Acute and sub-acute oral toxicity of Brazilian red propolis in rats

Toxicological safety evaluation of zengye granule through acute and 30-day toxicity studies in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Zengye granule (ZYG), a traditional Chinese medicine formula composed of Radix Scrophulariae, Radix Ophiopogonis, and Radix Rehmanniae in the ratio of 1.0:0.8:0.8, is listed in the Chinese Pharmacopoeia for treating diseases associated with yin deficiency, such as inner heat, dry mouth and pharynx, and dry bound stool. However, little information is available on its toxicological safety.

AIM OF THE STUDY

To evaluate the acute and subacute toxicity of ZYG after oral administration in rats.

MATERIALS AND METHODS

In the acute toxicity study, ZYG was orally administered to rats at a single dose of 10 g/kg/day. In the subacute toxicity study, ZYG was administered orally to rats at repeated daily doses of 2.5, 5.0, or 10 g/kg/day for 30 days. The toxicological effects were evaluated by assessing the rats' general behavior, body weight, food intake, water consumption, blood biochemical and hematological parameters, organ coefficients, and organ histopathology.

RESULTS

No obvious adverse reactions were found in the rats in the acute toxicity study, indicating that ZYG was non-toxic. In the subacute toxicity study, ZYG had no toxic effect on the rats at a dose of 2.5 g/kg/day but showed slight toxicity in the kidneys, and spleens of the rats at doses of 5 and 10 g/kg/day. Significant drug toxicity was observed in male and female rats at 5 and 10/kg/day; however, elevated WBCs counts, ALT, and LYMs levels were found in female rats.

CONCLUSIONS

The oral administration of ZYG at a dose of less than 10 g/kg/day for 1 day or 2.5 g/kg/day for 30 consecutive days can be considered safe, as these doses showed no distinct toxicity or side effects in the rats in this study. Therefore, the dosage should be set according to the clinically recommended dosage to ensure its safety.

Phytochemical Profile and Antimicrobial Potential of Propolis Samples from Kazakhstan

In the current paper, we present the results of Kazakh propolis investigations. Due to limited data about propolis from this country, research was focused mainly on phytochemical analysis and evaluation of propolis antimicrobial activity. uHPLC-DAD (ultra-high-pressure-liquid chromatography coupled with diode array detection, UV/VIS) and uHPLC-MS/MS (ultra-high-pressure-liquid chromatography coupled with tandem mass spectrometry) were used to phytochemical characteristics while antimicrobial activity was evaluated in the serial dilution method (MIC, minimal inhibitory concentration, and MBC/MFC, minimal bactericidal/fungicidal concentration measurements). In the study, Kazakh propolis exhibited a strong presence of markers characteristic of poplar-type propolis—flavonoid aglycones (pinocembrin, galangin, pinobanksin and pinobanskin-3-O-acetate) and hydroxycinnamic acid monoesters (mainly caffeic acid phenethyl ester and different isomers of caffeic acid prenyl ester). The second plant precursor of Kazakh propolis was aspen–poplar with 2-acetyl-1,3-di-p-coumaroyl glycerol as the main marker. Regarding antimicrobial activity, Kazakh propolis revealed stronger activity against reference Gram-positive strains (MIC from 31.3 to above 4000 mg/L) and yeasts (MIC from 62.5 to 1000 mg/L) than against reference Gram-negative strains (MIC ≥ 4000 mg/L). Moreover, Kazakh propolis showed good anti-Helicobacter pylori activity (MIC and MBC were from 31.3 to 62.5 mg/L). All propolis samples were also tested for H. pylori urease inhibitory activity (IC50, half-maximal inhibitory concentration, ranged from 440.73 to 11,177.24 µg/mL). In summary Kazakh propolis are potent antimicrobial agents and may be considered as a medicament in the future.

Genotoxicity and toxicological evaluations of Brazilian red propolis oral ingestion in a preclinical rodent model

ETHNOPHARMACOLOGICAL RELEVANCE

Brazilian red propolis is a natural product known due to its medicinal properties. The efficacy of this natural resin has been proved; however, few studies report the safety of its oral use. Some toxic effects of natural products may not be expressed in traditional use, and preclinical studies are necessary to guarantee their safety. Health regulatory agency currently requires these non-clinical studies to develop drugs and herbal medicines, including genotoxic and oral toxicity tests.

AIM OF THE STUDY

Accomplish the preclinical toxicity studies of Brazilian red propolis extract (BRP) in rodents, including genotoxicity, acute and sub-chronic toxicities.

