Chemical composition, cytotoxicity and insecticidal activities of Acorus calamus accessions from the western Himalayas

Twenty one accessions of Acorus calamus were evaluated for essential oil composition and biological activities during 2009-2014. Essential oil from fresh rhizomes of A. calamus was obtained by hydro-distillation method, and analyzed by GC-FID and GC-MS. The essential oil yield ranged from 1.10 ± 0.28 to 2.50 ± 0.01%. β-asarone, shyobunone and α-asarone were the major constituents in the rhizome oil. Accession IHBT/AC/16 recorded the lowest β-asarone content (31.56%) and IHBT/AC/1 recorded the highest (91.27%). Two accessions, viz., IHBT/AC/7 and IHBT/AC/16, representing triploid and diploid accessions that contain high and low β-asarone content, respectively, were tested for biological activities. The cytotoxicity of these accessions was evaluated against human colorectal adenocarcinoma (HT-29), human epidermoid carcinoma (KB) and human cervical cancer (SiHa) cells at 24, 48 and 72 h. Both accessions at 300 μg/mL and 72 h showed the highest activity against all the tumoral cells. The essential oils of two accessions showed promising larvicidal activities against 2nd instar larvae of Spodoptera litura and Plutella xylostella. However, P. xylostella larvae were more susceptible than the S. litura larvae, and essential oils of accession IHBT/AC/7 were more toxic than accession IHBT/AC/16.