Baccharis dracunculifolia and Dalbergia ecastophyllum, Main Plant Sources for Bioactive Properties in Green and Red Brazilian Propolis

Green propolis extract for the treatment of alkali-induced superficial corneal ulcers: local and systemic analyses

Green propolis, produced by honeybees from the resin of certain plants, has garnered attention for its potential health benefits. Green propolis contains compounds like artepillin C, which exhibits antioxidant, anti-inflammatory, and antimicrobial properties. This study's objective was to examine the effects of green propolis extract containing 21.05% artepillin C, topically administered (5, 10 and 15 mg/mL) in rats with induced superficial corneal ulcers with alkali, applied four times daily, for 96 hours. Rats treated with the green propolis extract exhibited of ulcer reduction more significant reduction after 24 hours of treatment than untreated animals, suggesting a similar healing activity of the commercial drug. After 96 hours of treatment, the rats were euthanized, and the corneas were submitted for histopathological analysis; no statistical difference was detected between rats treated with green propolis and those not treated in terms of polymorphonuclear and neovessel counts in the corneal stroma. In the toxicogenetic analysis, by the micronucleus test, no significant differences were observed in the frequencies of chromosomal damage and the ratio of polychromatic erythrocytes to the total number of erythrocytes between treated and untreated animals, revealing the absence of genotoxicity and cytotoxicity, respectively. The biochemical results did not indicate a hepatotoxic or nephrotoxic effect of the formulations containing green propolis. Like this, the standardized green propolis extract induced corneal epithelialization without toxic effects, rendering it a promising option for treating superficial keratitis.

Taiwan Green Propolis Nanoparticles Induce Antiproliferation and Apoptosis in Oral Cancer Cells

Introduction: Taiwan green propolis (TGP) is rich in prenylflavonoids and exhibits antioxidant, antibacterial, antiviral, and antitumour properties. It induces apoptosis in various cancer cells, making it a highly promising natural medicine. Although the health benefits and food applications of TGP are widely recognised, no study has explored its effects on Taiwan oral cancer cells (OECM1). This study investigated whether TGP induces apoptosis in OECM1 cells. Methods: High-performance liquid chromatography (HPLC), thin-layer chromatography, and liquid chromatography/mass spectrometry were used to identify the components in TGP and the fruit peel of Macaranga tanarius. The inhibitory activities of TGP dissolved in DMSO (TGPDMSO) and encapsulated in food-grade zein nanoparticles (TGPNP) against OECM1 cells were compared using MTT assays. The morphological changes, cell cycle analysis, and protein expression profiles of OECM1 cells after the TGP treatments were performed using microscopy, flow cytometry, and Western blot, respectively. Results: An MTT assay of TGPDMSO-treated OECM1 cells suggested an IC50 of 12.6 µg/mL, demonstrating that TGPDMSO exhibits significant cytotoxicity. Subsequent MTT assays revealed TGPNP's cytotoxicity against OECM1 with an IC50 of 11.6 µg/mL. Flow cytometry revealed that TGPNP induced a cell arrest in S phase and DNA fragmentation. Western blotting analyses manifested an increase in Bax and cl-Casp9 and a decrease in Bcl2 and PARP. Conclusion: This study demonstrated that both TGPDMSO and TGPNP treatments induced apoptosis in OECM1 cells with a comparable IC50. Notably, utilising edible zein as a nanoparticle carrier for TGP mitigates the cytotoxicity risk associated with DMSO, providing a novel and safe approach for cancer treatment.

Bioactive Compounds from Propolis on Bone Homeostasis: A Narrative Review

This narrative review explores the potential effects of Propolis and its bioactive compounds on bone health. Propolis, a resinous product collected by bees, is renowned for its antimicrobial, anti-inflammatory, and antioxidant properties. Recent research emphasizes its positive role in osteogenesis, primarily through the modulation of osteoclast and osteoblast activity via molecular pathways. Key mechanisms include reducing inflammatory cytokines, protecting against oxidative stress, and upregulating growth factor essential for bone formation. While compounds such as Caffeic Acid Phenethyl Ester, Apigenin, Quercetin, and Ferulic Acid have been well-documented, emerging evidence points to the significant roles of less-studied compounds like Pinocembrin, Kaempferol, p-Coumaric acid, and Galangin. This review synthesizes the current literature, focusing on the mechanisms by which these bioactive compounds influence osteogenesis. Firstly, it explores the techniques for characterizing bioactive compounds presented in propolis, the chemogeographic variations in its composition, and the effects of both crude extracts and isolated compounds on bone tissue, offering a comprehensive analysis of recent findings across different experimental models. Further, it discusses the effects of Propolis compounds on bone health. In summary, these compounds modulate signaling pathways, including nuclear factor kappa beta, wingless-related integration site, mitogen-activated protein kinase, vascular endothelial growth factor, and reactive oxygen species. These pathways influence the receptor activator of nuclear factor kappa-β/receptor activator of nuclear factor kappa-β ligand/osteoprotegerin system, fostering bone cell differentiation. This regulation mitigates excessive osteoclast formation, stimulates osteoblast activity, and ultimately contributes to the restoration of bone homeostasis by maintaining a balanced bone remodeling process.

