Lentinus strigosus is a nutritious and medicinal mushroom. This article highlights the effects of the fruiting body ethanolic extract of L. strigosus on the survival, food intake, and locomotion of N2 wild strain nematode, Caenorhabditis elegans, an animal model for obesity. Nematodes at L4 stage cultured on nematode growth medium (NGM) plates with Escherichia coli OP50 strain were treated with the different concentrations of mushroom extract (10, 100, 300, and 1,000 μg/ml) and dimethyl sulfoxide (DMSO) (1%) at varying times of exposure. Nematode lethality assay revealed that as the extract concentration increased and exposure prolonged, the percentage survival decreased. None of the extract concentrations showed 50% mortality; thus, it is considered safe to proceed to bioactivity assays. The increasing concentration of extract caused not only the decrease in the pharyngeal pumping rate (food intake) but also the increase in both reversal (dwelling) and body bend (roaming) movements of C. elegans. The dwelling and roaming locomotion of 300 μg/ml and 1,000 μg/ml extract-treated nematodes were significantly higher after 48 and 120 hours, respectively. It was also observed that nematodes treated with extract spent less time in the dwelling mode after 120 hours of exposure. Therefore, the fruiting body ethanolic extract of L. strigosus has an appetite-suppressing effect, which suggests a promising potential of this mushroom as a natural and effective remedy to prevent obesity.
Key words: Lentinus strigosus, pharyngeal behavior assay, locomotion, nematode, obesity.