Chemical composition and broad-spectrum anthelmintic activity of a cultivar of toothache plant, <i>Acmella oleracea</i>, from Mizoram, India

Abstract

<b>Context:</b> A variety of <i>Acmella oleracea</i> (L.) R.K. Jansen (Asteraceae) is used by the Mizo people of India and Myanmar for intestinal helminthiasis.<b>Objective:</b> To perform a chemical analysis of the plant extract using gas chromatography-mass spectrometry (GC-MS) and test the anthelmintic activity on intestinal parasites.<b>Materials and methods:</b> An extract of the aerial parts was prepared in hexane and analysed using GC-MS. Survival test was performed <i>in vitro</i> on the cestode, <i>Taenia tetragona</i>, and the nematode, <i>Ascaridia perspicillum</i>. Concentrations of 1.25, 2.5, 5, 10 and 20 mg/mL, prepared in phosphate-buffered saline (PBS) with 1% dimethylsulphoxide (DMSO), were tested. Negative control was maintained in PBS with DMSO, and albendazole was used as a reference drug. Each treatment consisted of six worms and was done until death was confirmed. Scanning electron microscopy was used to describe the structural changes.<b>Results:</b> Nineteen compounds were detected. The major compounds were fatty alcohols such as 3,7,11,15-tetramethylhexadec-2-en-1-ol and (9<i>Z</i>)-9-hexadecen-1-ol. Important bioactive compounds including an alkylamide, <i>N</i>-isobutyl-(2<i>E</i>,4<i>Z</i>,8<i>Z</i>,10<i>E</i>)-dodecatetraenamide, and a triterpenoid, lupeol, were also confirmed. The lethal concentration (LC₅₀) of the plant extract was 5128.61 ppm on <i>T. tetragona</i> and 8921.50 ppm on <i>A. perspicillum</i>. Tegumental shrinkage, erosion of microtriches, and distortion of the suckers were observed on the cestode. The nematode showed collapse of the lips and shrunk cuticle.<b>Conclusions:</b> <i>Acmella oleracea</i> contains important bioactive compounds, which are responsible for the broad-spectrum anthelmintic activity. Further study on the pharmacology of the compounds is warranted.