Evaluation of the antitrypanosomal activity, cytotoxicity and phytochemistry of red Brazilian propolis

Recently, the growth in the consumption of functional foods with potential nutritional and health benefits revealed rapid progress in phytochemical analysis to assure quality and profile the chemical composition. Bee propolis, a gummy exudate produced in beehives after harvesting from different plant species and showed to contain bioactive secondary metabolites with biological importance. The main goal of the current study is to profile the chemical composition of red propolis samples from the Brazilian stingless bee Tetragonula biroi for the first time using HPLC-UV-ELSD and NMR analysis for assignment of the abundant metabolites' classes as well as extraction and isolation of the major compounds. Column chromatography and size exclusion chromatography were applied for the purification of the major compounds in red Brazilian propolis. Further, testing the antitrypanosomal and cytotoxic activities against Trypanosoma brucei and human leukemia cell lines (U937) was performed. A total of 29 secondary metabolites were identified as two anthocyanins, 6 flavonoids, 8 isoflavonoids, 10 phenolics, two phenolic acids, and one triterpenoid. Two phenolic compounds were purified and identified using 1D and 2D NMR analysis along with MS analysis as liquiritigenin and calycosin. Red Brazilian propolis FB-3 fraction showed the highest inhibitory activity against T. brucei at 1.6 μg/ml, compared to 12.4 μg/ml of the crude extract. The isolated compounds showed moderate activity with an MIC of 8.5 μg/ml for liquiritigenin and 8.7 μg/ml for calycosin. Moreover, FB-3 fraction and calycosin were showed the potent cytotoxic effect with IC50 = 45.1 and 35.8μg/ml, respectively compared to IC50 = 29.5 μg/ml of the standard diminazen. Hence, red Brazilian propolis is rich source of polyphenols with myriad biological importance. Propolis fractions and purified compounds showed moderate antiprotozoal activity and potent cytotoxic activity against human leukemia cell lines.

Inhibition of Food Spoilage Fungi, Botrytis cinerea and Rhizopus sp., by Nanoparticles Loaded with Baccharis dracunculifolia Essential Oil and Nerolidol

This study investigates the antifungal potential of encapsulated essential oil (EO) from Baccharis dracunculifolia and nerolidol (NE) within Pluronic® F-127 nanoparticles (NPs). The EO, containing nerolidol, β-caryophyllene, and α-pinene as major bioactive compounds, exhibited superior antifungal activity compared to NE. The NP-EO formulations demonstrated high efficacy against Botrytis cinerea, with inhibition rates ranging from 29.73% to 87.60% and moderate efficacy against Rhizopus sp., with inhibition rates from 11.81% to 32.73%. In comparison, NP-NE showed lower antifungal activity. Both formulations effectively inhibited spore germination, with NP-EO showing greater inhibition compared to NP-NE. The encapsulation efficiency was significantly higher for NP-EO (80.1%) as compared to NP-NE (51.1%), attributed to the complex composition of EO facilitating better encapsulation and retention. Stability studies indicated that both NP formulations were stable at 25 °C for at least 15 days and exhibited changes in particle size and the formation of smaller particle populations at other temperatures (4 °C and 37 °C). Hemolytic activity was low across all NPs, suggesting their safety for food applications. The findings underscore the efficacy and applicability of EO-encapsulated NPs in extending food shelf life and maintaining product quality. The controlled and prolonged release of active compounds, coupled with their antifungal activity and safety, suggests that these NPs represent a promising and innovative approach for food preservation and active packaging development.

Potential Antitumor Mechanism of Propolis Against Skin Squamous Cell Carcinoma A431 Cells Based on Untargeted Metabolomics

Propolis is a sticky substance produced by honeybees (Apis mellifera) through the collection of plant resins, which they mix with secretions from their palate and wax glands. Propolis can inhibit tumor invasion and metastasis, thereby reducing the proliferation of tumor cells and inducing cell apoptosis. Previous research has shown that propolis has an inhibitory effect on skin squamous cell carcinoma A431 cells. Nevertheless, its inhibitory mechanism is unclear because of many significantly different Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between the ethanol extract of the propolis (EEP) group and the control group of cells. In this study, the main components of EEP and the antitumor mechanism at an IC50 of 29.04 μg/mL EEP were determined via untargeted metabolomics determined using ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS), respectively. The results revealed 43 polyphenolic components in the EEP and 1052 metabolites, with 160 significantly upregulated and 143 significantly downregulated metabolites between cells treated with EEP and solvent. The KEGG enrichment results revealed that EEP significantly inhibited A431 cell proliferation via the steroid hormone biosynthesis and linoleic acid metabolism pathways. These findings may provide valuable insights for the development of targeted therapies for the treatment of cutaneous squamous cell carcinoma.

