Apolar Bioactive Fraction of Melipona scutellaris Geopropolis on Streptococcus mutans Biofilm

Bioactives of Melipona rufiventris Propolis: Exploring its Antimicrobial, Anti-Inflammatory, and Antioxidant Activities

This study explores the potential of propolis, a resinous substance produced by bees, from Melipona rufiventris species. With its composition encompassing resin, wax, pollen, and soil, propolis holds historical significance in traditional medicine within tropical regions. This research is driven by the scarcity of information surrounding M. rufiventris propolis, prompting an investigation into its chemical constituents, in vivo toxicity, and antimicrobial, antioxidant, and anti-inflammatory properties. This exploration could potentially uncover novel applications for this natural product, bolstering both meliponiculture practices and the preservation of native bee populations. The propolis was sampled in Cabo Verde-MG and underwent ethanolic extraction to yield an extract (EEP) for analysis. Chemical assessments (Folin-Ciocalteau, and UHPLC-HRMS) revealed the presence of polyphenols, including flavonoids. The EEP demonstrated higher antimicrobial activity against Gram-positive bacteria and exhibited efficacy against multiresistant strains isolated from complex wounds. Synergistic interactions with commercial antibiotics were also observed. Furthermore, anti-inflammatory evaluations showcased the EEP's potential in reducing NF-kB activation and TNF-α release at non-toxic concentrations. Despite these promising biological activities, the EEP exhibited no antiproliferative effects and demonstrated safety in both the MTS assay and the G. mellonella model. Collectively, these findings highlight the M. rufiventris propolis extract as a valuable reservoir of bioactive compounds with multifaceted potential.

Cardanols detected in non-polar propolis extracts from Scaptotrigona aff. postica (Hymenoptera, Apidae, Meliponini)

Abstract The propolis produced by stingless bees of the tribe Meliponini is a viscous product that contains the resin collected from buds, leaves and plant exudates, mixed with salivary secretions, wax and soil. The species Scaptotrigona aff. postica (Latreille, 1807), (Hymenoptera, Apidae, Meliponinae) popularly known as “tubi” in Maranhão State, Brazil, does not mix soil to produce its propolis. The propolis from S. postica harvested in Barra do Corda, Maranhão State, is popularly used in the treatment of wounds and respiratory illnesses. The hydroalcoholic extract of this propolis, rich in flavone-6,8-di-C-glycosides (vicenin-2 and schaftoside), pyrrolizidine alkaloids derived from retronecine, catechin and caffeoylquinic acid derivatives exhibited antiviral activity against the herpes simplex and rubella viruses. The aim of this study was to increase knowledge about the chemical composition of the S. postica propolis by analyzing non-polar extracts obtained using hexane and chloroform as the solvents, by GC-EI-MS. A total of 15 constituents were identified comparing their respective mass spectral data with those available in the NIST data bases and those reported in the literature. The main constituents detected were the phenolic lipids, known as cardanols, 3-(4,7-heptadecadienyl) phenol (5), 3-(10-heptadecenyl) phenol (7), 3-heptadecylphenol (9) and 3-pentadecyl phenol or hydrocardanol (13), which predominated in the hexane extract, while the predominant constituents in the chloroform extract were 3-pentadecyl phenol or hydrocardanol (13) and 3-(8-pentadecenyl) phenol (12). The antioxidant, antitumoral, antifeedant, cytotoxic, anticarcinogenic, antiproliferative, antimicrobial, antileishmanial and larvicidal activities of the cardanols have been demonstrated in many studies.

Characterisation of phenolic compounds by UPLC-QTOF-MS/MS of geopropolis from the stingless bee Melipona subnitida (jandaíra)

INTRODUCTION

Melipona subnitida Ducke (jandaíra) is a stingless bee native to north-eastern Brazil, which produces geopropolis, a mixture of beeswax, plant resins, pollens and earth that is used for sealing beehives.

OBJECTIVE

To extend the knowledge on phenolic compounds in fractions obtained by C18-solid phase extraction (SPE) of nine geopropolis samples from Melipona subnitida collected at different times.

METHODOLOGY

Chromatographic profiles of nine samples of geopropolis from jandaíra were analysed by ultra-performance liquid chromatography coupled with a diode array detector and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS/MS) and combined with the use of data-independent acquisition (MSE) for the profiling and structural characterisation of the phenolic compounds. The isolated compound was identified by nuclear magnetic resonance of hydrogen and carbon (¹ H- and ¹³ C-NMR).