MATERIAL AND METHODS

Genotoxicity assays followed the erythrocyte micronucleus test protocol in a range of 500-2000 mg/kg BRP oral treatment on male Swiss mice. After an up-and-down procedure, acute oral toxicity (single dose) was performed on female Wistar Hannover rats, reaching a 2000 mg/kg BRP oral gavage concentration. Animals were monitored periodically until 14 days and euthanized for a macroscopic necropsy analysis. The sub-chronic oral toxicity test (90 days) was achieved with 1000 mg/kg of BRP on Wistar Hannover rats (males/females). Animals were monitored to evaluated behavioral and biometrical changes, then were euthanized to perfomed hematological, biochemical, and histopathological analyses.

RESULTS

No genotoxic effect of the BRP was detected. The acute toxicity indicated no toxicity of a single oral dose of 2000 mg/kg of BRP. The long-term oral toxicity performed with 1000 mg/kg of BRP altered water and food intake and the biometrics, hematological and biochemical parameters. Biochemical alterations in hepatic and renal parameters were detected only in the males. Despite the detection of biochemical alterations, no histopathological changes were detected in the organs of any group.

CONCLUSIONS

BRP, at a higher dose, showed no signs of immediate toxicity. However, the obtained results suggest that the chemical composition and the intake of higher doses deserve special attention regarding possible toxicity.

In-vivo and in-silico toxicity studies of daidzein: an isoflavone from soy

Daidzein is a naturally occurring compound belonging to the class isoflavones and found in soya beans and other legumes. Acute oral toxicity was performed as per OECD guideline (TG 423) with slight modifications. A repeated dose toxicity study was carried out as per OECD guideline (TG 407). In-silico toxicity such as AMES toxicity, carcinogenicity, mutagenicity, immunotoxicity, hepatotoxicity, skin irritation, reproductive effect, rat and mouse toxicity, LD50, hERG I, II inhibitor and minnow toxicity were predicted using online servers and tools. In an acute oral toxicity study, daidzein did not show any mortality in experimental animals. The No Observed Adverse Effect Level (NOAEL) of daidzein was found to be above 5000 mg/kg. 28 days treatment of diadzein at all doses did not show changes in hematology parameters, clinical biochemistry and kidney function parameters. Gross necropsy or histopathology of important organs showed no signs of toxicity. In-silico predicted parameters also demonstrated risks ranging from low to a nontoxic level. Thus, daidzein was found to be safe in acute and repeated oral dose toxicity studies at all selected doses. In-silico study also indicated that daidzein is safe.

In-vitro antioxidant, in-vivo anti-inflammatory, and acute toxicity study of Indonesian propolis capsule from Tetragonula sapiens

Propolis is widely used as traditional medicine since ancient times. It was necessary to conduct the pre-clinical study because of its relevant curative properties. This study aimed to investigate in-vitro antioxidant, standardize quality parameters, study acute toxicity, and determine in-vivo anti-inflammatory. Three spectrophotometric methods were used to determine antioxidant activity. The standardization includes physical, chemical, and microbiological evaluation. Furthermore, an acute toxicity test was conducted using 20 female Sprague Dawley (SD) strain rats divided into 4 groups with different dose of propolis. The in vivo anti-inflammatory test was carried out using the carrageenan induction method on rats' soles. A total of 36 female SD rats were classified into 6 groups as follows, Group normal, negative control, diclofenac sodium, and three propolis groups (72; 144; and 288 mg/kg BW). The results demonstrated the IC₅₀ values of the DPPH and ABTS scavenging activity 9.694 ppm and 2.213 ppm, respectively. The FRAP reducing power was 189.05 mg AaE/g. The physical appearance of propolis capsule was vegicaps as white – white, size 0, with light brown granule. Moreover, the content weight was 418.88 mg with a disintegration time of 7 min 53 s, while the water, flavonoid, and polyphenol contents were 9.07%, 1.59%, and 98.0821 mg GAE/g respectively. The content of heavy metal and microbial contamination were not detected. The acute toxicity results showed LD₅₀ ≥ 5 g/kg BW, no toxicity symptoms, and no abnormalities in all rats. The anti-inflammatory inhibition percentage for groups III, IV, V, and VI was 11.86%, 6.53%, 7.81%, and 6.63% respectively, while the anti-inflammatory drugs effectiveness percentage compared to positive controls were 55.00%, 65.83%, and 55.83% respectively. Based on these results, it can be concluded that propolis capsules fulfilled the standardization requirements, and it is likely to be non-toxic, and effective as antioxidant and anti-inflammatory.

