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This study aimed to elucidate the effects of storage temperature on various fruit quality attributes, physiological disorders, and associated metabolites in the 0.5, 3, or 10 °C stored hardy kiwifruit. Peel pitting, which was highest in the 0.5 °C stored fruit, was identified as a chilling injury symptom of hardy kiwifruit. Proline and branched-chain amino acid contents showed higher values at 0.5 °C stored fruit as chilling responses. On the other hand, fruit shriveling and decay were highest in the 10 °C after 5 weeks of storage. The 10 °C storage induced fruit ripening during 3 weeks, but fruit shriveling and decay were severe after 5 weeks of storage. Therefore, storing the 'Autumn Sense' hardy kiwifruit at proper temperatures would be more beneficial, as it alters targeted metabolites and helps reduce the incidence of physiological disorders during cold storage.

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A cold storage system is useful for maintaining the quality of hardy kiwifruit. However, extended cold storage periods inevitably result in cold stress, leading to lower fruit marketability; the severity of chilling injury depends on fruit types and cultivars. In this study, the impact of cold storage conditions on the physicochemical properties and antioxidant capacity of two phenotypically different hardy kiwifruit cultivars-'Cheongsan' (large type) and 'Daebo' (small type)-stored at low (L; 3 °C, relative humidity [RH]; 85-90%) and moderate-low (ML; 5 °C, RH; 85-90%) temperatures was determined. Significant differences in fruit firmness and titratable acidity between treatments L and ML were observed in both cultivars during the experimental storage period. Meanwhile, the browning and pitting rates of the 'Cheongsan' fruits in treatment L increased for 8 weeks compared with those of the 'Daebo' fruits in treatments L and ML; nonetheless, fruit decay was observed in the 'Daebo' fruits in treatment ML after 6 weeks. The total chlorophyll, carotenoid, flavonoid, and ascorbic acid concentrations as well as the antioxidant activities of both the cultivars significantly differed between treatments L and ML. After 2 weeks of storage, the 'Cheongsan' fruits in treatment L had lower antioxidant activities and ascorbic acid content than those in treatment ML. These results demonstrate that the quality attributes and antioxidant activity of hardy kiwifruit are influenced by the low-temperature storage conditions and the specific kiwifruit cultivars. Our findings suggest that optimal cold storage conditions, specific to each hardy kiwifruit cultivar, promise to maintain fruit quality, including their health-promoting compounds, during long-term storage.

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Cirsium setidens is commonly used as a food ingredient, and it is typically stored and distributed in a dried form to prolong its shelf life. In a previous study, a micro-oil-sprayed thermal air (MOTA) technique was developed, which effectively enhanced the rehydration properties and improved the color characteristics of Cirsium setidens after processing. Here, we investigated the relationship between the color characteristics and taste of MOTA-processed C. setidens and the effect of NaCl pretreatment, prior to processing, on the final quality of dried C. setidens. NaCl pretreatment, whether combined with the MOTA technique or not, showed improved color characteristics, in which MOTA-and NaCl+ MOTA-processed C. setidens manifested equal color characteristics. In contrast, NaCl + MOTA-processed C. setidens resulted in significantly higher values of sourness and saltiness than MOTA-processed C. setidens when the taste of the rehydrated C. setidens was examined using an electronic tongue (Astree II; Alpha MOS, Toulouse, France). Pearson correlation coefficient analysis showed that sourness and saltness were negatively correlated with Hunter a* values and positively correlated with Hunter L* and Hunter b* values, indicating that the color characteristics of dried and rehydrated C. setidens could be indicators of taste. Furthermore, the amounts of total phenol and chlorophyll were better preserved in C. setidens processed by the MOTA technique with NaCl than by the MOTA technique alone. Our data revealed that the color characteristics of dried plants are associated with the taste of processed C. setidens, and that the MOTA technique with NaCl pretreatment is a useful method for preserving health-promoting compounds during processing.