RESULTS

The present study with geopropolis of jandaíra resulted in the characterisation of 51 phenolics by UPLC-DAD-QTOF-MS/MS: four galloyl glucosides, one ellagic acid, 11 acyl-hexosides, 23 acyl-galloyl-hexosides and 12 flavonoids. The structures of two compounds (1,6-di-O-(E)-coumaroyl-2-O-galloyl-β-d-glucopyranoside and 1-O-cinnamoyl-6-O-(E)-coumaroyl-2-O-galloyl-β-d-glucopyranoside) were established by ¹ H and the attached proton test (APT) experiments as well as high-resolution electrospray ionisation mass spectroscopy (HR-ESI-MS) analysis.

CONCLUSION

The geopropolis of jandaíra showed phenolic compounds galloyl hexosides, ellagic acid, acyl-(cinnamoyl/coumaroyl)-hexosides, acyl-(cinnamoyl/coumaroyl)-galloyl-hexosides and flavonoids (aglycones and acylated-O-glycosides).

Effects of Terminalia catappa Linn. Extract on Candida albicans biofilms developed on denture acrylic resin discs

Background

Considering the prevalence of denture stomatitis and the challenge of controlling this pathology using conventional therapies, natural products have been suggested as important therapeutic alternatives due to their antifungal and anti-biofilm properties. Thus, this study investigated if immersion in Terminalia Catappa Linn. extract (TCE) affects Candida albicans biofilms developed on denture acrylic resin discs.

Material and Methods

The minimal inhibitory and minimal fungicidal concentrations (MIC and MFC, respectively) tests were performed for TCE against suspensions of C. albicans. For the biofilm assay, discs (10 x 2 mm) were fabricated using a denture acrylic resin with surface roughness standardized. The biofilms were allowed to develop for 24 hours. Then, they were immersed in the following treatments overnight (8 hours): phosphate-buffered saline (PBS, control), TCE at MIC, 5XMIC or 10XMIC. The biofilms were analyzed for cell counts and microscopy. Data were analyzed by ANOVA followed by a Tukey test at a 5% significance level.

Results

The minimal concentration of TCE required to inhibit C. albicans was 6.25 mg/mL, while MFC was 12.5 mg/mL. Immersion in TCE at MIC was sufficient to reduce 80% of the biofilm viable cells compared to the control group (p< 0.001). Microscopic images confirm that immersion at 5XMIC and 10XMIC had a fungicidal activity with no significant differences between the concentrations regarding viable cells counts (p> 0.05).

Conclusions

Within the limitations of this study, it was possible to conclude that immersion in TCE reduced the C. albicans biofilms cells developed on the denture acrylic surface.

Key words:Terminalia catappa Linn, Biofilm, Candida albicans.

Chemical Composition and Pharmacological Effects of Geopropolis Produced by Melipona quadrifasciata anthidioides

Stingless bees produce geopropolis, which is popularly described for its medicinal properties, but for which few scientific studies have demonstrated pharmacological effects. The objective of this study was to investigate the chemical composition of the geopropolis of Melipona quadrifasciata anthidioides and to evaluate its antioxidant, antimutagenic, anti-inflammatory, and antimicrobial activities. The composition of the hydroethanolic extract of geopropolis (HEG) included di- and trigalloyl and phenylpropanyl heteroside derivatives, flavanones, diterpenes, and triterpenes. HEG showed antioxidant action via the direct capture of free radicals and by inhibiting the levels of oxidative hemolysis and malondialdehyde in human erythrocytes under oxidative stress. HEG also reduced the frequency of gene conversion and the number of mutant colonies of S. cerevisiae. The anti-inflammatory action of HEG was demonstrated by the inhibition of hyaluronidase enzyme activity. In addition, HEG induced cell death in all evaluated gram-positive bacteria, gram-negative bacteria, and yeasts, including clinical isolates with antimicrobial drug resistance. Collectively, these results demonstrate the potential of M. q. anthidioides geopropolis for the prevention and treatment of various diseases related to oxidative stress, mutagenesis, inflammatory processes, and microbial infections.

Effects of Cinnamoyloxy-mammeisin from Geopropolis on Osteoclast Differentiation and Porphyromonas gingivalis-Induced Periodontitis

Bone-loss-related diseases such as rheumatoid arthritis, osteomyelitis, osteoporosis, and periodontitis are associated with high rates of morbidity worldwide. These disorders are characterized by an imbalance between the formation and activity of osteoblasts and osteoclasts, leading to bone loss. In this context, we evaluated the effect of cinnamoyloxy-mammeisin (CNM), an anti-inflammatory coumarin found in Melipona scutellaris geopropolis, on key targets related to bone remodeling. In the present study we investigated the in vitro effects of CNM on osteoclast differentiation and M-CSF+RANKL-induced osteoclastogenic marker expression. Additionally, the interference of CNM treatment on osteoclast activity was evaluated by zymography and resorption area. Finally, we assessed the capacity of the compound to mitigate alveolar bone loss in vivo in experimental murine periodontitis induced by Porphyromonas gingivalis. We observed that treatment with CNM impaired osteoclast differentiation, as evidenced by a reduced number of tartrate-resistant acid-phosphatase-positive multinucleated cells (TRAP+) as well as the expression of osteoclastogenic markers upon M-CSF+RANKL-induced stimulation. Similarly, we observed reduced gelatinolytic and resorption capacity in M-CSF+RANKL-induced cells in vitro. Lastly, CNM attenuated alveolar bone loss in an experimental murine periodontitis model. These findings indicate that CNM may be considered a promising treatment for bone loss diseases.

