Investigation of Volatile Compounds in Combination with Multivariate Analysis for the Characterization of Monofloral Honeys

Lately there has been a growing demand for monofloral honeys with distinctive properties. Considering the limitations of pollen analysis, the volatile profile of honey has been proposed as a helpful supplementary tool for the confirmation of monoflorality; however, research remains regarding the volatile markers that may characterize the monofloral honey types. Therefore, in this study, we tried to expand the research by investigating the aroma profiles of five monofloral honey types (fir, pine, erica, thyme, cotton) and discriminate them through chemometric approach. A purge and trap–gas chromatograph–mass spectrometer system was used for the extraction, separation, and identification of volatile and semi-volatile compounds. Thyme honey had the richest quantitatively aroma profile, with 97 volatile compounds, whereas fir and cotton honeys had 65 and 60 volatile compounds, respectively. From a total of 124 compounds, the 38 were detected in all the studied honey types. Thyme honey was distinguished by the presence (or percentage participation) of benzeneacetaldehyde, benzealdehyde, and benzyl nitrile; erica honey of isophorone and furfural; cotton honey of 1-butanol, 2-methyl, 1-pentanol, and 4-methyl-; and honeydew honeys of α-pinene, octane, and nonanal. The discriminant analysis confirmed that the percentage participation of volatile compounds may lead to the discrimination of the studied monofloral honey types.

Sensory Profile of Greek Islands Thyme Honey

The sensory profiles of thyme honey from the Greek islands with different thymus pollen grain contents (A: >60%, B: 40–60%, and C: 18–40%) were studied. The results of the physico-chemical analyses fulfilled the criteria set by international quality standards and, specifically, Greek legislation (moisture content < 18%, hydroxymethylfurfural < 10 mg/kg, and diastase activity > 20 DN). The sensory results showed that there were significant differences between groups with different pollen grain contents (p < 0.01) for all attributes except for floral aroma, with the Group A samples being the lightest in color (4.9 ± 1.8) and having the highest floral odor intensity (5.0 ± 2.0) and salty taste (3.5 ± 1.1). Additionally, samples with the highest pollen grain content (i.e., Group A) had olfactory notes of wood/wax/resin and a chemical aroma.

The Synergistic Beneficial Effect of Thyme Honey and Olive Oil against Diabetes and Its Complications Induced by Alloxan in Wistar Rats

Diabetes is a metabolic disorder characterized by a chronic increase in blood glucose. Owing to the limitations observed with antidiabetics in modern medicine, medicinal plants and bee products are known as good matrices for the search for new antidiabetic molecules. The present study focused on the evaluation of the hypoglycemic and the protective properties of two natural products widely used in complementary and alternative medicine (thyme honey and olive oil). To achieve this, the study was carried out on Wistar rats rendered diabetic by the injection of a single dose of alloxan monohydrate (65 mg/kg body weight (BW)). First, the physicochemical characterization and the phytochemical analysis of thyme honey and olive oil were carried out, and then in vivo study was conducted on 42 Wistar rats divided into seven groups: three groups were normal, one group was untreated diabetic, and three groups were diabetic rats treated with thyme honey (2 g/kg BW) or olive oil (10 mL/kg BW) or their combination ((1 g/kg BW of thyme honey) and (5 mL/kg BW of olive oil)). During the experiment, the glycemia was measured regularly every 10 days. After 30 days of treatment, the rats were sacrificed. The serum and urine were analyzed to determine hepatic enzymes levels (AST, ALT, ALP, and LDH), lipidic profile (total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein), and kidney parameters (urea, uric acid, creatinine, total protein, sodium, potassium, and chloride). The liver, pancreas, and kidneys were analyzed to evaluate their histological changes and to determine their enzymatic antioxidant content (catalase, GSH, and GPx) and the levels of MDA. The results obtained showed that thyme honey or olive oil, and especially their combination, improved significantly the blood glucose levels and they protect against metabolic changes and the complications induced by diabetes.

Response Surface Methodology to Optimize the Isolation of Dominant Volatile Compounds from Monofloral Greek Thyme Honey Using SPME-GC-MS

This study aimed at an experimental design of response surface methodology (RSM) in the optimization of the dominant volatile fraction of Greek thyme honey using solid-phase microextraction (SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). For this purpose, a multiple response optimization was employed using desirability functions, which demand a search for optimal conditions for a set of responses simultaneously. A test set of eighty thyme honey samples were analyzed under the optimum conditions for validation of the proposed model. The optimized combination of isolation conditions was the temperature (60 °C), equilibration time (15 min), extraction time (30 min), magnetic stirrer speed (700 rpm), sample volume (6 mL), water: honey ratio (1:3 v/w) with total desirability over 0.50. It was found that the magnetic stirrer speed, which has not been evaluated before, had a positive effect, especially in combination with other factors. The above-developed methodology proved to be effective in the optimization of isolation of specific volatile compounds from a difficult matrix, like honey. This study could be a good basis for the development of novel RSM for other monofloral honey samples.

