Preparation and antioxidant properties of water extract of propolis

Physical Treatments Modified the Functionality of Carrot Pomace

This study addressed the critical issue of food waste, particularly focusing on carrot pomace, a by-product of carrot juice production, and its potential reutilization. Carrot pomace, characterized by high dietary fiber content, presents a sustainable opportunity to enhance the functional properties of food products. The effects of physical pretreatments-high shearing (HS), hydraulic pressing (HP), and their combination (HSHP)-alongside two drying methods (freeze-drying and dehydration) on the functional, chemical, and physical properties of carrot pomace were explored. The results indicated significant enhancements in water-holding capacity, fat-binding capacity, and swelling capacity, particularly with freeze-drying. Freeze-dried pomace retained up to 33% more carotenoids and demonstrated an increase of up to 22% in water-holding capacity compared to dehydrated samples. Freeze-dried pomace demonstrated an increase of up to 194% in fat-binding capacity compared to dehydrated samples. Furthermore, HSHP pretreatment notably increased the swelling capacity of both freeze-dried (54%) and dehydrated pomace (35%) compared to pomace without pretreatments. Freeze-drying can enhance the functional properties of dried carrot pomace and preserve more carotenoids. This presents an innovative way for vegetable juice processors to repurpose their processing by-products as functional food ingredients, which can help reduce food waste and improve the dietary fiber content and sustainability of food products.

Deep Eutectic Solvents as New Extraction Media for Flavonoids in Mung Bean

Mung beans contain abundant flavonoids like vitexin and isovitexin, which contribute to their strong bioactivities, such as antioxidant effects, so efforts should focus on extracting bioactive flavonoids as well as aligning with the goal of green extraction for specific applications. Deep eutectic solvent coupled with ultrasound-assisted extraction (DES-UAE) was applied to extract flavonoids from mung beans, and eight different DESs were compared on the extraction yield. In addition, the traditional extraction method with 30% ethanol was performed as the reference. The results showed that ethylene glycol-glycolic acid achieved the highest yield among all the DESs, 1.6 times that of the reference values. Furthermore, the DES-UAE parameters were optimized as a 60 mL/g liquid-solid ratio, 30% water content in DES, 200 W ultrasonic power, 67 °C ultrasonic temperature, and 10 min extraction time, leading to the DES extract with the maximum extraction yield of 2339.45 ± 42.98 μg/g, and the significantly stronger DPPH and ABTS radical scavenging ability than the traditional extract. Therefore, employing DES and ultrasonic extraction together offers a green method for extracting flavonoids from mung beans, advancing the development and utilization of plant-derived effective components in a sustainable manner.

Characterization and stability evaluation of Egyptian propolis extract nano-capsules and their application

The increasing demand for natural products and biotechnological activities from bees facilitate their widespread use in food preservation and beneficial effects on humans. This study aimed to prepare and characterize the nano-capsules of Qaluiobia (PQG) governorates propolis extracted with water, ethanol and supercritical fluid-carbon dioxide at 50 °C with co-solvent. Propolis bioavailability was analyzed and introduced to prepare crackers to extend their shelf life. Nano-encapsulation was examined using transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and antioxidant activity. Ethanol and supercritical fluid-carbon dioxide (SCF-CO2) at 50 °C with ethanol as co-solvent recorded higher yield, antioxidant activities, total phenolics and total flavonoids. SCF-CO2 extracts had a higher flavonoid concentration. It was revealed that propolis nano-capsules had high-temperature stability and cytotoxic effects against the three tested human cancer cell lines (i.e. PC3, MCF7 and HePG2). The higher overall acceptability of crackers fortified with PQG was achieved with SCF-CO2 at 50 °C and ethanol extract nano-capsules, i.e. 86.57% and 86.29% respectively. The higher ability to retain antioxidant activity reduces the increase of peroxide value (PV), preventing rancidity and increasing the shelf life of crackers during the storage period. Practical application: This study can provide a suitable method for extracting bioactive compounds from propolis, and improve the biological properties and activities by nano-encapsulation, also reveals the extent of its use as a natural antioxidant and anticancer and its application in bakery products as a functional food.

Pitaya Nutrition, Biology, and Biotechnology: A Review

Pitaya (Hylocereus spp.) is a member of the cactus family that is native to Central and South America but is now cultivated throughout the sub-tropical and tropical regions of the world. It is of great importance due to its nutritional, ornamental, coloring, medicinal, industrial, and high consumption values. In order to effectively utilize and develop the available genetic resources, it is necessary to appreciate and understand studies pertaining to the usage, origin, nutrition, diversity, evaluation, characterization, conservation, taxonomy, and systematics of the genus Hylocereus. Additionally, to gain a basic understanding of the biology of the plant, this review has also discussed how biotechnological tools, such as cell and tissue culture, micropropagation (i.e., somatic embryogenesis, organogenesis, somaclonal variation, mutagenesis, androgenesis, gynogenesis, and altered ploidy), virus-induced gene silencing, and molecular marker technology, have been used to enhance pitaya germplasm.

