Antitumoral Potential of Artepillin C, a Compound Derived from Brazilian Propolis, against Breast Cancer Cell Lines

BACKGROUND

Breast cancer is the most commonly diagnosed cancer among women worldwide with limited treatment options. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) is one of the main constituents of Brazilian propolis presenting different activities, including antitumoral effects against various types of cancer.

OBJECTIVE

We evaluated the antitumoral potential and mechanisms of action of artepillin C against two distinct human breast cancer cell lines, MCF-7 and MDA-MB-231, to explore a new therapeutic candidate.

METHODS

Cell viability was assessed by MTT assay and the long-term cytotoxicity was performed by clonogenic assay. The morphological changes were observed by light microscopy, analysis of cell death pathway by Annexin V FITC/propidium iodide (PI), lactate dehydrogenase (LDH) by colorimetry, DNA fragmentation by agarose gel and senescence by β-galactosidase. Detection of total reactive oxygen species (ROS) by fluorescence microscopy and determination of mitochondrial transmembrane potential by flow cytometry were also performed.

RESULTS

Artepillin C presented a strong and dose-time-dependent cytotoxic effect on MCF-7 and MDA-MB-231 cell lines, with cytotoxicity more evident in MCF-7. In both cancer cell lines, the clonogenic potential was significantly reduced and the morphology of the cells was changed. The treatment also induced death by necrosis and late apoptosis in MCF-7 and MDA-MB-231 and induced cell senescence in MCF-7. Also, artepillin C increased total ROS in both cancer cells and decreased mitochondrial membrane potential in MDA-MB-231 cells.

CONCLUSION

Artepillin C presented antitumoral potential in two human breast cancer cell lines, MCF-7, and MDA-MB-231, suggesting a new promising option for the treatment and/or chemopreventive strategy for breast cancer.

Cytotoxicity evaluation of phytochemicals from stingless bee (Tetragonula biroi) propolis

Three prenylated flavonoids (1-3) were isolated from Tetragonula biroi propolis. The structures of the isolated compounds were characterized by NMR, IR, and UV spectroscopic and mass spectrometric analyses. The cytotoxicity activity of the crude extracts, fractions and the isolated compounds were established against four cell lines such as Caco-2, HeLa, MCF-7, and OVK-18. Among the tested compounds, compound 1 showed cytotoxicity activity against MCF-7 cell lines, whereas compound 2 showed good activity against Caco-2 and OVK-18 cell lines with IC50 values of 14.73 and 14.44, respectively. Moreover, compound 3 exhibited strong activity against OVK-18 cell lines. These findings contribute to the phytochemical understanding of the T. biroi propolis, and their cytotoxicity effects for future pharmaceutical purposes.

A Propolis-Derived Small Molecule Tectochrysin Ameliorates Type 2 Diabetes in Mice by Activating Insulin Receptor β

SCOPE

Propolis has been found to decrease glucose levels and increase insulin sensitivity in type 2 diabetes. However, the active ingredient responsible for these effects and its regulating mechanism are not fully understood.

METHODS AND RESULTS

To address this, molecular docking screening is used to screen the effective hypoglycemic ingredient in propolis and found that tectochrysin (TEC) has a high affinity to the insulin receptor (IR), highlighting its potential for glycemic control. In vivo tests show that TEC decreases glucose levels and enhances insulin sensitivity in db/db mice. By hyperinsulinemic euglycemic clamp test, this study further finds that TEC promotes glucose uptake in adipose tissue and skeletal muscle, as well as inhibits hepatic gluconeogenesis. Moreover, it finds that TEC promotes glucose uptake and adipocytes differentiation in 3T3-L1 cells like insulin, suggesting that TEC exerts an insulin mimetic effect. Mechanistically, pharmacology inhibition of IRβ abolishes the effects of TEC on glucose uptake and the phosphorylation of IR. The study further demonstrates that TEC binds to and activates IRβ by targeting its E1077 and M1079.

CONCLUSION

Therefore, this study sheds light on the mechanism underlying propolis' potential for ameliorating type 2 diabetes, offering a natural food-derived compound as a promising therapeutic option.