The Antibacterial Potential of Brazilian Red Propolis against the Formation and Eradication of Biofilm of Helicobacter pylori

Helicobacter pylori is associated with gastrointestinal diseases, and its treatment is challenging due to antibiotic-resistant strains, necessitating alternative therapies. Brazilian red propolis (BRP), known for its diverse bioactive compounds with pharmaceutical properties, was investigated for its anti-H. pylori activity, focusing on biofilm formation inhibition and eradication. BRP was tested against H. pylori (ATCC 43526) using several assays: time-kill, nucleotide leakage, biofilm formation inhibition (determining the minimum inhibitory concentration of biofilm of 50%-MICB50, and cell viability), and biofilm eradication (determining the minimum eradication concentration of biofilm of 99.9%-MBEC). Standardization of H. pylori biofilm formation was also conducted. In the time-kill assay, BRP at 50 µg/mL eliminated all H. pylori cells after 24 h. The nucleotide leakage assay showed no significant differences between control groups and BRP-treated groups at 25 µg/mL and 50 µg/mL. H. pylori formed biofilms in vitro at 109 CFU/mL after 72 h. The MICB50 of BRP was 15.6 µg/mL, and at 500, 1000, and 2000 µg/mL, BRP eradicated all bacterial cells. The MBEC was 2000 µg/mL. These findings suggest that BRP has promising anti-H. pylori activity, effectively inhibiting and eradicating biofilms. Further studies are necessary to elucidate BRP's mechanisms of action against H. pylori.

Physicochemical Properties, Antioxidant Activity, and High-Performance Thin-Layer Chromatography Profiling of Propolis Samples from Western Australia

This study reports on the physicochemical and antioxidant properties of propolis samples from various regions across Western Australia and identifies some phenolic constituents using high-performance thin-layer chromatography (HPTLC). Total phenolic content (TPC) was determined using a modified Folin-Ciocalteu assay, and antioxidant activity was investigated with the Ferric Reducing Antioxidant Power (FRAP) assay and also visualised and semi-quantified by HPTLC-DPPH analysis. TPC values ranged from 9.26 to 59.3 mg gallic acid equivalent/g of raw propolis and FRAP assay data from 4.34 to 53.8 mmol Fe2+ mmol/kg of raw propolis, although some of these variations might be related to differences in extraction yields obtained with 70% ethanol. The presence of luteolin, taxifolin, naringenin, and 4-hydroxyphenylacetic acid was confirmed based on a comprehensive, validated matching approach against an HPTLC-derived database. The findings of the study highlight the importance of future research on the chemical composition and bioactivity of Western Australian propolis.

Advances in the phytochemical screening and biological potential of propolis

Propolis is a natural resinous product collected from different parts of plants by bees and mixed with their salivary secretions. The occurrence of more than 180 different chemotypes has flavonoids, phenolic acids, esters, and phenolic aldehydes, as well as balsamic resins, beeswax, pollen, and essential and aromatic oils, among others. Its biological potential documented throughout the world justifies the need, from time to time, to organize reviews on the subject, with the intention of gathering and informing about the update on propolis. In this review (CRD42020212971), phytochemical advances, in vitro, in vivo, and clinical biological assays of pharmacological interest are showcased. The focus of this work is to present propolis clinical safety assays, antitumor, analgesic, antioxidant, anti-inflammatory, and antimicrobial activities. This literature review highlights propolis' promising biological activity, as it also suggests that studies associating propolis with nanotechnology should be further explored for enhanced bioprocessing applications.

Evaluation of the Chemical Profile and Antioxidant Capacity of Green, Brown, and Dark Propolis

The chemical composition of propolis varies between different types, due to the specific vegetation found near the hives and the climatic and soil conditions worldwide. Green propolis is exclusive to Brazil, produced by bees, with the resin of the plant Baccharis dracunculifolia. Brown propolis is a specific variety produced mainly in Northeast Brazil from the plant Hyptis divaricata, also known as "maria miraculosa". Dark propolis is a variety of propolis produced by bees from the resin of the plant known as Jurema Preta (Mimosa hostilis benth). In this study, the aqueous extracts of green, brown, and dark propolis were analyzed for their antioxidant capacity using ABTS, FRAP, and DPPH, and their chemical profiles were determined using paper spray mass spectrometry. Among the three extracts, green propolis had the highest content of total phenolic compounds (2741.71 ± 49.53 mg GAE. 100 g-1), followed by brown propolis (1191.55 ± 36.79 mg GAE. 100 g-1), and dark propolis had the lowest content (901.79 ± 27.80 mg GAE. 100 g-1). The three types of propolis showed high antioxidant capacity, with green showing the highest antioxidant capacity for the three methods used. Using paper spray mass spectrometry, it was possible to suggest the presence of 116 substances, including flavonoids (56), phenylpropanoids (30), terpenes (25), carboxylic acids (1), benzoic acid derivatives (1), fatty acids (1), amino acids (1) and alkaloids (1). The compounds in the green, brown, and dark propolis extracts reinforce the bioactive potential for application in these tree extracts' food and pharmaceutical products.

