Stachys byzantina K. Koch (Lamiaceae) as a potential ingredient for delaying skin ageing and treating hyperpigmentation disorders in pharmaceutical products.

Abstract

Objectives: This study aimed to investigate whether the plant species Stachys byzantina produces bioactives with the potential to delay the skin ageing process and treat hyperpigmentation conditions.

Methods: The antioxidant action was assessed by 2,2-diphenyl-1-picrylhydrazylradical scavenging, Griess reaction, oxygen radical absorption capacity, and β-carotene bleaching assays. Inhibitory activities for tyrosinase, hyaluronidase, and elastase enzymes were tested. The antiglycation activity, the sun protection factor (SPF), and the toxicity to skin cells by MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay were also evaluated.

Key findings: The ethanolic extract of S. byzantina aerial parts and all fractions obtained by solvent partition inhibited the tyrosinase enzyme at different levels. The dichloromethane fraction (DF) demonstrated the highest inhibition (IC50 = 63.5 ± 10.9 µg/ml). DF also inhibited the hyaluronidase enzyme with IC50 = 369 ± 11.64 μg/ml and elastase by 40% at 500 μg/ml. This fraction showed prominent antioxidant and antiglycation activities, high SPF, and no cytotoxicity at concentrations lower than 50 μg/ml. The phenolic and flavonoid contents were 116.30 ± 6.7 (mgTAE/g) and 66.38 ± 13.5 (mgQE/g), respectively. Chlorogenic acid (23.54 ± 2.46 mg/g) and verbascoside (203.97 ± 19.8 mg/g) were identified and quantified.

Conclusions: Stachys byzantina is a potential source of cosmetic and therapeutic ingredients to reduce hyperpigmentation and the impacts caused by free radicals, advanced glycation end products, and sun radiation in skin ageing.