Oral administration of Ganoderma lucidum extract protects gingival tissues against proinflammatory TNF and oxidative stress in periodontitis model rats

Ganoderma lucidum is a medicinal mushroom that has been tempting since ancient times. We investigated whether chronic oral administration of G. lucidum extract withstands the increases in levels of proinflammatory TNF and lipid peroxide (LPO), an indicator of oxidative stress, in gingival tissue of periodontitis model rats. It was also investigated if G. lucidum extract inhibits oxidative stress induced by Fenton’s reagents in whole homogenates of fresh rat gigival tissues in vitro. Prior to in vivo and in vitro experiments with rats, G. lucidum extract was quantitatively tested for its total polyphenols and/or flavonoids content and ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radicals. Chronic oral administration of G. lucidum extract (300 mg/kg BW, body weight) significantly reduced TNF and LPO levels in the gingival tissue of periodontitis model rats. G. lucidum extract also inhibited oxidative stress in vitro (P<0.05), as indicated by reduced LPO levels in gingival tissue whole homogenates preincubated with G. lucidum extract. The in vitro results were thus consistent with those in vivo inhibition of lipid peroxidation, DPPH free radical-scavenging effect and the presence of total polyphenols/flavonoids in G. lucidum extract. Our results provide, at least partial evidence for the beneficial effect of G. lucidum on periodontitis, an inflammatory disease of the gums associated with oxidative stress and preceding infectious gum disease.