Effect of in vitro simulated digestion on the anti-Helicobacter Pylori activity of different Propolis extracts

Helicobacter pylori (HP) is among the most common pathogens causing infection in humans worldwide. Oxidative stress and gastric inflammation are involved in the progression of HP-related gastric diseases, and they can be targeted by integrating conventional antibiotic treatment with polyphenol-enriched natural products. In this work, we characterised three different propolis extracts and evaluated their stability under in vitro simulated gastric digestion, compared to their main constituents alone. The extract with the highest stability to digestion (namely, the dark propolis extract, DPE) showed a minimum bactericidal concentration (MBC) lower than 1 mg/mL on HP strains with different virulence factors. Finally, since urease is one of the virulence factors contributing to the establishment of a microenvironment that promotes HP infection, we evaluated the possible inhibition of this enzyme by using molecular docking simulations and in vitro colorimetric assay, showing that galangin and pinocembrin may be involved in this activity.

Brazilian Green Propolis' Artepillin C and Its Acetylated Derivative Activate the NGF-Signaling Pathways and Induce Neurite Outgrowth in NGF-Deprived PC12 Cells

Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.

Efficacy of Bee Products (Anzer Honey, Pollen and Propolis) in Detection and Healing of Damage Induced by Antidiabetic Drug Vildagliptin/Metformin Hydrochloride in Healthy Human Pancreatic Cells: Cytotoxic, Genotoxic and Biochemical Studies

BACKGROUND AND OBJECTIVE

Although drugs are powerful therapeutic agents, they have a range of side effects. These side effects are sometimes cellular and not clinically noticeable. Vildagliptin/metformin hydrochloride is one of the most widely used oral antidiabetic drugs with two active ingredients. In this study, we investigated its harmful effects on the metabolic activation system in healthy human pancreatic cells "hTERT-HPNE", and we aimed to improve these harmful effects by natural products. To benefit from the healing effect, we used the unique natural products produced by the bees of the Anzer Plateau in the Eastern Black Sea Region of Turkey.

METHODS

Cytotoxic and genotoxic effects of the drug were investigated by different tests, such as MTT, flow cytometry-apoptosis and comet assays. Anzer honey, pollen and propolis were analyzed by gas chromatography/mass spectrometry (G/C-MS). A total of 19 compounds were detected, constituting 99.9% of the samples.

RESULTS

The decrease in cell viability at all drug concentrations was statistically significant compared to the negative control (P<0.05). A statistically significant decrease was detected in the apoptosis caused by vildagliptin/metformin hydrochloride with the supplementation of Anzer honey, pollen and propolis in hTERT-HPNE cells (P<0.05).

CONCLUSION

This study can contribute to other studies testing the healing properties of natural products against the side effects of oral antidiabetics in human cells. In particular, Anzer honey, pollen and propolis can be used as additional foods to maintain cell viability and improve heal damage and can be evaluated against side effects in other drug studies.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by caffeic acid phenethyl ester, a major component of Chinese propolis

OBJECTIVES

We evaluated the immune-modulatory effects of Chinese propolis (CP) and its major constituent, caffeic acid phenethyl ester (CAPE), on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells.

METHODS

Mouse spleen cells stimulated by anti-CD3 monoclonal antibody were co-cultured with CP, CAPE, and HC030031, a specific antagonist of the TRPA1 Ca2+-permeable cation channel. Cytokine production was assayed by enzyme-linked immunosorbent assay. Interleukin (IL)-2 mRNA expression was examined by reverse transcription-quantitative polymerase chain reaction.

RESULTS

In stimulated spleen cells treated with 1/16,000 CP diluent, IL-2 production was markedly enhanced, while IL-4 and IL-10 productions were not significantly affected. In contrast, interferon (IFN)-γ, IL-6, and IL-17 productions were markedly reduced. These effects of CP were reproduced by the CAPE treatment. A time-course observation demonstrated that, compared to control cells, IL-2 mRNA expression and production were significantly enhanced in the spleen cells stimulated by CAPE; however, IL-2 production was markedly delayed compared to that in the untreated control cells. The enhancement of IL-2 production by CAPE was scarcely alleviated by the addition of HC030031. These effects of CAPE upon IL-2 mRNA production were abolished in spleen cells without anti-CD3 antibody stimulation.

CONCLUSIONS

CAPE is an important regulator of CP for cytokine regulation in anti-CD3 antibody-stimulated spleen cells. The agent specifically reduced IFN-γ, IL-6, and IL-17 and slightly enhanced Th2 cytokine production while significantly enhancing IL-2 production at the transcriptional level.