Photoprotection and skin irritation effect of hydrogels containing hydroalcoholic extract of red propolis: A natural pathway against skin cancer

The use of natural products in sunscreen formulations as a prophylactic measure against skin cancer is receiving special attention attributed to the photoprotective and antioxidant properties of their chemical components. In this work, we describe the development of topical hydrogel formulations containing hydroalcoholic extract of red propolis (HERP), and the evaluation of the dermal sensitizing effect of the developed products. Sunscreen formulations composed of HERP in different concentrations (1.5, 2.5 or 3.5% w/w) alone or in combination with a chemical (octyl methoxycinnamate) and/or physical (titanium dioxide) filters were developed using poloxamer 407 as gel basis. The preliminary and accelerated stability tests, texture analysis and spreadability tests were performed. All formulations revealed to be stable in preliminary stability assessment. The formulations containing HERP 1.5 and 2.5% alone or associated with the filters showed intense modifications during accelerated stability test, which were confirmed by rheological analyses. The incorporation of HERP and filters in the poloxamer hydrogel decreased the toughness of product (p < 0.05) and the formulation containing HERP alone presented the lowest adhesivity (p < 0.001). The incorporation of HERP in the hydrogel decreased the poloxamer transition temperature, showing different rheological behavior with the increase of HERP concentration. The developed formulations were stable, exhibited non-Newtonian and pseudoplastic behavior, showing in vivo skin compatibility and no skin irritancy.

Development of a New Formulation Based on In Situ Photopolymerized Polymer for the Treatment of Spinal Cord Injury

Spinal Cord Injury (SCI) promotes a cascade of inflammatory events that are responsible for neuronal death and glial scar formation at the site of the injury, hindering tissue neuroregeneration. Among the main approaches for the treatment of SCI, the use of biomaterials, especially gelatin methacryloyl (GelMA), has been proposed because it is biocompatible, has excellent mechanical properties, favoring cell adhesion and proliferation. In addition, it can act as a carrier of anti-inflammatory drugs, preventing the formation of glial scars. The present work presents the development and in situ application of a light-curing formulation based on GelMA containing a natural extract rich in anti-inflammatory, antioxidant and neuroprotective substances (hydroalcoholic extract of red propolis—HERP) in an experimental model of SCI in rats. The formulations were prepared and characterized by time of UV exposition, FTIR, swelling and degradation. The hydrogels containing 1 mg/mL of HERP were obtained by the exposure to UV radiation of 2 μL of the formulation for 60 s. The locomotor evaluation of the animals was performed by the scale (BBB) and demonstrated that after 3 and 7 days of the injury, the GelMA-HERP group (BBB = 5 and 7) presented greater recovery compared to the GelMA group (BBB = 4 and 5). Regarding the inflammatory process, using histomorphological techniques, there was an inflammation reduction in the groups treated with GelMA and GelMA-HERP, with decreases of cavitation in the injury site. Therefore, it is possible to conclude that the use of GelMA and GelMA-HERP hydrogel formulations is a promising strategy for the treatment of SCI when applied in situ, as soon as possible after the injury, improving the clinical and inflammatory conditions of the treated animals.

Nonclinical Toxicological Studies of Brazilian Red Propolis and Its Primary Botanical Source Dalbergia ecastaphyllum

Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is Dalbergia ecastaphyllum (L.) Taub. Despite the potential of Brazilian red propolis for developing new products with pharmacological activity, few studies guarantee safety in its use. The objective of this study was the evaluation of the possible toxic effects of Brazilian red propolis and D. ecastaphyllum, as well as the cytotoxicity assessment of the main compounds of red propolis on tumoral cell lines. Hydroalcoholic extracts of the Brazilian red propolis (BRPE) and D. ecastaphyllum stems (DSE) and leaves (DLE) were prepared and chromatographed for isolation of the major compounds. RP-HPLC-DAD was used to quantify the major compounds in the obtained extracts. The XTT assay was used to evaluate the cytotoxic activity of the extracts in the human fibroblast cell line (GM07492A). The results revealed IC₅₀ values of 102.7, 143.4, and 253.1 μg/mL for BRPE, DSE, and DLE, respectively. The extracts were also evaluated for their genotoxic potential in the micronucleus assay in Chinese hamster lung fibroblasts cells (V79), showing the absence of genotoxicity. The BRPE was investigated for its potential in vivo toxicity in the zebrafish model. Concentrations of 0.8-6.3 mg/L were safe for the animals, with a LC₅₀ of 9.37 mg/L. Of the 11 compounds isolated from BRPE, medicarpin showed a selective cytotoxic effect against the HeLa cell line. These are the initial steps to determine the toxicological potential of Brazilian red propolis.

