Mechanisms underlying the wound healing potential of propolis based on its in vitro antioxidant activity

One sampler to see it all: The use of APIStrips for beehive characterization and pesticide residue evaluation based on mass spectrometry

Environmental monitoring is crucial for assessing the overall state of the ecosystems in terms of contaminant impact and chemical landscape. The use of honey bee (Apis mellifera) colonies considerably eases the sampling activities, as honey bees are exposed to a wide range of substances that are transported and accumulated within the beehives. In this work, combining low-resolution and high-resolution mass spectrometry, the APIStrip passive sampler has been employed to evaluate the presence of pesticide residues and the overall characterization of beehive environments. A total of 180 APIStrips have been deployed in 10 Danish apiaries, located in different landscapes, during a five-month sampling period. The targeted methodology for pesticide analysis was based on gas and liquid chromatography coupled with triple quadrupole mass spectrometry, covering 430 pesticide residues. A total of 29 pesticide residues were identified (fluopyram and azoxystrobin being the most frequently detected), with remarkable differences in the pesticide load between apiaries. For its part, the use of non-targeted approaches through liquid chromatography coupled with an Orbitrap mass spectrometer allowed the detection of unknown compounds that were specific of certain environments. Natural products such as eupatilin and gnaphaliin, which are derived from plant sources, were present exclusively in one of the apiaries. Additionally, the detection of drimane sesquiterpenoids, including compounds potentially originating from the Aspergillus genus, suggests the capability of APIStrips to early detect fungal contamination within beehives. This dual approach of low- and high-resolution mass spectrometry maximizes the analytical potential of APIStrips as a tool capable of detecting a wide range of substances with implications for both agricultural practices and ecological health.

Electrospinning-netting of spider-inspired polycaprolactone/collagen nanofiber-nets incorporated with Propolis extract for enhanced wound healing applications

Nanofibers hold significant promise for wound healing applications, but their potential is limited by their large diameter. To overcome this limitation, the development of nanofibrous systems with refined nanonets (approximately 20 nm in diameter) represents a notable improvement. In this study, a composite of polycaprolactone/collagen (PCLC) nano-fiber/nets (NFNs) was fabricated using benign solvents (acetic acid and formic acid) via the electro-spinning/netting (ESN) technique, harnessing the regenerative potential of collagen as a biological macromolecule. Additionally, to enhance the natural attributes of the NFNs structure, Propolis extract, renowned for its wound healing properties, was incorporated. Five ESN solutions were prepared: PCL, PCLC, PCLC/Pro 5 %, PCLC/Pro 10 %, and PCLC/Pro 15 %. NaCl salt was introduced into all ESN solutions to improve nanonets formation. FE-SEM imaging demonstrated successful nano-net formation in all ESN solutions except for the PCL formulation. The fabricated scaffolds exhibited spider-like nanonets with the addition of collagen and further enhanced nano-net formation with Propolis incorporation. Trunk nanofibers showed filamentous structures without any beads, with an average diameter of 164-728 nm, while the diameter of branched fibers (nanonets) was approximately 20 nm. WVTR values of the NFNs were comparable to commercial dressings such as Tegaderm. The results also demonstrated the potent cytoprotective effects of Propolis-loaded NFNs in a dose-dependent manner. Furthermore, the viability of HFF-2 cells after 72 h of culture on PCLC NFNs significantly increased compared to PCL nanofibers. The highest cell viability was observed in PCLC/Pro 15 % nanofibers after 24, 48, and 72 h of cell culture, indicating the proliferative effect of Propolis extract in nanoformulated form. Additionally, the scaffolds exhibited a hemocompatibility of <3 %, further highlighting their potential in wound healing therapeutics.

Propolis-Loaded Poly(lactic-co-glycolic Acid) Nanofibers: An In Vitro Study

Nanofibers have high potential through their high porosity, small pore sizes, lightweight materials, and their ability to mimic the extracellular matrix structure for use in the manufacture of wound dressings for wound treatment. In this study, poly(lactic-co-glycolic acid) (PLGA) nanofibers were produced by electrospinning. Propolis was loaded into the PLGA nanofibers by the dropping method. The average diameters and effects of propolis loading on the morphology of 37.5, 50, and 100% propolis-loaded PLGA nanofibers (PLGA-P37.5, PLGA-P50, and PLGA-P100) were evaluated by scanning electron microscopy (SEM). The successful loading of propolis into PLGA nanofibers was confirmed with Fourier transform infrared spectroscopy (FTIR) analysis. In vitro propolis release was examined at physiological pH. The antioxidant activity of propolis-loaded nanofibers was studied with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Antimicrobial activities of the nanofibers against Escherichia coli, Staphylococcus aureus and Candida albicans strains were determined by the disk diffusion method. Consequently, PLGA-P50 and PLGA-P100 showed high antimicrobial activity on S. aureus and C. albicans. Cell viability was tested by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and propolis-loaded PLGA nanofibers were found to be biocompatible with human fibroblast cells. In the wound scratch assay, propolis-loaded nanofibers supported wound closure with cell migration and proliferation. Thus, in vitro wound closure properties of propolis-loaded PLGA nanofibers were evaluated for the first time in the literature.

