. The results showed that Tsv caused no local inflammation, but it induced an increase of blood neutrophils and serum IL-6, TNF-α and IL-10. After 360 min of envenomation there was a reduction in the cells number from peritoneum and spleen, but there was an increase in the cell number from lymph nodes. In conclusion, the Tsv induces systemic alterations characterized by changes in the cell number in lymphoid organs, increase pro and anti-inflammatory cytokines.

Mechanisms underlying hypertriglyceridemia in rats with monosodium l-glutamate-induced obesity: Evidence of XBP-1/PDI/MTP axis activation

Non-alcoholic fatty liver disease (NAFLD) is intimately associated with insulin resistance and hypertriglyceridemia, whereas many of the mechanisms underlying this association are still poorly understood. In the present study, we investigated the relationship between microsomal triglyceride transfer protein (MTP) and markers of endoplasmic reticulum (ER) stress in the liver of rats subjected to neonatal monosodium L-glutamate (MSG)-induced obesity. At age 120 days old, the MSG-obese animals exhibited hyperglycemia, hypertriglyceridemia, insulin resistance, and liver steatosis, while the control (CTR) group did not. Analysis using fast protein liquid chromatography of the serum lipoproteins revealed that the triacylglycerol content of the very low-density lipoprotein (VLDL) particles was twice as high in the MSG animals compared with the CTR animals. The expression of ER stress markers, GRP76 and GRP94, was increased in the MSG rats, promoting a higher expression of X-box binding protein 1 (XBP-1), protein disulfide isomerase (PDI), and MTP. As the XBP-1/PDI/MTP axis has been suggested to represent a significant lipogenic mechanism in the liver response to ER stress, our data indicate that hypertriglyceridemia and liver steatosis occurring in the MSG rats are associated with increased MTP expression.

Sunflower Seed Oil-Enriched Product Can Inhibit Ehrlich Solid Tumor Growth in Mice

Background: Sunflower seed oil (SSO) effect on solid and ascitic forms of Ehrlich tumor was evaluated. Methods: Solid or ascitic Ehrlich tumor-bearing Swiss mice were treated daily, by subcutaneous route, with 200 µl of SSO. The solid tumor-bearing footpad was measured every 3 days and ascitic tumor-bearing mice had their ascites collected and quantified. At the end of the SSO treatment, the total cell number in lymphoid organs was quantified. Results: Subcutaneous treatment with SSO inhibits the solid tumor growth and increases lymph node cell number in animals with solid tumor, but has no effect on animals with ascitic tumor. Conclusions: SSO can delay the solid tumor growth, possibly due to better absorption of this treatment by draining lymph nodes.

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.

Chenopodium ambrosioides L. Reduces Synovial Inflammation and Pain in Experimental Osteoarthritis

The chronicity of osteoarthritis (OA), characterized by pain and inflammation in the joints, is linked to a glutamate receptor, N-methyl-D-aspartate (NMDA). The use of plant species such as Chenopodium ambrosioides L. (Amaranthaceae) as NMDA antagonists offers a promising perspective. This work aims to analyze the antinociceptive and anti-inflammatory responses of the crude hydroalcoholic extract (HCE) of C. ambrosioides leaves in an experimental OA model. Wistar rats were separated into six groups (n = 24): clean (C), negative control (CTL-), positive control (CTL+), HCE0.5, HCE5 and HCE50. The first group received no intervention. The other groups received an intra-articular injection of sodium monoiodoacetate (MIA) (8 mg/kg) on day 0. After six hours, they were orally treated with saline, Maxicam plus (meloxicam + chondroitin sulfate) and HCE at doses of 0.5 mg/kg, 5 mg/kg and 50 mg/kg, respectively. After three, seven and ten days, clinical evaluations were performed (knee diameter, mechanical allodynia, mechanical hyperalgesia and motor activity). On the tenth day, after euthanasia, synovial fluid and draining lymph node were collected for cellular quantification, and cartilage was collected for histopathological analysis. Finally, molecular docking was performed to evaluate the compatibility of ascaridole, a monoterpene found in HCE, with the NMDA receptor. After the third day, HCE reduced knee edema. HCE5 showed less cellular infiltrate in the cartilage and synovium and lower intensities of allodynia from the third day and of hyperalgesia from the seventh day up to the last treatment day. The HCE5 and HCE50 groups improved in forced walking. In relation to molecular docking, ascaridole showed NMDA receptor binding affinity. C. ambrosioides HCE was effective in the treatment of OA because it reduced synovial inflammation and behavioral changes due to pain. This effect may be related to the antagonistic effect of ascaridole on the NMDA receptor.