Inhibitory effect of Brazilian red propolis on planktonic and biofilm forms of Clostridioides difficile

Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacillus which is the leading cause of health-care-associated infective diarrhea. The rising incidence of antibiotic resistance in pathogens such as C. difficile makes researches on alternative antibacterial products very important, especially those exploring natural products like propolis. Brazilian Red Propolis, found in the Northeast region of Brazil, is composed by products from regional plants that have the antimicrobial properties. This study aimed to evaluate the in vitro activity of Brazilian Red Propolis (BRP) against C. difficile strains in planktonic and biofilm forms. The susceptibility of four strains of C. difficile to BRP was analyzed by broth microdilution method and vancomycin was included as control drug. BRP-exposed C. difficile cells were evaluated by scanning electron microscopy (SEM). Then, the effects of BRP on growing and mature C. difficile biofilms were also evaluated. BRP minimum inhibitory concentration was 625 μg/mL against all tested strains, while vancomycin MIC range was 0.5-2 μg/mL. SEM showed the loss of homogeneity in bacterial cell wall and cell fragmentation, after BRP-exposure. BRP, at MIC, reduced (P < 0.05) the biomass, matrix proteins and matrix carbohydrates of growing biofilms, and, at 8xMIC, reduced (P < 0.05) the biomass and matrix proteins of mature biofilms. The present study demonstrated that BRP inhibits planktonic growth, damages cell wall, decreases biofilm growth and harms mature biofilms of C. difficile.

Safety and bioactive potential of nanoparticles containing Cantaloupe melon (Cucumis melo L.) carotenoids in an experimental model of chronic inflammation

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Carotenoids present anti-inflammatory effects in healthy and overweight adults.

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Nanotechnology can enhance carotenoid's bioactive potential.

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Nanoparticles loaded with carotenoids from Cantaloupe melon were used in obese rats.

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Animals receiving the nanoparticles showed no signs of toxicity.

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Animals treated with nanoparticles had organs better aspect compared to untreated.

The safety and bioactive potential of crude carotenoid extract from Cantaloupe melon nanoencapsulated in porcine gelatin (EPG) were evaluated in a chronic inflammatory experimental model. Animals were fed a high glycemic index and high glycemic load (HGLI) diet for 17 weeks and treated for ten days with 1) HGLI diet, 2) standard diet, 3) HGLI diet + crude carotenoid extract (CE) (12.5 mg/kg), and 4) HGLI diet + EPG (50 mg/kg). General toxicity signals were investigated, considering body weight, food intake, hematological, biochemical parameters, relative weight, morphology, and histopathology of organs. The biochemical parameters indicated the low toxicity of EPG. Acute hepatitis was observed in animals' livers, but CE and EPG groups presented improved tissue appearance. Chronic enteritis was observed in animals, with villi and intestinal glands preservation in the EPG group. The results suggest the safety and the bioactive effect of EPG, possibly related to its anti-inflammatory potential.

Souto E, Cardoso JC. Red Propolis and Its Dyslipidemic Regulator Formononetin: Evaluation of Antioxidant Activity and Gastroprotective Effects in Rat Model of Gastric Ulcer

Propolis has various pharmacological properties of clinical interest, and is also considered a functional food. In particular, hydroalcoholic extracts of red propolis (HERP), together with its isoflavonoid formononetin, have recognized antioxidant and anti-inflammatory properties, with known added value against dyslipidemia. In this study, we report the gastroprotective effects of HERP (50–500 mg/kg, p.o.) and formononetin (10 mg/kg, p.o.) in ethanol and non-steroidal anti-inflammatory drug-induced models of rat ulcer. The volume, pH, and total acidity were the evaluated gastric secretion parameters using the pylorus ligature model, together with the assessment of gastric mucus contents. The anti-Helicobacter pylori activities of HERP were evaluated using the agar-well diffusion method. In our experiments, HERP (250 and 500 mg/kg) and formononetin (10 mg/kg) reduced (p < 0.001) total lesion areas in the ethanol-induced rat ulcer model, and reduced (p < 0.05) ulcer indices in the indomethacin-induced rat ulcer model. Administration of HERP and formononetin to pylorus ligature models significantly decreased (p < 0.01) gastric secretion volumes and increased (p < 0.05) mucus production. We have also shown the antioxidant and anti-Helicobacter pylori activities of HERP. The obtained results indicate that HERP and formononetin are gastroprotective in acute ulcer models, suggesting a prominent role of formononetin in the effects of HERP.