Therapeutic potential of propolis in alleviating inflammatory response and promoting wound healing in skin burn

Burns can cause inflammation and delayed healing, necessitating alternative therapies due to the limitations of conventional treatments. Propolis, a natural bee-produced substance, has shown promise in facilitating burn healing. This literature review provides a comprehensive overview of propolis' mechanisms of action, wound-healing properties, and its application in treating skin burns. Propolis contains bioactive compounds with antimicrobial, antioxidant, and anti-inflammatory properties, making it a promising candidate for managing skin burn injuries. It helps prevent infections, neutralize harmful free radicals, and promote a well-balanced inflammatory response. Moreover, propolis aids in wound closure, tissue regeneration, collagen synthesis, cellular proliferation, and angiogenesis, contributing to tissue regeneration and remodeling. The article discusses various propolis extracts, extraction methods, chemical composition, and optimized formulations like ointments and creams for burn wound treatment. Considerations regarding dosage and safety are addressed. Further research is needed to fully understand propolis' mechanisms, determine optimal formulations, and establish suitable clinical dosages. Nevertheless, propolis' natural origin and demonstrated benefits make it a compelling avenue for burn care exploration, potentially complementing existing therapies and improving burn management outcomes.

Propolis Protects GC-1spg Spermatogonial Cells against Tert-Butyl Hydroperoxide-Induced Oxidative Damage

Propolis is a natural resin produced by honeybees with plenty of pharmacologic properties, including antioxidant activity. Oxidative stress disrupts germ cell development and sperm function, with demonstrated harmful effects on male reproduction. Several natural antioxidants have been shown to reduce oxidative damage and increase sperm fertility potential; however, little is known about the effects of propolis. This work evaluated the role of propolis in protecting spermatogonial cells from oxidative damage. Propolis' phytochemical composition and antioxidant potential were determined, and mouse GC-1spg spermatogonial cells were treated with 0.1-500 µg/mL propolis (12-48 h) in the presence or absence of an oxidant stimulus (tert-butyl hydroperoxide, TBHP, 0.005-3.6 µg/mL, 12 h). Cytotoxicity was assessed by MTT assays and proliferation by Ki-67 immunocytochemistry. Apoptosis, reactive oxygen species (ROS), and antioxidant defenses were evaluated colorimetrically. Propolis presented high phenolic and flavonoid content and moderate antioxidant activity, increasing the viability of GC-1spg cells and counteracting TBHP's effects on viability and proliferation. Additionally, propolis reduced ROS levels in GC-1spg, regardless of the presence of TBHP. Propolis decreased caspase-3 and increased glutathione peroxidase activity in TBHP-treated GC-1spg cells. The present study shows the protective action of propolis against oxidative damage in spermatogonia, opening the possibility of exploiting its benefits to male fertility.

Applications of propolis-based materials in wound healing

Due to its excellent antiseptic efficacy and antimicrobial properties, propolis has shown attractive advantages in wound dressings. However, an inclusive review of the propolis-based materials as a wound dressing is still lacking. The current short review summarizes the skin wound healing process, relates evaluation parameters, and then reviews the refined propolis-based materials dressings such as antimicrobial property, adhesion and hemostasis, anti-inflammatory and substance delivery. The approaches implemented to achieve these functions are classified and discussed. Furthermore, applications of propolis wound dressing for treating different types of wounds such as heal wounds, burns, and ulcers are presented. The future directions of propolis-based wound dressings for wound healing are further proposed. This review showed that propolis-based materials might be a promising new dressing for wound occlusion and tissue repairing.

Comparison of the Chemical Composition and Antioxidant Properties of Propolis from Urban Apiaries

Bee products from urban apiaries are increasingly used. They are mainly used to promote local apiaries and cities in which they are located. The aim of the study was to compare the chemical composition and antioxidant activity of propolis from 6 Polish apiaries located in cities (Legionowo, Torun, Cracow, Warsaw, Katowice, Lodz). The chemical composition was analyzed using liquid chromatography (HPLC-DAD) and the analysis of antioxidant activity by scavenging free radicals (ABTS and DPPH) and FRAP. The obtained results showed the presence of 24 phenolic compounds in propolis extracts. The tested samples showed differentiation in terms of the content of individual chemical components, however, cinnamic acid and its derivatives were dominant. High antioxidant activity of the tested extracts was demonstrated (ABTS was in the range of 16.80-51.53 mg Te/mL, DPPH was in the range of 7.54-22.13 mg Te/mL, while FRAP reduction was in the range of 10.93-29.55 mg Te/mL). The obtained results compared with literature data on propolis from agricultural areas allow to conclude that propolis samples from both Poland types of areas are similar and can be classified as poplar propolis.

The effect of propolis supplementation in improving antioxidant status: A systematic review and meta-analysis of controlled clinical trials

The present study aimed to assess the effect of propolis supplementation on oxidative status, a key contributor to the etiology of many chronic diseases. A systematic search of multiple databases, including Web of Science, SCOPUS, Embase, PubMed, and Google Scholar, was conducted from inception to October 2022 to identify articles examining the effect of propolis on glutathione (GSH), glutathione peroxidase (GPX), total antioxidant capacity (TAC), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. The quality of the included studies was evaluated using the Cochrane Collaboration tool. A total of nine studies were included in the final analysis, and a random-effects model was used to pool the estimated effects. Results showed that propolis supplementation significantly increased the levels of GSH (SMD = 3.16; 95% CI: 1.15, 5.18; I2  = 97.2%), GPX (SMD = 0.56; 95% CI: 0.07, 1.05; p = 0.025; I2  = 62.3%), and TAC (SMD = 3.26; 95% CI: 0.89, 5.62; I2  = 97.8%, p < 0.001). However, the effect of propolis on SOD was not significant (SMD = 0.05; 95% CI: -0.25, 0.34; I2  = 0.0%). Although the MDA concentration was not significantly decreased overall (SMD = -0.85, 95% CI: -1.70, 0.09; I2  = 93.3%), a significant decrease in MDA levels was observed at doses ≥1000 mg/day (SMD = -1.90; 95% CI: -2.97, -0.82; I2  = 86.4) and supplementation durations of less than 11 weeks (SMD = -1.56; 95% CI: -2.60, -0.51; I2  = 90.4). These results suggest that propolis is a safe supplement with a beneficial effect on GSH, GPX, and TAC levels and may be an effective adjunctive therapy for diseases where oxidative stress is a key factor in the etiology. However, further high-quality studies are necessary to make more precise and comprehensive recommendations given the limited number of studies, clinical diversity, and other limitations.

