Phytochemical profiling of Pelargonium graveolens l'Hér and evaluation of its activity against D-galactose induced skin ageing.

Pelargonium graveolens L'Hér is an evergreen small shrub with pink flowers. Metabolite profiling of its extract by UHPLC/MS analysis revealed the identification of 51 secondary metabolites. Interestingly, 29 compounds identified for the first time. The colorimetric assays revealed high content of phenolic, flavonoids and tannins (100.19 ± 3.94 µg Gallic acid Eq/mg, 47.38 ± 2.04 µg Rutin Eq/mg and 332.75 ± 8.85 µg Catechin Eq/mg of extract) respectively along with good antioxidant activity. Moreover, the in vitro analysis showed a significant anti-hyaluronidase activity (IC₅₀ ± SD = 15.75 ± 0.8), as compared to standard luteolin. Topical application of the characterised P. graveolens hydrogel (1% and 2% w/w) was tested using the D-galactose-induced ageing model in mice. Histopathological examination demonstrated an increase in the dermal collagen expression, alleviation of ageing-related oxidative stress, and stabilisation of MMP-1/TIMP-1 balance. Ultimately, P. graveolens could be a valuable source of natural antioxidants with a promising antiaging activity.