Propolis Ethanolic Extract Attenuates D-gal-induced C2C12 Cell Injury by Modulating Nrf2/HO-1 and p38/p53 Signaling Pathways

Previous study has shown that propolis ethanolic extract (PEE) has a protective effect on aging skeletal muscle atrophy. However, the exact molecular mechanism remains unclear. This study aimed to investigate the effect of PEE on D-galactose (D-gal)-induced damage in mouse C2C12 cells. The results revealed that PEE increased the viability of senescent C2C12 cells, decreased the number of senescence-associated β-galactosidase (SA-β-Gal)-positive cells and promoted the differentiation of C2C12 cells. PEE resisted oxidative stress caused by D-gal by activating the Nrf2/HO-1 signaling pathway and maintained the differentiation ability of C2C12 cells. PEE inhibited apoptosis by suppressing p38 phosphorylation and reducing p53 expression. In summary, our findings reveal the molecular mechanism by which PEE protects D-gal-induced C2C12 cells, providing a theoretical basis for the development of PEE for the alleviation of muscle atrophy.

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.

Antibacterial efficacy of hubballi propolis against aggregatibacter actinomycetemcomitans one of the major causative organisms of perimplantitis: An In vitro study

Background:

Peri-implantitis can be attributed to many underlying causes, one of the chief ones being due to infection caused by oral micro flora and particularly Aggregatibacter actinomycetemcomitans. Antibiotics are administered along with mechanical debridement to control the infection. The side effect of conventional antibiotic therapy and drug resistance has led to the necessity for alternate approaches to handle infections. Natural products are being investigated because of their multi-target activity and structurally different from the normal antibiotics. Propolis a product by Apis Mellifera bees as a wound healing and bone regenerating effect along with antimicrobial effect. One of the important features of Propolis is the chemical properties of Propolis changes with the different locations of procurement. Antimicrobial activity of Hubballi propolis against Aggregatibacter actinomycetemcomitans is not been reported in the literature.

Aim:

The aim of this study is to evaluate the antimicrobial effect of the Hubballi Propolis against Aggregatibacter actinomycetemcomitans.

Methods:

The two solvents used for the study were water and 70% Aq ethanol. Minimum inhibitory concentration (MIC), total phenolic contents (TPC), and total flavonoid content (TFC) were tested.

Results:

Hubballi Propolis sample showed antimicrobial effect against Aggregatibacter actinomycetemcomitans with MIC range from 0.1 mg/ml to 0.25 mg/ml.

Conclusion:

Hubballi Propolis is effective against Aggregatibacter actinomycetemcomitans infection thus may help in treating peri-implantitis. Propolis extracted with water as solvent showed better MIC, higher TPC and TFC than the propolis extracted using alcohol as solvent. This feature is noteworthy as the formulations produced using water extract is favorable than alcohol extract of propolis which irritates the mucosa and hence difficult for its application in dentistry.

The use of propolis in dentistry, oral health, and medicine: A review

BACKGROUND

Propolis is a resinous product that is collected from plants by bees to cover holes and crevices in their hives. Propolis has potent antibacterial, antiviral, anti-inflammatory, wound healing, and anticancer properties. Propolis has been used therapeutically by humans for centuries, including the treatment of dental caries and mouth infections.

HIGHLIGHT

This review article attempts to analyze the potential use of propolis in general dentistry and oral health management.

CONCLUSION

Propolis is potentially useful in dentistry and oral health management based on available in vitro, in vivo, and ex vivo studies, as well as human clinical trials.

Analysis of antimicrobial activity of Karnataka propolis against oral pathogens – An in vitro study

Background:

Propolis, a natural antibiotic, which is in high demand in dentistry is a resinous substance. The main ingredient of propolis that is required for antibiotic effect is flavonoids and phenolic acids. Although propolis is a promising option for the control of oral microbes with lower related hazards and a good immunomodulator effect, its composition differs considerably depending on its botanical origin, the site and the season of collection. This original research aims to find the chemical composition and minimum inhibitory concentration (MIC) of propolis procured from different places of Karnataka state. The results would help the dentist and the pharmacist to select the best propolis to use as antibiotics in treating oral disease.

Materials and Methods:

Propolis sample from 5 different locations of Karnataka was procured from single apiary in Bangalore. Extraction of propolis using two different extracting solvents was carried out. The total phenolic content, total flavonoid content and MIC of each sample were analyzed.

Results:

Water extract propolis of Sullia and Hubli was highly active against tested organism with the MIC <0.312; alcohol extract of Sullia, Hubli and Chitradurga was moderately active with the MIC between 0.312 and 5 mg/ml. Vijayapura and Bagalkot were least active with the MIC >5 mg/ml at tested concentration.

Conclusion:

Propolis procured from different locations of Karnataka can be used as an antimicrobial agent with varying concentrations. However, when propolis is procured for therapeutic purpose, then it needs to be tested for its chemical composition before being utilized.