Evaluation of Chemical Composition, Sun Protection Factor and Antioxidant Activity of Lithuanian Propolis and Its Plant Precursors

The growing interest in polyphenols of natural origin and their plant sources encourages the study of their chemical composition and biological activity. Propolis is widely used as a source of phenolic compounds. The aim of this study is to evaluate and compare the chemical composition, antioxidant activity and sun protection factor (SPF) of the ethanolic extracts of the poplar buds, birch buds and pine buds of propolis plant precursors collected in Lithuania. The IC50 concentration of the extracts was evaluated using DPPH and ABTS methods. Extracts of poplar buds, birch buds and propolis showed a lower IC50 concentration by ABTS and DPPH methods compared with pine buds extracts. Poplar buds and propolis extracts showed the highest SPF value, while birch and pine buds extracts showed a lower SPF value. High-performance liquid chromatography (HPLC) analysis results showed that phenolic acids, such as p-coumaric acid and cinnamic acid, and flavonoids, such as pinobanksin and pinocembrin, were identified in all the tested extracts. Salicin has been identified only in poplar buds extracts. The results of antioxidant activity showed that propolis poplar and birch buds are a promising source of biologically active polyphenols.

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.

Use of propolis for skin wound healing: systematic review and meta-analysis

Propolis is a natural resin that is produced by bees. It has anti-inflammatory and antibiotic properties, promotes reepithelization, and stimulates skin regeneration. Propolis has great potential for the development of new therapeutic approaches to treat skin ulcers. The present study performed a systematic review and meta-analysis of published studies of the use of propolis for the regeneration of cutaneous wounds and its efficacy as a therapeutic agent. Data were collected from articles in the PubMed, SCOPUS, and Web of Science databases that were published since 1900 by searching the terms "propolis" AND "wound healing." This search yielded 633 articles, of which 43 were included in this systematic review and meta-analysis. The results showed that interest in the therapeutic efficacy of propolis has increased over the years. The studies reported that the propolis was effective for the treatment of skin ulcers by promoting a higher percentage of healing than classically employed interventions. The mode of propolis application has also evolved. An increasing number of studies combined it with other substances and materials to achieve additive or synergistic effects on the skin regeneration process. Propolis appears to be an effective therapeutic alternative for the treatment of skin ulcers.

Bud-Poplar-Extract-Embedded Chitosan Films as Multifunctional Wound Healing Dressing

Wounds represent a major global health challenge. Acute and chronic wounds are sensitive to bacterial infection. The wound environment facilitates the development of microbial biofilms, delays healing, and promotes chronic inflammation processes. The aim of the present work is the development of chitosan films embedded with bud poplar extract (BPE) to be used as wound dressing for avoiding biofilm formation and healing delay. Chitosan is a polymer with antimicrobial and hydrating properties used in wound dressing, while BPE has antibacterial, antioxidative, and anti-inflammatory properties. Chitosan-BPE films showed good antimicrobial and antibiofilm properties against Gram-positive bacteria and the yeast Candida albicans. BPE extract induced an immunomodulatory effect on human macrophages, increasing CD36 expression and TGFβ production during M1/M2 polarization, as observed by means of cytofluorimetric analysis and ELISA assay. Significant antioxidant activity was revealed in a cell-free test and in a human neutrophil assay. Moreover, the chitosan-BPE films induced a good regenerative effect in human fibroblasts by in vitro cell migration assay. Our results suggest that chitosan-BPE films could be considered a valid plant-based antimicrobial material for advanced dressings focused on the acceleration of wound repair.

Molecular and Cellular Mechanisms of Propolis and Its Polyphenolic Compounds against Cancer

In recent years, interest in natural products such as alternative sources of pharmaceuticals for numerous chronic diseases, including tumors, has been renewed. Propolis, a natural product collected by honeybees, and polyphenolic/flavonoid propolis-related components modulate all steps of the cancer progression process. Anticancer activity of propolis and its compounds relies on various mechanisms: cell-cycle arrest and attenuation of cancer cells proliferation, reduction in the number of cancer stem cells, induction of apoptosis, modulation of oncogene signaling pathways, inhibition of matrix metalloproteinases, prevention of metastasis, anti-angiogenesis, anti-inflammatory effects accompanied by the modulation of the tumor microenvironment (by modifying macrophage activation and polarization), epigenetic regulation, antiviral and bactericidal activities, modulation of gut microbiota, and attenuation of chemotherapy-induced deleterious side effects. Ingredients from propolis also "sensitize" cancer cells to chemotherapeutic agents, likely by blocking the activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). In this review, we summarize the current knowledge related to the the effects of flavonoids and other polyphenolic compounds from propolis on tumor growth and metastasizing ability, and discuss possible molecular and cellular mechanisms involved in the modulation of inflammatory pathways and cellular processes that affect survival, proliferation, invasion, angiogenesis, and metastasis of the tumor.

