In any civil action against the publisher, owner, editor, reporter or employee of any newspaper, magazine or periodical under § 8.01-45, or for libel or defamation, because of any article, statement or other matter contained in any such newspaper, magazine or periodical, the defendant, whether punitive damages be sought or not, may introduce in evidence in mitigation of general and punitive damages, or either, but not of actual pecuniary damages, all the circumstances of the publication, including the source of the information, its character as affording reasonable ground of reliance, any prior publication elsewhere of similar purport, the lack of negligence or malice on the part of the defendant, the good faith of the defendant in such publication, or that apology or retraction, if any, was made with reasonable promptness and fairness; provided that the defendant may introduce in evidence only such circumstances and to the extent set forth in his or its grounds of defense.