Phenolic Profile, Antioxidant Capacities and Enzymatic Inhibitory Activities of Propolis from Different Geographical Areas: Needs for Analytical Harmonization

Propolis is a resinous vegetal exudate modified by bees, and is interesting as a preservative and potentially functional product. This work dealt with studying the common phenolic profiles and antioxidant capacities of 13 bee propolis from different geographical areas. Both hyaluronidase and angiotensin converting enzyme (ACE) inhibitory activities were also assessed and related when possible with particular phenolic compounds. High performance liquid chromatography-ultraviolet detection (HPLC-UV) analysis showed that every propolis contained p-coumaric acid (1.2–12.2 mg/g) and ferulic acid (0.3–11.0 mg/g). Pinocembrin, catechin, and caffeic acid phenethyl ester (CAPE) plus galangin were the main flavonoids. Antioxidant activities were higher than 280 µmol trolox/g for trolox equivalent antioxidant capacity (TEAC), 0.099 mmol uric acid/g for radical-scavenging effect on hydroxyl radicals, and 0.19 mg/mL for half maximal inhibitory concentration (IC₅₀) of antioxidant activity against superoxide anion radical. Working with solutions of 10 mg/mL propolis, hyaluronidase inhibitory activity ranged between 0% and 68.20%, being correlated to ferulic acid content. ACE inhibitory effect determined by HPLC was higher than 78%, being correlated with catechin and p-coumaric acid. Therefore, propolis could be useful for food, pharmaceutical, and cosmetic companies, also helping to reduce risk factors for diseases related to oxidative damage, inflammatory processes, and hypertension. This research also highlights the necessity for harmonized analysis methods and the expression of results for propolis.

Identification and quantitation of bioactive components from honeycomb (Nidus Vespae)

Honeycomb (Nidus Vespae) as an agri-food waste in bee product industry is in soaring demand for high-value utilization. This study is dedicated to investigate the physicochemical properties, chemical composition, and nutritional value of honeycomb by determination of physicochemical parameters, total phenolic and total flavonoid contents, antioxidant capacity in vitro, and bioactive components. By using ultra high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) method, a total of 76 bioactive components from hydro-ethanolic extracts of honeycomb (EHB) were tentatively identified, where the principal ones are polyphenols and fatty acids, which were further quantified by LC-MS and GC-MS, respectively. Moreover, antimicrobial activities test has been conducted, verifying that EHB can inhibit both Gram-negative (G^-) bacteria and Gram-positive (G+) bacteria, which is beneficial for the high-value utilization of honeycomb.

Comparison of the effects of dynamic high-pressure microfluidization and conventional homogenization on the quality of peach juice

BACKGROUND

Dynamic high-pressure microfluidization (DHPM) is an emerging and promising technique for continuous production of fluid foods. This study aimed to investigate the influence of DHPM and conventional homogenization (CH) on the quality of peach juice. Processing was performed by passing peach juice through CH at 20 MPa and DHPM at 20-160 MPa for one or three passes. The effect of DHPM pressure and passing number were also assessed.

RESULTS

The results indicate that DHPM could maintain the antioxidant activity of peach juice much better than CH processing. Total phenolic compounds were decreased by 11.7% and 7.9%-15.8% through CH and DHPM processing in different conditions. Moreover, particle size, non-enzymatic browning index and turbidity decreased significantly under DHPM and CH processing, and decreased more and more with the increasing of DHPM pressure and treatment times. However, vitamin C content and zeta-potential did not reveal remarkable variation before and after these two types of processing.

CONCLUSION

Taken together, DHPM is able to maintain the quality and stability of peach juice, which can be a reliable technological alternative to CH to produce fresh-like peach juices. © 2019 Society of Chemical Industry.

Identification of Resveratrol as Bioactive Compound of Propolis from Western Romania and Characterization of Phenolic Profile and Antioxidant Activity of Ethanolic Extracts

The present study aimed to assess the phenolic content of eight ethanolic propolis samples (P1–P8) harvested from different regions of Western Romania and their antioxidant activity. The mean value of total phenolic content was 214 ± 48 mg gallic acid equivalents (GAE)/g propolis. All extracts contained kaempferol (514.02 ± 114.80 μg/mL), quercetin (124.64 ± 95.86 μg/mL), rosmarinic acid (58.03 ± 20.08 μg/mL), and resveratrol (48.59 ± 59.52 μg/mL) assessed by LC-MS. The antioxidant activity was evaluated using 2 methods: (i) DPPH (2,2-diphenyl-1-picrylhydrazyl) assay using ascorbic acid as standard antioxidant and (ii) FOX (Ferrous iron xylenol orange OXidation) assay using catalase as hydrogen peroxide (H₂O₂) scavenger. The DPPH radical scavenging activity was determined for all samples applied in 6 concentrations (10, 5, 3, 1.5, 0.5 and 0.3 mg/mL). IC₅₀ varied from 0.0700 to 0.9320 mg/mL (IC₅₀ of ascorbic acid = 0.0757 mg/mL). The % of H₂O₂ inhibition in FOX assay was assessed for P1, P2, P3, P4 and P8 applied in 2 concentrations (5 and 0.5 mg/mL). A significant H₂O₂% inhibition was obtained for these samples for the lowest concentration. We firstly report the presence of resveratrol as bioactive compound in Western Romanian propolis. The principal component analysis revealed clustering of the propolis samples according to the polyphenolic profile similarity.

