Gastroprotective Effects of PMK-S005 against Ethanol-Induced Acute Gastric Damage in Rats.

BACKGROUND/AIMS: This study aimed to examine the gastroprotective effects of PMK-S005, which is a synthetic S-allyl-Lcysteine (SAC; a sulfur-containing amino acid), against acute ethanol-induced gastric damage in rats. METHODS: Sprague- Dawley rats were divided into six groups, including a nonethanol group, groups treated with absolute ethanol 1 hour after pretreatment with various doses of PMK-S005 (1, 5, and 10 mg/kg) or rebamipide (50 mg/kg), and an absolute ethanolonly group. Ethanol-induced gross ulcer and mucus levels were measured. Myeloperoxidase, tumor necrosis factor a, interleukin 1ß, PGE2, LTB4, cPLA2, COX-1, and COX-2 levels were estimated by enzyme-linked immunosorbent assay or Western blot analysis. Furthermore, the protein expression levels of antioxidant enzymes, including heme oxygenase-1 (HO-1), NAD(P)Hquinine oxidoreductase 1 (NQO-1), GCLC, and GCLM, were assessed. RESULTS: PMK-S005 significantly attenuated the ethanol-induced gastric damage; it reduced mucosal inflammatory cytokine production and increased mucus levels. The expression levels of cPLA2, COX-1, and COX-2 were decreased by PMK-S005. PMK-S005 did not affect PGE2 synthesis, but LTB4 production was significantly suppressed. In addition, long-term administration of PMKS005 significantly increased the expression of HO-1, NQO-1, GCLC, and GCLM. CONCLUSIONS: These results strongly suggest that PMK-S005 prevents gastric mucosal damage and that these gastroprotective activities are due to anti-inflammatory effects and enhancement of the gastric defense system, including antioxidant enzymes.

Anti-inflammatory effect of a standardized triterpenoid-rich fraction isolated from Rubus coreanus on dextran sodium sulfate-induced acute colitis in mice and LPS-induced macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Rubus coreanus Miquel (Rosaceae), the Korean black raspberry, has traditionally been used to treat inflammatory diseases including diarrhea, asthma, stomach ailment, and cancer. Although previous studies showed that the 19α-hydroxyursane-type triterpenoids isolated from Rubus coreanus exerted anti-inflammatory activities, their effects on ulcerative colitis and mode of action have not been explored. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms involving19α-hydroxyursane-type triterpenoid-rich fraction from Rubus coreanus (TFRC) on a mice model of colitis and lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. MATERIALS AND METHODS: Experimental colitis was induced by DSS for 7 days in ICR mice. Disease activity indices (DAI) took into account body weight, stool consistency, and gross bleeding. Histological changes and macrophage accumulation were observed by immunohistochemical analysis. Pro-inflammatory markers were determined using immunoassays, RT-PCR, and real time PCR. Signaling pathway involving nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation was determined by luciferase assay and Western blotting. RESULTS: In DSS-induced colitis mice, TFRC improved DAIs and pathological characteristics including colon shortening and colonic epithelium injury. TFRC suppressed tissue levels of pro-inflammatory cytokines and reduced macrophage infiltration into colonic tissues. In LPS-induced RAW 264.7 macrophages, TFRC inhibited the production of NO, PGE2, and pro-inflammatory cytokines by down-regulating the activation of NF-κB and p38 MAPK signaling. CONCLUSION: The study demonstrates that TFRC has potent anti-inflammatory effects on DSS-induced colonic injury and LPS-induced macrophage activation, and supports its possible therapeutic and preventive roles in colitis.

Protective effects of garlic extract, PMK-S005, against nonsteroidal anti-inflammatory drugs-induced acute gastric damage in rats.

