Augmentation of pyrethrins content in callus of Chrysanthemum cinerariaefolium and establishing its insecticidal activity by molecular docking of NavMS Sodium Channel Pore receptor.

Pyrethrins are effective food-grade bio-pesticides obtained from the flowers of Chrysanthemum cinerariaefolium and this
crop cannot be cultivated widely in India due to its specific agro-climatic requirement. Hence pyrethrins are mostly imported
from Kenya. Therefore, the present study aims to develop a process for augmentation of pyrethrin contents in C. cinerariaefolium
callus and establish the correlation between early knockdown effects through docking on grain storage insect. In vitro
seedlings were used as explants to induce callus on MS medium with different concentrations of auxins and cytokinins.
Pyrethrin extracted from the callus was estimated by RP-HPLC. In callus, total pyrethrin was found to be 17.5 μg/g, which
is higher than that found in natural flowers of certain Pyrethrum cultivars. The concentrations of cinerin II, pyrethrin II and
jasmoline II were quite high in callus grown on solid medium. Bio-efficacy of pyrethrum extracts of flower and callus on
insect Tribolium sp., showed higher repellency and early knock-down effect when compared with pure compound pestanal.
Further, the rapid knockdown effect of all pyrethrins components was established by molecular docking studies targeting
NavMS Sodium Channel Pore receptor docking followed by multiple ligands simultaneous docking, performed to investigate
the concurrent binding of different combinations of pyrethrin. Among the six pyrethrin components, the pyrethrin I and II
were found to be a more efficient, binding more firmly to the target, exhibiting higher possibilities of insecticidal effect by
an early knockdown mechanism.