Characterization of Brazilian green propolis as a photosensitizer for LED light-induced antimicrobial photodynamic therapy (aPDT) against methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-intermediate Staphylococcus aureus (VISA)

Staphylococcus aureus is the primary cause of skin and soft tissue infections. Its significant adaptability and the development of resistance are the main factors linked to its spread and the challenges in its treatment. Antimicrobial photodynamic therapy emerges as a promising alternative. This work aimed to characterize the antimicrobial photodynamic activity of Brazilian green propolis, along with the key bioactive compounds associated with this activity. Initially, a scanning spectrometry was conducted to assess the wavelengths with the potential to activate green propolis. Subsequently, reference strains of methicillin-resistant Staphylococcus aureus (MRSA ATCC 43300) and vancomycin-intermediate Staphylococcus aureus (VISA ATCC 700699) were exposed to varying concentrations of green propolis: 1 µg/mL, 5 µg/mL, 10 µg/mL, 50 µg /mL and 100 µg/mL and were stimulated by blue, green or red LED light. Finally, high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques, along with classic molecular networking analysis, was performed to identify potential bioactive molecules with photodynamic activity. Brazilian green propolis exhibits a pronounced absorption peak and heightened photo-responsiveness when exposed to blue light within the range of 400 nm and 450 nm. This characteristic reveals noteworthy significant photodynamic activity against MRSA and VISA at concentrations from 5 µg/mL. Furthermore, the propolis comprises compounds like curcumin and other flavonoids sourced from flavone, which possess the potential for photodynamic activity and other antimicrobial functions. Consequently, Brazilian green propolis holds promise as an excellent bactericidal agent, displaying a synergistic antibacterial property enhanced by light-induced photodynamic effects.

Floral Visitation, Phytochemical and Biological Activities of Bioproducts from Tetragonisca angustula (Hymenoptera, Apidae, Meliponini): A Review

Tetragonisca angustula (Latreille, 1811) is an indigenous neotropical stingless bee, popularly known as "Jataí", with a wide distribution in the Brazilian territory. T. angustula produces other derivatives such as propolis, geopropolis, fermented (saburá pollen), cerumen and resins, which are important in folk medicine. In this review, the objective was to gather research on the main plant species visited by T. angustula, as well as studies that verified the chemical composition and biological properties of T. angustula bioproducts. The bibliographic review was performed by searching the Scopus, Web of Science, ScienceDirect, and PubMed databases for publications from 2003 to February 2023. We found 78 studies that analyzed the interactions between T. angustula and floral species, with species from the botanical families Fabaceae, Asteraceae, Malvaceae, Bignoniaceae, Solanaceae, Myrtaceae and Lamiaceae being the most reported as the main food sources for this species. The presence of compounds belonging to the class of flavonoids, phenolic acids, terpenoids and alkaloids has been identified by studying the chemical composition of honey, propolis, geopropolis and fermented pollen (saburá) in 21 studies. The data collected in the literature emphasize that these T. angustula products have remarkable biological properties, especially their antibacterial and antioxidant activities.

Comparison of cytotoxic and apoptosis-inducing effects of MTA, propolis, and propolis-MTA on immature dental pulp stem cells

BACKGROUND

Pulpotomy is a treatment option for the preservation of pulp vitality in primary teeth with extensive caries. Propolis is a natural resinous substance with optimal antimicrobial, anti-inflammatory, and immune-regulatory properties. Thus, this study aimed to compare the cytotoxic and apoptosis-inducing effects of mineral trioxide aggregate (MTA), propolis, and MTA-propolis on immature dental pulp stem cells (IDPSCs).

METHODS

In this in vitro, experimental study, primary IDPSCs were exposed to propolis, MTA, and MTA-propolis for 24 and 72-h. The cytotoxicity and apoptosis-inducing effects were evaluated using the methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. Data were analyzed using ANOVA and Tukey's test at 0.05 level of significance.

RESULTS

The cytotoxicity of MTA and MTA-propolis was higher than that of propolis alone at both 24/48 h. In addition, all tested concentrations showed higher biocompatibility at 72-h compared with 24-h (P < 0.0001). In the assessment of apoptosis, propolis-MTA showed higher cell viability compared with other materials (P < 0.0001).

CONCLUSION

Propolis-MTA showed higher biocompatibility than MTA. Addition of propolis to MTA improved cell proliferation in the first 24-h. Also, the cytotoxicity of propolis was lower than other materials in the first 24-h. Thus, propolis may serve as a promising pulp capping agent given that its other properties are approved.