BACKGROUND: PMK-S005 is synthetic s-allyl-L-cysteine (SAC), a sulfur-containing amino acid, which was initially isolated from garlic. The antioxidant and anti-inflammation activities of SAC have been demonstrated in diverse experimental animal models. AIMS: The purpose of this study was to investigate the gastroprotective effects of PMK-S005 against NSAIDs-induced acute gastric damage in rats. METHODS: Eight-week SD rats were pretreated with PMK-S005 (1, 5, or 10 mg/kg) or rebamipide (50 mg/kg) 1 h before administration of NSAIDs including aspirin (200 mg/kg), diclofenac (80 mg/kg), and indomethacin (40 mg/kg). After 4 h, the gross ulcer index, histological index, and gastric mucus level were determined. Myeloperoxidase (MPO), TNF-α, IL-1ß, PGE2, and LTB4 levels were estimated in the gastric mucosal tissue by ELISA. Protein expressions of cPLA2, COX-1, and COX-2 were assessed by Western blot analysis. RESULTS: Pretreatment with PMK-S005 significantly attenuated the NSAIDs-induced gastric damage and increased the gastric mucus level. In addition, PMK-S005 attenuated increases in MPO, TNF-α, and IL-1ß production. The expressions of cPLA2 and COX-2 induced by NSAIDs were decreased by PMK-S005 pretreatment. PMK-S005 did not cause suppression of PGE2 synthesis induced by NSAIDs, but LTB4 production was significantly suppressed by PMK-S005. The effects of PMK-S005 were consistently maximized at a concentration of 5 mg/kg, which were frequently superior to those of rebamipide. CONCLUSIONS: These results strongly suggest that PMK-S005 can be a useful gastroprotective agent against acute gastric mucosal damage by suppressing proinflammatory cytokines, down-regulating cPLA2, COX-2 and LTB4 expression, and increasing the synthesis of mucus.

Pharmacokinetic comparison of ginsenoside metabolite IH-901 from fermented and non-fermented ginseng in healthy Korean volunteers.

ETHNOPHARMACOLOGICAL RELEVANCE: IH-901 (20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol) is a novel ginseng saponin metabolite formed by human intestinal bacteria and is known to have antitumor and antimetastatic effects. However, there has been no pharmacokinetic study of IH-901 in human beings. AIM OF THE STUDY: The aim of this study was to investigate the pharmacokinetic differences of IH-901 from fermented and non-fermented ginseng. MATERIALS AND METHODS: To investigate whether the pharmacokinetics of IH-901 differ between fermented and non-fermented ginseng, an open label, randomized, single dose, fasting, two-period, cross-over, pharmacokinetic study was conducted. A total of 24 healthy Korean male volunteers participated in this study. All subjects were allocated into two equal groups and administered 3g of fermented or non-fermented Panax ginseng. Serial blood samples for pharmacokinetic analysis were collected in the 24 h after dosing. Plasma IH-901 concentration was measured by a validated high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic parameters including AUC(t), C(max), and T(max) were calculated by noncompartmental models in the BA-CALC program (KFDA, 2008, 1.0.0, Korea). RESULTS: After oral administration of fermented ginseng, 5 subjects experienced diarrhea. The means of AUC(t) and C(max) were significantly different between the two groups. In the fermented ginseng group, AUC(t) was 2083.09±91.97 ng h/mL, a 15.5-fold increase over that of IH-901 from the non-fermented group (134.50±63.10 ng h/mL), and the mean C(max) was 325.00±91.97 ng/mL in the fermented ginseng group, a 27-fold higher value than that in the non-fermented group (13.88±7.24 ng/mL). T(max) was 3.29±1.00 and 12.04±4.96 h in the fermented and non-fermented group, respectively. CONCLUSIONS: The results of this study showed that the pharmacokinetic parameters of IH-901 from fermented Panax ginseng are different from those of non-fermented ginseng, from which IH-901 is formed by intestinal fermentation.

Gluco-obtusifolin and its aglycon, obtusifolin, attenuate scopolamine-induced memory impairment.

In the present study, we assessed the effects of gluco-obtusifolin, isolated from the seeds of Cassia obtusifolia L., and its aglycone, obtusifolin, on the learning and memory impairments induced by scopolamine using the passive avoidance and the Morris water maze tasks in mice. Gluco-obtusifolin (1, 2, and 4 mg/kg, p.o.) and obtusifolin (0.25, 0.5, 1, and 2 mg/kg, p.o.) significantly reversed scopolamine-induced cognitive impairments in the passive avoidance test (P<0.05). Moreover, gluco-obtusifolin (2 mg/kg, p.o.) and obtusifolin (0.5 mg/kg, p.o.) improved escape latencies, swimming times in the target quadrant, and crossing numbers in the zone where the platform previously existed in the Morris water maze test. In the acetylcholinesterase assay, gluco-obtusifolin and obtusifolin were found to inhibit acetylcholinesterase activity in vitro (IC(50) = 37.2 and 18.5 microM, respectively) and ex vivo. These results suggest that gluco-obtusifolin and its aglycone may be useful for the treatment of cognitive impairment, and that its beneficial effects are mediated, in part, by the enhancement of cholinergic signaling.