Immunomodulatory and Antimicrobial Activity of Babassu Mesocarp Improves the Survival in Lethal Sepsis

Attalea speciosa syn Orbignya phalerata Mart. (babassu) has been used in the treatment of inflammatory and infectious diseases. Aim of the study. To investigate the antimicrobial and immunological activity of babassu mesocarp extract (EE). Material and Methods. The in vitro antimicrobial activity was evaluated by disk diffusion assay and by determination of the minimum inhibitory concentration (MIC) to Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). The flavonoids and phenolic acids content were determined by chromatography. The in vivo assays were performed in Swiss mice submitted to sepsis by cecal ligation and puncture (CLP). The mice received EE subcutaneously (125 or 250 mg/Kg), 6 hours after the CLP. The number of lymphoid cells was quantified and the cytokines production was determined by ELISA after 12 h. Results. EE was effective as antimicrobial to E. faecalis, S. aureus, and MRSA. EE is rich in phenolic acids, a class of compounds with antimicrobial and immunological activity. An increased survival can be observed in those groups, possibly due to a significant inhibition of TNF-α and IL-6. Conclusions. The EE showed specific antimicrobial activity in vitro and an important antiseptic effect in vivo possibly due to the antimicrobial and immunomodulatory activity.

Evaluation of acute toxicity of babassu mesocarp in mice

The safety of babassu mesocarp (Orbignya phalerata Mart., Arecaceae), which exhibited anti-inflammatory and antithrombotic activities, was evaluated by determining the potential acute toxicity in mice. A lyophilized ethanol extract of babassu mesocarp (BME) was administered to C3H/HePas mice (10/group) in a single dose of 1000, 3000 and 5000 mg/kg, by gavage. General behavior adverse effects and mortality were determined for up to fourteen days. Selected biochemical parameters including glucose, triacylglyceride, cholesterol, urea, alkaline phosphatase and creatinine were determined by colorimetric assay. The heart, liver, spleen, kidneys and brain were weighted and evaluated macro and microscopically. The median lethal dose (LD50) of BME was greater than 5000 mg/kg. No behavior or body weight alterations were detected after the treatment. The acute treatment with BME has no effect on macroscopic and microscopic aspect of examined organs. Instead, BME increased the alkaline phosphatase and reduced the urea concentration in all groups. A significant increase on triacylglyceride was detected in the group BME1000. In conclusion, the acute treatment with high doses of BME can affect some biochemical parameters with a long lasting effect, although any change was detected at tissue level or body and organ weight.

Effects of stingless bee propolis on experimental asthma.

Bee products have been used empirically for centuries, especially for the treatment of respiratory diseases. The present study evaluated the effect of treatment with a propolis hydroalcoholic extract (PHE) produced by Scaptotrigona aff. postica stingless bee in a murine asthma model. BALB/c mice were immunized twice with ovalbumin (OVA) subcutaneously. After 14 days, they were intranasally challenged with OVA. Groups P50 and P200 received PHE by gavage at doses of 50 and 200 mg/kg, respectively. The DEXA group was treated with intraperitoneal injection of dexamethasone. The OVA group received only water. The mice were treated daily for two weeks and then they were immunized a second time with intranasal OVA. The treatment with PHE decreased the cell number in the bronchoalveolar fluid (BAL). Histological analysis showed reduced peribronchovascular inflammation after treatment with PHE especially the infiltration of polymorphonuclear cells. In addition, the concentration of interferon-γ (IFN-γ) in the serum was decreased. These results were similar to those obtained with dexamethasone. Treatment with S. aff postica propolis reduced the pathology associated with murine asthma due an inhibition of inflammatory cells migration to the alveolar space and the systemic progression of the allergic inflammation.

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.