Santali Albi Lignum: From traditional efficacies to pharmacological properties and modern therapeutic applications

Santali Albi Lignum (SA), the dry heartwood of the trunk of Santalum album L., was originally discovered in India. It has a long history of use in Ayurveda and traditional Chinese medicine (TCM), mainly to treat skin, cardiovascular and lung diseases. In recent years, SA has received worldwide attention because of its diverse pharmacological effects, including anti-tumour, neuroprotective and gastrointestinal regulatory effects.

This paper aims to systematically review progress in the research on SA, focusing on its ethnopharmacology, phytochemical ingredients, pharmacological effects, quality control and clinical applications; directions for further research and development of this herbal medicine are also discussed.

Information on SA was obtained mainly from published materials, classic ancient books on TCM and electronic databases (PubMed, Google Scholar, Science Direct, Web of Science China National Knowledge Infrastructure and traditional Chinese medicine classics).

A total of 216 molecules have been identified in SA, including terpenoids, fatty acids, organic acids, phenols, aldehydes, alkanes, esters, ketones, steroids, alcohols, phenylpropanoids and other compounds, of which sesquiterpenes have emerged as the primary bioactive ingredients. A wide spectrum of biological activities of extracts or compounds of SA, including neuroprotective, antitumour, anti-inflammatory, antioxidant and gastrointestinal effects, have been verified in in vitro and in vivo pharmacological studies. Quality is monitored by the quantification and identification of α⁃santalol, β⁃santalol and volatile oils. TCM formulations that contain SA are commonly used to treat coronary heart disease, heart failure, ischaemic stroke, skin diseases and others.

This systematic review demonstrates that modern bioactivities and clinical research reports provide scientific evidence for the efficacy of SA, especially the ability to circulate qi and alleviate pain. Current studies have focused mainly on the chemical composition and pharmacological effects of the volatile oil fraction of SA. Moreover, the integrated pharmacological mechanisms of the active compounds and extracts of SA still need to be comprehensively elucidated. Furthermore, research on its toxicology and pharmacokinetics should be expanded to ensure the reasonable and safe clinical use of SA.