Propolis relieves the cardiotoxicity of chlorpyrifos in diabetic rats via alleviations of paraoxonase-1 and xanthine oxidase genes expression

Pesticides cardiotoxicity in case of diabetic-induced cardiac complications is unidentified. The probable amelioration role of propolis is gauged against the cardiotoxic effects of chlorpyrifos in the diabetic rats through paraoxonase-1 (PON1) and xanthine oxidase (XO) genes dysregulation. Fifty-six male rats were distributed (n = 7) into eight groups. The first one saved as control whereas the 2nd, 3rd, and 4th were kept for propolis aqueous extract (100 mg/kg), diabetes (60 mg/kg streptozotocin) and chlorpyrifos (2.5 mg/kg), respectively. The 5th was diabetes/chlorpyrifos combination, while 6th, 7th, and 8th were intubated with propolis for four weeks after diabetic induction, chlorpyrifos intoxication, and their combination, respectively. The plasma glucose, lipid profiles, cardiac enzymes and interleukin-6 (IL-6) significantly elevated, while insulin decreased in the diabetic and combination groups. Although the cardiac acetylcholinesterase, total thiols, and PON1 significantly reduced after diabetic and/or chlorpyrifos gavage, the protein carbonyl, superoxide dismutase, catalase, and XO significantly elevated. The mRNA genes expression of PON1 and XO have also confirmed the enzymatic activities. Interestingly, propolis significantly restored the hyperglycemia, hypoinsulinemia, hyperlipidemia, IL-6 elevations, and antioxidant defense system disorder. These records revealed that the immunomodulatory, anti-diabetic and antioxidant tasks are fine pointers for the cardiovascular defender of propolis especially during diabetes and/or pesticides exposure.

Purification of Polyphenols from Distiller's Grains by Macroporous Resin and Analysis of the Polyphenolic Components

We aimed to purify polyphenols from distiller’s grain extract using macroporous resins and to identify its polyphenolic components. The influence of operational parameters on purification efficiency was investigated. The polyphenolic composition was analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and then quantified by UPLC-MS using authenticated standards. The results showed that the optimal purifying conditions were D101 resin with a dosage of 3 g, four hours adsorption, three hours desorption time, and 60% ethanol as the eluent, producing the highest purification rate of 51%. The purified distiller’s grain extract exhibited stronger antioxidant activity than the unpurified extracts, which was assessed using DPPH and ABTS methods (IC₅₀ DPPH = 34.03 and 16.21 μg/mL, respectively; IC₅₀ ABTS = 20.31 and 5.73 μg/mL, respectively). UPLC-MS results indicated that (−)-epicatechin is the major compound found in distiller’s grain extract which was quantified as 562.7 μg/g extract, followed by ferulic acid (518.2 μg/g), p-hydroxybenzoic acid (417.7 μg/g), caffeic acid (217.1 μg/g), syringic acid (158.0 μg/g) and quercetin (147.8 μg/g). Two compounds, vanillic acid (66.5 μg/g) and gallic acid (41.4 μg/g), were found in lower concentrations. The findings of this study suggest that purification of polyphenolic compounds from distiller’s grain by macroporous resins is feasible, providing a new and effective method for the secondary use of distiller’s grain resources.

A DFT-based study of the hydrogen-bonding interactions between myricetin and ethanol/water

Flavonoids are vital constituents of propolis that are responsible for its medicinal activity. Flavonoid extraction commonly employs ethanol and water as solvents. In the extraction reaction, hydrogen-bonding interactions play a crucial role. In this study, hydrogen-bonding interactions between myricetin-an abundant flavonoid in propolis-and ethanol or water were studied theoretically using density functional theory (DFT) methods. The molecular geometry and charge properties of the myricetin monomer were analyzed first. After careful optimization, nine stable myricetin-CH₃CH₂OH/H₂O complex geometries were obtained. Hydrogen bonds were confirmed to exist in these optimized structures. The most stable structures were found to be those with hydrogen bonds involving the hydrogen atoms of hydroxyl groups and the oxygen atom of the keto group of myricetin. The characteristics of the hydrogen-bonding interactions in the optimized structures were carefully analyzed. The hydrogen bonds in the optimized geometries were shown to be closed-shell-type interactions. H5' in ring B of myricetin presented the strongest interaction. The hydrogen bonds were found to be Coulombic interactions. Those between the hydrogen atoms of the hydroxyl groups in myricetin and the oxygen atoms in CH₃CH₂OH and H₂O were of moderate strength and had some covalent character, while the others were weak and were dominantly electrostatic in character.

