Rosmarinus officinalis L. hexane extract: phytochemical analysis, nanoencapsulation, and in silico, in vitro, and in vivo anti-photoaging potential evaluation

Abstract

A shift towards natural anti-aging ingredients has spurred the research to valorize traditionally used plants. In this context, Rosmarinus officinalis L. was evaluated for its photoprotective, antioxidant, anti-inflammatory, and anti-wrinkling properties. GC/MS and LC-ESI-HRMS based phytochemical profiling of rosemary leaves hexane extract resulted in the identification of 47 and 31 compounds, respectively and revealed rich content in triterpenoids, monoterpenoids and phenolic diterpenes. In vitro assays confirmed the antioxidant, anti-aging, and wound healing potential of rosemary extract along with a good safety profile, encouraging further development. A systematic molecular modelling study was conducted to elucidate the mechanistic background of rosemary anti-aging properties through the inhibitory effects of its major constituents against key anti-aging targets viz. elastase, collagenase, and hyaluronidase. Development of rosemary extract lipid nanocapsules-based mucoadhesive gels was performed to improve skin contact, permeation, and bioavailability prior to in vivo testing. The developed formulae demonstrated small particle size (56.55-66.13 nm), homogenous distribution (PDI of 0.207-0.249), and negatively charged Zeta potential (- 13.4 to - 15.6). In UVB-irradiated rat model, topical rosemary hexane extract-loaded lipid nanocapsules-based gel provided photoprotection, restored the antioxidant biochemical state, improved epidermal and dermal histological features, and decreased the level of inflammatory and wrinkling markers. The use of rosemary hexane extract in anti-aging and photoprotective cosmeceuticals represents a safe, efficient, and cost-effective approach.

Figure 1

3D docking pose and 2D interaction diagram of verbenone in the binding site of elastase (A,B), collagenase (C,D) (showing lack of metal coordination interaction) and hyaluronidase (E,F) (showing excessive water exposure).

Figure 2

3D docking pose and 2D interaction diagram of camphor in the binding site of collagenase (A,B) and hyaluronidase (C,D).

Figure 3

Histopathological examination of rat dorsal skin. Negative control: normal rats, positive control: subjected to UVB irradiation and received no treatment, while T1, T2, T3 and T4 received RHE, 4%-RM-LNC gel, 10% RM-LNC gel and plain LNC gel.

Figure 3

Histopathological examination of rat dorsal skin. Negative control: normal rats, positive control: subjected to UVB irradiation and received no treatment, while T1, T2, T3 and T4 received RHE, 4%-RM-LNC gel, 10% RM-LNC gel and plain LNC gel.