Inflammation is often caused by bacteria and fungi. Research has shown pine oil (from Pinus sylvestris) to have a suppressive effect against both. (Motiejunaite O and Peciulyte D. 2004).
The antifungal effect of pine buds is mainly explained by the presence of pinosylvin and its monomethyl ether (PMME) (Hovelstad H et al 2006).
The polyphenylpropanoid polysaccharide complex in pine buds is thought to be a factor in stimulating the immune system (Bradley WG et al 2014).