Evaluation of Antianxiety Potential of Four Ganoderma (Agaricomycetes) Species from India in Mice

The genus Ganoderma consists of widespread polypore mushrooms that have traditionally been used to reduce stress and anxiety. However, scientific evidence for this is not adequate. Hence, this study was designed to investigate the anxiolytic potential of G. applanatum, G. brownii, G. lucidum, and G. philippii collected from Uttarakhand, India. Various extracts of dried, powdered basidiocarps were prepared using different solvents-namely, petroleum ether, chloroform, methanol, and distilled water-by successive Soxhlet extraction. All the extracts were tested for antianxiety activity using the elevated plus maze (EPM) model in Swiss albino mice. The results showed that the methanol extract of G. lucidum at a dose of 200 mg/kg, administered orally, shows a significant increase in the average time spent in the open arms of the EPM when compared with the control; this was comparable to the effect of the standard drug (diazepam, 2 mg/kg by mouth). This bioactive methanol extract was subjected to bioactivity-guided fractionation. The results show that the n-butanol fraction of the methanol extract evinced significant antianxiety activity at a dose of 100 mg/kg. This fraction showed the presence of phenols and flavonoids and thus was standardized with respect to total phenol content and total flavonoid content. The antianxiety activity may be the result of the phenols/flavonoids present. This study clearly demonstrated that the n-butanol fraction from the methanol extract of G. lucidum can be developed as source of new anxiolytic agents.