Chemical Profile and Antioxidant, Anti-Inflammatory, Antimutagenic and Antimicrobial Activities of Geopropolis from the Stingless Bee Melipona orbignyi

Geopropolis is a resin mixed with mud, produced only by stingless bees. Despite being popularly known for its medicinal properties, few scientific studies have proven its biological activities. In this context, the objective of this study was to determine the chemical composition and antioxidant, anti-inflammatory, antimutagenic and antimicrobial activities of the Melipona orbignyi geopropolis. The hydroalcoholic extract of geopropolis (HEGP) was prepared and its chemical composition determined by high performance liquid chromatography coupled to diode array detector and mass spectrometry (HPLC-DAD-MS). The antioxidant activity was determined by the capture of free radicals and inhibition of lipid peroxidation in human erythrocytes. The anti-inflammatory activity was evaluated by the inhibition of the hyaluronidase enzyme and the antimutagenic action was investigated in Saccharomyces cerevisiae colonies. The antimicrobial activities were determined against bacteria and yeasts, isolated from reference strains and hospital origin. The chemical composition of HEGP included flavonoids, derivatives of glycosylated phenolic acids and terpenoids. HEGP showed high antioxidant activity, it inhibited the activity of the inflammatory enzyme hyaluronidase and reduced the mutagenic effects in S. cerevisiae. In relation to the antimicrobial activity, it promoted the death of all microorganisms evaluated. In conclusion, this study reveals for the first time the chemical composition of the HEGP of M. orbignyi and demonstrates its pharmacological properties.

Prediction of pharmacokinetic and toxicological parameters of a 4-phenylcoumarin isolated from geopropolis: In silico and in vitro approaches

In silico and in vitro methodologies have been used as important tools in the drug discovery process, including from natural sources. The aim of this study was to predict pharmacokinetic and toxicity (ADME/Tox) properties of a coumarin isolated from geopropolis using in silico and in vitro approaches. Cinnamoyloxy-mammeisin (CNM) isolated from Brazilian M. scutellaris geopropolis was evaluated for its pharmacokinetic parameters by in silico models (ACD/Percepta™ and MetaDrug™ software). Genotoxicity was assessed by in vitro DNA damage signaling PCR array. CNM did not pass all parameters of Lipinski's rule of five, with a predicted low oral bioavailability and high plasma protein binding, but with good predicted blood brain barrier penetration. CNM was predicted to show low affinity to cytochrome P450 family members. Furthermore, the predicted Ames test indicated potential mutagenicity of CNM. Also, the probability of toxicity for organs and tissues was classified as moderate and high for liver and kidney, and moderate and low for skin and eye irritation, respectively. The PCR array analysis showed that CNM significantly upregulated about 7% of all DNA damage-related genes. By exploring the biological function of these genes, it was found that the predicted CNM genotoxicity is likely to be mediated by apoptosis. The predicted ADME/Tox profile suggests that external use of CNM may be preferable to systemic exposure, while its genotoxicity was characterized by the upregulation of apoptosis-related genes after treatment. The combined use of in silico and in vitro approaches to evaluate these parameters generated useful hypotheses to guide further preclinical studies.

Vestitol Isolated from Brazilian Red Propolis Inhibits Neutrophils Migration in the Inflammatory Process: Elucidation of the Mechanism of Action

Vestitol is an isoflavonoid isolated from Brazilian red propolis with potential anti-inflammatory activity. This study investigated the mechanism of action of vestitol on the modulation of neutrophil migration in the inflammatory process. Pre-treatment with vestitol at 1, 3, or 10 mg/kg reduced LPS- or mBSA-induced neutrophil migration and the release of CXCL1/KC and CXCL2/MIP-2 in vivo. Likewise, pre-treatment with vestitol at 1, 3, or 10 μM reduced the levels of CXCL1/KC and CXCL2/MIP-2 in macrophage supernatants in vitro. Moreover, the administration of vestitol (10 mg/kg) reduced leukocyte rolling and adherence in the mesenteric microcirculation of mice. The pre-treatment with vestitol (10 mg/kg) in iNOS(-/-) mice did not block its activity concerning neutrophil migration. With regard to the activity of vestitol on neutrophils isolated from the bone marrow of mice, there was a reduction on the chemotaxis of CXCL2/MIP-2 or LTB4-induced neutrophils and on calcium influx after pre-treatment with the compound at 3 or 10 μM. There was no change in CXCR2 expression by neutrophils treated with vestitol at 10 μM. These findings demonstrate that vestitol is a promising novel anti-inflammatory agent.

