lower

index.php:

$smarty = new Smarty;
$smarty->assign('articleTitle', 'Two Convicts Evade Noose, Jury Hung.');
$smarty->display('index.tpl');

index.tpl:

{$articleTitle}
{$articleTitle|lower}

OUTPUT:

Two Convicts Evade Noose, Jury Hung.
two convicts evade noose, jury hung.