Unveiling the ethnomedicinal potential of Alchemilla speciosa Buser: An underexplored source of bioactive compounds for skin health.

ETHNOPHARMACOLOGICAL RELEVANCE

Alchemilla (lady's mantle) species have been used for centuries in traditional medicine to treat various skin ailments. Topical preparations of Alchemilla (e.g., A. vulgaris L.) are applied to wounds, rashes, eczema, and acne, leveraging the plant's notable astringent and anti-inflammatory properties. These longstanding uses underscore the therapeutic potential of Alchemilla for skin health in ethnomedicine.

AIM OF THE STUDY

This study aimed to determine the phytochemical composition of A. speciosa Buser aerial parts and to evaluate their biological activities in vitro, with an emphasis on potential dermatological applications.

MATERIALS AND METHODS

Mass spectrometry analyses (LC-ESI-MS/MS, LC-APCI-MS/MS and GC-MS) were used to profile the chemical constituents of A. speciosa extracts and fractions. Spectrophotometric assays quantified total phenolic, flavonoid, and phenolic acid contents. Antioxidant capacity was determined using ABTS decolorization, DPPH scavenging, and metal chelation assays. Enzyme inhibition assays (collagenase, elastase, tyrosinase) were performed to evaluate anti-aging and skin-lightning potential. Antibacterial activity (MIC and MBC) was tested against skin pathogens associated with acne and seborrheic conditions (Cutibacterium acnes, Staphylococcus epidermidis, etc.). Normal human skin fibroblasts were used to examine cytotoxicity and protective effects (anti-lipid-peroxidation activity) of the samples. All experiments were conducted in at least triplicate and results were validated statistically.

RESULTS

Phytochemical profiling revealed a rich spectrum of secondary metabolites, including phenolic acids, flavonoids, pentacyclic triterpenes, volatile and semi-volatile compounds. The samples were abundant in polyphenols, with total phenolic content (TPC) ranging up to 485.61 mg GAE/g DE and substantial total flavonoid (TFC up to 427.68 mg QE/g DE) and phenolic acid (TPAC up to 20.90 mg CAE/g DE) levels. All A. speciosa extracts and fractions exhibited strong antioxidant activity, efficiently neutralizing ABTS and DPPH radicals and showing moderate metal ion chelation. They also inhibited skin-degrading enzymes, with moderate inhibition of collagenase and tyrosinase and a weaker effect on elastase. Additionally, the samples demonstrated notable antibacterial efficacy against microaerobic skin bacteria implicated in acne (MIC 12.5-200 μg/mL), while displaying minimal cytotoxicity towards normal human fibroblasts (viability ≥80 % at 62.5 μg/mL). The most active samples showed a high in vitro therapeutic indexes (TI ≥ 10), indicating a wide safety margin. Notably, the extracts and fractions also inhibited HO-induced lipid peroxidation in fibroblasts, further confirming their cellular antioxidant capacity.

CONCLUSIONS

A. speciosa exhibits considerable therapeutic potential for dermatological applications. Its extracts combine potent antioxidant, enzyme-inhibitory, and antimicrobial effects with a favorable safety profile, which justifies further in vivo evaluation. These findings underscore A. speciosa as a promising source of natural ingredients for future skin-care formulations aimed at managing skin disorders. However, translation to practice will require formulation of the active fractions in biocompatible solvents and confirmation of efficacy in vivo.