Pharmacological mechanism responsible for the Atractylodes japonica-induced distal colonic contraction in rats.

BACKGROUND AND AIM: Atractylodes japonica Koidz (Compositae) has been commonly used to treat the gastrointestinal (GI) disorders in Korean traditional medicine, but its pharmacological roles in the regulation of GI motility have not been clarified yet. METHODS: Atractylodes japonica was sequentially partitioned with MeOH, n-hexane, CHCl(3), EtOAc and n-BuOH saturated with H(2)O, and the effects of Atractylodes japonica extracts on the spontaneous contractility of GI muscle strips prepared from rats were measured. RESULTS: Among five different fractionations, EtOAc extracts of Atractylodes japonica (AJEA) dose-dependently increased the low frequency contraction of distal colon longitudinal muscles (DCLM), and the ED(50) values were revealed to be 1.71×10(-9) g/ml. Among GI tracts, a prominent contractile response to AJEA was observed only in the DCLM. The contractile patterns produced by AJEA remarkably differed from those caused by acetylcholine and 5-HT. 4-DAMP and methoctramine at 0.5 µM significantly blocked the AJEA (1.0 µg/ml)-induced contraction of DCLM, but ondansetron, GR113808 and methysergide at 1.0 µM in combination did not change the AJEA-induced DCLM contractions. Acetylethylcholine mustard (5.0 µM) significantly diminished the AJEA-induced DCLM contractions, whereas p-chlorophenyl alanine (1.0 µM) did not affect the stimulatory effects of AJEA on the DCLM contractions. CONCLUSION: The present results suggest that AJEA may specifically act on the DCLM among GI smooth muscles, and AJEA-induced DCLM contraction is likely mediated, at least, by activation of ChAT and acetylcholinergic muscarinic receptors.

Acetylene compound isolated from Atractylodes japonica stimulates the contractility of rat distal colon via inhibiting the nitrergic-purinergic relaxation.

AIM OF THE STUDY: Our previous research has showed that rhizome of Atractylodes japonica Koidz (Compositae) exhibits an increase in the spontaneous contractility of distal colon in rats. The aims of this study are to identify the phytochemical(s), which stimulate(s) the colonic contractility, contained in Atractylodes japonica and to evaluate the pharmacological mechanism responsible for the colonic muscle contraction. MATERIALS AND METHODS: Based on the stimulatory activity-guided fractionation on the isometric contraction of rat distal colonic strips, atractylodiol (ATD) and diacetyl-atractylodiol (DATD) were isolated from the CHCl(3) fractions of Atractylodes japonica. RESULTS: ATD and DATD dose-dependently increased both tension and amplitude of distal colon longitudinal muscle (DCLM), but they stimulated only amplitude in the distal colon circular muscle. The ED(50) values of ATD and DATD to stimulate the amplitude of DCLM were revealed as 9.1×10(-9)M and 1.8×10(-8)M, respectively. l-NAME (0.1mM) significantly increased the ADT (1µM)-induced contraction of DCLM, whereas SNAP (0.1mM) markedly reduced the stimulatory effects of ATD on DCLM contractility. The combined effects of SNAP and atropine (0.5µM) on the ATD-induced contraction of DCLM were similar to the inhibitory effects of SNAP alone. Suramin (0.1mM) significantly enhanced the increase of ATD-induced DCLM contraction, whereas ADPßS (0.1mM) markedly abolished the stimulatory effects of ATD on the spontaneous contractility of DCLM. CONCLUSIONS: The present results demonstrate that acetylene compounds, ATD and DATD, are the effective phytochemical of Atractylodes japonica to stimulate the motility of distal colon in rats, and ATD possibly enhances the spontaneous contractility of distal colon through inhibiting the mechanism of nitrergic-purinergic relaxation.

Hexane extract of Poncirus trifoliata (L.) Raf. stimulates the motility of rat distal colon.