Biotransformation of propolis phenols by L. plantarum as a strategy for reduction of allergens

Propolis is a natural product produced by honeybees. It has antioxidant effects as well as antimicrobial, antiseptic, antibacterial, anti-inflammatory and antimutagenic properties. Except these important healthy properties some cytotoxic effects causing allergies also have been reported. In this study have been evaluated changes of phenolic compounds including allergens molecules found in propolis. Before biotransformation, propolis samples were treated with different solvent (ethanol and polyethylene glycol) to facilitate solvation of solid samples. Biotransformation was done by three different strains of Lactobacillus plantarum (10, 8014, ATCC). Results demonstrated the importance of used solvent/treatment for extraction procedure and strains of L. plantrum. The lowest values of main allergens were determined as 321 ng/mL for BCAFE, 320 ng/mL for 1.1 DMAECAFE and 8.02 ng/mL for CAPE. The study is the first work deal with evaluation of bioconversion of propolis by different L. plantarum strains and their effects on phenolic profile.

Lip creams with propolis special extract GH 2002 0.5% versus aciclovir 5.0% for herpes labialis (vesicular stage) : Randomized, controlled double-blind study

A lip cream with special propolis extract GH 2002 at a concentration of 0.5% (199 patients) was tested against aciclovir 5% (198 patients) in the treatment of episodes of herpes labialis under double-blind conditions. Upon inclusion, all patients were in the vesicular phase. Application was five times daily of approximately 0.2 g of cream to the entire upper and lower lip. The primary parameter was the difference in time between groups to complete encrustation or epithelization of the lesions. Secondary endpoints were the course of typical herpes symptoms (pain, burning and itching, tension and swelling), the global assessment of efficacy and the safety of application. The predefined clinical situation was reached after a (median) 3 days with propolis and 4 days with aciclovir (p < 0.0001). Significant differences in favor of propolis were also found for all secondary parameters. No allergic reactions, local irritations or other adverse events occurred.

Production and characterisation of exopolysaccharide from Streptomyces carpaticus isolated from marine sediments in Egypt and its effect on breast and colon cell lines

Twenty streptomycete strains were isolated from marine sediment samples collected from Nabq area, Sharm El-Sheikh, Red Sea Coast, Egypt. Four of them produce exopolysaccharides (EPS) showing marked in vitro antitumor activities. Morphological and cultural characteristics of the most significant strain (No. 3) were shown. Moreover, the sequence of this strain showed similarity with Streptomyces carpaticus. The results reveal that EPS produced by Streptomyces carpaticus No. 3 had high cytotoxicity reaching 51.7% and 59.1% against human tumor cells of breast and colon lines respectively. A chemical analysis of EPS indicated that the composing monosaccharides were galactouronic acid, glucose, xylose, galactose, mannose, and fructose with relative ratio of 3:1:1:2:2:1 respectively, with an average molecular weight (Mw) 1.180 × 10⁵ g/mol and of a number average molecular weight (Mn) 1.052 × 10⁵ g/mol. Also the EPS contained uronic acid (0.5072%) and monosaccharide sulphates (21.753%).

Antioxidant Activity of Quercetin and Its Glucosides from Propolis: A Theoretical Study

Among the multiple components of propolis, flavonoids contribute greatly to the antioxidant activities of propolis. Flavonoids mainly exist in the form of sugar-conjugated derivatives. Quercetin glycosides represent the predominant flavonoid fraction in propolis. In this work, density functional theory (DFT) calculations were applied to analyze the antioxidative properties of quercetin and its glucosides in the gas and in the liquid phase (ethanol, water). Three main antioxidant mechanisms, hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) were used to analyze the antioxidative capacity of the investigated compounds. Solvent effects dominantly affect SET-PT and SPLET. Thus, the thermodynamically preferred mechanism can be altered. HAT and SPLET are the thermodynamically dominant mechanisms in gas and solvent phases, respectively. Therefore, in the gas phase, the sequence of the antioxidative capacity is similar with the bond dissociation enthalpy values: quercetin > quercetin-5-O-glucoside > quercetin-7-O-glucoside > quercetin-3-O-glucoside > quercetin-3'-O-glucoside > quercetin-4'-O-glucoside. While, in the solvent phases, the sequence is similar with the proton affinity values: quercetin-4'-O-glucoside > quercetin-5-O-glucoside > quercetin > quercetin-3-O-glucoside > quercetin-7-O-glucoside > quercetin-3'-O-glucoside. OH groups in B-ring and C-ring contribute mainly to the antioxidative activities of quercetin and glucosides compared with A-ring.

Antioxidant Properties and Cardioprotective Mechanism of Malaysian Propolis in Rats

Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

Effect of climate change on phytochemical diversity, total phenolic content and in vitro antioxidant activity of Aloe vera (L.) Burm.f

Background

The aim of the present study was to analyse the effect of climate change on phytochemicals, total phenolic content (TPC) and antioxidant potential of methanolic extracts of Aloe vera collected from different climatic zones of the India.

Methods

Crude methanolic extracts of A. vera from the different states of India were screened for presence of various phytochemicals, total phenolic content and in vitro antioxidant activity. Total phenolic content was tested by Folin–Ciocalteau reagent based assay whilst DPPH free radical scavenging assay, metal chelating assay, hydrogen peroxide scavenging assay, reducing power assay and β carotene-linoleic assay were used to assess the antioxidant potential of A. vera methanolic leaf extracts.

Results

Alkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all accessions. A significant positive correlation was found between TPC and antioxidant activity of different accessions. Extracts of highland and semi-arid zones possessed maximum antioxidant potential. Accessions from tropical zones showed the least antioxidant activity in all assays.

