A double-blind randomized clinical trial of Brazilian red propolis dentifrice efficacy in orthodontic patients.

PURPOSE: The objective was to evaluate the efficacy of a dentifrice containing Brazilian Red Propolis (BRP) against salivary Lactobacillus spp. and plaque formation. METHODS: This was a randomized, double-blind clinical trial. Forty-two participants were randomized into two groups according to the dentifrice employed: G1 (fluoridated BRP dentifrice) and G2 (fluoridated common dentifrice). Saliva was collected and the visible plaque index (VPI) was recorded at the baseline (D0) and 4 weeks after day 0 (D28). Microbiological analysis was performed using two dilutions. Lactobacillus spp. isolates were identified and their abundance was expressed as log (CFU/mL). RESULTS: For the first dilution, the counts of Lactobacillus spp. in G1 was 1.15 ± 0.41 at D0 and 0.68 ± 0.15 at D28 (P < 0.05) and in G2 it was 1.33 ± 0.52 at D0 and 1.84 ± 0.39 at D28 (P < 0.05). For the second dilution, the corresponding values in G1 and G2 were 0.87 ± 0.34 and 0.64 ± 0.37, respectively (P = 0.1547), and 1.54 ± 0.47 and 1.62 ± 0.37, respectively (P = 0.9999). The corresponding VPI values for G1 and G2 were 38.10 ± 17.95 and 20.60 ± 16.44, respectively (P < 0.05), and 38.38 ± 19.65 and 27.40 ± 14.63, respectively (P = 0.03). CONCLUSION: The dentifrice containing BRP showed antimicrobial activity against Lactobacillus spp. and decreased the VPI for up to 4 weeks.

Anti-inflammatory effects and possible mechanism of action of lupeol acetate isolated from Himatanthus drasticus (Mart.) Plumel.

BACKGROUND: The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba" and belongs to the family Apocynaceae. The latex collected from its stem bark is used for several purposes including anti-inflammatory properties and presents among its bioactive constituents the pentacyclic triterpene lupeol. The objective of the present work was to study in vivo and in vitro the lupeol acetate (LA) isolated from the plant latex, in several models of inflammation. METHODS: Male Swiss mice (25-30 g, 6-24 animals per group) were administered with LA, 30 min before the test initiation. In the evaluation of analgesic activity the formalin test was used. The anti-inflammatory activity was evaluated by the following tests: paw edema induced by carrageenan and dextran, and the carrageenan-induced neutrophil migration into peritoneal cavities. Furthermore, the effect of LA on the myeloperoxidase release (MPO, an inflammation biomarker) from human neutrophils was also determined, as well as its antioxidant potential by the DPPH assay. RESULTS: In the formalin test, LA (10, 25 and 50 mg/kg, i.p.) inhibited both the 1st (neurogenic, 0-5 min) and mainly the 2nd (inflammatory, 20-25 min) phase. Naloxone completely reversed the LA effect, indicating the participation of the opioid system. LA also significantly inhibited carrageenan- and dextran-induced paw edemas, as well as the neutrophil migration to the peritoneal cavity evaluated by the carrageenan-induced pleurisia. In this model, the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. LA (25 and 50 µg/ml) was also very effective in inhibiting MPO released from stimulated human neutrophils, and significantly decreased the number of cells expressing iNOS activity in the paw of mice submitted to carrageenan-induced edema, suggesting a drug involvement with the NO system. CONCLUSIONS: The anti-inflammatory effect of LA probably involves the opioid system, as indicated by the complete blockade of the opioid antagonist naloxone. Furthermore, the LA effect was potentiated by PTX (a TNF-alpha inhibitor). LA also decreased the number of iNOS cells, suggesting the participation of pro-inflammatory cytokines and the NO system in the drug action.

Neuroprotective effects of chalcones from Myracrodruon urundeuva on 6-hydroxydopamine-induced cytotoxicity in rat mesencephalic cells.

In the present work, we showed that a chalcone-enriched fraction (CEF) isolated from the stem bark of a Brazilian medicinal plant, Myracrodruon urundeuva, presents neuroprotective actions on 6-hydroxydopamine (6-OHDA)-induced neuronal cell death, in rat mesencephalic cells. In the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] assay, which is an index of cell viability, CEF (1-100 microg/ml) reversed in a concentration-dependent manner the 6-OHDA-induced cell death. While cells exposed to 6-OHDA (40 microM) showed an increased concentration of thiobarbituric acid reactive substances (TBARS), the pretreatment with CEF (10-100 microg/ml) significantly decreased the 6-OHDA-induced TBARS formation, indicative of a neuroprotection against lipoperoxidation. Furthermore, the drastic increase of nitrite levels induced by 6-OHDA, indicative of nitric oxide formation and free radicals production, was prevented by CEF. Double staining with acridine orange/ethidium bromide showed that cultures exposed to 6-OHDA (40 and 200 microM) presented an increase of apoptotic and necrotic cell numbers in a concentration-dependent manner. CEF (100 microg/ml) protected cells from apoptosis and necrosis and increased number of cells presenting a normal morphology. The immunohistochemical analysis for tyrosine hydroxylase (TH) positive neurons indicated that 6-OHDA (40 and 200 microM) caused a concentration-dependent loss of TH+ and TH- neurons. CEF protected both cells types from 6-OHDA-induced cell death. All together, our results demonstrated neuroprotective effects of chalcones, which are able to reduce oxidative stress and apoptotic injury caused by 6-OHDA. Our findings suggest that chalcones could provide benefits, along with other therapies, in neurodegenerative injuries, such as Parkinson's disease.