|Opis:||Royal Jelly (RJ) is a secretion from the hypopharyngeal and mandibular glands of 6 to 15 days old bees (bee nurse), a type of Carniolan bee, Apis mellifera carnica. RJ is the exclusive food of the queen bee. It is a white to white - yellow viscous liquid that is usually non-homogeneous, since it contains insoluble granules of different sizes and shapes. Its smell is sour and pungent, while the taste is sour, pungent and slightly spicy. The composition of RJ is complex, while its general composition includes: 60 – 70 % water, 9 – 18 % protein, 7 – 18 % carbohydrates, 3 – 8 % fat, and 0.8 – 3 % of minerals, vitamins, phenolic compounds, and flavonoids in trace amounts. Knowledge of the chemical composition of RJ and proper storage is key for assessing its quality. RJ is a functional food, due to a number of positive properties: its antioxidant activity, as well its antibacterial, antiviral and antitumor activities. In RJ phenolic compounds can be found in the form of flavonoids, which are responsible for most of its functional properties, e.g. its antioxidant activity.
The skin is the largest human organ, which protects the body from fluid loss, penetration of micro-organisms, chemical, mechanical and osmotic damage. A wound is defined as the disruption of the cellular and anatomic continuity of a tissue and may occur due to physical, chemical, thermal, or microbial tissue trauma.
The purpose of this study was to evaluate the RJ produced in the Beekeeping Mlinarič – Plohl, from Grabe, in the municipality Središče ob Dravi, in terms of its chemical composition (the content of sugar, fatty acids, the content of total polyphenols and flavonoids), its pH value and solubility in different solvents, as well as to examine its impact on the growth of the human skin derived fibroblasts. Based on the combination of all the mentioned tests, an preliminary determination of the RJ potential for topical application was planned. In the case of positive results, RJ could be applied in the form of medical patches for wound treatment, or in the future as a possible additive in the pharmacotherapy of skin cancer.
The fresh RJ sample used in this study was collected on 30. May 2016 in the village Grabe – Obrež, and stored in a glass jar which was stored in a Styrofoam packaging in a fridge, at a temperature of 4°C. The cultivation and growth of cells, the preparation of RJ solutions in ultra-pure water, in phosphate buffer (PBS), ethanol and methanol, and the application of RJ on the skin fibroblasts, were performed at the Faculty of Medicine, University of Maribor. The obtained results were statistically analysed and presented in the form of tables and graphs. We found that RJ from the Beekeeping Mlinarič – Plohl had a pH value of 3.97, which is comparable with the standard chemical composition of RJ. With the analysis of the RJ sample using GC – MS, we have detected different sugars and fatty. The total polyphenol and flavonoid contents of the fresh RJ were determined twice. The total polyphenol content was found to be 3.12 mg/g and 4.22 mg/g, respectively. The flavonoid content was 0.68 mg/g and 1.88 mg/g, respectively.
We have found that ultra-pure water and ethanol were the best solvents for RJ, while tetrahydrofuran did not dissolve RJ at all. Based on the results obtained using the MTT assay on skin derived fibroblasts, which showed a lower viability compared to the control sample, alcoholic solutions (ethanol and methanol) of the fresh RJ were shown not suitable for direct application onto the skin to promote wound healing. The lower viability could on the other hand point to their alternative use, namely as disinfectant solutions. Water solutions and solutions in the phosphate buffered saline (PBS) have proven to be suitable for application to the skin fibroblast cells, and are interesting for further evaluation of possible pharmacological activities (for example anti-tumor activity) either on the same or other cell types.|