Improvement of the In Vitro Cytotoxic Effect on HT-29 Colon Cancer Cells by Combining 5-Fluorouacil and Fluphenazine with Green, Red or Brown Propolis

Cancer is regard as one of the key factors of mortality and morbidity in the world. Treatment is mainly based on chemotherapeutic drugs that, when used in targeted therapies, have serious side effects. 5-fluorouracil (5-FU) is a drug commonly used against colorectal cancer (CRC), despite its side effects. Combination of this compound with natural products is a promising source in cancer treatment research. In recent years, propolis has become the subject of intense pharmacological and chemical studies linked to its diverse biological properties. With a complex composition rich in phenolic compounds, propolis is described as showing positive or synergistic interactions with several chemotherapeutic drugs. The present work evaluated the in vitro cytotoxic activity of the most representative propolis types, such as green, red and brown propolis, in combination with chemotherapeutic or CNS drugs on HT-29 colon cancer cell lines. The phenolic composition of the propolis samples was evaluated by LC-DAD-ESI/MSⁿ analysis. According to the type of propolis, the composition varied; green propolis was rich in terpenic phenolic acids and red propolis in polyprenylated benzophenones and isoflavonoids, while brown propolis was composed mainly of flavonoids and phenylpropanoids. Generally, for all propolis types, the results demonstrated that combing propolis with 5-FU and fluphenazine successfully enhances the in vitro cytotoxic activity. For green propolis, the combination demonstrated an enhancement of the in vitro cytotoxic effect compared to green propolis alone, at all concentrations, while for brown propolis, the combination in the concentration of 100 μg/mL gave a lower number of viable cells, even when compared with 5-FU or fluphenazine alone. The same was observed for the red propolis combination, but with a higher reduction in cell viability. The combination index, calculated based on the Chou-Talalay method, suggested that the combination of 5-FU and propolis extracts had a synergic growth inhibitory effect in HT-29 cells, while with fluphenazine, only green and red propolis, at a concentration of 100 μg/mL, presented synergism.

Brazilian red propolis exerts a cytotoxic action against prostate cancer cells and upregulates human monocyte functions

Different propolis samples can be obtained in Brazil, such as green, brown and red. Studies related to Brazilian red propolis (BRP) have increased in the last few years, so the aim of this study was to investigate its effects on the prostate cell lines LNCaP and PC-3 and on human monocytes. BRP chemical composition was analyzed by HPLC-DAD, the viability of monocyte and cancer cell by MTT assay. Cytokine production (TNF-α, IL-1β, IL-6, IL-10) by monocytes was quantitated by ELISA, the expression of cell markers (TLR-2, TLR-4, HLA-DR, CD80) and reactive oxygen species by flow cytometry. The candidacidal activity and the effects of supernatant of treated monocytes on tumor cells were assessed. BRP affected LNCaP viability after 48 and 72 h, while PC-3 cells were more resistant over time. BRP upregulated CD80 and HLA-DR expression, and stimulated TNF-α, IL-6 and IL-10 production. BRP enhanced the fungicidal activity of monocytes, displayed an antioxidant action and the supernatant of BRP-treated monocytes diminished LNCaP viability. In the search for new immunomodulatory and antitumoral agents, BRP exerted a selective cytotoxic activity on prostate cancer cells and an immunomodulatory action, suggesting its potential for clinical trials with oncological patients and for the discovery of new immunomodulatory and antitumor drugs.

Potential in vitro anti-periodontopathogenic, anti-Chikungunya activities and in vivo toxicity of Brazilian red propolis

Bacterial and viral infections are serious public health issue. Therefore, this study aimed to evaluate the antibacterial, antibiofilm and antiviral potential of the Brazilian Red Propolis (BRP) crude hydroalcoholic extract, fractions, and isolated compounds, as well as their in vivo toxicity. The antibacterial activity was evaluated by determining the Minimum Inhibitory Concentration and the antibiofilm activity by determining the Minimum Inhibitory Concentration of Biofilm (MICB₅₀). The viable bacteria count (Log₁₀ UFC/mL) was also obtained. The antiviral assays were performed by infecting BHK-21 cells with Chikungunya (CHIKV) nanoluc. The toxicity of the BRP was evaluated in the Caenorhabditis elegans animal model. The MIC values for the crude hydroalcoholic extract sample ranged from 3.12 to 100 μg/mL, while fractions and isolated compounds the MIC values ranged from 1.56 to 400 μg/mL.The BRP crude hydroalcoholic extract, oblongifolin B, and gutiferone E presented MICB₅₀ values ranging from 1.56 to 100 μg/mL against monospecies and multispecies biofilms. Neovestitol and vestitol inhibited CHIKV infection by 93.5 and 96.7%, respectively. The tests to evaluate toxicity in C. elegans demonstrated that the BRP was not toxic below the concentrations 750 μg/mL. The results constitute an alternative approach for treating various infectious diseases.

In Vitro Study on Green Propolis as a Potential Ingredient of Oral Health Care Products

Propolis is increasingly being discussed as an alternative to commonly used antiseptics. This in vitro study focused on the ethanolic extract of green Brazilian propolis (EEPg) as an additive in an oral health care product. We investigated (i) a potential inflammation-modulation activity of EEPg when a periodontal or Candida biofilm was exposed to monocytic (MONO-MAC-6) cells, (ii) the adhesion of oral pathogens to gingival keratinocytes and (iii) the antimicrobial and antibiofilm effect of different toothpaste formulations. EEPg decreased the levels of interleukin (IL)-1β and increased IL-10 in MONO-MAC cells challenged with a periodontal biofilm. In contact with TIGK cells, EEPg reduced the numbers of adherent Porphyromonas gingivalis to 0.5% but did not affect the adhesion of Candida albicans. The frequent brushing of a cariogenic biofilm with a toothpaste supplemented with EEPg reduced the surface microhardness loss of enamel specimens. Mixing an experimental erythritol toothpaste with 25 and 50 mg/mL of EEPg confirmed the antibacterial activity of EEPg against oral bacteria and particularly inhibited periodontal biofilm formation. The suggested toothpaste formulations seem to have potential in the prevention of caries, gingivitis and periodontitis and should be evaluated in further in vitro research and in clinical trials.