Effectiveness of Different Analytical Methods for the Characterization of Propolis: A Case of Study in Northern Italy

Propolis is used as folk medicine due to its spectrum of alleged biological and pharmaceutical properties and it is a complex matrix not still totally characterized. Two batches of propolis coming from two different environments (plains of Po Valley and the hilly Ligurian–Piedmont Apennines) of Northern Italy were characterized using different analytical methods: Spectrophotometric analysis of phenols, flavones and flavonols, and DPPH radical scavenging activity, HPLC, NMR, HSPME and GC–MS and HPLC–MS Orbitrap. Balsam and moisture content were also considered. No statistical differences were found at the spectrophotometric analysis; balsam content did not vary significantly. The most interesting findings were in the VOCs composition, with the Po Valley samples containing compounds of the resins from leaf buds of Populus nigra L. The hills (Appennines) samples were indeed characterize by the presence of phenolic glycerides already found in mountain environments. HPLC–Q-Exactive-Orbitrap^®–MS analysis is crucial in appropriate recognition of evaluate number of metabolites, but also NMR itself could give more detailed information especially when isomeric compounds should be identified. It is necessary a standardized evaluation to protect and valorize this production and more research on propolis characterization using different analytical techniques.

Anti-inflammatory activity of Tetragronula species from Indonesia

Anti-inflammatory drugs inhibit inflammation, particularly those classified as nonsteroidal anti-inflammatory drugs (NSAIDs). Several studies have reported that propolis has both anti-ulcerogenic and anti-inflammatory effects. In this study, we investigated the bioactive compound and in vivo anti-inflammatory properties of both smooth and rough propolis from Tetragronula sp. To further identify anti-inflammatory markers in propolis, LC-MS/MS was used, and results were analyzed by Mass Lynx 4.1. Rough and smooth propolis of Tetragonula sp. were microcapsulated with maltodextrin and arabic gum. Propolis microcapsules at dose 25–200 mg/kg were applied for carrageenan-induced rat’s paw-inflammation model. Data were analyzed by one-way ANOVA and Kruskal–Wallis statistical tests. LC-MS/MS experiments identified seven anti-inflammatory compounds, including [6]-dehydrogingerdione, alpha-tocopherol succinate, adhyperforin, 6-epiangustifolin, deoxypodophyllotoxin, kurarinone, and xanthoxyletin. Our results indicated that smooth propolis at 50 mg/kg inhibited inflammation to the greatest extent, followed by rough propolis at a dose of 25 mg/kg. SPM and RPM with the dose of 25 mg/kg had inflammatory inhibition value of 62.24% and 58.12%, respectively, which is comparable with the value 70.26% of sodium diclofenac with the dose of 135 mg/kg. This study suggests that propolis has the potential candidate to develop as a non-steroid anti-inflammatory drug.

Antitrypanosomal, antileishmanial and cytotoxic activities of Brazilian red propolis and plant resin of Dalbergia ecastaphyllum (L) Taub

The treatment for leishmaniasis and Chagas disease can be hard and painful, such that many patients give up on the treatment. In order to find an alternative path for the treatment of these diseases, researchers are using natural products to fight these parasites. The aim of this study was to evaluate the antiprotozoan and cytotoxic activities of red propolis samples collected from different Brazilian states and seasons whilst searching for possible activity differences. We also compared the red propolis results with the ones obtained for the plant resin extract collected from Dalbergia ecastaphyllum trees. The hydroethanolic red propolis extracts from Pernambuco and Alagoas, and the D. ecastaphyllum resin were evaluated regarding their antileishmanial, antitrypanosomal and cytotoxic activity. All extracts showed antiprotozoan and cytotoxic activity. RP-PER showed to be more cytotoxic against protozoan parasites and fibroblast cells. All propolis extracts showed a higher cytotoxic activity when compared to resin extracts. The propolis sample collected in Pernambuco during the rainy season killed the parasites with lower concentrations than the sample collected in the dry season. The IC₅₀ observed against the parasites could be used without high fibroblast cell damage.

Expression of vascular endothelial growth factor and matrix metalloproteinase-9 in Apis mellifera Lawang propolis extract gel-treated traumatic ulcers in diabetic rats

Aim:

The aim of this study was to determine the effect of Apis mellifera propolis extract gel on vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) expression in the traumatic ulcers of rats afflicted with diabetes mellitus (DM).

Materials and Methods:

The study was conducted on 24 male Wistar rats (Rattus norvegicus) induced with DM by injecting 50 mg/kg of Streptozotocin, intraperitoneally, and a traumatic ulcer on their lower lip mucosa. These were divided into eight groups: Four each for control and treatment groups. Each control and treatment group consisted of three rats. The control groups treated with hydroxypropyl methylcellulose 5% gel and treatment groups were administered with propolis extract gel. The expression of VEGF and MMP-9 was observed on days 3, 5, 7, and 9. Furthermore, mice sacrificed and the lower lip labial mucosa tissue of mice has been taken to make the histopathology anatomy preparation by means of immunohistochemical examination with monoclonal antibodies anti-VEGF and anti-MMP-9.

