Effect of polymorphic crystal forms of lantana toxins on icterogenic action in guinea pigs.

A partially purified preparation of toxin isolated from lantana (Lantana camara L., red variety) leaves, called fraction C, was obtained in two crystalline forms: form I, white, fluffy, rod-shaped and form II, irregular, polyhedral, shining crystals. The two forms differed in melting point behaviour and icterogenic action when administered orally to guinea pigs. Only form II was icterogenic to guinea pigs and was associated with decreased feed intake and faecal output, hepatomegaly, increase in plasma bilirubin level and acid phosphatase activity.