Phytochemical Landscape, Pharmacological Activities, and Translational Prospects of Callistemon citrinus: An Integrative Review
Callistemon citrinus (Myrtaceae), a traditional medicinal herb, has been used to treat various disorders associated with metabolism, digestion, inflammation, and respiration. Recent discoveries in pharmacology, together with the herb's diverse phytochemistry, have raised the possibility of multiple targets for medicinal interventions. This review attempts to critically analyse the phytochemical profile and pharmacology of C. citrinus. PubMed, Scopus, Web of Science, and ScienceDirect databases were used to do a systematic literature search until 2025. PRISMA-based guidelines were used to screen and analyze peer-reviewed research, including in vitro, in vivo, and in silico studies. Information on biological activity, mechanisms, safety profiles, and phytochemistry was retrieved. Flavonoids, terpenoids, phenolic acids, tannins, and sterols are just a few of the many bioactive components found in C. citrinus. Pharmacological research demonstrates the antioxidant, antibacterial, anti-inflammatory, antidiabetic, gastroprotective, neuroprotective, and anticancer properties. While other activities remain restricted to experimental models with inconsistent methodological quality, antioxidant and antibacterial benefits are supported by rather consistent preclinical data. Mechanistically, oxidative stress, inflammatory mediators, and metabolic pathways are all modulated. However, there is little experimental confirmation; new in silico research points to multi-target interactions. In acute and subacute models, toxicological research shows a favourable safety profile. C. citrinus has various pharmacological properties due to its unique phytochemistry. Although there is substantial research on its antioxidant and anti-microbial properties, all the information is based on experimental data. There is a need for clinical trials to prove its potential therapeutic benefits. Although C. citrinus has remarkable therapeutic promise, the paucity of clinical studies and pharmacokinetic data, and the lack of standardization hinder its clinical translation. Welldesigned clinical trials, bioavailability improvement, and mechanistic validation should be the top priorities for future research.