Results:

This experiment revealed higher VEGF expression and lower MMP-9 expression in the treatment group as compared to that of the control group. Analysis of Variance showed significant differences (p<0.01) of both VEGF expression and MMP-9 expression between the two groups. A Tukey’s analysis did not find strong contrasts in VEGF and MMP-9 expressions between various treatment groups. However, those between treatment and control groups were found to be considerable.

Conclusion:

Propolis extract gel increased the expression of VEGF and decreased that of MMP-9 during the healing process of traumatic ulcers on the oral mucosa of diabetes afflicted Wistar rats (R. norvegicus).

Acute and sub-acute oral toxicity studies of the aqueous extract from radix, radix with cortex and cortex of Psammosilene tunicoides in mice and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Psammosilene tunicoides is one of the important ingredients of a famous Chinese traditional medicine formulation "Yunnan Baiyao". Also, this plant is commonly used as an anodyne and hemostatic agent in southwest China. Currently, little toxicological information is available on its safety following prolonged use.

AIM OF THE STUDY

In this study, we sought to evaluate the toxicity of the three different parts of Psammosilene tunicoides: Psammosilenes Radix (PR), Psammosilenes Radix with Cortex (PRC) and Psammosilenes Cortex (PC) by acute and sub-acute toxicity studies.

MATERIALS AND METHODS

In the acute toxicity study, mice were orally administrated with different doses of PR, PRC and PC. General behavior and mortality were observed up to 14 days. In sub-acute toxicity study, these aqueous extracts were given orally as a single administration to rats at doses of 0.3, 0.6 and 1.2g/kg/day, respectively, for 28 days. General behavior, body weight, biochemical, hematological, organ coefficients and pathological morphology parameters were detected.

RESULTS

In acute study, single oral administration of the aqueous extract of PR, PRC and PC caused dose-dependent general behavior adverse effects and mortality. The LD50 values of PR, PRC and PC were 4.64g/kg, 4.85g/kg and 6.40g/kg, respectively. In sub-acute study, the administration of the extract of PR, PRC and PC during 28 days at all doses reduced spontaneous activities with both genders. Occasional nasal secretion with blood at high doses (1.2g/kg) of PR, PRC and PC were observed. Daily single oral administration provoked varying degrees of growth retardation in female rats. The relative heart and spleen weight in the female rats were reduced after the administration. On the hematological and biochemical analyses, the administration of the extract of PR, PRC and PC during 28 days mainly caused variation of indexes in female rats. Histopathological analysis has shown vascular congestion in heart, thickened alveolar wall and emphysema in lung, and vascular congestion in kidney of rats after sub-acute oral administrations.

CONCLUSIONS

As shown in the results, Psammosilene tunicoides has a toxic potential in acute and sub-acute oral administrations. However, there is no direct relationship between toxicity and the cortex. Daily oral administration of three different parts from Psammosilene tunicoides (PR, PRC and PC) may cause damages to heart, lung and kidney in rats. Thus these extracts should be used with caution.

Evaluation of bioactive compounds potential and antioxidant activity of brown, green and red propolis from Brazilian northeast region

The aim of the present study was to determine the contents of bioactive compounds present in brown, green and red species of propolis cultivated in the Brazilian northeast states of Alagoas and Sergipe. The contents of phenolic compounds, flavonoids and antioxidant activity (DPPH, ABTS⁺, FRAP, ORAC) were determined. Identification and quantification of phenolic and flavonoid compounds were performed by using UHPLC-QqQ-MS/MS system. The results revealed high contents of total phenolics and flavonoids. Among the three species, the antioxidant potential had higher capacity in the red propolis. The presence of some of bioactive compounds viz. acacetin, artepellin C, eriodictyol, gallic acid, isorhamnetin, protocatechuic acid, vanillin and vanillic acid in Brazilian red propolis is reported for the first time in this work. Positive correlation between total phenolics versus the FRAP and ORAC methods was established which led to conclusion that antioxidant activity of propolis is mainly due to its phenolic compounds.

Propolis from Southwest of Parana produced by selected bees: Influence of seasonality and food supplementation on antioxidant activity and phenolic profile

Propolis produced by selected bees Apis mellifera were collected from March to June of 2013 and in March of 2015 and analyzed in order to evaluate the influence of climate, colony of origin, and food supplementation of colonies on the content of total phenolic and flavonoid by chromatographic analysis and antioxidant activity by radical scavenging of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods. The Principal Component Analysis (PCA) was carried out with propolis collected in 2013 and two clusters were formed. Propolis produced in the months of March and April showed a higher content of total phenolic compounds (TPC) and antioxidant capacity than those produced in May and June. The results of PCA obtained from samples collected in March of 2013 and 2015 showed two clusters, and propolis collected in 2015 were more bioactive and presented a higher content of TPC. The chromatographic analysis of extracts allowed the identification of phenolic acids p-coumaric, ferulic and caffeic with similar chemical profiles that could be closely related to the botanical origin of propolis. It can be concluded that the season and food supplementation of colonies influenced the chemical composition and the biological activity of samples analysed.

