Comparison of Ethanolic and Aqueous-Polyethylenglycolic Propolis Extracts: Chemical Composition and Antioxidant Properties.

In recent years, particular attention has been paid to the natural antioxidants. Bee products, especially propolis, are characterized by multifunctional (antioxidant, anti-inflammatory, antibacterial, antiviral, and food preservative) effects and can be used for the development of functional food or food preservatives. Propolis extracts that are commonly produced are ethanolic; therefore, to certain groups of consumers, for example, children and alcohol sensitive group, their applicability is limited. The aim of this study was to develop alternative propolis from aqueous-polyethylenglycolic propolis extract (AQUA-PEG) and compare the chemical composition as well as antioxidant (radical-scavenging and reduction properties) activities to those of ethanolic propolis extract (EEP). Polyethylene glycol is quite a good solvent, which can be successfully used for the preparation of NEP. The total quantity of phenolic compounds identified in AQUA-PEG (400.36 µg/mL), prepared according to our technology, is very similar to that of EEP (433.53 µg/mL), whereas the amount of phenolic acids was greater by 1.31-fold in AQUA-PEG and of flavonoids was greater by 2.38-fold in EEP. The antioxidant activity depends on the method used: by applying the ABTS and CUPRAC methods, both extracts demonstrate similar antioxidant (antiradical and reducing) activity, whereas in the case of the DPPH and FRAP method, significantly higher antioxidant activity was detected in EEP. This should be taken by researchers into account especially when interpreting the results and drawing conclusions about the antioxidant activity of propolis extracts. On the basis of the results, AQUA-PEG, prepared by the developed technology, can be used as an alternative form to ethanolic propolis extract, since it contains a large quantity of antioxidants, namely, flavonoids and phenolic acids. We believe that nonethanolic propolis extract has the prospect of being applied for the development of functional foods in order to alleviate certain symptoms of oxidative stress or for the prevention of some oxidative-stress-related diseases.

In vitro antiviral activity of fifteen plant extracts against avian infectious bronchitis virus.

BACKGROUND: Avian infectious bronchitis (IB) is a disease that can result in huge economic losses in the poultry industry. The high level of mutations of the IB virus (IBV) leads to the emergence of new serotypes and genotypes, and limits the efficacy of routine prevention. Medicinal plants, or substances derived from them, are being tested as options in the prevention of infectious diseases such as IB in many countries. The objective of this study was to investigate extracts of 15 selected medicinal plants for anti-IBV activity. RESULTS: Extracts of S. montana, O. vulgare, M. piperita, M. officinalis, T. vulgaris, H. officinalis, S. officinalis and D. canadense showed anti-IBV activity prior to and during infection, while S. montana showed activity prior to and after infection. M. piperita, O. vulgare and T. vulgaris extracts had > 60 SI. In further studies no virus plaques (plaque reduction rate 100%) or cytopathogenic effect (decrease of TCID50 from 2.0 to 5.0 log10) were detected after IBV treatment with extracts of M. piperita, D. canadense and T. vulgaris at concentrations of extracts ≥0.25 cytotoxic concentration (CC50) (P < 0.05). Both PFU number and TCID50 increased after the use of M. piperita, D. canadense, T. vulgaris and M. officinalis extracts, the concentrations of which were 0.125 CC50 and 0.25 CC50 (P < 0.05). Real-time PCR detected IBV RNA after treatment with all plant extracts using concentrations of 1:2 CC50, 1:4 CC50 and 1:8 CC50. Delta cycle threshold (Ct) values decreased significantly comparing Ct values of 1:2 CC50 and 1:8 CC50 dilutions (P < 0.05). CONCLUSIONS: Many extracts of plants acted against IBV prior to and during infection, but the most effective were those of M. piperita, T. vulgaris and D. canadense .

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.

Evaluation of Beeswax Influence on Physical Properties of Lipstick Using Instrumental and Sensory Methods.

The aim of this study was to optimize the lipsticks formulation according to the physical properties and sensory attributes and investigate the relationship between instrumental and sensory analyses and evaluate the influence of the main ingredients, beeswax and oil, with analysis of lipsticks properties. Central composite design was used to optimize the mixture of oils and beeswax and cocoa butter for formulation of lipsticks. Antioxidant activity was evaluated by DPPH free radical scavenging method spectrophotometrically. Physical properties of lipsticks melting point were determined in a glass tube; the hardness was investigated with texture analyzer. Sensory analysis was performed with untrained volunteers. The optimized mixture of sea buckthorn oil and grapeseed oil mixture ratio 13.96 : 6.18 showed the highest antioxidative activity (70 ± 0.84%) and was chosen for lipstick formulation. According to the sensory and instrumental analysis results, optimal ingredients amounts for the lipstick were calculated: 57.67% mixture of oils, 19.58% beeswax, and 22.75% cocoa butter. Experimentally designed and optimized lipstick formulation had good physical properties and high scored sensory evaluation. Correlation analysis showed a significant relationship between sensory and instrumental evaluations.

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.