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Shiitake mushroom (Lentinula edodes) hold high nutritional and medicinal value as they contain an abundance of health-promoting compounds. However, the effect of long-term postharvest storage on the variation in the levels of health-promoting compounds has not been extensively studied. In this study, we investigated the changes in the levels of phenolic compounds, antioxidants, eritadenine, and ergothioneine in shiitake mushrooms stored at three different temperatures (1, 3, and 5 °C) for 4 weeks. Compared to mushrooms stored at lower temperatures, those stored at 5 °C exhibited a higher level of total phenolics in their pileus after 2 weeks of storage; however, storage at 5 °C also increased the deterioration of the fruiting body of these mushrooms. In mushrooms stored at all temperatures, the eritadenine content in the pilei tended to increase up to 2 weeks of storage. In contrast, the ergothioneine content in the pileus decreased during storage, with a significantly lower level detected in mushrooms stored at 5 °C for 4 weeks. Together, these results suggest that the mechanisms underlying the accumulation of phenolics and eritadenine may be related to mushroom deterioration during storage. Our findings indicate that the levels of health-promoting compounds in shiitake mushrooms are influenced by storage temperature, suggesting the potential to control adjustments of specific bioactive compounds by regulating storage conditions.

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As the national flower of Korea, the Hibiscus syriacus L. (Rose of Sharon) is symbolic in its abundance and is a prominent feature of Korean culture. H. syriacus has played an important role in Korea, not only as an ornamental plant but also as an essential ingredient in folk remedies through its various parts. This study aimed to characterize the nutritional and biochemical composition of each plant unit of H. syriacus "Wonhwa." The units are namely: the petals, leaves, roots, and sprouts from its seeds. According to the results each unit produced, the sprouts had the highest content of amino acids and fatty acids which adhere to the requirements of nutritionally excellent food ingredients. The petals produced high quantities of glucose, sucrose, and fumaric acid, with the highest antioxidant activity among the four units. The main bioactive compounds detected in H. syriacus extracts in the four units were o-coumaric acid, p-coumaric acid, schaftoside, isoschaftoside, apigenin-6-C-glucoside-7-o-glucoside, and kaempferol-3-O-galactoside-7-O-rhamnoside. Overall, the highest number of bioactive compounds, 2 phenolic acids and 22 flavonoids, were identified in the petals. These results suggest the possibility of excellent pharmacological activity in the petals.

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This study was conducted to compare the synbiotic activity between Corni fructus (C. fructus) and Limosilactobacillus reuteri (L. reuteri) on dextran sulfate sodium (DSS)-induced colitis and cognitive dysfunction in C57BL/6 mice. C. fructus (as prebiotics, PRE), L. reuteri (as probiotics, PRO), and synbiotics (as a mixture of L. reuteri and C. fructus, SYN) were fed to mice for 3 weeks. Consumption of PRE, PRO, and SYN ameliorated colitis symptoms in body weight, large intestinal length, and serum albumin level. Moreover, SYN showed a synergistic effect on intestinal permeability and intestinal anti-inflammation response. Also, SYN significantly improved cognitive function as a result of measuring the Y-maze and passive avoidance tests in DSS-induced behavioral disorder mice. Especially, SYN also restored memory function by increasing the cholinergic system and reducing tau and amyloid ß pathology. In addition, PRE, PRO, and SYN ameliorated dysbiosis by regulating the gut microbiota and the concentration of short-chain fatty acids (SCFAs) in feces. The bioactive compounds of C. fructus were identified with quinic acid, morroniside, loganin, and cornuside, using ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS2). In conclusion, synbiotic supplementation alleviated DSS-induced colitis and cognitive dysfunction by modulating gut microbiota, proinflammatory cytokines, and SCFAs production.

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Berchemia floribunda (Wall.) Brongn. (BF), which belongs to Rhamnaceae, is a special plant of Anmyeon Island in Korea. BF has been reported to have antioxidant and whitening effects. However, the anti-inflammatory activity of BR has not been elucidated. In this study, we evaluated the anti-inflammatory effect of leaves (BR-L), branches (BR-B) and fruit (BR-F) extracted with 70% ethanol of BR and elucidated the potential signaling pathway in LPS-induced RAW264.7 cells. BR-L showed a strong anti-inflammatory activity through the inhibition of NO production. BR-L significantly suppressed the production of the pro-inflammatory mediators such as iNOS, COX-2, IL-1ß, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells. BR-L suppressed the degradation and phosphorylation of IκB-α, which contributed to the inhibition of p65 nuclear accumulation and NF-κB activation. BR-L obstructed the phosphorylation of MAPKs (ERK1/2, p38 and JNK) in LPS-stimulated RAW264.7 cells. Consequently, these results suggest that BR-L may have great potential for the development of anti-inflammatory drugs to treat acute and chronic inflammatory disorders.

