From Chinese herbal medicine to active substance: explore the traditional uses, biological activities, pharmacological effects, potential therapeutic applications and quality control of Ramulus cinnamomi essential oil

Ramulus cinnamomi (known as Guizhi in China), the dried young branch of Cinnamomum cassia (L.) J. Presl (WFO-verified), is a classic Chinese herb traditionally used for fever, headache, wind-cold syndrome, cardiovascular and gynecological diseases. This review summarizes the traditional uses, chemical composition, biological activities, pharmacological effects, toxicity, therapeutic applications, and quality control of its essential oil (RCEO). Literature was sourced from CNKI, PubMed, SciFinder, ScienceDirect, and Baidu Scholar, along with classical TCM texts. RCEO contains over 96 compounds, with cinnamaldehyde, cinnamyl alcohol, benzaldehyde, and methylcinnamaldehyde as major active components. It exhibits antipyretic, analgesic, anti-inflammatory, antibacterial, antiviral, antitumor, neuroprotective, and antioxidant effects with extremely low toxicity, showing therapeutic potential against dermatomycosis, chronic diarrhea, and depression. Current quality control faces challenges of heterogeneity and adulteration. Future studies should develop rapid non-destructive techniques integrated with chemometrics and AI for comprehensive quality evaluation.