Essential oil of Indian propolis: chemical composition and repellency against the honeybee Apis florea

Exploring the Chemical Constituents and Nutritive Potential of Bee Drone (Apilarnil): Emphasis on Antioxidant Properties

A lesser-known bee product called drone brood homogenate (DBH, apilarnil) has recently attracted scientific interest for its chemical and biological properties. It contains pharmacologically active compounds that may have neuroprotective, antioxidant, fertility-enhancing, and antiviral effects. Unlike other bee products, the chemical composition of bee drone larva is poorly studied. This study analyzed the chemical compostion of apilarnil using several methods. These included liquid chromatography-mass spectrometry (LC-MS/MS) and a combination of gas chromatography/mass spectrometry with solid phase micro-extraction (SPME/GC-MS). Additionally, antioxidant activity of the apilarnil was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. A chemical assessment of apilarnil showed that it has 6.3±0.00, 74.67±0.10 %, 3.65±0.32 %, 8.80±1.01 %, 13.16±0.94 %, and 8.79±0.49 % of pH, moisture, total lipids, proteins, flavonoids, and carbohydrates, respectively. LC-MS/MS analysis and molecular networking (GNPS) of apilarnil exhibited 44 compounds, including fatty acids, flavonoids, glycerophospholipids, alcohols, sugars, amino acids, and steroids. GC-MS detected 30 volatile compounds in apilarnil, mainly esters (24 %), ketones (23.84 %), ethers (15.05 %), alcohols (11.41 %), fatty acids (10.06), aldehydes (6.73 %), amines (5.46), and alkene (5.53 %). The antioxidant activity of apilarnil was measured using DPPH with an IC50 of 179.93±2.46 μg/ml.

Developing a computational toolbased on an artificial neural network for predicting and optimizing propolis oil, an important natural product for drug discovery

Propolis is a promising natural product that has been extensively researched and studied for its potential health and medical benefits. The lack of requisite high oil-containing propolis and existing variation in the quality and quantity of essential oil within agro-climatic regions pose a problem in the commercialization of essential oil. As a result, the current study was carried out to optimize and estimate the essential oil yield of propolis. The essential oil data of 62 propolis samples from ten agro-climatic areas of Odisha, as well as an investigation of their soil and environmental parameters, were used to construct an artificial neural network (ANN) based prediction model. The influential predictors were determined using Garson's algorithm. To understand how the variables interact and to determine the optimum value of each variable for the greatest response, the response surface curves were plotted. The results revealed that the most suited model was multilayer-feed-forward neural networks with an R2 value of 0.93. According to the model, altitude was found to have a very strong influence on response, followed by phosphorous & maximum average temperature. This research shows that using an ANN-based prediction model with a response surface methodology technique to estimate oil yield at a new site and maximize propolis oil yield at a specific site by adjusting variable parameters is a viable commercial option. To our knowledge, this is the first report on the development of a model to optimize and estimate the essential oil yield of propolis.

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

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

Propolis: chemical diversity and challenges in quality control

Propolis is a resinous natural product produced by honeybees using beeswax and plant exudates. The chemical composition of propolis is highly complex, and varies with region and season. This inherent chemical variability presents several challenges to its standardisation and quality control. The present review was aimed at highlighting marker compounds for different types of propolis, produced by the species Apis mellifera, from different geographical origins and that display different biological activities, and to discuss strategies for quality control. Over 800 compounds have been reported in the different propolises such as temperate, tropical, birch, Mediterranean, and Pacific propolis; these mainly include alcohols, acids and their esters, benzofuranes, benzopyranes, chalcones, flavonoids and their esters, glycosides (flavonoid and diterpene), glycerol and its esters, lignans, phenylpropanoids, steroids, terpenes and terpenoids. Among these, flavonoids (> 140), terpenes and terpenoids (> 160) were major components. A broad range of biological activities, such as anti-oxidant, antimicrobial, anti-inflammatory, immunomodulatory, and anticancer activities, have been ascribed to propolis constituents, as well as the potential of these compounds to be biomarkers. Several analytical techniques, including non-separation and separation methods have been described in the literature for the quality control assessment of propolis. Mass spectrometry coupled with separation methods, followed by chemometric analysis of the data, was found to be a valuable tool for the profiling and classification of propolis samples, including (bio)marker identification. Due to the rampant chemotypic variability, a multiple-marker assessment strategy considering geographical and biological activity marker(s) with chemometric analysis may be a promising approach for propolis quality assessment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-022-09816-1.

Mediterranean Propolis from the Adriatic Sea Islands as a Source of Natural Antioxidants: Comprehensive Chemical Biodiversity Determined by GC-MS, FTIR-ATR, UHPLC-DAD-QqTOF-MS, DPPH and FRAP Assay

There is no systematic report about propolis chemical biodiversity from the Adriatic Sea islands affecting its antioxidant capacity. Therefore, the samples from the islands Krk, Rab, Pag, Biševo and Korčula were collected. Comprehensive methods were used to unlock their chemical biodiversity: headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) followed by gas chromatography and mass spectrometry (GC-MS); Fourier transform mid-infrared spectroscopy (FT-MIR); ultra high performance liquid chromatography with diode array detector and quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QqTOF-MS) and DPPH and FRAP assay. The volatiles variability enabled differentiation of the samples in 2 groups of Mediterranean propolis: non-poplar type (dominated by α-pinene) and polar type (characterized by cadinane type sesquiterpenes). Spectral variations (FT-MIR) associated with phenolics and other balsam-related components were significant among the samples. The UHPLC profiles allowed to track compounds related to the different botanical sources such as poplar (pinobanksin esters, esters and glycerides of phenolic acids, including prenyl derivatives), coniferous trees (labdane, abietane diterpenes) and Cistus spp. (clerodane and labdane diterpenes, methylated myricetin derivatives). The antioxidant potential determined by DPPH ranged 2.6-81.6 mg GAE/g and in FRAP assay 0.1-0.8 mmol Fe2+/g. The highest activity was observed for the samples of Populus spp. origin. The antioxidant potential and phenolic/flavonoid content was positively, significantly correlated.