In vitro antiviral effect of Mexican and Brazilian propolis and phenolic compounds against human coronavirus 229E

Propolis is a resinous substance collected by bees (Apis mellifera). It is used for its biological properties. This natural product is available as a safe therapeutic option. Herein, we report the antiviral effects of brown propolis extract from Mexico and green and red propolis extracts from Brazil, as well as their phenolic compounds (quercetin, caffeic acid, and rutin) in preventing infection of MRC-5 cells by HCoV-229E. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. All samples studied showed antiviral activity. Green and brown propolis extracts, and quercetin exhibited the best EC50 values with values of 19.080, 11.240, and 77.208 µg/mL against HCoV-229E, respectively, and with TC50 of 62.19, 29.192, and 298 µg/mL on MRC-5 cells, respectively. These results are the first in vitro study of the effects of propolis on HCoV-229E and provide the basis for the development of natural formulations against other coronavirus strains.

Antitumor Effect of Poplar Propolis on Human Cutaneous Squamous Cell Carcinoma A431 Cells

Propolis is a gelatinous substance processed by western worker bees from the resin of plant buds and mixed with the secretions of the maxillary glands and beeswax. Propolis has extensive biological activities and antitumor effects. There have been few reports about the antitumor effect of propolis against human cutaneous squamous cell carcinoma (CSCC) A431 cells and its potential mechanism. CCK-8 assays, label-free proteomics, RT-PCR, and a xenograft tumor model were employed to explore this possibility. The results showed that the inhibition rate of A431 cell proliferation by the ethanol extract of propolis (EEP) was dose-dependent, with an IC50 of 39.17 μg/mL. There were 193 differentially expressed proteins in the EEP group compared with the control group (p < 0.05), of which 103 proteins (53.37%) were upregulated, and 90 proteins (46.63%) were downregulated. The main three activated and suppressed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were extracellular matrix (ECM)-receptor interaction, amoebiasis, cell adhesion molecules (CAMs), nonalcoholic fatty liver disease (NAFLD), retrograde endocannabinoid signaling, and Alzheimer's disease. The tumor volume of the 100 mg/kg EEP group was significantly different from that of the control group (p < 0.05). These results provide a theoretical basis for the potential treatment of human CSCC A431 cell tumors using propolis.

Propolis prevents vascular endothelial dysfunction by attenuating inflammation and oxidative damage in the chronic unpredictable stress model of depression in rats

OBJECTIVES

Chronic stress may lead to depression and vascular endothelial dysfunction. We aimed to evaluate the effects of propolis on vascular functions and the possible mechanisms of its vascular effects in the rat model of chronic unpredictable mild stress (CUMS)-induced depression.

METHODS

Male Wistar rats were divided into control, stress (exposure to CUMS), control+propolis and stress+propolis groups (n = 8/each group). CUMS model was induced by exposing rats to various mild stressors daily for 5 weeks. The extract of propolis (100 mg/kg/day) was administered orally to propolis-treated groups for 5 weeks. The depression-like behaviours were assessed with the forced swimming test (FST). Chronic stress resulted in increased immobility response in FST and elevated serum corticosterone levels. Thoracic endothelial functions and expressions of endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha (TNFα), interleukin-1beta (IL-1β), Heme oxygenase-1 (HO-1) and superoxide dismutase (SOD) level were assessed.

KEY FINDINGS

Compared to control group, stress group exhibited a significant decrease in endothelium-dependent relaxations, and eNOS, SOD and HO-1 expressions, whereas a significant increase in the thoracic expressions of TNFα and IL-1β. Propolis ameliorated depression-like behaviours, vascular endothelial dysfunctions and alterations of protein expressions.

CONCLUSION

Propolis exerted antidepressant-like and vasculoprotective effects in CUMS-induced depression in rats. Chronic propolis treatment may have a protective effect on CUMS-induced vascular endothelial dysfunction by its anti-inflammatory and antioxidant effects.

Brazilian green propolis prevent Alzheimer's disease-like cognitive impairment induced by amyloid beta in mice

BACKGROUND

The increasing incidence of cognitive impairment has become a health problem in the aging society. Owing to its antioxidant and anti-inflammatory properties, Brazilian green propolis-derived from Baccharis dracunculifolia-is anticipated to possess anticognitive properties. However, the preventive effect of Brazilian green propolis on cognitive impairment remains unexplained. This study aimed to investigate the effect of Brazilian green propolis on cognitive impairment using a mouse model of Alzheimer's disease (AD) induced by intracerebroventricular injection of amyloid beta (Aβ)25‒35.