AIM OF THE STUDY: Poncirus trifoliata (L.) Raf. (Rutaceae, PT) has been commonly used for treating gastrointestinal (GI) disorders in Korean traditional medicine, but its pharmacological roles in the regulation of colonic motility have not been clarified. This study investigated the regulatory effects of PT on the colonic motility. MATERIALS AND METHODS: Immature fruits of PT were sequentially partitioned with MeOH, n-hexane, CHCl(3), EtOAc, n-BuOH and H(2)O, and the effects of PT extracts on the contractility of colonic strips and colonic luminal transit in rats were measured in vitro and in vivo, respectively. RESULTS: Among six different extracts, only hexane extract of PT (PTHE) dose-dependently increased the low frequency contraction of longitudinal muscle in distal colonic strips, and the ED(50) value was revealed to be 0.71 microg/ml. The contractile patterns induced by PTHE were remarkably different from those caused by acetylcholine (ACh) and serotonin (5-HT). The stimulatory effects of PTHE on the whole distal colonic strips were more prominent than on the mucosa/submucosa-denuded segments. The M(2) receptor-preferring, methoctramine (0.5 microM), and M(3) receptor-preferring antagonist, 4-DAMP (0.5 microM) significantly blocked the PTHE (1 microg/ml)-induced contraction of distal colon longitudinal muscles, whereas the 5-HT receptor antagonists (1.0 microM, alone or in combination) selective for 5-HT(3) (ondansetron), 5-HT(4) (GR113808) and 5-HT(1, 2, 5-7) (methysergide) receptors did not change the PTHE (1 microg/ml)-induced contractility of distal colon longitudinal muscles. SNAP (0.1mM), a NO donor, enhanced the stimulatory effects of PTHE on the longitudinal muscle of distal colon, but l-NAME (0.1mM), a NO synthesis inhibitor, had no effects. PTHE (10-100mg/kg) caused a dose-dependent increase of colonic luminal transit. CONCLUSIONS: Collectively, these findings suggest that PTHE specifically acts on the longitudinal muscle of distal colon in rats, and these stimulatory effects are likely mediated, at least, by activation of acetylcholinergic M(2) and M(3) receptors.

alpha-Spinasterol isolated from the root of Phytolacca americana and its pharmacological property on diabetic nephropathy.

Based on an inhibitory activity-guided fractionation for the high glucose-induced proliferation of glomerular mesangial cells (GMCs), chloroform extracts of the roots of Phytolacca americana were found to contain alpha-spinasterol (C (29)H (48)O), a delta (7)-sterol. This phytosterol proved to be a potent inhibitor (IC (50) = 3.9 x 10 (-12) g/mL, 9.5 pmol/L) of glomerular mesangial cell proliferation caused by high-ambient glucose (5.6 mM vs. 25 mM), and its inhibitory potency was about 1,000 times higher than that of simvastatin, an HMG-CoA reductase inhibitor used as a positive control. alpha-Spinasterol also significantly reduced the increases of serum triglycerides, renal weight and urinary protein excretion in streptozotocin-induced diabetic mice, and these were comparable to the results observed in insulin-treated diabetic mice. Therefore, the results obtained in this study suggest that alpha-spinasterol has a significant therapeutic potential to modulate the development and/or progression of diabetic nephropathy.

Phytolacca americana inhibits the high glucose-induced mesangial proliferation via suppressing extracellular matrix accumulation and TGF-beta production.

This study describes a potential of Phytolaccaceae (Phytolacca americana var.) as an inhibitor of high glucose-stimulated production of extracellular matrix (ECM) proteins and TGF-beta in cultured glomerular mesangial cells (GMCs). Raising the ambient glucose concentration for 24 hrs caused a dose-dependent increase in [3H]thymidine incorporation of GMCs, and the maximal response was achieved at 20 mM. Phytolaccaceae extracts (2.5-20 microg/ml) inhibited the high glucose-induced [3H]thymidine incorporation in a dose-dependent manner, and the concentrations tested here did not affect to the cell viability. Exposure of the GMCs to 20 mM glucose caused both ECM (collagen and fibronectin) accumulation and TGF-beta secretion, and these changes were significantly diminished by treatment of GMCs with Phytolaccaceae (10 microg/ml). Taken together, these results indicate that Phytolaccaceae inhibits the high glucose-induced GMCs proliferation partially through suppressing accumulation of ECM components and TGF-beta production, suggesting that Phytolaccaceae may be a promising agent for treating the development and progression of diabetic glomerulopathy.