Propolis: An update on its chemistry and pharmacological applications

Propolis, a resinous substance produced by honeybees from various plant sources, has been used for thousands of years in traditional medicine for several purposes all over the world. The precise composition of propolis varies according to plant source, seasons harvesting, geography, type of bee flora, climate changes, and honeybee species at the site of collection. This apiary product has broad clinical applications such as antioxidant, anti-inflammatory, antimicrobial, anticancer, analgesic, antidepressant, and anxiolytic as well asimmunomodulatory effects. It is also well known from traditional uses in treating purulent disorders, improving the wound healing, and alleviating many of the related discomforts. Even if its use was already widespread since ancient times, after the First and Second World War, it has grown even more as well as the studies to identify its chemical and pharmacological features, allowing to discriminate the qualities of propolis in terms of the chemical profile and relative biological activity based on the geographic place of origin. Recently, several in vitro and in vivo studies have been carried out and new insights into the pharmaceutical prospects of this bee product in the management of different disorders, have been highlighted. Specifically, the available literature confirms the efficacy of propolis and its bioactive compounds in the reduction of cancer progression, inhibition of bacterial and viral infections as well as mitigation of parasitic-related symptoms, paving the way to the use of propolis as an alternative approach to improve the human health. However, a more conscious use of propolis in terms of standardized extracts as well as new clinical studies are needed to substantiate these health claims.

"Jianbing" styling multifunctional electrospinning composite membranes for wound healing

Wound infection and excessive exudate can affect the process of wound healing. However, the disadvantage of the anti-microbial wound dressings is that the biological fluids are ineffectively removed. Inspired by making "Chinese Jianbing", a composite wound nano-dressing was developed consisting of a hydrophilic outer layer (chitosan&polyvinyl alcohol: CTS-PVA) and a hydrophobic inner layer (propolis&polycaprolactone: PRO-PCL) by combining casting and electrospinning methods for effective antibacterial and unidirectional removing excess biofluids. In vitro, the composite wound nano-dressing of PRO-PCL and CTS-PVA (PPCP) could strongly inhibit Pseudomonas aeruginosa. Furthermore, PPCP wound dressing had excellent antioxidant properties and blood coagulation index for effective hemostatic. Importantly, it had a preferable water absorption for removing excess biofluid. In vivo, it had anti-inflammatory properties and promoted collagen Ⅰ preparation, which realized 80% wound healing on day 7. In short, the PPCP wound dressing provides a new direction and option for antibacterial and removes excess biofluid.

Research Progress on Therapeutic Effect and Mechanism of Propolis on Wound Healing

Propolis is a kind of reduct collected by bees from various plant sources. Because propolis is a mixture, it has a variety of biological activities, excellent anti-inflammatory and bactericidal effects. Especially in the treatment of infectious wounds, acute wounds, burns, and scalds and promoting wound healing, more and more scientists began to apply it to the research field of wound healing. The standard preparation of propolis combined with other compound components has a safer and less toxic effect in the treatment of trauma. In order to more effectively use propolis products in wound treatment. This paper reviews the effect and treatment mechanism of propolis on different types of wound healing, as well as the synergistic effect of propolis and other compounds, in order to provide ideas for the further exploration of the biological activity and pharmacological function of propolis in the future, as well as its in-depth development in the field of wound healing. It will also provide a theoretical reference for the further development and utilization of propolis.

Computational Study of Asian Propolis Compounds as Potential Anti-Type 2 Diabetes Mellitus Agents by Using Inverse Virtual Screening with the DIA-DB Web Server, Tanimoto Similarity Analysis, and Molecular Dynamic Simulation

Propolis contains a wide range of pharmacological activities because of their various bioactive compounds. The beneficial effect of propolis is interesting for treating type-2 diabetes mellitus (T2DM) owing to dysregulation of multiple metabolic processes. In this study, 275 of 658 Asian propolis compounds were evaluated as potential anti-T2DM agents using the DIA-DB web server towards 18 known anti-diabetes protein targets. More than 20% of all compounds could bind to more than five diabetes targets with high binding affinity (<−9.0 kcal/mol). Filtering with physicochemical and pharmacokinetic properties, including ADMET parameters, 12 compounds were identified as potential anti-T2DM with favorable ADMET properties. Six of those compounds, (2R)-7,4′-dihydroxy-5-methoxy-8-methylflavone; (RR)-(+)-3′-senecioylkhellactone; 2′,4′,6′-trihydroxy chalcone; alpinetin; pinobanksin-3-O-butyrate; and pinocembrin-5-methyl ether were first reported as anti-T2DM agents. We identified the significant T2DM targets of Asian propolis, namely retinol-binding protein-4 (RBP4) and aldose reductase (AKR1B1) that have important roles in insulin sensitivity and diabetes complication, respectively. Molecular dynamic simulations showed stable interaction of selected propolis compounds in the active site of RBP4 and AKR1B1. These findings suggest that Asian propolis compound may be effective for treatment of T2DM by targeting RBP4 and AKR1B1.

Bee-Derived Products: Chemical Composition and Applications in Skin Tissue Engineering

Skin tissue regeneration is one of the population's most common problems, and the complications that may appear in the healing process can have detrimental consequences. An alternative to conventional treatments could be represented by sustainable materials based on natural products, such as honey and its derivates (propolis, royal jelly, bee pollen, beeswax, and bee venom). They exhibit significant inhibitory activities against bacteria and have great potential in dermal tissue regeneration. Research in the pharmaceutical field demonstrates that conventional medication combined with bee products can deliver better results. The advantages include minimizing side effects and maintaining the same effectiveness by using low concentrations of antibiotic, anti-inflammatory, or chemotherapy drugs. Several studies suggested that bee products can replace the antimicrobial activity and efficiency of antibiotics, but further investigation is needed to establish a topical mixture's potential, including honey, royal jelly, and propolis. Bee products seem to complete each other's deficiencies, and their mixture may have a better impact on the wound healing process. The topic addressed in this paper highlights the usefulness of honey, propolis, royal jelly, bee pollen, beeswax, and bee venom in the re-epithelization process and against most common bacterial infections.