The effect of seasons on Brazilian red propolis and its botanical source: chemical composition and antibacterial activity

The aim of this study was to evaluate the effect of seasons on the chemical composition and antibacterial activity of Brazilian red propolis (BRP) and its plant source. BRP was collected from Maceio, Alagoas state, north-east of Brazil, during one year. Chemical composition was determined by physicochemical analyses and HPLC while antimicrobial activity was assessed against Streptococcus mutans, Streptococcus sobrinus, Staphylococcus aureus and Actinomyces naeslundii by determining the minimal inhibitory and bactericidal concentrations (MIC and MBC, respectively). The comparative chemical profiles varied quantitatively according to the collection period. Formononetin was the most abundant compound in both propolis and resin, while isoliquiritigenin, (3S)-neovestitol, (3S)-vestitol are suggested to be responsible for antimicrobial activity of Brazilian red propolis. MIC varied from 15.6 to 125 μg/mL, whereas MBC varied from 31.2 to 500 μg/mL. Therefore, season in which propolis and its botanical source are collected indeed influences their chemical compositions, resulting in variations in their antibacterial activity.

Cytotoxic and Nitric Oxide Inhibition Activities of Propolis Extract along with Microencapsulation by Complex Coacervation

In this study, cytotoxicity of ethanol extract of propolis (EEP) originating from Sivas, Turkey was screened against several cancer cell lines, namely PC-3, U87MG, A-549, mPANC96, CaCo-2, MCF-7, HeLa, MDA-MB-231 and a non-tumor cell line HEK293 by MTT assay. The inhibition levels of inducible nitric oxide synthase (iNOS) were also determined by using RAW 264.7 macrophage cells following lipopolysaccharide (LPS) treatment. EEP exhibited significant cytotoxic nitric oxide inhibition activities with an IC50 value of 0.1 ± 0.1 μg/ml indicating a high potential as an anti-inflammatory agent. In spite of these promising results and the fact that propolis is a highly nutritive substance, its low solubility and bitter taste limit the applications as a natural supplement. Encapsulation might serve as a good strategy in order to overcome these problems. Complex coacervation was applied where the main focus was on surfactant type, polymer ratio (alginate:gelatin), stirring rate and concentration of core material. The mean particle size of unloaded microparticles were 22.62 μm obtained with gelatin:alginate ratio of 1:1 at a stirring rate of 1400 rpm with 2 ml of 1 % (w/v) sodium carboxymethyl cellulose (Na-CMC), whereas addition of EEP at a concentration of 100 mg/ml increased the mean particle size to 36.44 μm and yielded an encapsulation efficiency of 98.77 %. The cytotoxicities of EEP loaded microparticles were also assessed both on MCF-7 and MDA-MB-231 where similar results were achieved as free EEP which can enhance the possible use of propolis extract in the industry as a natural supplement.

Ethanol-Extracted Brazilian Propolis Exerts Protective Effects on Tumorigenesis in Wistar Hannover Rats

The present study was conducted over a course of 104 weeks to estimate the carcinogenicity of ethanol-extracted Brazilian green propolis (EEP). Groups of 50 male and 50 female Wistar Hannover rats, 6-week-old at commencement were exposed to EEP at doses of 0, 0.5 or 2.5% in the diet. Survival rates of 0.5% and 2.5% EEP-treated male and female rats, respectively, were significantly higher than those of respective control groups. Overall histopathological evaluation of neoplasms in rat tissues after 2 years showed no significant increase of tumors or preneoplastic lesions in any organ of animals administered EEP. Significantly lower incidences of pituitary tumors in 0.5% EEP male and 2.5% EEP female groups, malignant lymphoma/leukemia in both 2.5% EEP-treated males and females and total thyroid tumors in 0.5% EEP male group were found. Administration of EEP caused significant decreases of lymphoid hyperplasia of the thymus and lymph nodes in 2.5% EEP-treated rats, tubular cell hyperplasia of kidneys in all EEP groups, and cortical hyperplasia of adrenals in EEP-treated females. In the blood, significant reduction of neutrophils in all EEP-treated males and band neutrophils in 2.5% EEP-treated females was found indicating lower levels of inflammation. Total cholesterol and triglicerides levels were significantly lower in the blood of 2.5% EEP-treated female rats. In conclusion, under the conditions of the 2-year feeding experiment, EEP was not carcinogenic, did not induce significant histopathological changes in any organ, and further exerted anti-inflammatory and antitumorigenic effects resulting in increase of survival of Wistar Hannover rats.

