Abstract

Lawsonia inermis L. (Lythraceae), popularly known as henna, is an ancient cosmetic and medicinal plant widely used across Africa, Asia, and the Middle East. Although several reviews have summarized its ethnomedicinal relevance, few have integrated recent mechanistic, toxicological, and biotechnological findings. To provide an updated and comprehensive synthesis of the phytochemistry, pharmacological mechanisms, ethnomedicinal applications, and safety perspectives of L. inermis, highlighting advances from 2020–2025 and identifying future research directions. Data were collected from peer-reviewed journals indexed in Scopus, PubMed, and Google Scholar using the keywords Lawsonia inermis, lawsone, pharmacology, toxicity, and ethnomedicine. Emphasis was placed on recent experimental and analytical studies elucidating molecular mechanisms and structure–activity relationships. More than seventy secondary metabolites have been reported, dominated by naphthoquinones, flavonoids, triterpenes, and phenolics. Modern evidence demonstrates that L. inermis exerts antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, anticancer, and wound-healing effects primarily through activation of Nrf2/ARE signaling, inhibition of NF-κB and COX-2, and modulation of apoptotic and fibrotic pathways. Toxicological evaluations indicate a wide safety margin for leaf-based preparations, whereas toxicity is mainly associated with adulterants such as para-phenylenediamine (PPD) and excessive dosing. Emerging industrial applications include green nanocomposites, biosorbents, and natural dyes. This updated review extends earlier literature by linking phytochemical diversity to specific molecular mechanisms, integrating safety and regulatory data, and outlining translational and biotechnological opportunities. Future research should prioritize standardization, pharmacokinetics, and clinical validation to enable evidence-based therapeutic utilization of L. inermis.

Keywords: Lawsonia inermis, henna, phytochemistry, pharmacology, molecular mechanisms, toxicity, ethnomedicine, safety, bioactive compounds

How to Cite:

Enoghase, J. R. & Edokpolo, F. O., (2025) “Lawsonia inermis (Henna): phytochemistry, pharmacological activities, ethnomedicinal uses, and safety perspectives—A comprehensive review”, Lekovite Sirovine 45(1), 1-7. doi: https://doi.org/10.61652/leksir2545341E