Radix Sophorae Flavescentis inhibits proliferation and induces apoptosis of AGS human gastric cancer cells.

Traditional herbal medicines are being increasingly used worldwide to treat cancer. Radix Sophorae Flavescentis (RSF) is a Chinese herb, which has numerous pharmacological properties, including anti­tumour effects. In this study, we investigated the mechanisms underlying RSF­induced apoptosis in human gastric cancer cells (AGS cells). We found that RSF treatment (20­200 µg/ml) inhibited the proliferation of AGS cells and increased the sub­G1 phase ratio. RSF­induced cell death was associated with the downregulation of BCl­2 and upregulation of Bax. In addition to increasing the expression levels of apoptosis­mediating surface antigen FAS and Fas ligand, RSF also activated caspase­3; however, mitogen­activated protein kinase appeared to inhibit RSF­induced cell death. RSF also led to an increased production of reactive oxygen species. Based on these results, we propose that RSF could be a potential therapeutic agent for gastric cancer.

Modulation of Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal by Gamisoyo-San, a Traditional Chinese Herbal Medicine.

BACKGROUND: The Gamisoyo-san (GSS) has been used for -improving the gastrointestinal (GI) symptoms. The purpose of this study was to investigate the effects of GSS, a traditional Chinese herbal medicine, on the pacemaker potentials of mouse small intestinal interstitial cells of Cajal (ICCs). METHODS: ICCs from the small intestines were dissociated and cultured. Whole-cell patch-clamp configuration was used to record pacemaker potentials and membrane currents. RESULTS: GSS depolarized ICC pacemaker potentials in a dose-dependent manner. Pretreatment with 4-diphenylacetoxypiperidinium iodide completely inhibited GSS-induced pacemaker potential depolarizations. Intracellular GDP-ß-S inhibited GSS-induced effects, and in the presence of U-73122, GSS-induced effects were inhibited. Also, GSS in the presence of a Ca2+-free solution or thapsigargin did not depolarize pacemaker potentials. However, in the presence of calphostin C, GSS slightly depolarized pacemaker potentials. Furthermore, GSS inhibited both transient receptor potential melastatin7 and Ca2+-activated Cl- channel (anoctamin1) currents. CONCLUSION: GSS depolarized pacemaker potentials of ICCs via G protein and muscarinic M3 receptor signaling pathways and through internal or external Ca2+-, phospholipase C-, and protein kinase C-dependent and transient receptor potential melastatin 7-, and anoctamin 1-independent pathways. The study shows that GSS may regulate GI tract motility, suggesting that GSS could be a basis for developing novel prokinetic agents for treating GI motility dysfunctions.

Effects of Lizhong Tang on cultured mouse small intestine interstitial cells of Cajal.

AIM: To investigate the effects of Lizhong Tang, an herbal product used in traditional Chinese medicine, on mouse small intestine interstitial cells of Cajal (ICCs). METHODS: Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. The ICCs were morphologically distinct from other cell types in culture and were identified using phase contrast microscopy after verification with anti c-kit antibody. A whole-cell patch-clamp configuration was used to record potentials (current clamp) from cultured ICCs. All of the experiments were performed at 30-32 °C. RESULTS: ICCs generated pacemaker potentials, and Lizhong Tang produced membrane depolarization in current-clamp mode. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by Lizhong Tang. Pretreatment with thapsigargin (a Ca²âº-ATPase inhibitor in the endoplasmic reticulum) also abolished the generation of pacemaker potentials by Lizhong Tang. However, pacemaker potentials were completely abolished in the presence of an external Ca²âº-free solution, and under this condition, Lizhong Tang induced membrane depolarizations. Furthermore, When GDP-ß-S (1 mmol/L) was in the pipette solution, Lizhong Tang still induced membrane depolarizations. In addition, membrane depolarizations were not inhibited by chelerythrine or calphostin C, which are protein kinase C inhibitors, but were inhibited by U-73122, an active phospholipase C inhibitors. CONCLUSION: These results suggest that Lizhong Tang might affect gastrointestinal motility by modulating pacemaker activity in interstitial cells of Cajal.

Modulation of pacemaker potentials by pyungwi-san in interstitial cells of cajal from murine small intestine: pyungwi-san and interstitial cells of cajal.

OBJECTIVE: Pyungwi-san (PWS) plays a role in a number of physiologic and pharmacologic functions in many organs. Interstitial cells of Cajal (ICCs) are pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We aimed to investigate the beneficial effects of PWS in mouse small-intestinal ICCs. METHODS: Enzymatic digestion was used to dissociate ICCs from the small intestine of a mouse. The wholecell patch-clamp configuration was used to record membrane potentials from the cultured ICCs. RESULTS: ICCs generated pacemaker potentials in the GI tract. PWS produced membrane depolarization in the current clamp mode. Pretreatment with a Ca(2+) -free solution and a thapsigargin, a Ca(2+) -ATPase, inhibitor in the endoplasmic reticulum, eliminated the generation of pacemaker potentials. However, only when the thapsigargin was applied in a bath solution, the membrane depolarization was not produced by PWS. Furthermore, the membrane depolarizations due to PWS were inhibited not by U-73122, an active phospholipase C inhibitor, but by chelerythrine and calphostin C, protein kinase C inhibitors. CONCLUSIONS: These results suggest that PWS might affect GI motility by modulating the pacemaker activity in the ICCs.

Melatonin synergistically increases resveratrol-induced heme oxygenase-1 expression through the inhibition of ubiquitin-dependent proteasome pathway: a possible role in neuroprotection.

Melatonin is an indoleamine secreted by the pineal gland as well as a plant-derived product, and resveratrol (RSV) is a naturally occurring polyphenol synthesized by a variety of plant species; both molecules act as a neuroprotector and antioxidant. Recent studies have demonstrated that RSV reduced the incidence of Alzheimer's disease and stroke, while melatonin supplementation was found to reduce the progression of the cognitive impairment in AD. The heme oxygenase-1 (HO-1) is an inducible and redox-regulated enzyme that provides tissue-specific antioxidant effects. We assessed whether the co-administration of melatonin and RSV shows synergistic effects in terms of their neuroprotective properties through HO-1. RSV significantly increased the expression levels of HO-1 protein in a concentration-dependent manner both in primary cortical neurons and in astrocytes, while melatonin per se did not. Melatonin + RSV showed a synergistic increase in the expression levels of HO-1 protein but not in the HO-1 mRNA level compared to either melatonin or RSV alone, which is mediated by the activation of PI3K-Akt pathway. Treatment of melatonin + RSV significantly attenuated the neurotoxicity induced by H(2) O(2) in primary cortical neurons and also in organotypic hippocampal slice culture. The blockade of HO-1 induction by shRNA attenuated HO-1 induction by melatonin + RSV and hindered the neuroprotective effects against oxidative stress induced by H(2) O(2) . The treatment of MG132 + RSV mimicked the effects of melatonin + RSV, and melatonin + RSV inhibited ubiquitination of HO-1. These data suggest that melatonin potentiates the neuroprotective effect of RSV against oxidative injury, by enhancing HO-1 induction through inhibiting ubiquitination-dependent proteasome pathway, which may provide an effective means to treat neurodegenerative disorders.