Ethnomedicinal, phytochemical and pharmacological investigations of Baccharis dracunculifolia DC. (ASTERACEAE)

Baccharis dracunculifolia DC (Lamiaceae) (Asteraceae) is found in South America, mainly in Argentina, Brazil, Bolivia, Paraguay and Uruguay. Folk medicine is used as a sedative, hypotensive, bronchodilator, cardiovascular disorders, anti-flu, and also in skin wounds. Considered the main source of green propolis, which increases the pharmacological interest in this species. It is also known as a "benefactor" plant facilitating the development of other plant species around it, being indicated for the recovery of degraded areas. This species has been studied for decades in order to isolate and identify the active principles present in the aerial parts (leaves and flowers) and roots. The present study consists of a review of the scientific literature addressing the ethnobotanical, ethnomedicinal, phytochemical, pharmacological and potential cytotoxic effects of the B. dracunculifolia species. In this survey, we sought to investigate issues related to the botanical and geographic description of the species, the ethnobotanical uses, as well as the phytochemical studies of the essential oil, extracts and green propolis obtained from the aerial parts and roots of B. dracunculifolia. Using high precision analytical tools, numerous compounds have already been isolated and identified from leaves and flowers such as the flavonoids: naringenin, acacetin, dihydrokaempferol, isosakuranetin and kaempferide; phenolic acids: p-coumaric, dihydrocoumaric, ferulic (E)-cinnamic, hydroxycinnamic, gallic, caffeic, and several caffeoylquinic acids derivatives; phenolic acids prenylated: artepillin C, baccharin, drupanin; the glycosides dracuculifosides and the pentacyclic triterpenoids: Baccharis oxide and friedelanol. The predominant class in the essential oil of leaves and flowers are terpenoids comprising oxygenated monoterpenes and sesquiterpenes, highlighting the compounds nerolidol, spathulenol, germacrene D and bicyclogermacrene. These compounds give the species high antimicrobial, antioxidant, antitumor, analgesic, immunomodulatory and antiparasitic potential, making this species a promising herbal medicine. In vitro toxicity assays with B. dracunculifolia extract showed low or no cytotoxicity. However, in vivo analyses with high doses of the aqueous extract resulted in genotoxic effects, which leads us to conclude that the toxicity of this plant is dose-dependent.

Brazilian Red Propolis Presents Promising Anti-H. pylori Activity in In Vitro and In Vivo Assays with the Ability to Modulate the Immune Response

Helicobacter pylori is a Gram-negative, microaerophilic, curved-rod, flagellated bacterium commonly found in the stomach mucosa and associated with different gastrointestinal diseases. With high levels of prevalence worldwide, it has developed resistance to the antibiotics used in its therapy. Brazilian red propolis has been studied due to its biological properties, and in the literature, it has shown promising antibacterial activities. The aim of this study was to evaluate anti-H. pylori from the crude hydroalcoholic extract of Brazilian red propolis (CHEBRP). For this, in vitro determination of the minimum inhibitory and bactericidal concentration (MIC/MBC) and synergistic activity and in vivo, microbiological, and histopathological analyses using Wistar rats were carried out using CHEBRP against H. pylori strains (ATCC 46523 and clinical isolate). CHEBRP presented MIC/MBC of 50 and 100 μg/mL against H. pylori strains (ATCC 43526 and clinical isolate, respectively) and tetracycline MIC/MBC of 0.74 µg/mL. The association of CHEBRP with tetracycline had an indifferent effect. In the stomach mucosa of rats, all treatments performed significantly decreased the number of H. pylori, and a concentration of 300 mg/kg was able to modulate the inflammatory response in the tissue. Therefore, CHEBRP showed promising anti-H. pylori in in vitro and in vivo assays.

Plants: Sources of Diversity in Propolis Properties

Propolis or “bee glue” is a resinous waxy substance that is produced by honeybees (Apis mellifera) by mixing the exudates collected from plants, namely tree buds, sap flows, leaves, branches and barks with their saliva and beeswax. Propolis composition is very complex. Its main constituents are resins and volatiles originating from plants and wax added by the bee. The biological activity of propolis is assigned to these plant-derived substances. The main three types of propolis are European propolis, called poplar type propolis; Green Brazilian propolis (derived mainly from the leaf resin of Baccharis dracunculifolia) and Red Cuban propolis (from the floral resin of Clusia rosea). The plant’s source gives it a specific composition and properties for the propolis types that are coming from different regions of the world. For this reason, studies on the chemical composition of propolis as well as its botanical sources resulting in its geographically conditioned diversity, were a very good theme for the present Special Issue (SI) of Plants journal. The present SI contains nine original contributions addressing propolis plant sources, their chemical composition and different bioactive properties derived from this origin. The chemical composition of propolis that is made by the bees was also discussed, as well as the different medical activities of propolis extract. The papers cover a wide range of subjects, including (i) the plant species used by the bees as raw material for propolis production, (ii) the biological activities of plant extracts related to propolis, (iii) the chemical composition of different types of propolis, (iv) the biological activity of propolis, (v) propolis and human health, and (vi) synergism between plants and propolis in human health. The studies have been carried out in both in vitro and in vivo surveys and a wide range of geographic regions are covered in the sample collection.

