Highlights on bee pollen

In apitherapy, bee pollen of known botanical origin, chemically well-defined and contaminant-free should be recommended as a food supplement for the prevention and/or treatment of diseases. Pollen grains placed in the anthers of flowering plants are male gametophytes. They play a crucial role in pollination, which is a key process for the next generations. For pollination, most plants need pollen grains to be transported to the stigma by various ways such as wind, and one of the most important of these carriers is honeybees (Abrol, 2012). Honeybees are electrically charged by friction of air. As the honeybees fly around the flower to collect nectar, they attract thousands of pollen grains due to the weak electrostatic field formed between the negatively charged flower and the positively charged bee body. To combine pollen grains on their body honeybees first comb pollen grains by their stiff hair-like structures and then process these grains into pellets by using their secretions, flower nectar, and honey (Denisow & Denisow-Pietrzyk, 2016). These pellets, which acquire characteristic properties different from flower pollen carried by wind, are called bee pollen. Honeybees carry bee pollen to their hives by using pollen baskets found in their hind legs (Figure 1). During the process of bee pollen, it acquires some different properties and differs from flower pollen grains blown by the wind. Therefore, when pollen allergy is mentioned, it should not be directly associated with the bee pollen. Some situations such as sneezing, runny nose, and difficulty in breathing that most people suffer from, especially in the spring when pollination is intense, are caused by flower pollen grains entering the respiratory system (Yeşilada, 2015). However, in some circumstances, bee pollen may also cause allergies due to some compounds it contains which are linked with its floral sources. For this reason, an allergy test may be useful as a precaution. The formation of bee pollen from flower pollen grains. Bee pollen is carried to the beehive via pollen basket which is part of the tibia on the hind legs. According to the botanical sources of bee pollen, it can be grouped as "monofloral bee pollen" and "multifloral bee pollen." Monofloral bee pollen is mainly composed of pollen grains from one plant species and has uniform organoleptic and biochemical properties. On the other hand, multifloral bee pollen is composed of different plant species and thus shows variable properties (Alimoglu et al., 2021). In ancient years, bee pollen was described as "Life-giving dust." Recent studies have shown that the composition of bee pollen in terms of proteins, carbohydrates, and fats meets the main requirements of dietetic recommendations (Villanueva et al., 2002). Additionally, it contains main essential vitamins, minerals, and bond-form or free amino acids, mainly proline (Thakur & Nanda, 2020). Based on these data, the question may arise whether a person may live a healthy life by eating only bee pollen. Apart from macronutrients and micronutrients, bee pollen contains a wide range of chemical compounds related with its floral sources. For instance, N1, N5, N10-tricaffeoylspermidine is one of the main compounds of bee pollen originated from Castanea sativa (sweet chestnut) whereas marker compounds of Hedera helix (ivy) sourced bee pollen are afzelin, platanoside, and quercetin-3-O-β-glucopyranosyl-(1→2)-β-galactopyranoside (Glavnik et al., 2024; Sen et al., 2023). These chemical variations in bee pollen composition are directly related to the plant source around the beehive and may affect bee pollen pharmacological activity (antioxidant, anti-inflammatory, hepatoprotective activities etc.). Thus, especially monofloral bee pollen having uniform characteristic properties is getting importance in usage of prevention and treatment of some diseases. Briefly, to get reproducible biological activity, chemical composition of a bee pollen should be well defined, and standardization should be done accordingly. Apart from health beneficial chemical composition, bee pollen originated from Senecio spp., Echium spp. or Eupatorium spp. may possess pyrrolizidine alkaloids which may cause hepatic veno-occlusive disease (Friedle et al., 2022). Thus, identification of botanical source of bee pollen is crucial both for evaluating bee pollen health benefits and risks. The commonly applied method to identify the botanical origin of bee pollen is palynological analysis (microscopic analysis) which investigates pollen color, size, and structure. Although it is a widely used technique, it has some limitations since it needs to be performed by experts in pollen morphology, the characteristics of various pollen grains should be comprehensively known, and some pollen grains are difficult to distinguish. For this reason, plant family or genus other than species can be determined by using a microscope. Therefore, to identify the botanical origin of bee pollen there is a need for other techniques such as high-performance thin-layer chromatography which enables simultaneous analysis of chemical composition of flower pollen and bee pollen (Sen et al., 2023). Additionally, DNA metabarcoding technique has also been used to identify plant resources in bee pollen (Ilahi, 2021). However, there are limited studies in these fields. Although bee pollen consumption is beneficial and safe to use, it should be also considered that bee pollen should be free from contaminants such as microbial toxins, heavy metals, and pesticides (Tutun et al., 2022). In apitherapy, chemically well-defined and contaminant-free bee pollen should be recommended as a dietary supplement for the prevention and/or treatment of diseases. Etil Guzelmeric: Conceptualization; data curation; investigation; writing – original draft; writing - review & editing. The author declares no conflict of interest. Not applicable. The data that support the findings of this study are available from the corresponding author upon reasonable request.