# Sea Buckthorn, Aronia, and Black Currant Pruning Waste Biomass as a Source of Multifunctional Skin-Protecting Cosmetic and Pharmaceutical Cream Ingredients

## TL;DR

This paper explores how pruning waste from sea buckthorn, aronia, and black currant shrubs can be used to create skin-protecting cosmetics and pharmaceuticals.

## Contribution

The study identifies agro-waste biomass as a novel source of multifunctional ingredients for topical formulations.

## Key findings

- Lignocellulosic biomass extracts improved the oxidative stability of lipid-based systems.
- Hydrophilic extracts from sea buckthorn and aronia showed high antimicrobial activity.
- Aronia extracts supported the highest viability of human keratinocytes without significant cytotoxicity.

## Abstract

Fruit shrubs’ lignocellulosic biomass remaining as waste after harvesting and/or after pruning is an underutilized, little-explored bioresource. Sea buckthorn (Hippophae rhamnoides L.), aronia (Aronia melanocarpa) and blackcurrant (Ribes nigrum) berries are rich in biologically active compounds, so these shrubs’ woody biomass derivatives are prospective investigation objects. The influence of pre-treated biomass, extracts, and purified proanthocyanidins on the oxidative stability of lipid-based systems was studied by accelerated oxidation method. Emulsion stability, antimicrobial activity against bacteria that causes acne—Cutibacterium acnes; contaminating wounds; skin care products—Streptococcus pyogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus; cytotoxicity and phototoxicity of extracts and proanthocyanidins on HaCaT human keratinocytes were tested. The study established that biomass, lipophilic extracts obtained using liquefied hydrofluorocarbon, and hydrophilic extracts obtained by aqueous ethanol increased oxidative stability of lipid-based formulations. Compounds with skin-protecting properties were detected. Sea buckthorn and aronia hydrophilic extracts and proanthocyanidins had the highest antimicrobial activity. Low phototoxicity was revealed, emphasizing safety and applicability in topical formulations; human HaCaT keratinocyte viability was the best with aronia extracts, but none of the other samples decreased cell viability by more than 50%. It was proven that agro-waste biomass is a prospective source of multifunctional ingredients for cosmetic and pharmaceutical topical formulations.