Plant genetic diversity by DNA barcoding to investigate propolis origin

Identify the botanical origins of a certain type of propolis may be challenging and time demanding, since it involves bee's behavior observation, plant resins collection and chemical analysis. Thus, this study aimed to determine the plant genetic materials in propolis from southern Brazil using the DNA barcoding to investigate their botanical origins, as well as to compare it with the phytochemical composition determined by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) and with the pollinic profile. As principal results, non-native Populus carolinensis Moench (Salicaceae) was almost the only DNA source in some propolis samples, which coincided with the presence of flavonoids typical from poplar exudates. Conversely, other propolis samples had DNA material coming mainly from native plant species, most of them characterized to the species level, although no specific chemical markers from those plants could be identified by UHPLC-HRMS. However, pollen from several plants identified by the DNA barcoding were extracted from some propolis samples. Despite the identification of typical diterpenes, DNA material from Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae), which have been indicated as a major resin source for propolis from preservation areas in southern Brazil, was found in very small abundancies, likely because bees do not drag tissue material containing DNA when collecting resin from this native species. In conclusion, DNA barcoding analysis successfully provided information about the provenance of propolis, although, depending on the plant resin sources, this information is likely to come from pollen.

A review on the anti-inflammatory activities of Brazilian green, brown and red propolis

Humanity has used propolis since ancient times, and its use as a food supplement has significantly increased. Several reports on propolis´ biological activity and toxicity have highlighted its anti-inflammatory properties, unlike many natural food supplements. This review addresses the anti-inflammatory roles of Brazilian green, brown, and red propolis produced by Apis mellifera, their extracts, isolated compounds, and their mode of action. Despite advances in anti-inflammatory therapies, the development of inflammatory processes in several diseases has been a concern for centuries. Demands for new anti-inflammatory drugs have led to studies on propolis products as diet components to treat and prevent inflammatory disorders. Brazilian green, brown, and red propolis are alternatives for obtaining extracts and compounds of valuable anti-inflammatory properties. PRACTICAL APPLICATIONS: Currently, propolis is a food supplement, and to the best of our knowledge, several studies have shown that despite advances in anti-inflammatory therapies, the inflammatory process continues to be a significant concern. However, due to the demand for new anti-inflammatory drugs, propolis products as dietary components can be used to treat and prevent inflammatory disorders.

Active Potential of Bacterial Cellulose-Based Wound Dressing: Analysis of Its Potential for Dermal Lesion Treatment

The use of innate products for the fast and efficient promotion of healing process has been one of the biomedical sector's main bets for lesion treatment modernization process. The aim of this study was to develop and characterize bacterial cellulose-based (BC) wound dressings incorporated with green and red propolis extract (2 to 4%) and the active compounds p-coumaric acid and biochanin A (8 to 16 mg). The characterization of the nine developed samples (one control and eight active wound dressings) evidenced that the mechanics, physics, morphological, and barrier properties depended not only on the type of active principle incorporated onto the cellulosic matrix, but also on its concentration. Of note were the results found for transparency (28.59-110.62T₆₀₀ mm^-1), thickness (0.023-0.046 mm), swelling index (48.93-405.55%), water vapor permeability rate (7.86-38.11 g m² day^-1), elongation (99.13-262.39%), and antioxidant capacity (21.23-86.76 μg mL^-1). The wound dressing based on BC and red propolis was the only one that presented antimicrobial activity. The permeation and retention test revealed that the wound dressing containing propolis extract presented the most corneal stratum when compared with viable skin. Overall, the developed wound dressing showed potential to be used for treatment against different types of dermal lesions, according to its determined proprieties.

Comparison of the Antioxidant Activity of Propolis Samples from Different Geographical Regions

Propolis composition depends on several factors. The classification of propolis is based on its geographical location, color and agricultural characteristics. It is also classified according to the flora where the bees collect the resins, which represent the raw material for propolis production. Propolis possesses high antioxidant activity determined by its phenolic compounds. Due to diverse composition and possible impact on human health, eight samples of propolis were evaluated for their phenolic composition and antioxidant activity. Samples of Polish, Romanian, Turkish and Uruguayan origin propolis were used for phenolic spectrum determination using high performance liquid chromatography and photodiode array detection and in vitro DPPH and ABTS methods were used to determine the antioxidant activity of the extracts. PCA and HCA models were applied to evaluate the correlation between isolated polyphenols and antioxidant activity. The results confirmed variability in propolis composition depending on the geographical region of collection and the plant sources, and correlation between chemical composition and antioxidant activity. Results of PCA and HCA analyses confirm that Polish propolis is similar to that from different provinces of Romania, while Turkish and Uruguay are completely different. Polish and Romanian propolis belong to the poplar type. The assessed phenolic compounds of propolis samples used in the study are responsible for its antioxidant effect. The observed antioxidant activity of the analyzed samples may suggest directing subsequent research on prophylactic and therapeutic properties concerning cardiovascular, metabolic, neurodegenerative, and cancerous diseases, which are worth continuing.

