Oral and Topical Anti-Inflammatory and Antipyretic Potentialities of Araucaria bidiwillii Shoot Essential Oil and Its Nanoemulsion in Relation to Chemical Composition.

Different parts of Araucaria bidiwillii (bunya pin) trees, such as nuts, seeds, bark, and shoots, are widely used in cooking, tea, and traditional medicines around the world. The shoots essential oil (EO) has not yet been studied. Herein, the chemical profile of A. bidiwillii shoots EO (ABSEO) was created by GC-MS analysis. Additionally, the in vivo oral and topical anti-inflammatory effect against carrageenan-induced models, as well as antipyretic potentiality of ABSEO and its nanoemulsion were evaluated. Forty-three terpenoid components were identified and categorized as mono- (42.94%), sesqui- (31.66%), and diterpenes (23.74%). The main compounds of the ABSEO were beyerene (20.81%), α-pinene (16.21%), D-limonene (14.22%), germacrene D (6.69%), β-humulene (4.14%), and sabinene (4.12%). The ABSEO and its nanoemulsion exhibited significant inflammation suppression in carrageenan-induced rat paw edema model, in both oral (50 and 100 mg/kg) and topical (5% in soyabean oil) routes, compared to the control and reference drugs groups. All the results demonstrated the significant inflammation reduction via the inflammatory cytokines (IL-1β and IL8), nitrosative (NO), and prostaglandin E2 (PGE2) supported by the histopathological studies and immunohistochemical assessment of MMP-9 and NF-κβ levels in paw tissues. Moreover, the oral administration of ABSEO and its nanoemulsion (50 and 100 mg/kg) exhibited antipyretic activity in rats, demonstrated by the inhibition of hyperthermia induced by intramuscular injection of brewer's yeast. These findings advised that the use of ABSEO and its nanoemulsion against numerous inflammatory and hyperthermia ailments that could be attributed to its active constituents.