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Heracleum moellendorffii (H. moellendorffii) is a family of Umbelliferae and has long been used for food and medicinal purposes. However, the immune-enhancing activity of H. moellendorffii has not been studied. Thus, we evaluated in vitro immune-enhancing activity of H. moellendorffii through macrophage activation using RAW264.7 cells. Heracleum moellendorffii Root extracts (HMR) increased the production of immunomodulators such as NO, iNOS, IL-1ß, IL-6 IL-12, TNF-α, and MCP-1 and activated phagocytosis in RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by HMR. Inhibition of MAPK signaling attenuated the production of immunomodulators induced by HMR, but inhibitions of NF-κB or PI3K/AKT signaling did not affect HMR-mediated production of immunomodulators. HMR activated MAPK signaling pathway, and activation of MAPK signaling pathways by HMR was reversed by TLR2 and TLR4 inhibition. Based on the results of this study, HMR is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4-dependent MAPK signaling pathway. Therefore, it is thought that HMR has the potential to be used as an agent for enhancing immunity.

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Honeyberry (Lonicera caerulea) has long been used as a traditional medicine in China, Japan and northern Russia. Functional studies of honeyberry have mainly focused on the fruits, which have been reported to exert various pharmacological activities, including anti­inflammatory activity, with limited or no studies on the other parts of the plant, such as the leaves and branches. In the present study, the anti­inflammatory effects of extracts of the leaves (HBL), branches (HBB) and fruit (HBF) of honeyberry plant were evaluated in lipopolysaccharide (LPS)­stimulated RAW264.7 cells. HBL and HBB significantly inhibited the production of pro-inflammatory mediators in LPS­stimulated RAW264.7 cells, and the inhibitory effects of HBL and HBB were stronger than those of HBF. HBL and HBB blocked the nuclear accumulation of p65 independently of IκB­α. HBL did not inhibit the phosphorylation of ERK1/2 or p38; however, HBB effectively inhibited the phosphorylation of p38 but not ERK1/2. HBL and HBB increased the expression of heme oxygenase­1 (HO­1) protein by inducing the nuclear accumulation of nuclear factor erythroid 2­related factor 2 (Nrf2) through the activation of the reactive oxygen species (ROS)/p38 pathway; the reduction in inducible nitric oxide synthase (iNOS) and interleukin­1ß (IL­1ß) expression by HBL and HBB was inhibited by HO­1 knockdown. In addition, HBL and HBB increased the expression of activating transcription factor­3 (ATF3), and the reduction in iNOS and IL­1ß expression by HBL and HBB was inhibited by ATF3 knockdown. Collectively, HBL and HBB inhibited LPS­induced nuclear factor­κB activation by blocking the nuclear accumulation of p65, increasing HO­1 expression through activation of the ROS/p38/Nrf2 pathway, and increasing ATF3 expression. Furthermore, HBB inhibited LPS­induced p38 phosphorylation. These findings suggest that HBL and HBB may have great potential as natural products for the development of anti­inflammatory drugs.

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ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng Meyer) is a very well-known traditional herbal medicine that has long been used to enhance the body's immunity. Because it is a type of ginseng, it is believed that wild simulated ginseng (WSG) also has immune-enhancing activity. However, study on the immune-enhancing activity of WSG is quite insufficient compared to ginseng. AIM OF THE STUDY: In this study, we evaluated immune-enhancing activity of WSG through macrophage activation to provide a scientific basis for the immune enhancing activity of WSG. MATERIALS AND METHODS: The effect of WSG on viability of RAW264.7 cells was evaluated by MTT assay. The NO level was measured by Griess reagent. The expression levels of mRNA or protein in WSG-treated RAW264.7 cells were analyzed by RT-PCR and Western blot, respectively. RESULTS: WSG increased the production of immunomodulators such as NO, iNOS, COX-2, IL-1ß, IL-6 and TNF-α and activated phagocytosis in mouse macrophages RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by WSG. WSG activated MAPK, NF-κB and PI3K/AKT signaling pathways, and inhibition of such signaling activation blocked WSG-mediated production of immunomodulators. In addition, activation of MAPK, NF-κB and PI3K/AKT signaling pathways by WSG was reversed by TLR2 or TLR4 inhibition. CONCLUSION: Based on the results of this study, WSG is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4-dependent MAPK, NF-κB and PI3K/AKT signaling pathways. Therefore, it is thought that WSG have the potential to be used as an agent for enhancing immunity.

