Untreated A549 cell (a), arrow-cell membrane, two-headed arrow-nucleus, circle-mitochondrion with compact cristae, asterisk-cytoskeleton. A549 cell treated with IC50 value of silymarin (b), Arrow-swollen mitochondria, rectangle-lacerated cisterna of endoplasmic reticulum, arrow head- holes on cytoskeletal disintegration, asterisk-granular cytoplasm, circle-condensed chromatin. A549 cell exposed to IC50 value of silymarin-loaded SLN for 24 h (c), two-headed arrow-pyknotic nucleus with extremely condensed chromatin, arrow-disintegrated mitochondrion with excessive loss of cristae, circle-highly swollen cisterna of endoplasmic reticulum and asterisk-fragmentation of nucleus.