METHODS

Five-week-old male Slc:ddY mice were randomly divided into five groups (n = 8). The groups were pretreated with vehicle and propolis at a dose of 100, 300 and 900 mg/kg body weight for 8 days, then AD-like phenotypes were induced by intracerebroventricular (ICV) injection of Aβ25‒35. A sham operation group was set as the control. Memory and learning ability were measured at 7 to 8 days after ICV injection. Gene expression and histological studies were performed at the endpoint of the study.

RESULTS

In a passive avoidance test, the administration of Brazilian green propolis prevented the impairment of learning and memory function. Furthermore, comprehensive gene expression analysis in the hippocampus and forebrain cortex revealed that Brazilian green propolis suppressed Aβ25-35-induced inflammatory and immune responses. In particular, Brazilian green propolis prevented alterations in gene expressions of microglial and astrocytic markers such as Trem2 and Lcn2 induced by Aβ25‒35 injection, suggesting the suppression of excessive activation of glial cells in the brain. In addition, Brazilian green propolis suppressed the elevation of plasma interleukin (IL)-6 levels induced by Aβ25‒35 injection.

CONCLUSIONS

The results suggest that the prophylactic administration of Brazilian green propolis has a preventive effect against AD by suppressing excessive inflammation and immune response in glial cells. To our knowledge, this study is the first to demonstrate that Brazilian green propolis may inhibit the hyperactivation of microglia and astrocytes as a mechanism of action to prevent AD. Thus, it is a promising ingredient for preventing AD-type dementia.

The Phenolic Profile and Anti-Inflammatory Effect of Ethanolic Extract of Polish Propolis on Activated Human Gingival Fibroblasts-1 Cell Line

Propolis, owing to its antibacterial and anti-inflammatory properties, acts as a cariostatic agent, capable of preventing the accumulation of dental plaque and inhibiting inflammation. The anti-inflammatory properties of propolis are attributed to caffeic acid phenethyl ester (CAPE), which is present in European propolis. The objective of the conducted study was to assess the anti-inflammatory effects of the Polish ethanolic extract of propolis (EEP) and isolated CAPE on stimulated with LPS and IFN-α, as well as the combination of LPS and IFN-α. The cytotoxicity of the tested compounds was determined using the MTT assay. The concentrations of specific cytokines released by the HGF-1 cell line following treatment with EEP (25-50 µg/mL) or CAPE (25-50 µg/mL) were assessed in the culture supernatant. In the tested concentrations, both CAPE and EEP did not exert cytotoxic effects. Our results demonstrate that CAPE reduces TNF-α and IL-6 in contrast to EEP. Propolis seems effective in stimulating HGF-1 to release IL-6 and IL-8. A statistically significant difference was observed for IL-8 in HGF-1 stimulated by LPS+IFN-α and treated EEP at a concentration of 50 µg/mL (p = 0.021201). Moreover, we observed that CAPE demonstrates a stronger interaction with IL-8 compared to EEP, especially when CAPE was administered at a concentration of 50 µg/mL after LPS + IFN-α stimulation (p = 0.0005). Analysis of the phenolic profile performed by high-performance liquid chromatography allowed identification and quantification in the EEP sample of six phenolic acids, five flavonoids, and one aromatic ester-CAPE. Propolis and its compound-CAPE-exhibit immunomodulatory properties that influence the inflammatory process. Further studies may contribute to explaining the immunomodulatory action of EEP and CAPE and bring comprehensive conclusions.

Activity of propolis from Mexico on the proliferation and virulence factors of Candida albicans

BACKGROUND

This research evaluated the anti-Candida albicans effect of Mexican propolis from Chihuahua. Chemical composition of the ethanolic extract of propolis was determined by GC-MS, HPLC-DAD, and HPLC-MS. The presence of anthraquinone, aromatic acid, fatty acids, flavonoids, and carbohydrates was revealed.

RESULTS

The anti-Candida activity of propolis was determined. The inhibitions halos were between 10.0 to 11.8 mm; 25% minimum inhibitory concentration (0.5 mg/ml) was fungistatic, and 50% minimum inhibitory concentration (1.0 mg/ml) was fungicidal. The effect of propolis on the capability of C. albicans to change its morphology was evaluated. 25% minimum inhibitory concentration inhibited to 50% of germ tube formation. Staining with calcofluor-white and propidium iodide was performed, showing that the propolis affected the integrity of the cell membrane. INT1 gene expression was evaluated by qRT-PCR. Propolis significantly inhibited the expression of the INT1 gene encodes an adhesin (Int1p). Chihuahua propolis extract inhibited the proliferation of Candida albicans, the development of the germ tube, and the synthesis of adhesin INT1.