Protective Effect of Thyme Honey against Valproic Acid Hepatotoxicity in Wistar Rats

Introduction. Valproic acid is a medication most commonly used in the treatment of emotional and neurological depression, psychological imbalances, epilepsy, and bipolar disorder. Dark honey, like thyme honey, contains more antioxidant compounds than other samples. The purpose of this study was to evaluate the effect of thyme honey on the potential hepatic effects of valproic acid. Methods. In this study, 48 male rats were randomly divided into 8 groups ( n = 6 ): G1 (control): healthy rats (normal saline 0.9%), G2: thyme honey (1 g/kg), G3: thyme honey (2 g/kg dose), G4: thyme honey (3 g/kg dose), G5: VPA (500 mg/kg), G6: VPA (500 mg/kg) and thyme honey (1 g/kg), G7: VPA (500 mg/kg) and thyme honey (2 g/kg dose), and G8: VPA (500 mg/kg) and thyme honey (3 g/kg dose). Groups G1 to G5 received the drug for 28 days. On day 14, administration of thyme honey for G6 to G8 groups was carried out using gavage until day 28. VPA was administered one hour after honey. To carry out the biochemical evaluation, blood samples were collected from all the groups and their serums were used for MDA, TAC, and liver enzymes (AST, ALT, and GGT). Tissue samples of each rat were also removed for histological studies with hematoxylin-eosin and Masson’s trichrome staining. Results. The use of thyme honey significantly improved the histopathological parameters of the liver tissue, including hypertrophic degeneration and nucleus alteration, expansion of sinusoids, fibrosis and hepatic necrosis, and inflammation as well as hypertrophy of Kupffer cells. In the groups receiving VPA, the rate of lipid peroxidation increased, which indicates the destruction of the liver cell membrane due to drug consumption. TAC levels also increased following increase in thyme honey dosage ( p ≤ 0.05 ). The results of liver enzyme analysis showed a decrease in AST and ALT levels in the G6 group and a decrease in GGT level in the G8 group ( p ≤ 0.05 ). Conclusion. Based on the results of this study, it seems that high percentage of antioxidants in thyme honey enabled it to improve hepatic complications and reduce the rate of hepatocellular destruction.

Alternative therapies for chronic rhinosinusitis: A review

The use of alternative medicine in chronic rhinosinus-itis (CRS) continues to increase in popularity, for the most part without meeting the burden of being based on sound clinical evidence. New and emerging treat-ments, both natural and developed, are numerous, and it remains a challenge for otolaryngologists as well as general practitioners to keep up to date with these therapies and their efficacy. In this systematic review, we discuss a number of alternative therapies for CRS, their proposed physiologic mechanisms, and evidence supporting their use. This analysis is based on our re-view of the English-language literature on alternative therapies for CRS (we did not include any therapies that are already recommended by accepted profession-al bodies). Data collection was performed using the PubMed database (not restricted to MEDLINE due to the nature of the subject matter), the Cochrane data-bases, and bibliography searches. We found that while many of the alternative therapies we reviewed might have a firm basis in science, they lack any clinical ev-idence to support their use specifically for CRS. Some emerging therapies, such as therapeutic ultrasonog-raphy and phonophoresis, show some promise, based on a growing body of positive evidence. In addition, the use of baby shampoo, thyme honey, and bromelain additives to saline lavage in CRS are all supported by clinical evidence, as is Sinupret, an oral preparation that contains echinacea. However, higher levels of ev-idence gleaned from large, well-designed, prospective, randomized, controlled trials are needed before any of these therapies can be recommended.

The effect of thyme honey on anemia in hemodialysis patients

Background & Aim: Anemia is one of the most common complications of chronic renal failure, which is associated with increased fatigue, dyspnea, depression, malaise, prolonged hospitalization and mortality. Some patients are resistant to erythropoietin therapy. Therefore, the purpose of this study was to determine the effect of thyme honey on anemia in hemodialysis patients. Methods & Materials: The present clinical trial was conducted in 2018 at Kowsar Hospital of Semnan on hemodialysis patients randomly selected with convenience sampling method within two groups of case (n=28) and control (n=27). The case group received thyme honey (33 g) daily for one month. The control group did not consume thyme honey. Blood samples were taken from the patients before and after the intervention with 10-hour fasting and then blood parameters were assessed. Results: The mean ±SD reduction rate in hemoglobin level was 0.46±0.96 in the case group and 0.23±3.15 g/dl in the control group, but no significant difference using independent t-test (P=0.758). The mean±SD reduction rate in hematocrit percentages was 1.20±2.78 in the case group and 0.11±8.53 in the control group, but there is no significant difference between the two groups using independent t-test (P=0.590). Conclusion: Results showed that daily administration of 33 grams of thyme honey had no effect on anemia in hemodialysis patients. Further studies are recommended with modification of the methodology regarding the type, dose, duration and instructions of honey consumption for better results.