Use of autologous serum or Vizoovet to improve healing rates of spontaneous chronic corneal epithelial defects after diamond burr debridement in dogs

PURPOSE

To determine whether the use of autologous serum or Vizoovet® improved healing rates of spontaneous chronic corneal epithelial defects (SCCEDs) after diamond burr debridement (DBD) in dogs.

STUDY DESIGN

Two parallel group randomized prospective study with a historical control group.

MATERIALS AND METHODS

Canine patients having undergone DBD for treatment of SCCEDs were included. Data for the control group (ofloxacin only) were gathered from patient records. Patients were randomly assigned to treatment groups for post-procedural medical treatments of ofloxacin and autologous serum (group 1) or ofloxacin and Vizoovet®, an all-natural eyed drop containing propolis, aloe vera, and chamomile (group 2). Each dog was examined between 2 and 3 weeks until the cornea was fluorescein stain negative. Data points collected included age, sex, breed, type of medications used, retention of bandage contact lens (BCL), time to healing, and number of DBD performed.

RESULTS

A total of 120 dogs, each contributing one eye to the study, underwent DBD for SCCEDs. Mean (± standard deviation) days until healed were 20.1 ± 11.1 days, 16.3 ± 4.5 days, and 16.0 ± 3.7 days for the control group, group 1, and group 2, respectively. There was a marginally significant difference in days until healed between groups (p = .0515). SCCEDs healed significantly faster in group 2 (p = .03) and marginally faster in group 1 (p = .06) compared with the control group. Days until healing between group 1 and 2 were not significantly different (p = .76).

CONCLUSIONS

As compared to the control group, use of Vizoovet® as adjunctive medical treatment resulted in shorter corneal healing time after DBD.

In vitro transcriptome response to propolis in differentiated SH-SY5Y neurons

Propolis is the extract of a resinous compound that protects plants from both cold and microorganism attack and has gained a strong and sticky property because it is transformed after being collected by honey bees. Up to date, many studies have shown that propolis exhibited various beneficial biological activities, such as antifungal, antibacterial, antiviral, antioxidant, antimutagenic, and antitumor effects. Recent reports propounded the in vitro and in vivo neuroprotective effect of propolis; however, the exact molecular genetic mechanisms are still unclear. Therefore, we aimed to investigate the toxicogenomic and beneficial properties, including cytotoxic, antioxidant, apoptotic/necrotic as well as genotoxic effects of propolis (1.56-200 µg/ml) on differentiated SH-SY5Y neuronal cells. Additionally, microarray analysis was conducted on cell cultures following propolis application to explore gene differentiation. Differentially expressed genes were further analyzed using string software to characterize protein-protein interactions between gene pathways. Our results revealed that propolis applications could not have a prominent effect on cell viability even at concentrations up to 200 µg/ml. The highest propolis concentration induced apoptotic rather than necrotic cell death. The alterations in gene expression profiles, including CYP26A1, DHRS2, DHRS3, DYNC1I1, IGF2, ITGA4, SVIL, TGFβ1, and TGM2 could participate in the neuroprotective effects of propolis. In conclusion, propolis supplementation exerted remarkable advantageous; thus, it may offer great potential as a natural component in the prevention and treatment of neurodegenerative disorders. Whole-genome gene expression pattern following propolis application was investigated for the first time in neuronal cell culture to fill a gap in the literature about propolis toxicogenomics. PRACTICAL APPLICATIONS: Propolis is a very rich product in terms of benefits. In addition to its antibacterial, antiviral, antifungal, and anti-inflammatory content, it is known to have preventive and therapeutic properties for many different ailments. On the other hand, molecular mechanisms of propolis on gene expression differentiations haven't been investigated until now. Moreover, gene expression pattern is vital for all living organisms to maintain homeostasis. Thus, we conduct an experiment series for analyzing gene expression differentiation effects on neuronal cells to understand beneficial properties of propolis. Hence, it could be possible to comment on the use of propolis as a nutritional factor and beneficial diet.

Mitigating Nosema ceranae infection in western honey bee (Apis mellifera) workers using propolis collected from honey bee and stingless bee (Tetrigona apicalis) hives

Beekeepers need sustainable control options to treat Nosema ceranae infection in colonies of western honey bees (Apis mellifera L.) they manage. Propolis is a natural product derived from plant resins and contains chemical compounds with potential antimicrobial activity against N. ceranae. Here, we determined the efficacy of propolis from A. mellifera (USA) and Tetrigona apicalis (stingless bees, Thailand) colonies as treatments for N. ceranae infection in honey bee workers. Newly emerged bees were individually fed 2 μL of 50% (w/v) sucrose solution containing 1 × 10⁵N. ceranae spores. Following this, the infected bees were treated with 50% propolis extracted from A. mellifera or T. apicalis hives and fed in 50% sucrose solution (v/v). All bees were maintained at 34 ± 2 °C and 55 ± 5% RH. Dead bees were counted daily for 30 d to calculate survival. We also determined infection rate (# infected bees/100 bees), infectivity (number of spores per bee) and protein content in the hypopharyngeal glands and hemolymph on 7, 14, and 21 d post infection as measures of bee health. Propolis from both bee species significantly reduced bee mortality, infection rate and infectivity compared with those of untreated bees and led to significantly greater protein contents in hypopharyngeal glands and hemolymph in treated bees than in untreated ones (p < 0.0001). In conclusion, propolis from A. mellifera and T. apicalis colonies shows promise as a control against N. ceranae infection in honey bees.