CONCLUSIONS

Given the properties demonstrated for Chihuahua propolis, we propose that it is a candidate to be considered as an ideal antifungal agent to help treat this infection since it would not have the toxic effects of conventional antifungals.

Red propolis extract as a natural ionophore for confined sheep: performance and morphological and histopathological changes

This study aimed to evaluate the effect of increasing levels of red propolis extract (RPE) in the diet of confined sheep on performance and histomorphometric parameters of rumen and intestine and histopathological parameters of liver and kidney. Thirty-five male sheep (17.08 ± 2.36 kg) were used, distributed in a completely randomized design, with five treatments (0, 7, 14, 21, and 28 mL day-1 RPE) and seven replications, submitted to 68 days of experiment. At the end of the experimental period, the animals were euthanized, and samples of rumen, intestine, liver, and kidney were collected to histomorphometry and histopathology analyzes. Higher RPE inclusions (21 and 28 mL day-1) maintained dry matter intake and increased total weight (5.78 x 6.14 and 6.95 kg, respectively) gain up to 20.24%. In the rumen, the inclusion of RPE led to an increase in the thickness of the epithelium and the highest level also increased the thickness of the keratinized portion of this epithelium (21.71 x 32.15 μm). The level of 21 mL day-1 provided larger ruminal papillae (1620.68 x 1641.70 μm) and greater ruminal absorption area (561791.43 x 698288.50 μm2). In intestine 21 and 28 mL-1 of RPE provided greater mucosal thickness (468.54 x 556.20 and 534.64 μm), higher goblet cell index (23.32 x 25.82 and 25.64) and higher hepatic glycogen index (1.47 x 1.64 and 1.62), supporting higher nutrients absortion and glicogenolise and intestinal health, corroborating the weight gain indices. The inclusion of RPE did not cause renal histopathological lesions. Therefore, levels of 21 and 28 mL day-1 of RPE can be used in sheep diets, promoting greater final weight gain, causing positive histomorphological changes in the rumen, intestine and liver, without causing kidney or liver damage.

Toxicological and chemoprevention studies of Brazilian brown propolis from Araucaria sp

Brazilian brown propolis (BBP) is a natural product derived predominantly from the south region of Brazil, where Araucaria forests are dominant. Despite its potential as a source of bioactive compounds with leishmanicidal, anti-inflammatory, nociceptive, and antimicrobial properties, BBP has not been comprehensively studied compared to green propolis. Therefore, this study aimed to determine the safety and chemopreventive potential of BBP. The cytotoxicity attributed to BBP was assessed using two different assays, while the Salmonella/microsome assay was employed to evaluate mutagenicity. The acute toxicity attributed to BBP was determined using a zebrafish model, while the chemopreventive potential was investigated utilizing Chinese hamster lung (V79) cell lines. Data demonstrated that BBP exerted cytotoxic effects at concentrations greater than or equal to 10 µg/ml and did not exhibit mutagenicity in Salmonella typhimurium strains TA98 and TA100. However, at the highest concentration tested (4000 µg/plate), BBP induced a significant increase in revertant colonies in S. typhimurium TA102 strain. The LC50 equivalent to 8.83 mg/L was obtained in the acute toxicity evaluation in zebrafish. BBP also showed antigenotoxic effect by significantly reducing chromosomal damage induced by the mutagen doxorubicin in V79 cell cultures at a concentration of 2.5 μg/ml. Compared to Brazilian green and red propolis, BBP exhibited greater toxicity. On the other hand, at lower concentrations, BBP displayed chemopreventive potential, which may be associated with the antioxidant capacity of the extract. These findings contribute to a better understanding of the biological properties and potential applications of BBP in treating various diseases.