Evaluating the role of propolis and bee venom on the oxidative stress induced by gamma rays in rats

Honeybee products consist of many substances, which have long been known for their medicinal and health-promoting properties. This study set out to appraise the protective potential of Egyptian propolis (EP) and bee venom (BV) separately or combined against total body irradiation (TBI) induced oxidative injury in rats. Besides, we assessed the bioactive components in EP and BV using HPLC and UPLC/ ESI-MS analysis in the positive ion mode. The animals were subjected to a source of gamma ionizing radiation at a dose of 6 Gy. Propolis and BV were administered independently and in combination before 14 days of γ-irradiation. Liver and kidney functions were estimated besides, DNA damage index (8- OHdG) by ELISA. Antioxidants, including glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were detected. Gene expression technique investigated for BAX, BCL2, and in plasma also miR125b expression in serum of rats. Besides, the histopathological for the brain, liver, kidney, and heart were investigated. In addition, lipid peroxidation was investigated in plasma and in the previous organs. The present results provide opportunities to advance the use of bee products as promising medicinal sources.

Antioxidant for Neurological Diseases and Neurotrauma and Bioengineering Approaches

Antioxidants are a class of molecules with an innate affinity to neutralize reactive oxygen species (ROS), which are known to cause oxidative stress. Oxidative stress has been associated with a wide range of diseases mediated by physiological damage to the cells. ROS play both beneficial and detrimental roles in human physiology depending on their overall concentration. ROS are an inevitable byproduct of the normal functioning of cells, which are produced as a result of the mitochondrial respiration process. Since the establishment of the detrimental effect of oxidative stress in neurological disorders and neurotrauma, there has been growing interest in exploring antioxidants to rescue remaining or surviving cells and reverse the neurological damage. In this review, we present the survey of different antioxidants studied in neurological applications including neurotrauma. We also delve into bioengineering approaches developed to deliver antioxidants to improve their cellular uptake in neurological applications.

Contribution of Green Propolis to the Antioxidant, Physical, and Sensory Properties of Fruity Jelly Candies Made with Sugars or Fructans

Enrichment with phenolic compounds is proposed as a strategy to obtain more stable and healthier candy products. A green propolis ethanolic dry extract (PEE) from Braccharis dracunculifolia (Brazilian Alecrim-do Campo) was assessed as an antioxidant in jelly candies. Three levels (0, 0.01, and 0.02% w/w) of PEE were tested in jelly candies alternatively made with two carbohydrate bases (sugars or fructans) and three fruity dyes and flavours (menthe, orange, or strawberry). Propolis polyphenol content (identified by HPLC-MS and quantified by HPLC-DAD/UV-Vis), antioxidant capacity (total phenolics and radical scavenging activity), physical properties (moisture, pH, CIELab colour, and texture profile analysis), and flavour were studied in candies. PEE was rich in polyphenols (>8.7%), including several prenylated p-coumaric, caffeoylquinic and diterpenic acids, and flavonoids, with Artepillin-C (3.4%) as the main bioactive compound. The incorporation of PEE into the hot liquor at 80 °C for 5 min before moulding allowed a good retention of propolis polyphenols in the final product (recovery percentages of up to 97.4% for Artepillin-C). Jelly candies made with sugars or dietetic fructans have poor antioxidant properties, which depend on the dyes and flavours used. Using PEE (at 0.02%) strongly improved the antioxidant capacity (relative increases of up to 465%) of candies without altering the pH, colour, or texture, although off-flavour may appear. Propolis, due to its good antioxidant properties, has potential for use as a functional ingredient in jelly candies.

How diverse is the chemistry and plant origin of Brazilian propolis?

Propolis is a honey bee product containing chiefly beeswax and resins originated from plant buds or exudates. Propolis resin exerts a diversity of biological activities, such as antitumoral, anti-inflammatory, antimicrobial, and defense of the hive against pathogens. Chemical standardization and identification of botanical sources is crucial for characterization of propolis. Types of Brazilian propolis are characteristic of geographical regions and respective biomes, such as savannas (Cerrado), mangroves, dry forest (Caatinga), rain forests (Amazon, Atlantic, and Interior forests), altitudinal fields ("Campos Rupestres"), Pantanal, and Araucaria forests. Despite the wide diversity of Brazilian biomes and flora, relatively few types of Brazilian propolis and corresponding resin plant sources have been reported. Factors accounting for the restricted number of known types of Brazilian propolis and plant sources are tentatively pointed out. Among them, the paper discusses constraints that honey bees must overcome to collect plant exudates, including the characteristics of the lapping-chewing mouthpart of honey bee, which limit their possibilities to cut and chew plant tissues, as well as chemical requirements that plant resins must fulfil, involving antimicrobial activity of its constituents and innocuity to the insects. Although much still needs to be done toward a more comprehensive picture of Brazilian propolis types and corresponding plant origins, the prospects indicate that the actual diversity of plant sources of honey bee propolis will remain relatively low.