Inhibitory effect of procyanidin oligomer from elm cortex on the matrix metalloproteinases and proteases of periodontopathogens.

OBJECTIVES: The purpose of this study was to evaluate a partially purified extract (elm extract) from the Ulmi cortex (Ulmi macrocarpa Hance) and its active ingredient, a mix of procyanidin oligomers (3 to 12 flavan-3-ol monomers, an average molecular weight of 1,518 with an average polymerization degree of 5.3) for a possible inhibitory effect against proteases. BACKGROUND: Host-derived matrix metalloproteinases (MMPs) and bacterial proteases play important roles in the gingival tissue destruction that is a characteristic of periodontitis. The inhibitors of these proteases may be developed into therapeutic agents against periodontitis. METHODS: The inhibitory effects were assessed by gelatin zymography. The MMPs tested were originated from the gingival crevicular fluid (GCF) of adult periodontitis patients and from the conditioned media of cultured periodontal ligament (PDL) cells, which provided the proMMP-2 and activated MMP-2 when treated with a periodontopathogen, Treponema lecithinolyticum. Bacterial enzymes tested were secreted forms from two major periodontopathogens, Porphyromonas gingivalis and Treponema denticola. In addition, the inhibitory effects on trypsin-like enzymes from these two periodontopathogens were assayed by the n-benzoyl-DL-arginine-naphthylamide (BANA) test. RESULTS: The elm extract and the procyanidin oligomer (100-1,000 microg/ml) exhibited potent inhibitory effects on the MMPs in GCF (chiefly MMP-8 and MMP-9), the pro and active forms of MMP-2, and secreted and trypsin-like enzymes from T. denticola and P. gingivalis. CONCLUSIONS: These results suggest that elm cortex should be considered as a potential agent against periodontal diseases, due to its inhibitory action on MMPs and the proteases of periodontopathogens.

Anti-angiogenic activities of Cnidium officinale Makino and Tabanus bovinus.

This study investigated the anti-angiogenic activities of Cnidium officinale Makino and Tabanus bovinus by using cultured glomerular capillary endothelial cells (GECs), chorioallantoic membrane (CAM) and rat cornea. Treatment of GECs with several concentrations (5-50 microg/ml) of C. officinale Makino and T. bovinus extracts for 24 h inhibited angiotensin II (10(-8) M)-induced increases of [3H]thymidine uptake and cell numbers in a concentration-dependent manner. The extent of inhibitory rate of [3H]thymidine incorporation by C. officinale Makino and T. bovinus at 50 microg/ml was a similar to that by 10(-5) M of retinoic acid. Herbal extracts also conspicuously inhibited the neovascularization. In contrast to the normal branching of vascular vessels, blood vessel patterns in CAMs treated with extracts (50 microg per egg) of C. officinale Makino and T. bovinus were ran parallel to each other without much branching. Moreover, oral administration of herbal extracts (20 mg/kg per day) for 4 weeks significantly inhibited the rat corneal neovascularization induced by suture, and the length of blood vessels in herbal medicine-treated rat cornea was conspicuously lower than that in control animals. A similar inhibitory effect to these was also observed in the rat cornea treated with thalidomide (200 mg/kg per day). These findings indicate that the anti-angiogenic properties of C. officinale Makino and T. bovinus may be one of the pharmacological mechanisms underlying the anti-tumor and anti-metastatic activities of herbal extracts tested in this study.