Conclusions

It could be concluded that different agro-climatic conditions have effects on the phytochemicals, total phenolic content (TPC) and antioxidant potential of the A. vera plant. The results reveal that A. vera can be a potential source of novel natural antioxidant compounds.

Hydrogen-bonding Interactions between Apigenin and Ethanol/Water: A Theoretical Study

In this work, hydrogen-bonding interactions between apigenin and water/ethanol were investigated from a theoretical perspective using quantum chemical calculations. Two conformations of apigenin molecule were considered in this work. The following results were found. (1) For apigenin monomer, the molecular structure is non-planar, and all of the hydrogen and oxygen atoms can be hydrogen-bonding sites. (2) Eight and seven optimized geometries are obtained for apigenin (I)–H₂O/CH₃CH₂OH and apigenin (II)–H₂O/CH₃CH₂OH complexes, respectively. In apigenin, excluding the aromatic hydrogen atoms in the phenyl substituent, all other hydrogen atoms and the oxygen atoms form hydrogen-bonds with H₂O and CH₃CH₂OH. (3) In apigenin–H₂O/CH₃CH₂OH complexes, the electron density and the E(2) in the related localized anti-bonding orbital are increased upon hydrogen-bond formation. These are the cause of the elongation and red-shift of the X−H bond. The sum of the charge change transfers from the hydrogen-bond acceptor to donor. The stronger interaction makes the charge change more intense than in the less stable structures. (4) Most of the hydrogen-bonds in the complexes are electrostatic in nature. However, the C4−O5···H, C9−O4···H and C13−O2···H hydrogen-bonds have some degree of covalent character. Furthermore, the hydroxyl groups of the apigenin molecule are the preferred hydrogen-bonding sites.

Antioxidant Activity of Flesh and Skin of Eptatretus Burgeri (Hag Fish) and Enedrias Nebulosus (White Spotted Eel)

Ethyl acetate and diethyl ether extracts, previously extracted with methanol, were obtained from flesh and skin of Eptatretus burgeri (hag fish) and Enedrias nebulosus (white spotted eel). Eight different extracts (4 mg/mL) were tested for DPPH free radical scavenging activity and the values were compared with commercial antioxidants (α-tocopherol and BHT). All extracts of E. burgeri exhibited significantly positive results (> 65%) in scavenging DPPH radicals compared to E. nebulosus. Thus, only E. burgeri extracts were tested for dose effect, hydrogen peroxide, hydroxyl radical, superoxide scavenging assays and heat stability at 25, 50, 75 and 100 °C for 30 min. All extracts of E. burgeri showed higher DPPH radical scavenging activities by increasing concentration. Significantly higher results were observed for hydroxyl radical scavenging activity when compared with commercial antioxidants. Relatively moderate activity and very low activity were exhibited for superoxide scavenging and hydrogen peroxide activities, respectively. Diethyl ether extracts of E. burgeri were stable with increased temperature, while ethyl acetate extracts were stable up to 75 °C. Thus, there is a high potential for E. burgeri being rich with heat-stable antioxidants that can scavenge hydroxyl radicals.

Antioxidant Potential of Ecklonia cavaon Reactive Oxygen Species Scavenging, Metal Chelating, Reducing Power and Lipid Peroxidation Inhibition

The antioxidative potential of different fractions (respective organic and aqueous fractions of n-hexane, chloroform and ethyl acetate) of 70% methanol extract of Ecklonia cava(a brown seaweed) was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide, hydroxyl radical, nitric oxide, ferrous ion chelating, reducing power and lipid peroxidation inhibition (conjugated diene hydroperoxide and thiobarbituric acid-reactive substances production) assays. The 70% methanol extract showed significant (p< 0.05) activities in all antioxidant assays and contained a high level of total phenolic content. It was observed that the level of hydrophilic phenolic content was higher than that of hydrophobics. Among those organic solvent fractions, ethyl acetate fraction exhibited significant activities due to the highest level of total phenolic content and their IC50 values were 0.013mg/mL, 0.009mg/mL and 0.33mg/mL in DPPH, hydrogen peroxide and nitric oxide radical inhibition, respectively. These activities were superior to those of a commercial synthetic and natural antioxidants tested. The aqueous chloroform and ethyl acetate fractions also exhibited significant (p< 0.05) activities in reactive oxygen species (ROS) scavenging and metal chelating, attributed to the high amount of hydrophilic phenolics. Moreover, E. cava extracts showed strong reducing power and a notable capacity to suppress lipid peroxidation.