Standardization, anti-carcinogenic potential and biosafety of Indian propolis

Background

Propolis from apiculture is known for wide range of medicinal properties owing to its vast chemical constituents including polyphenols, flavonoids and anticancer agent Caffeic acid phenethyl ester (CAPE).

Objectives

The objective of the study was to extract and standardize Indian propolis (IP) with respect to selected markers by newly developed High performance liquid chromatography (HPLC) method, to evaluate in vitro and in vivo anticancer activity and biosafety of Indian propolis.

Materials and methods

IP was extracted, optimized and standardized using a newly developed and validated HPLC method for simultaneous estimation of caffeic acid, apigenin, quercetin and CAPE. The standardised ethanolic extract of IP (EEIP) was screened for in vitro cytotoxicity using sulforhodamine B (SRB) assay, in vivo anti-carcinogenic effect against Dalton’s Lymphoma ascites (DLA) cells, hemolytic effect and pesticide analysis.

Results

The EEIP was found to contain more amount of total flavonoids (23.61 ± 0.0452 mg equivalent of quercetin/g), total polyphenolics (34.82 ± 0.0785 mg equivalent of gallic acid/g) and all selected markers except caffeic acid compared to all other extracts. EEIP showed better anti-cancer potential than CAPE on MCF-7 and HT-29 cell line and significant (p < 0.01) in vivo anti-carcinogenic effects against DLA in comparison with 5-fluorouracil. EEIP was found to be non-hemolytic.

Conclusion

From in vitro cytotoxicity, in vivo anti-carcinogenicity and biosafety studies it can be concluded that the standardized EEIP is safe and can be considered for further development as a biomedicine.

Revisiting Greek Propolis: Chromatographic Analysis and Antioxidant Activity Study

Propolis is a bee product that has been extensively used in alternative medicine and recently has gained interest on a global scale as an essential ingredient of healthy foods and cosmetics. Propolis is also considered to improve human health and to prevent diseases such as inflammation, heart disease, diabetes and even cancer. However, the claimed effects are anticipated to be correlated to its chemical composition. Since propolis is a natural product, its composition is consequently expected to be variable depending on the local flora alignment. In this work, we present the development of a novel HPLC-PDA-ESI/MS targeted method, used to identify and quantify 59 phenolic compounds in Greek propolis hydroalcoholic extracts. Amongst them, nine phenolic compounds are herein reported for the first time in Greek propolis. Alongside GC-MS complementary analysis was employed, unveiling eight additional newly reported compounds. The antioxidant activity study of the propolis samples verified the potential of these extracts to effectively scavenge radicals, with the extract of Imathia region exhibiting comparable antioxidant activity to that of quercetin.

Drug leads agents from methanol extract of Nigerian bee (Apis mellifera) propolis

BACKGROUND

Propolis is a bee (Apis mellifera) product of plant origin with varied chemical composition depending on the ecology of the botanical origin. It has been reported in literature to possess various therapeutic effects both traditionally, clinical trial, and animal study.

OBJECTIVES

In the present study bioactive principle in methanol extract of Nigerian bee (A. mellifera) propolis was determined by gas chromatography-mass spectrometry (GC/MS) study.

MATERIALS AND METHODS

The methanol extract of Nigerian bee (A. mellifera) propolis was characterized for its chemical composition by preliminary phytochemicals screening and GC/MS analysis using standard procedures and methods.

RESULTS

Phytochemical screening revealed the presence of flavonoids, saponins, alkaloids, tannins, cardiac glycosides, anthraquinones phlobatannins, and steroids while GC/MS chromatogram revealed nineteen peaks representing 60 different chemical compounds. The first compounds identified with less retention time (RT) (13.33s) were methyl tetradecanoate, tridecanoic acid, methyl ester, decanoic acid, methyl ester while squalene, all-trans-squalene, 2,6,10-dodecatrien-1-ol, 3,7,11-trimethyl-, (E,E)- and farnesol isomer a took longest RT (23.647s) to identify. Methyl 14-methylpentadecanoate, hexadecanoic acid methyl ester, methyl isoheptadecanoate, and methyl tridecanoate were the most concentrated constituent as revealed by there peak height (26.01%) while eicosanoic acid was the least concentrated (peak height 0.81%) constituent of Nigerian bee propolis.

CONCLUSION

The presence of these chemical principles is an indication that methanol extract of Nigeria bee propolis, if properly screened could yield a drug of pharmaceutical importance.

Propolis volatile compounds: chemical diversity and biological activity: a review

Propolis is a sticky material collected by bees from plants, and used in the hive as building material and defensive substance. It has been popular as a remedy in Europe since ancient times. Nowadays, propolis use in over-the-counter preparations, “bio”-cosmetics and functional foods, etc., increases. Volatile compounds are found in low concentrations in propolis, but their aroma and significant biological activity make them important for propolis characterisation. Propolis is a plant-derived product: its chemical composition depends on the local flora at the site of collection, thus it offers a significant chemical diversity. The role of propolis volatiles in identification of its plant origin is discussed. The available data about chemical composition of propolis volatiles from different geographic regions are reviewed, demonstrating significant chemical variability. The contribution of volatiles and their constituents to the biological activities of propolis is considered. Future perspectives in research on propolis volatiles are outlined, especially in studying activities other than antimicrobial.