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OBJECTIVE: Recently, Rodgersia podophylla has been reported to exhibit anti-inflammatory activity. However, little is known about the potential mechanisms about its anti-inflammatory activity. We elucidated the anti-inflammatory mechanisms of leaves extracts from Rodgersia podophylla (RP-L) in RAW264.7 cells. MATERIALS AND METHODS: LPS-induced NO was measured by Griess and mRNA of pro-inflammatory mediators was analyzed by RT-PCR. Cell viability was measured using MTT assay. The protein level was analyzed by Western blot. RESULTS: RP-L significantly inhibited the production of the pro-inflammatory mediators such as NO, iNOS, IL-1ß and IL-6 in LPS-stimulated RAW264.7 cells. RP-L increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of RP-L against LPS-induced NO production in RAW264.7 cells. Inhibition of p38, ROS and GSK3ß attenuated RP-L-mediated HO-1 expression. Inhibition of ROS inhibited p38 phosphorylation and GSK3ß expression induced by RP-L. In addition, inhibition of GSK3ß blocked RP-L-mediated p38 phosphorylation. RP-L induced nuclear accumulation of Nrf2, and inhibition of p38, ROS and GSK3ß abolished RP-L-mediated nuclear accumulation of Nrf2. Furthermore, RP-L blocked LPS-induced degradation of IκB-α and nuclear accumulation of p65. RP-L also attenuated LPS-induced phosphorylation of ERK1/2 and p38. In GC/MS analysis of RP-L, pyrogallol was detected as bioactive compound for anti-inflammatory activity of RP-L. Pyrogallol was observed to activate HO-1 expression through ROS/GSK3ß/p38/Nrf2/HO-1 signaling. CONCLUSIONS: Our results suggest that RP-L exerts potential anti-inflammatory activity by activating ROS/GSK3ß/p38/Nrf2/HO-1 signaling and inhibiting NF-κB and MAPK signaling in RAW264.7 cells. These findings suggest that RP-L may have great potential for the development of anti-inflammatory drug.

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BACKGROUND: Vaccinium oldhamii (V. oldhamii) has been reported to exert a variety of the pharmacological properties such as anti-oxidant activity, anti-cancer activity, and inhibitory activity of α-amylase and acetylcholinesterase. However, the anti-inflammatory activity of V. oldhamii has not been studied. In this study, we aimed to investigate anti-inflammatory activity of the stem extracts from V. oldhamii, and to elucidate the potential mechanisms in LPS-stimulated RAW264.7 cells. METHODS: Cell viability was evaluated by MTT assay. The determination of NO and PGE2 production was performed using Griess reagent and Prostaglandin E2 ELISA Kit, respectively. The change of mRNA or protein level was evaluated by RT-PCR and Western blot. RESULTS: Among VOS, VOL and VOF, the inhibitory effect of NO and PGE2 production induced by LPS was highest in VOS treatment. Thus, VOS was selected for the further study. VOS dose-dependently blocked LPS-induced NO and PGE2 production by inhibiting iNOS and COX-2 expression, respectively. VOS inhibited the expression of pro-inflammatory cytokines such as IL-1ß, IL-6 and TNF-α. In addition, VOS suppressed TRAP activity and attenuated the expression of the osteoclast-specific genes such as NFATc1, c-FOS, TRAP, MMP-9, cathepsin K, CA2, OSCAR and ATPv06d2. VOS inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. VOS inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. Furthermore, VOS inhibited ATF2 phosphorylation and blocked ATF2 nuclear accumulation. CONCLUSIONS: These results indicate that VOS may exert anti-inflammatory activity by inhibiting NF-κB and MAPK/ATF2 signaling. From these findings, VOS has potential to be a candidate for the development of chemopreventive or therapeutic agents for the inflammatory diseases.