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

Nowadays, propolis is used as a highly valuable product in alternative medicine for improving health or treating a large spectrum of pathologies, an ingredient in pharmaceutical products, and also as a food additive. Different vegetal materials are collected by honeybees and mixed with wax and other own substances in order to obtain the final product, called propolis. It is known as the bee product with the widest chemical composition due to the raw material collected by the bees. Different types are known worldwide: green Brazilian propolis (having Baccharis dracunculifolia as the major plant source), red Brazilian propolis (from Dalbergia ecastophyllum), European propolis (Populus nigra L.), Russian propolis (Betula verrucosa Ehrh), Cuban and Venezuelan red propolis (Clusia spp.), etc. An impressive number of scientific papers already demonstrate the pharmacological potential of different types of propolis, the most important activities being the antimicrobial, anti-inflammatory, antitumor, immunomodulatory, and antioxidant activities. However, the bioactive compounds responsible for each activity have not been fully elucidated. This review aims to collect important data about the chemical composition and bioactive properties of the vegetal sources and to compare with the chemical composition of respective propolis types, in order to determine the connection between the floral source and the propolis properties.

Historical and modern research on propolis and its application in wound healing and other fields of medicine and contributions by Polish studies

ETHNOPHARMACOLOGICAL RELEVANCE

The history of medical application of propolis (also known as bee glue) dates back to the times of ancient Greeks, Romans, Persians and Egyptians. Honey and other bee products, including propolis, occupy an important place in Polish folk medicine. Scientific research on propolis in Poland began in the early 1960s in Zabrze and continues until now.

AIM OF THE REVIEW

The aim of this review is to provide an overview of information on Polish research on propolis and its medical application with particular emphasis on studies concerning wound healing. Consequently, our goal is also to shed a new light on therapeutic potential of Polish propolis in order to support future research in the field.

MATERIALS AND METHODS

A systematic review of scientific literature on propolis and its medical application was performed by using the literature databases (PubMed, Web of Science, Google Scholar). We paid special attention to papers describing the effect of propolis on skin wound healing as well as to Polish contribution to research on propolis.

RESULTS

Professor Stan Scheller was the first Polish scientist dealing with propolis and its medical potential. His legacy was continued by several research teams that studied the topic in various aspects. They analyzed propolis composition, its antioxidant, anti-inflammatory, antimicrobial, antiapoptotic and anticancer properties as well as its application in dentistry and wound treatment. Burn wound healing physiology after propolis administration was thoroughly studied on pig model, whereas research on patients proved the efficacy of propolis in chronic venous leg ulcer treatment.

CONCLUSION

Polish scientists have made a significant contribution to the research on propolis, its biological properties and influence on wound healing. Propolis ointments can effectively accelerate the healing process and improve healing physiology, so they can be recommended as a promising topical medication for wound treatment in the future clinical and preclinical trials.

Efficacy of adjunctive therapy using Vizoovet in improving clinical signs of keratoconjunctivitis sicca in dogs: A pilot study

OBJECTIVE

To assess the clinical safety and efficacy of adjunctive therapy using Vizoovet to ameliorate clinical signs of keratoconjunctivitis sicca (KCS) in dogs.

ANIMALS STUDIED

Twenty client-owned dogs.

PROCEDURES

Canine patients diagnosed with KCS were enrolled in this prospective study. Patients were randomly selected to receive either Vizoovet or GenTeal drops twice daily in addition to twice daily tacrolimus 0.03% solution. Data were collected from only one eye of each patient and included STT-1, IOP, TFBUT, and results of objective clinical scoring performed by pet owners. Statistical significance was set at P ≤ .05.

RESULTS

In all, 20 dogs (20 eyes) were enrolled in this prospective randomized study. Females (n = 12; 60%) outnumbered males (n = 8; 40%) and all dogs were spayed/neutered. Mean age of all dogs was 10.6 ± 3.79 years. In both treatment groups, the improvement in STT-1 values over the course of the study was significant (P = .002). When comparing the STT-1 improvements between groups, no significance was found (P = .78). In both groups, the improvement in TFBUT was significant (P = .0018). When comparing the TFBUT improvements between groups, no significance was found (P = .14). Squinting, rubbing, ocular discharge, and medication administration scores all significantly improved throughout the course of the study; however, they did not differ significantly between groups. Throughout the study, no adverse side effects were noted clinically or by the pet owner in either group.

CONCLUSIONS AND CLINICAL RELEVANCE

Adjunctive treatment with Vizoovet was as safe and effective as GenTeal drops at improving clinical signs of dry eye in dogs.

Comparison of the Chemical Composition and Biological Activity of Mature and Immature Honey: An HPLC/QTOF/MS-Based Metabolomic Approach

Harvesting uncapped immature honey (IMH) followed by dehydration is a typical counterfeit honey production process, but the differences between IMH and capped mature honey (MH) have not been well described previously. In this study, MH and IMH from Apis mellifera colonies during the same rapeseed flower season were compared. MH was found to have lower water content, lower acidity, and higher fructose content. High-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry-based untargeted metabolomic analysis indicated that MH had a distinct metabolite composition to IMH. Targeted metabolomic analysis on 20 major polyphenolic constituents showed higher accumulation in MH. MH had greater bacteriostatic effect and stronger free radical scavenging effect. While both the honeys mitigated cell damage caused by H₂O₂, the effective dosage of IMH was higher and its inducing effect on the antioxidant gene expression was weaker. Overall, MH was shown to be of better quality than IMH not only because of its richer polyphenolic composition but also because of its stronger biological activity.

