# Brood-Derived Fat Extracts from Apis mellifera as Sustainable Alternatives to Beeswax in Topical Nanostructured Lipid Carriers

## TL;DR

This study shows that fat from honeybee brood can be a sustainable and effective alternative to beeswax in making anti-inflammatory skin care products.

## Contribution

The study introduces honeybee brood fat as a novel, sustainable lipid source for topical nano-formulations with enhanced anti-inflammatory properties.

## Key findings

- Ethyl acetate extraction of brood fat yielded the highest amount of usable lipid.
- Brood fat-based nanostructured lipid carriers showed strong anti-inflammatory activity and were non-irritating and non-cytotoxic.
- Brood fat NLCs had favorable particle size and stability, making them suitable for topical drug delivery.

## Abstract

This study investigated a new and more sustainable approach to developing ingredients for skin care products with anti-inflammatory properties. Beeswax, a natural substance produced by honeybees, is commonly used in many skin care products to help deliver active ingredients to the skin. However, relying only on beeswax may not be the most sustainable option. The researchers therefore explored whether fat from honey bee brood, which are developing young bees, could be used as an alternative. The fat was extracted using different solvents and then tested to examine its composition, safety, and ability to reduce inflammation. The results showed that extraction using ethyl acetate produced the highest amount of useful fat. The brood fat contained beneficial fatty acids that support skin health and showed stronger anti-inflammatory effects than beeswax. Safety tests confirmed that the fat did not irritate tissue or damage cells. The researchers also produced very small fat particles designed to deliver active ingredients through the skin more effectively. These particles were stable, uniform, and maintained their anti-inflammatory activity. In conclusion, the findings suggest that honey bee brood fat could be a safe, effective, and environmentally friendly alternative to beeswax for improved skin care preparations.

This study evaluated Apis mellifera brood fat extracts as a sustainable alternative to beeswax for anti-inflammatory topical delivery, including their formulation into nanostructured lipid carriers (NLCs). Brood fat was extracted using acetone, ethyl acetate (EA), and hexane, and the resulting extracts were characterized for fatty acid composition and physicochemical properties. Safety was assessed using the hen’s egg chorioallantoic membrane test and cytotoxicity testing in RAW 264.7 macrophages. Anti-inflammatory activity was assessed by inhibition of lipopolysaccharide-induced interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production. The most suitable extract was formulated into NLCs using sugar squalane as liquid lipid, and the effects of lipid ratio and preparation method were investigated. The results showed that the ethyl acetate extract had the highest yield. Compared with beeswax, all fat extracts exhibited a favorable oleic acid–rich fatty acid profile with comparable crystallinity and thermal behavior, while showing significantly enhanced anti-inflammatory activity (p < 0.05). All extracts and their NLCs were non-irritating and non-cytotoxic. Ethyl acetate extract-based NLCs exhibited favorable particle sizes (72.1 ± 0.3 nm) and narrow polydispersity (0.14 ± 0.00), with high-pressure homogenization producing smaller particles compared to probe sonication without affecting IL-6 or TNF-α inhibition. Therefore, A. mellifera brood fat extract is a sustainable anti-inflammatory lipid source with strong potential as an alternative to beeswax in topical nano-formulations.