An insight into the immunomodulatory potential of wood oil of Aquilaria malaccensis Lam. with an emphasis into related phytomedicine, biomarkers, pharmacology, and toxicity

ABSTRACT

Critically endangered Aquilaria malaccensis Lam. is known for highly expensive agarwood with unique aroma. Agarwood has been used as a phytomedicine in chronic degenerative neurological disorders, paralysis, rheumatism, asthma, and others. Its production is dependent naturally or artificially on interaction of endophytic fungi, and by nailing, drilling, and microbial inoculation respectively. The majorly produced biomarkers of terpenes, fatty acids, alkanes, chromones, and flavonoids exhibited several biological activities in congruence to their ethnomedicinal claims. During the pandemic, several in-silico, studies showed the potential of a few sesquiterpene hydrocarbons against covid-19. The review aimed to deliver a comprehensive outline of the immunomodulatory potential of agarwood oil with allied traditional medicinal use, biomarkers, pharmacological evaluation, toxicity, and mechanistic action. The review eventually showed the agarwood oil, extracts, and major biomarkers viz., aromadendrene II, valencene, phytol, octacosane, caryophyllene oxide, b-caryophyllene, hinesol, agarospirol, with immunomodulatory, anti-inflammatory, and allied neural, antidiabetic, antimicrobial activity, toxicity, along with molecular target binding potential against 3CLpro, RDRP, Mpro, PLpro, Spike protein S1 of SARS-CoV2 through in-vitro, in-vivo, in silico studies and limited human clinical trials. The expression of HMGR, ASS, ADXPS, ADXPR, FPS, and WRKY genes of sesquiterpenoid biosynthetic pathways were upregulated for signature aroma and immunomodulatory markers viz., d-guaiene, dodecane, tetracosane, agarospirol, farnesol, and geranylgeraniol acetate as a defensive response. The review would ignite future research on potential immunomodulatory markers viz., caryophyllene oxide, octacosane, heneicosane, agarospirol, n-hexadecanoic acid, a-eudesmol, a-santalol and inoculum guided invitro agarwood production restoring the prized aroma, therapeutic efficacy, and wild population. (c) 2022 SAAB. Published by Elsevier B.V. All rights reserved.