Lipid Peroxidation Inhibitory Effects of Hizikia Fusiformis Methanolic Extract on Fish Oil and Linoleic Acid

The lipid peroxidation inhibitory effects of Hizikia fusiformis methanolic extract (HME) on fish oil and linoleic acid were studied by means of peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), conjugated diene hydroperoxides (CDH) and weight gaining assays. Heat and UV light stability were determined by DPPH assay. HME significantly (p<0.05) reduced the lipid peroxidation in a dosedependent manner. Increasing the level of HME from 0.01 to 0.1% caused a higher antioxidative effect than the one produced by butylated hydroxytoluene (BHT) (BHT reported the best effect compared to -tocopherol and butylated hydroxyanisole). HME reduced the formation of primary oxidation products as showed by the lower CDH values compared to its control counterpart. HME reduced also the addition of oxygen to form lipid peroxyl radicals that indicated a low weight gaining in HME-treated oils. Moreover, it could reduce the formation of lipid peroxide. Furthermore, it diminished the total lipid peroxidation resulting in low TBARS values. The heat and UV light study showed that H. fusiformis contained heat- and UV-light resistant antioxidants. These results indicated that the H. fusiformis antioxidants could be useful in preventing oxidative damages of food oils.

Antioxidant Activity of Hizikia fusiformis on Reactive Oxygen Species Scavenging and Lipid Peroxidation Inhibition

Water and organic extracts (diethyl ether, chloroform, ethyl acetate, acetone, ethanol and methanol) obtained from Hizikia fusiformis were screened on reactive oxygen species (ROS) scavenging assays (1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide and hydroxyl radical) and lipid peroxidation (inhibition of linoleic acid oxidation) inhibitory assays. Water, methanol and ethanol extracts showed significant ROS radical scavenging activities. Water extracts showed high scavenging activities on hydrogen peroxide (around 76%) and DPPH radicals (around 75%) while it presented a moderate scavenging activity on hydroxyl radicals (around 54%). Comparatively higher ROS scavenging activities were recorded in hydroxyl radical and DPPH scavenging assays. DPPH radical scavenging activities were well correlated with the polyphenolic content. ROS scavenging and lipid peroxidation inhibition activities indicated that H. fusiformis might be a valuable natural antioxidative source containing both water and fatsoluble antioxidative components.

Effects of sub-acute methanol extract treatment of Calliandra portoricensis root bark on antioxidant defence capacity in an experimental rat model

BACKGROUND

The attendant side effects associated with some synthetic drugs used in the management of diseases have led to the search for safer alternative therapies that are relatively cheaper with minimal side effects.

METHODS

The methanol extract of Calliandra portoricensis root bark (CPRB) was orally administered at the doses of 5, 10, 20, and 25 mg/kg body weight for 14 consecutive days of 5 rats in each group. The control rats were given distilled water.

RESULTS

The 95% methanol extract of CPRB significantly (p<0.05) scavenged NO• and OH• radicals compared to vitamin C. The level of lipid peroxidative products (malondialdehyde, MDA) was significantly (p<0.05) attenuated in a dose-dependent manner. Antioxidant enzymes including superoxide dismutase and catalase were significantly (p<0.05) exercabated in both liver and kidney in a dose-dependent manner. Furthermore, serum AST, alanine aminotransaminase and γ-glutamyltransferase (GGT) activity depicted non-significant (p>0.05) increase in the treated animals. The histological examination showed mild vacuolar, portal congestion and cell infiltration by mononuclear of the hepatic tissues.

CONCLUSIONS

The study then concluded that a therapeutic dose of the methanol extract of CPRB triggered the antioxidant defence systems in male rats. It is, therefore, recommended that the doses should be carefully and clinically chosen because higher doses may cause some health risks.

Antioxidant activity, acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum extracts

In this study several investigations and tests were performed to determine the antioxidant activity and the acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum aqueous extracts (10% mass) and ethanolic extracts (10% mass and 70% ethanol), respectively. Moreover, for each type of the prepared extracts of P. officinalis and of C. umbellatum the content in the biologically active compounds – polyphenols, flavones and proanthocyanidins was determined. The antioxidant activity was assessed using two methods, namely the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power assay. The analyzed plant extracts showed a high acetylcholinesterase and tyrosinase inhibitory activity in the range of 72.24–94.24% (at the highest used dose – 3 mg/mL), 66.96% and 94.03% (at 3 mg/mL), respectively correlated with a high DPPH radical inhibition – 70.29–84.9% (at 3 mg/mL). These medicinal plants could provide a potential natural source of bioactive compounds and could be beneficial to the human health, especially in the neurodegenerative disorders and as sources of natural antioxidants in food industry.

Chemical Composition and Biological Activity of Extracts Obtained by Supercritical Extraction and Ethanolic Extraction of Brown, Green and Red Propolis Derived from Different Geographic Regions in Brazil

The variations in the chemical composition, and consequently, on the biological activity of the propolis, are associated with its type and geographic origin. Considering this fact, this study evaluated propolis extracts obtained by supercritical extraction (SCO2) and ethanolic extraction (EtOH), in eight samples of different types of propolis (red, green and brown), collected from different regions in Brazil. The content of phenolic compounds, flavonoids, in vitro antioxidant activity (DPPH and ABTS), Artepillin C, p-coumaric acid and antimicrobial activity against two bacteria were determined for all extracts. For the EtOH extracts, the anti-proliferative activity regarding the cell lines of B16F10, were also evaluated. Amongst the samples evaluated, the red propolis from the Brazilian Northeast (states of Sergipe and Alagoas) showed the higher biological potential, as well as the larger content of antioxidant compounds. The best results were shown for the extracts obtained through the conventional extraction method (EtOH). However, the highest concentrations of Artepillin C and p-coumaric acid were identified in the extracts from SCO2, indicating a higher selectivity for the extraction of these compounds. It was verified that the composition and biological activity of the Brazilian propolis vary significantly, depending on the type of sample and geographical area of collection.