Dietary propolis improves the growth performance, redox status, and immune response of Nile tilapia upon a cold-stress challenge

The purpose of this research was to demonstrate the potential of adding propolis (PR) to the diet of Nile tilapia (Oreochromis niloticus) to mitigate the harmful effect of cold stress (CS) on the growth performance, redox status, and immunological response. Two trials were conducted in this study. First, 210 Nile tilapia fingerlings (28.61±0.20 g) were used in a preliminary trial to determine the appropriate PR level and supplementation period to be applied for the main trial. Fish were assigned into 7 treatment groups (3 aquaria replicates × 10 fish per aquarium in each treatment group) according to the rate of PR supplementation in the fish diets at 0, 2, 4, 6, 8, 10, and 12 g/kg for 6 consecutive weeks. The average body weight and body weight gain were determined weekly. It was found that PR supplementation at 10 g/kg in fish diet for 4 weeks was enough to obtain significant results on the growth performance of Nile tilapia. For the main trial of the present study, 480 Nile tilapia fingerlings (average weight 29.93±0.11 g) were distributed into randomized 2 PR × 2 CS factorial treatment groups (6 replicate aquariums containing 20 fish in each group). Fish of PR groups received a basal diet for a feeding period of 4 weeks, included with 10 g/kg PR (+ PR group) or without PR inclusion (- PR group). Fish of the CS groups were either challenged with cold stress at 18°C (+ CS group) or maintained at a temperature of 26°C during the feeding period (- CS group). The results showed that CS challenge significantly (p < 0.05) impaired the growth indices, redox status, and immune response in the challenged fish compared to the non-challenged fish. On contradictory, the inclusion of PR into fish diets enhanced (p < 0.05) the feed intake, growth indices, antioxidant enzyme activity, and immunological parameters. Moreover, PR treatment alleviated the CS deterioration of fish weights, specific growth rates, feed efficiency, antioxidant enzyme activity, lymphocyte proliferation, and phagocytosis activity and alleviated the elevated mortality, H/L ratio, and malondialdehyde levels by cold stress. It is concluded that the inclusion of propolis at 10 g/kg in the diet of Nile tilapia fish could be approved as a nutritional approach to enhance their performance, especially when stressed by low-temperature conditions.

Chemical Composition and Evaluation of Antibacterial, Antibiofilm, and Mutagenic Potentials of a Propolis Sample from the Atlantic Forest of Midwest Brazil

Sixteen triterpenoids with various skeletal types, five phenylpropanoid derivatives, and two flavonoids were isolated from a propolis sample produced by Apis mellifera collected in the Atlantic Forest of Midwest Brazil. Among these compounds, six triterpenes, namely 3β,20R-dihydroxylanost-24-en-3-yl-palmitate, (23E)-25-methoxycycloartan-23-en-3-one, 24-methylenecycloartenone, epi-lupeol, epi-α-amyrin, and epi-β-amyrin are being reported for the first time in propolis, while cycloartenone, (E)-cinnamyl benzoate, and (E)-cinnamyl cinnamate are new findings in Brazilian propolis. The presence of cycloartane- and lanostane-type triterpenoids, the latter being a class of compounds of restricted distribution in propolis worldwide, has not been reported in propolis from Midwest Brazil until now. The ethyl acetate phase obtained from the ethanol extract was effective in preventing biofilm formation by Staphylococcus aureus, with an inhibition rate of about 96 % at 0.5 mg.mL-1 , and with quercetin isolated as one of its active constituents. In contrast, the hexane phase exhibited notable antibacterial activity against Pseudomonas aeruginosa, inhibiting bacterial growth by 92 % at 0.5 mg.mL-1 ; however, none of the triterpenoids isolated from this phase proved active against this pathogen. The ethanol extract was neither toxic nor mutagenic at the concentrations tested, as determined by the in vivo SMART assay on Drosophila melanogaster, even under conditions of high metabolic activation.

Effectiveness of natural biomaterials in the protection and healing of experimentally induced gastric mucosa Ulcer in rats

BACKGROUND

A gastric ulcer is a painful lesion of the gastric mucosa that can be debilitating or even fatal. The effectiveness of several plant extracts in the therapy of this illness has been demonstrated in traditional pharmacopoeias.

AIM

this study was aimed to see if propolis, ginseng in normal or nano form, and amygdalin might help in preventing the ulcerative effects of absolute ethanol.

METHODS

Gastroprotective properties of pretreatments before ethanol gavage in rats were compared to omeprazole. The ulcer and stomach parameters (ulcerated regions) were measured (mm2), ulcer inhibition percentage, the stomachs were assessed macroscopically with gastric biopsy histological examinations.