Hydroalcoholic extract of red propolis promotes functional recovery and axon repair after sciatic nerve injury in rats

CONTEXT

Peripheral axon injury and degeneration are often mediated by oxidative stress and inflammation. The hydroalcoholic extract of the red propolis (HERP) has attracted great attention because of its antioxidant and anti-inflammatory activities.

OBJECTIVE

The objective of this work is to study the effect of HERP on nerve repair and functional recovery after sciatic nerve injury (SNI) in rats.

MATERIALS AND METHODS

The chemical markers in HERP were identified using high-resolution mass spectroscopy. After axonotmesis of sciatic nerve, ibuprofen (IBP) and HERP treatments were orally administered for 28 d. Behavioural tests were performed weekly after SNI. The myelinated axon number was counted using morphometric analysis.

RESULTS

The compounds found in HERP were pinocembrin, formononetin, vestitol, and biochanin A. The animals that underwent SNI showed a significant decrease in motor function based on the Basso, Beattie and Bresnahan scale and sciatic functional index compared with sham animals until 7 d after the surgery (p < 0.05). After 14 and 21 d, the SNI groups treated with either HERP or IBP showed significant improvement (p < 0.01), and the SNI group treated with HERP 10 mg/kg showed accelerated motor recovery compared with the other groups (p < 0.01). SNI caused also a reduction in the myelinated axon counts, and treatment with HERP 10 mg/kg induced a significant increase in the number of myelinated fibres compared with all other groups.

CONCLUSION

HERP promoted regenerative responses and accelerated functional recovery after sciatic nerve crush. Thus, it can be considered to be a new strategy or complementary therapy for treating nerve injuries.

Antinociceptive and anti-inflammatory effects of Brazilian red propolis extract and formononetin in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis has been used as a folk medicine for centuries around the world due to its wide spectrum of biological activities. The red propolis, a new Brazilian variety of this apimaterial, has presented an unusual chemical composition, including isoflavones such as formononetin and biochanin A. Since both the green and red varieties of propolis are traditionally used as medicine and commercialized with no label differentiation, the study of the activities of red propolis extract has become important in order to clarify whether this product has the same activities as commercial ones. In this work, we demonstrated the potential action of the hydroalcoholic extract of red propolis (HERP) and its biomarker, formononetin, as antinociceptive and anti-inflammatory drugs on experimental models.

MATERIALS AND METHODS

The HERP was chemically characterised by HPLC/DAD analyses. The biological activities of the HERP (3, 10, and 30mg/kg) and formononetin (10mg/kg) were evaluated using the antinociceptive (acetic acid, formalin, and glutamate injections) and anti-inflammatory (carrageenan-induced hindpaw oedema and peritonitis) models in mice after oral administration. The open field test was also performed.

RESULTS

Formononetin, one of the main biomarker of red propolis, was identified in the HERP (21.62mg/g). Pretreatment with the HERP (10 and 30mg/kg) and formononetin (10mg/kg) produced reduction (P<0.001) in the number of abdominal writhes, but the HERP was more effective (P<0.001) than formononetin. In the formalin test, all HERP doses (3, 10, and 30mg/kg, P<0.001) inhibited the late phase (inflammatory pain) of formalin-induced licking, but the inhibition of neurogenic pain was observed only when the higher doses (10 and 30mg/kg; P<0.05) were used. Formononetin caused inhibition (P<0.001) only in the second phase of formalin-induced nociception similarly at all HERP doses in the same phase of the test. The responses in glutamate-induced model presented crescent inhibition (P<0.05) with 10 and 30mg/kg of HERP. Also, formononetin inhibited (P<0.001) the nociception induced by glutamate similarly to 30mg/kg of HERP. There were no significant differences in the open field test after HERP administration, but formononetin decrease the spontaneous motor behaviour. Regarding the anti-inflammatory assessment, the HERP (10 and 30mg/kg, P<0.05) and formononetin (P<0.001) treatments caused a significant inhibition of the oedema response. All doses of HERP (3, 10, and 30mg/kg, P<0.05) and formononetin (P<0.001) also inhibited the carrageenan-induced leukocyte migration. In both cases, the results for the HERP at 30mg/kg and formononetin were similar.

CONCLUSIONS

The HERP and formononetin presented significant anti-inflammatory activity. Moreover, the HERP presented antinociceptive action on inflammatory and neurogenic pain without motor side effects, possibly due to the action of other constituents present in the extract. These results, together, support the popular usage of this natural product.