Effect of Carrot Intake in the Prevention of Gastric Cancer: A Meta-Analysis

Purpose

Gastric cancer is the third leading cause of cancer-related mortality, with the incidence and mortality being higher in men than in women. Various studies have shown that eating carrots may play a major role in the prevention of gastric cancer. We conducted a meta-analysis to determine the relationship between carrot consumption and gastric cancer.

Materials and Methods

We searched multiple databases including PubMed, Cochrane Library, Scopus, ScienceDirect, and Persian databases like Scientific Information Database (SID) and IranMedx. The following search terms were used: stomach or gastric, neoplasm or cancer, carcinoma or tumor, and carrot. Statistical analyses were performed using Comprehensive Meta Analysis/2.0 software.

Results

We retrieved 81 articles by searching the databases. After considering the inclusion and exclusion criteria, 5 articles were included in this study. The odds ratio (OR) obtained by fixed effects model showed that a 26% reduction in the risk of gastric cancer has been associated with the consumption of carrots) OR=0.74; 95% confidence interval=0.68~0.81; P<0.0001). According to funnel graph, the results showed that the possibility of a publication bias does not exist in this study.

Conclusions

The findings of this study showed an inverse relationship between the consumption of carrots and the risk of gastric cancer.

Alternative preparation of propolis extracts: comparison of their composition and biological activities

Background

Propolis is the bee product noted for multiple biological effects, and therefore it is widely used for the prevention and treatment of a variety of diseases. The active substances of propolis are easily soluble in ethanol. However ethanolic extracts cannot be used in treatment of certain diseases encountered in ophthalmology, pediatrics, etc. Unfortunately, the main biologically active substances of propolis are scarcely soluble in water, oil and other solvents usually used in pharmaceutical industry. The aim of this study was to investigate chemical composition, radical scavenging and antimicrobial activity of propolis extracts differently made in nonethanolic solvents.

Methods

Total content of phenolic compounds in extracts was determined using Folin-Ciocalteu method. Chemical composition and radical scavenging activity of extracts were determined using HPLC system with free radical reaction detector. Antimicrobial activity of examined preparations was evaluated using the agar-well diffusion assay.

Results

Total amount of phenolic compounds in extracts made in polyethylene glycol 400 (PEG) and water mixture or in PEG, olive oil and water mixture at 70 °C was comparable to that of ethanolic extract. Predominantly identified compounds were phenolic acids, which contribute ca. 40 % of total radical scavenging activity.

Investigated nonethanolic extracts inhibited the growth and reproduction of all tested microrganisms. Antimicrobial activity of some extracts was equal or exceeded the antimicrobial effect of ethanolic extract. Extracts made in pure water or oil only at room temperature, contained more than 5 – 10-fold lower amount of phenolic compounds, and demonstrated no antimicrobial activity.

Conclusions

Nonethanolic solvent complex and the effect of higher temperature allows more effective extraction of active compounds from propolis. Concentration of total phenolic compounds in these extracts does not differ significantly from the concentration found in ethanolic extract. Propolis nonethanolic extracts have radical scavenging and antimicrobial activity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0677-5) contains supplementary material, which is available to authorized users.

Brazilian red propolis attenuates hypertension and renal damage in 5/6 renal ablation model

The pathogenic role of inflammation and oxidative stress in chronic kidney disease (CKD) is well known. Anti-inflammatories and antioxidant drugs has demonstrated significant renoprotection in experimental nephropathies. Moreover, the inclusion of natural antioxidants derived from food and herbal extracts (such as polyphenols, curcumin and lycopene) as an adjuvant therapy for slowing CKD progression has been largely tested. Brazilian propolis is a honeybee product, whose anti-inflammatory, antimicrobial and antioxidant effects have been widely shown in models of sepsis, cancer, skin irritation and liver fibrosis. Furthermore, previous studies demonstrated that this compound promotes vasodilation and reduces hypertension. However, potential renoprotective effects of propolis in CKD have never been investigated. The aim of this study was to evaluate the effects of a subtype of Brazilian propolis, the Red Propolis (RP), in the 5/6 renal ablation model (Nx). Adult male Wistar rats underwent Nx and were divided into untreated (Nx) and RP-treated (Nx+RP) groups, after 30 days of surgery; when rats already exhibited marked hypertension and proteinuria. Animals were observed for 90 days from the surgery day, when Nx+RP group showed significant reduction of hypertension, proteinuria, serum creatinine retention, glomerulosclerosis, renal macrophage infiltration and oxidative stress, compared to age-matched untreated Nx rats, which worsened progressively over time. In conclusion, RP treatment attenuated hypertension and structural renal damage in Nx model. Reduction of renal inflammation and oxidative stress could be a plausible mechanism to explain this renoprotection.