Ameliorating effect of balloon flower saponin on the ethanol-induced memory impairment in mice.

The ameliorating effect of the root extract of Platycodon grandiflorum (Campanulaceae) on ethanol-induced cognitive dysfunction in mice was investigated. The mice with repeated administration of the root extract of P. grandiflorum, crude saponin fraction and platycoside E, a main ingredient of crude saponin fraction, showed a markedly prolonged step-through latency period (STL) on the passive avoidance task performed after acute ethanol intoxication, respectively. The present results suggest that the memory enhancing effect of the extract was ascribed mainly to the saponin fraction and that saponin of P. grandiflorum, particularly platycoside E could exert a beneficial effect on memory impairment in mice.

Inhibition of tumor invasion and metastasis by aqueous extract of the radix of Platycodon grandiflorum.

Platycodon grandiflorum is a traditional oriental herbal medicine that is known for its immunostimulatory and anti-tumor effects. This study examined the anti-metastatic activities of an aqueous extract from the root of P. grandiflorum (Changkil: CK) using in vitro and in vivo metastasis assays. CK inhibited the invasion of B16-F10 melanoma cells through a reconstituted basement membrane (Matrigel)-coated filter, and strongly inhibited the adhesion of B16-F10 melanoma cell to extracellular matrices such as Matrigel, fibronectin and laminin substrates. CK also inhibited an experimentally induced lung cancer and prolonged the survival time in vivo. In addition, CK augmented NK cell activity. These results show that CK can reduce the extent of a lung metastasis of B16-F10 melanoma cells by inhibiting the adhesion of tumor cells to the basement membrane possibly and activating NK cells.

Inhibitory effect of the saponins derived from roots of Platycodon grandiflorum on carrageenan-induced inflammation.

Previous studies have reported that the saponins isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), inhibited cyclooxygenase-2 (COX-2) expression in cultured lipopolysaccharide-activated macrophages. The aim of this presented study was to confirm the anti-inflammatory effects of CKS by examining their effect on the inflammatory response induced by carrageenan in a rat by using an acute air pouch inflammation model. CKS significantly reduced the levels of the inflammatory process markers in the air pouch, such as the volume of exudates, the amount of protein and the number of leukocytes and neutrophils. The levels of TNF-alpha and prostaglandin E2 (PGE2) were also markedly lower in the air pouch of the CKS-treated animals than in the controls. An immunoblot analysis showed that CKS reduced the COX-2 expression level in the exudate cells. In addition, CKS significantly reduced the paw edema induced by carrageenan and also markedly reduced the level of PGE2 production in the inflamed paw. These results suggest that CKS had significant anti-inflammatory effects in vivo.

Inhibition of tumor necrosis factor-alpha-induced expression of adhesion molecules in human endothelial cells by the saponins derived from roots of Platycodon grandiflorum.

Adhesion molecules play an important role in the development of atherogenesis and are produced by endothelial cells after being stimulated with various inflammatory cytokines. This study examined the effect of saponins that were isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. CKS significantly inhibited the TNFalpha-induced increase in monocyte adhesion to endothelial cells as well as decreased the protein and mRNA expression levels of vascular adhesion molecule-1 and intercellular cell adhesion molecule-1 on endothelial cells. Furthermore, CKS significantly inhibited the TNFalpha-induced production of intracellular reactive oxygen species (ROS) and activation of NF-kappaB by preventing IkappaB degradation and inhibiting IkappaB kinase activity. Overall, CKS has anti-atherosclerotic and anti-inflammatory activity, which is least in part the result of it reducing the cytokine-induced endothelial adhesion to monocytes by inhibiting intracellular ROS production, NF-kappaB activation, and cell adhesion molecule expression in endothelial cells.

Isolation of a new saponin and cytotoxic effect of saponins from the root of Platycodon grandiflorum on human tumor cell lines.

A novel triterpenoid saponin, deapioplatycoside E (1) was isolated from the root extract of Platycodon grandiflorum, together with the seven known saponins 2 - 8, i. e., platycoside E (2), deapioplatycodin D3 (3), platycodin D3 (4), polygalacin D2 (5), platycodin D2 (6), deapioplatycodin D (7) and platycodin D (8). The structure of the new saponin 1 was determined on the basis of spectral analysis and chemical evidence. The crude saponin fraction (ED50: ca. 10 - 15 microg/mL) and compounds 6 - 8 (ED50: ca. 4 - 18 microg/mL) exhibited significant inhibition on the proliferation of five kinds of cultured human tumor cell lines, i. e., A549 (non-small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCT-15 (colon), in vitro.

Protective effect of saponins derived from roots of Platycodon grandiflorum on tert-butyl hydroperoxide-induced oxidative hepatotoxicity.

There is increasing evidence that oxidative stress is implicated in the pathogenesis of various diseases, including alcoholic liver injury. In the present work, we investigate the protective effects of the saponins isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), on the tert-butyl hydroperoxide (t-BHP)-induced oxidative injury (hepatotoxicity) in cultured rat primary hepatocytes and in rat livers. CKS significantly reduced t-BHP-induced oxidative injuries in cultured rat hepatocytes, as determined by cell cytotoxicity, intracellular glutathione (GSH) content and lipid peroxidation in a dose-dependent manner. CKS provided good protection from the t-BHP-induced production of intracellular reactive oxygen species and DNA damage. In addition, CKS was able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and the superoxide radical. The in vivo study showed that the pretreatment with CKS prior to the administration of t-BHP significantly prevented the increase in the serum levels of hepatic enzyme markers (alanine aminotransferase and aspartate aminotransferase) and reduced oxidative stress, such as GSH content and lipid peroxidation, in the liver in a dose-dependent manner. These results support the anti-oxidative role of CKS, and demonstrate that CKS can scavenge oxygen free radicals and protect cells from oxidative stress.