Pepsin-Soluble Collagen from the Skin of Lophius litulo: A Preliminary Study Evaluating Physicochemical, Antioxidant, and Wound Healing Properties

The structure of pepsin-solubilized collagen (PSC) obtained from the skin of Lophius litulon was analyzed using the sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). SDS-PAGE results showed that PSC from Lophius litulon skin was collagen type I and had collagen-specific α1, α2, β, and γ chains. FTIR results indicated that the infrared spectrum of PSC ranged from 400 to 4000 cm^-1, with five main amide bands. SEM revealed the microstructure of PSC, which consisted of clear fibrous and porous structures. In vitro antioxidant studies demonstrated that PSC revealed the scavenging ability for 2,2-diphenyl-1-picrylhydrazyl (DPPH), HO·, O₂^-·, and ABTS·. Moreover, animal experiments were conducted to evaluate the biocompatibility of PSC. The collagen sponge group showed a good biocompatibility in the skin wound model and may play a positive role in the progression of the healing process. The cumulative results suggest that collagen from the skin of Lophius litulon has potential applications in wound healing due to its good biocompatibility.

Evidence on the Health Benefits of Supplemental Propolis

Propolis is a honey-related product with reported health benefits such as improved immunity, lowered blood pressure, treated allergies and skin conditions. A literature review and narrative synthesis were conducted to investigate the evidence on the reported health benefits and future direction of propolis products. Using a predefined search strategy we searched Medline (OvidSP), Embase and Central for quantitative and qualitative studies (1990-2018). Citation, reference, hand searches and expert consultation were also undertaken. Studies of randomised control trials and observational data on humans with health-related outcomes were included. Collected data were entered into NVivo software (Version 12, QRS International) and analysed using a thematic framework and a narrative synthesis of emergent themes. A total of 63 publications were discussed. The majority were cell-based and animal studies, with a few key human trials conducted. There is significant promise for propolis as an effective antioxidant and anti-inflammatory agent with particular promise in cardiometabolic health.

In Vitro Evaluation of Antioxidant, Anti-Inflammatory, Antimicrobial and Wound Healing Potential of Thymus Sipyleus Boiss. Subsp. Rosulans (Borbas) Jalas

Thymus sipyleus Boiss. subsp. rosulans (Borbas) Jalas (TS) is a commonly used plant in the treatment of various complaints, including skin wounds in Turkish folk medicine. Despite the widespread traditional use of TS, there is not any scientific report confirming the effectiveness of this plant on the healing process. This research aimed to investigate the effects of different extracts obtained from TS on biological events during wound healing, on a cellular basis. In this context, proliferative activities of the extracts, as well as the effects on wound closure and hydroxyproline synthesis, were determined. In addition to wound healing properties, the antioxidant, antibacterial and anti-inflammatory activities of the extracts were evaluated. Decoction (D) and infusion (I) extracts contained the highest amount of phenolic content and showed the most potent activity against DPPH radical. All extracts exhibited complete protection against the damage induced by hydrogen peroxide (H2O2) by increasing cell viability compared to only H2O2-treated groups, both in co-treatment and pre-treatment protocols. None of the extracts exhibited cytotoxic activity, and most of the extracts from the TS stimulated fibroblast proliferation and migration. All TS extracts exert anti-inflammatory activity by suppressing the overproduction of tumor necrosis factor-alpha (TNF-α) and nitric oxide (NO). The most pronounced activity on hydroxyproline synthesis was observed in D extract. In summary, it was observed that TS extracts can promote the healing process by enhancing fibroblast migration, proliferation and collagen synthesis as well as suppressing pro-inflammatory cytokines. The obtained data in this work support the traditional use of TS as a valuable plant-based compound for the treatment of wounds.

Ethanol Extract of Chinese Propolis Attenuates Early Diabetic Retinopathy by Protecting the Blood-Retinal Barrier in Streptozotocin-Induced Diabetic Rats

Propolis has been shown to reduce the level of blood glucose and suppress the histopathological changes in diabetics. However, it still remains unknown if propolis has a similar effect on diabetic retinopathy (DR). Our study aimed to evaluate the effect of the ethanol extract of Chinese propolis (EECP) on early DR in streptozotocin (STZ)-induced diabetic rats. EECP was given to diabetic rats by oral intubation for 12 weeks. The concentrations of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), malondialdehyde (MDA), reactive oxygen species (ROS), and reactive nitrogen species (RNS) were measured. Pathological examinations, including hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), and immunofluorescence, were also conducted to provide further evidence of EECP's effect on early DR. EECP was able to attenuate diabetes via directly decreasing the levels of FBG and HbA1c, which also resulted in the reduction of MDA, ROS, and RNS. Furthermore, EECP could protect against the damages of photoreceptor cells, as well as retinal thickening. And the inhibition of blood-retinal barrier (BRB) leakage was also observed in EECP-treated diabetic rats, along with the inhibition the loss of tight junction proteins (occludin, ZO-1). These results suggest that EECP has an ameliorating effect on early DR by inhibition of blood-retinal barrier breakdown. PRACTICAL APPLICATION: This study sheds light on the protective effect of the ethanol extract of Chinese propolis on early diabetic retinopathy and the molecular actions underlying the inhibition of blood-retinal barrier breakdown. Our study suggests that ethanol extract of Chinese propolis can be considered as a potential therapeutic agent in the treatment of early diabetic retinopathy.