In Vitro Activity of Propolis on Oral Microorganisms and Biofilms

Natural products are being discussed as alternatives to commonly used chemicals in antimicrobial therapy. The study aimed to investigate the antimicrobial activity of propolis against microbial species associated with caries, periodontal disease, and Candida infections. Two commercially available ethanolic extracts of Brazilian and one of European propolis (EEP) were used. The minimal inhibitory concentrations (MIC) of propolis and controls against eight microbial strains were determined. Scanning and transmission electron microscopy (SEM and TEM) images visualized the effect of propolis on microorganisms. Subsequently, the activity on three different multi-species biofilms (both formation and existing biofilms) was assessed. All MIC values of the Brazilian EEPs were low against the tested oral species (≤0.1 mg/mL–3.13 mg/mL propolis (Candida albicans)). The European EEP had slightly higher MICs than the Brazilian EEPs. The SEM and TEM images suggest an interaction of propolis with the microbial cell wall. The European EEP exhibited the strongest effect on retarding biofilm formation, whereas the Brazilian EEPs were highly active against preformed biofilms (100 mg/mL propolis of both EEPs reduced colony forming unit counts always by more than 6 log10). The antimicrobial and anti-biofilm activities point to the potential of propolis as an adjunct in oral health care products.

Spectroscopy NIR and MIR toward predicting simultaneous phenolic contents and antioxidant in red propolis by multivariate analysis

Conventional methods for determining phenolics and their bioactive properties are expensive, time-consuming, and laborious. This hinders the quality control of red propolis, recognized for having different types of phenolic constituents with different bioactive properties, for example, its antioxidant properties. In this sense, we present a new application of near and medium infrared spectroscopy to predict phenolic constituents, total flavonoids, gallic acid, kaempferol, pyrocatechin, quercetin, and different antioxidant tests (DPPH radical, reducing power and protection of the β-carotene: linoleic acid system) of red propolis using chemometry. The optimized models showed good predictive capacity with a minimum correlation coefficient of 0.70, low associated error, and figures of merit that indicate the good predictive capacity in the validation of the models. These data show infrared spectroscopy as efficient to simultaneously predict nine quality analyzes of red propolis quickly and simply. This also avoids tedious procedures for traditional chromatographic and spectrophotometric tests.

Geographic Area of Collection Determines the Chemical Composition and Antimicrobial Potential of Three Extracts of Chilean Propolis

The biological properties of chilean propolis have been described and include antibacterial, antifungal and antibiofilm activities. Propolis has a strong antimicrobial potential. Clinical experiences with synthetic antibiotics indicated the need to discover new sources of bioactive compounds associated with ethnopharmacological knowledge or natural sources such as propolis. The microscopic analysis of pollen grains from plants allows us to determine the botanical origin of the propolis samples. In Angol, sample pollen grains were obtained from fodder plants (Sorghum bicolor; Lotus sp.) and trees, such as Acacia sp., Pinus radiata, Eucalyptus sp. and Salix babylonica. Propolis from the Maule region contains pollen grains from endemic plants such as Quillaja saponaria. Finally, the sample obtained from Melipilla presented a wider variety of pollen extracted from vegetable species.Colorimetric assays performed to quantify the total polyphenols present in Chilean propolis samples established that PCP2 (Angol sample) showed high amounts of phenolics compounds, with significant statistical differences in comparison with the other samples. The main compounds identified were pinocembrin, quercetin and caffeic acid phenethyl ester (CAPE). The Angol sample showed a high content of polyphenols.Studies that determine the influence of geographical and floral variables on the chemical composition of propolis are a valuable source of information for the study of its biological properties.

The Metabolite Profile in Culture Supernatant of Aster yomena Callus and Its Anti-Photoaging Effect in Skin Cells Exposed to UVB

Aster yomena (A. yomena) extract has anti-inflammatory, antioxidant, anti-asthma, and anti-atopic effects. However, the commercial use of A. yomena extract requires a long processing time with specific processing steps (including heat treatment and ethanol precipitation), and there are various environmental problems. We aimed to build a system to produce A. yomena extract by culturing the callus in a bioreactor that can allow rapid process scale-up to test the effect of extract (AYC-CS-E) isolated from culture supernatant of A. yomena callus on photoaging of human keratinocytes (HaCaT) caused by ultraviolet B (UVB) exposure. Through screening analysis based on ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS), 17 major metabolites were tentatively identified from AYC-CS-E for the first time. The suppression of cell proliferation caused by UVB was effectively alleviated in UVB-irradiated HaCaT cells treated with AYC-CS-E. Treatment with AYC-CS-E strongly induced the formation of type I procollagen and the inhibition of elastase in UVB-irradiated HaCaT cells and significantly reduced the expression of matrix metalloproteinase (MMP)-1. In addition, treatment of UVB-irradiated HaCaT cells with AYC-CS-E effectively improved various factors associated with an inflammatory reaction, skin damage recovery, skin moisture retention, and hyper-keratinization caused by photoaging, such as reactive oxygen species (ROS), pro-inflammatory cytokines, transforming growth factor beta (TGF-β), MMP-3, MMP-9, filaggrin, hyaluronic acid synthase 2 (HAS-2), keratin 1 (KRT-1), nuclear factor-kappa B (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2) at the gene and protein levels. These results suggest that AYC-CS-E can be used as a cosmetic ingredient for various skin diseases caused by photoaging, and the current callus culture system can be used commercially to supply cosmetic ingredients.