Inhibitory activity of a phytochemically characterized fraction from Streptocaulon juventas on lung cancer in nude mice.

In the present study, a 75% ethanol extract of Streptocaulon juventas (SJ), which had a strong inhibitory effect on the proliferation of human lung A549 adenocarcinoma cells, was subjected to bioassay-guided fractionation. The most active fraction (SJF) was obtained using a macroreticular resin column followed by a silica-gel column. Then its in vivo effect on lung cancer was investigated in athymic nude mice with A549 tumors while its effects on body weight, blood biochemical indicators, and organ indices were monitored. The results showed that SJF inhibited the tumor growth significantly at day 10 and day 15 during treatment without physical side effects. Following HPLC and NMR spectrometry, the main components of SJF were identified as digitoxigenin, periplogenin, and periplogenin glucoside.