Comparison of aqueous, polyethylene glycol-aqueous and ethanolic propolis extracts: antioxidant and mitochondria modulating properties

BACKGROUND

Propolis is multicomponent substance collected by honeybees from various plants. It is known for numerous biological effects and is commonly used as ethanolic extract because most of active substances of propolis are ethanol-soluble. However, water-based propolis extracts could be applied more safely, as this solvent is more biocompatible. On the other hand, water extracts has significantly smaller range and quantity of active compounds. The extraction power of water could be enhanced by adding co-solvent which increases both solubility and penetration of propolis compounds. However, variation of solvents results in different composition of active substances that might have distinct effects. The majority of biological effects of propolis are attributed to the antioxidant properties of its active compounds. Antioxidant effect might be a result of either direct scavenging of ROS or modulation of ROS producing organelle activity. Therefore, the aim of this study was to investigate and compare chemical composition, antioxidant properties and effects on mitochondrial respiration of aqueous (AqEP), polyethylene glycol-aqueous (Pg-AqEP) and ethanolic (EEP) propolis extracts.

METHODS

Chemical composition of propolis extracts was determined using HPLC and Folin-Ciocalteu method. Ability to neutralize H2O2 and intracellular ROS concentration in C6 glioma cells were determined fluorometrically by using 10-acetyl-3,7-dihydroxyphenoxazine and 2',7'-dichlorofluorescein diacetate, respectively. Mitochondrial superoxide generation was assessed under fluorescent microscope by using MitoSOX Red. Oxygen uptake rates of mitochondria were recorded by high-resolution respirometer Oxygraph-2 k.

RESULTS

Our data revealed that phenolic acids and aldehydes make up 40-42% of all extracted and identified compounds in AqEP and Pg-AqEP and only 16% in EEP. All preparations revealed similar antioxidant activity in cell culture medium but Pg-AqEP and EEP demonstrated better mitochondrial superoxide and total intracellular ROS decreasing properties. At higher concentrations, AqEP and EEP inhibited mitochondrial respiration, but Pg-AqEP had concentration-dependent mitochondria-uncoupling effect.

CONCLUSIONS

Aqueous and non-aqueous propolis extracts differ by composition, but all of them possess antioxidant properties and neutralize H2O2 in solution at similar efficiency. However, both Pg-AqEP and EEP were more effective in decreasing intracellular and intramitochondrial ROS compared to AqEP. At higher concentrations, these preparations affect mitochondrial functions and change energy production in C6 cells.

Antioxidant Potential of Propolis, Bee Pollen, and Royal Jelly: Possible Medical Application

Honeybees products comprise of numerous substances, including propolis, bee pollen, and royal jelly, which have long been known for their medicinal and health-promoting properties. Their wide biological effects have been known and used since antiquity. Bee products are considered to be a potential source of natural antioxidants such as flavonoids, phenolic acids, or terpenoids. Nowadays, the still growing concern in natural substances capable of counteracting the effects of oxidative stress underlying the pathogenesis of numerous diseases, such as neurodegenerative disorders, cancer, diabetes, and atherosclerosis, as well as negative effects of different harmful factors and drugs, is being observed. Having regarded the importance of acquiring drugs from natural sources, this review is aimed at updating the current state of knowledge of antioxidant capacity of selected bee products, namely, propolis, bee pollen, and royal jelly, and of their potential antioxidant-related therapeutic applications. Moreover, the particular attention has been attributed to the understanding of the mechanisms underlying antioxidant properties of bee products. The influence of bee species, plant origin, geographic location, and seasonality as well as type of extraction solutions on the composition of bee products extracts were also discussed.

A Comparison of the Effects of Grayanotoxin-Containing Honey (Mad Honey), Normal Honey, and Propolis on Fracture Healing

OBJECTIVES

Delayed healing and non-union of fractures have a significant effect upon patient morbidity. Studies have therefore largely concentrated on accelerating fracture healing. This study was intended to compare the effect of "mad honey" and propolis on fracture healing using radiological and histopathological analysis.

SUBJECTS AND METHODS

Femur fracture was surgically performed on 48 rats, followed by fixation. Animals were then divided into 8 groups: 2 control groups (15- and 30-day) and 6 treatment groups (15- and 30-day normal honey, 15- and 30-day "mad honey," and 15- and 30-day propolis). Rats were sacrificed at the end of these periods, and radiological and histological examinations were performed.

RESULTS

Radiological healing in the propolis group after 15-day therapy was statistically better than in the control (p = 0.004) and normal honey (p = 0.006) groups. After 30-day therapy, healing in the propolis group (p = 0.005) and grayanotoxin-containing "mad honey" group (p = 0.007) were significantly better than in the control group. Histologically, there was a statistically significant difference between the 15-day propolis group and the other groups (control, honey, mad honey: p = 0.003, p = 0.003, and p = 0.002, respectively). We also found a statistically significant difference when the 30-day propolis group (p = 0.005) and "mad honey" group (p = 0.007) were compared to the control group.

CONCLUSIONS

This study shows that grayanotoxin-containing "mad honey" and propolis can accelerate fracture healing.

Skin Wound Healing: Refractory Wounds and Novel Solutions

This overview of the current state of skin wound healing includes in vitro and in vivo approaches along with some recent clinical trials. From an introduction to wound healing, to tissue engineering as applied to the skin, we cover the basis for the current wound care techniques as well as novel and promising approaches. Special emphasis is given to refractory wounds which include wounds in diabetic patients. Natural compounds have been ever present in wound healing, and so we devote a section to highlighting current attempts to understand their mechanisms and to use them in novel ways.