Brazilian Red Propolis Attenuates Inflammatory Signaling Cascade in LPS-Activated Macrophages

Although previous studies suggested an anti-inflammatory property of Brazilian red propolis (BRP), the mechanisms involved in the anti-inflammatory effects of BRP and its activity on macrophages were still not elucidated. This study aimed to evaluate whether BRP attenuates the inflammatory effect of LPS on macrophages and to investigate its underlying mechanisms. BRP was added to RAW 264.7 murine macrophages after activation with LPS. NO production, cell viability, cytokines profile were evaluated. Activation of inflammatory signaling pathways and macrophage polarization were determined by RT-qPCR and Western blot. BRP at 50 μg/ml inhibited NO production by 78% without affecting cell viability. Cd80 and Cd86 were upregulated whereas mrc1 was down regulated by BRP indicating macrophage polarization at M1. BRP attenuated the production of pro-inflammatory mediators IL-12, GM-CSF, IFN-Ɣ, IL-1β in cell supernatants although levels of TNF- α and IL-6 were slightly increased after BRP treatment. Levels of IL-4, IL-10 and TGF-β were also reduced by BRP. BRP significantly reduced the up-regulation promoted by LPS of transcription of genes in inflammatory signaling (Pdk1, Pak1, Nfkb1, Mtcp1, Gsk3b, Fos and Elk1) and of Il1β and Il1f9 (fold-change rate > 5), which were further confirmed by the inhibition of NF-κB and MAPK signaling pathways. Furthermore, the upstream adaptor MyD88 adaptor-like (Mal), also known as TIRAP, involved in TLR2 and TLR4 signaling, was down- regulated in BRP treated LPS-activated macrophages. Given that BRP inhibited multiple signaling pathways in macrophages involved in the inflammatory process activated by LPS, our data indicated that BRP is a noteworthy food-source for the discovery of new bioactive compounds and a potential candidate to attenuate exhacerbated inflammatory diseases.

Gastroprotective Effect of Geopropolis from Melipona scutellaris Is Dependent on Production of Nitric Oxide and Prostaglandin

The aim of this study was to evaluate the gastroprotective activity of ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and to investigate the possible mechanisms of action. The gastroprotective activity of the EEGP was evaluated using model ulcer induced by ethanol. To elucidate the possible mechanisms of action, we investigated the involvement of the nonprotein sulfhydryl (NP-SH) groups, nitric oxide and prostaglandins. In addition, the antisecretory activity of EEGP was also evaluated by pylorus ligated model. The EEGP orally administrated (300 mg/kg) reduced the ulcerative lesions induced by the ethanol (P < 0.05). Regarding the mechanism of action, the prior administration of nitric oxide and prostaglandins antagonists suppressed the activity of gastroprotective EEGP (P < 0.05). On the other hand the gastroprotective activity of EEGP was kept in the group pretreated with the antagonist of the NP-SH groups; furthermore the antisecretory activity was not significant (P > 0.05). These results support the alternative medicine use of geopropolis as gastroprotective and the activities observed show to be related to nitric oxide and prostaglandins production.

The Effect of Essential Oils and Bioactive Fractions on Streptococcus mutans and Candida albicans Biofilms: A Confocal Analysis

The essential oils (EO) and bioactive fractions (BF) from Aloysia gratissima, Baccharis dracunculifolia, Coriandrum sativum, Cyperus articulatus, and Lippia sidoides were proven to have strong antimicrobial activity on planktonic microorganisms; however, little is known about their effects on the morphology or viability of oral biofilms. Previously, we determined the EO/fractions with the best antimicrobial activity against Streptococcus mutans and Candida spp. In this report, we used a confocal analysis to investigate the effect of these EO and BF on the morphology of S. mutans biofilms (thickness, biovolume, and architecture) and on the metabolic viability of C. albicans biofilms. The analysis of intact treated S. mutans biofilms showed no statistical difference for thickness in all groups compared to the control. However, a significant reduction in the biovolume of extracellular polysaccharides and bacteria was observed for A. gratissima and L. sidoides groups, indicating that these BF disrupt biofilm integrity and may have created porosity in the biofilm. This phenomenon could potentially result in a weakened structure and affect biofilm dynamics. Finally, C. sativum EO drastically affected C. albicans viability when compared to the control. These results highlight the promising antimicrobial activity of these plant species and support future translational research on the treatment of dental caries and oral candidiasis.