RESULTS

Amygdalin, normal and nano ginseng, nano propolis followed by propolis all showed great efficacy in protecting the cyto-architecture and function of the gastric mucosa. The number of ulcerated sites was greatly reduced, and the percentage of stomach protection was increased. Histopathological examination had confirmed great protective effects of the nanoformulations followed by amygdalin. The protection and healing rate was completed to about 100% in all tested materials while ulcer areas were still partially unhealed in normal propolis and omeprazole. Quantitative assay of the m-RNA levels Enothelin 1(ET-1), leukotriene4 (LT-4), and caspase 3(Cas-3) genes and Histamine were done and revealed significant up-regulations in ethanol group and the maximum protective effect was reported with ginseng nano, moreover the histamine content was significantly decreased with nano- formulated extracts.

CONCLUSION

Amygdalin and the nanoformulated ginseng and propolis had exhibited a marked protective effect against the ulcerative toxic effects of ethanol.

Effects of simulated gastrointestinal digestion/epithelial transport on phenolics and bioactivities of particles of brewer's spent yeasts loaded with Brazilian red propolis

Red propolis from northeast Brazil contains mainly isoflavonoids as bioactive compounds, and its consumption may counteract unregulated and exacerbated formation of reactive oxygen species and inflammatory cytokines/chemokines. Moreover, the production of particles using sustainable carriers have been studied to increase the use of propolis as a functional food ingredient. Hence, the objective of this work was to investigate the effects of simulated gastrointestinal digestion followed by a cell-based epithelial transport on phenolic profile, anti-inflammatory and antioxidant activities of particles of brewer's spent yeasts (BSY) loaded with ethanolic extract of Brazilian red propolis (EEP). As a result, the EEP phenolic diversity decreased throughout the simulated gastrointestinal system, and was modulated by the particle production, as detected by high-performance liquid chromatography - electrospray ionization - quadrupole-time-of-flight-mass spectrometry (HPLC-ESI-QTOF-MS). Concomitantly, the antioxidant activity, as assessed by the ability to scavenge peroxyl and superoxide radicals, hydrogen peroxide, and hypochlorous acid, generally decreased at a higher extent for the particles of EEP with BSY (EEP-BSY) throughout the experiments. Nonetheless, after epithelial transport through the Caco-2 cell monolayer, the basolateral fraction of both EEP-BSY and EEP decreased the activation of pro-inflammatory transcription factor NF-κB by 83% and 65%, respectively, as well as the release of TNF-α (up to 51% and 38%, respectively), and CXCL2/MIP-2 (up to 33% and 25%, respectively). Therefore, BSY may be an interesting carrier for EEP bioencapsulation, since it preserves its anti-inflammatory activity. Further studies should be encouraged to investigate the feasibility of adding it in formulations of functional foods, considering its effect on sensory attributes.

Cytoprotective effect of propolis on heat stress induces alteration to histological, ultrastructural, and oxidative stress in catfish (Clarias gariepinus)

Our study helps to evaluate the immune response, antioxidative status, and resistance against heat stress (HS) in Clarias gariepinus treated with propolis extraction; the results will contribute to theories of fish physiology and immunity under high-temperature conditions. Forty-five fish were divided into three equal groups: the control, the HS group at 36 °C, and the HS treated with alcoholic extraction of propolis that dissolved in water for 3 weeks. The results of our study suggested that the stress response differs among tissues thymus, spleen, and liver. All the tissues showed alteration in morphological and cytological structure at the light microscope (LM) and transmission electron microscope (TEM); thymus showed edema and thymocyte destruction; the spleen detected collagen deposition, and the liver displayed endoplasmic reticulum amplification (ER). In addition, we examined oxidative stress and antioxidant defenses (lipid peroxidation, catalase, and glutathione) of the spleen and measured blood biochemical parameters (alanine transaminase and aspartic transaminase levels) after heat stress. However, this toxic effect of HS was neutralized by the propolis extraction. To conclude, propolis is recommended to cope with the impacts of heat stress on catfish (Clarias gariepinus) by improving immunity and antioxidative resistance.

Evaluation of the flexural strength of orthodontic acrylic resin incorporated with propolis nanoparticles: an in vitro study

AIM

Nanopropolis has become the subject of interest in medicine and dentistry as a natural product due to its outstanding properties, particularly antimicrobial activity. This study aimed at investigating the effect of nanopropolis on flexural strength of polymethyl methacrylate (PMMA).

Socket preservation using a combination of propolis extract and bovine bone graft towards the expression of receptor activator of nuclear κB ligand and osteoprogerin

AIM

This study was undertaken to comprehend the effect of a combination of bovine bone graft (BBG) and propolis extract on the receptor activator of nuclear κB ligand (RANKL) and osteoprotegerin (OPG) expressions in post-extraction tooth sockets.