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BACKGROUND: Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R. METHODS: The cytotoxicity of HM-R against RAW264.7 cells was evaluated using MTT assay. The inhibition of NO and PGE2 production by HM-R was evaluated using Griess reagent and Prostaglandin E2 ELISA Kit, respectively. The changes in mRNA or protein level following HM-R treatment were assessed by RT-PCR and Western blot analysis, respectively. RESULTS: HM-R dose-dependently blocked LPS-induced NO and PGE2 production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, IL-1ß and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced NF-κB signaling activation through blocking IκB-α degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound. CONCLUSIONS: These results indicate that HM-R may exert anti-inflammatory activity by inhibiting NF-κB and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. These findings suggest that HM-R has a potential as a natural material for the development of anti-inflammatory drugs.

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Sageretia thea (S. thea) commonly known as Chinese sweet plum or Chinese bird plum has been used for treating hepatitis and fevers in Korea and China. S. thea has been reported to exert anti-oxidant, anticancer and anti-human immunodeficiency virus activity. However, there is little study on the anti-inflammatory activity of S. thea. Thus, we evaluated the anti-inflammatory effect of extracts of leaves (ST-L) and branches (ST-B) from Sageretia thea in LPS-stimulated RAW264.7 cells. ST-L and ST-B significantly inhibited the production of the pro-inflammatory mediators such as NO, iNOS, COX-2, IL-1 ß and IL-6 in LPS-stimulated RAW264.7 cells. ST-L and ST-B blocked LPS-induced degradation of I κ B- α and nuclear accumulation of p65, which resulted in the inhibition of NF- κ B activation in RAW264.7 cells. ST-L and ST-B also attenuated the phosphorylation of ERK1/2, p38 and JNK in LPS-stimulated RAW264.7 cells. In addition, ST-L and ST-B increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of ST-L and ST-B against LPS-induced NO production in RAW264.7 cells. Inhibition of p38 activation and ROS elimination attenuated HO-1 expression by ST-L and ST-B, and ROS elimination inhibited p38 activation induced by ST-L and ST-B. ST-L and ST-B dramatically induced nuclear accumulation of Nrf2, but this was significantly reversed by the inhibition of p38 activation and ROS elimination. Collectively, our results suggest that ST-L and ST-B exerts potential anti-inflammatory activity by suppressing NF- κ B and MAPK signaling activation, and activating HO-1 expression through the nuclear accumulation of Nrf2 via ROS-dependent p38 activation. These findings suggest that ST-L and ST-B may have great potential for the development of anti-inflammatory drug to treat acute and chronic inflammatory disorders.

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BACKGROUND: Sageretia thea (S. thea) has been used as the medicinal plant for treating hepatitis and fevers in Korea and China. Recently, anticancer activity of S. thea has been reported, but the potential mechanism for the anti-cancer property of S. thea is still insufficient. Thus, we evaluated whether extracts from the leaves (STL) and branches (STB) of S. thea exert anticancer activity and elucidated its potential mechanism in SW480 cells. METHODS: MTT assay was performed for measuring cell viability. Western blot and RT-PCR were used for analyzing the level of protein and mRNA, respectively. RESULTS: Treatment of STL or STB decreased the cell viability and induced apoptosis in SW480 cells. Decreased level of cyclin D1 protein was observed in SW480 cells treated with STL or STB, but no change in cyclin D1 mRNA level was observed with the treatment of STL or STB. MG132 blocked downregulation of cyclin D1 protein by STL or STB. Thr286 phosphorylation of cyclin D1 by STL or STB occurred faster than downregulation of cyclin D1 protein in SW480 cells. When SW480 cells were transfected with T286A-cyclin D1, cyclin D1 degradation by STL or STB did not occur. Inhibition of GSK3ß and cyclin D1 nuclear export attenuated STL or STB-mediated cyclin D1 degradation. In addition, STL or STB increased HO-1 expression, and the inhibition of HO-1 attenuated the induction of apoptosis by STL or STB. HO-1 expression by STL or STB resulted from Nrf2 activation through ROS-dependent p38 activation. CONCLUSIONS: These results indicate that STL or STB may induce GSK3ß-dependent cyclin D1 degradation, and increase HO-1 expression through activating Nrf2 via ROS-dependent p38 activation, which resulted in the decrease of the viability in SW480 cells. These findings suggest that STL or STB may have great potential for the development of anti-cancer drug.

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Silymarin from milk thistle (Silybum marianum) has been reported to show an anti-cancer activity. In previous study, we reported that silymarin induces cyclin D1 proteasomal degradation through NF-κB-mediated threonine-286 phosphorylation. However, mechanism for the inhibition of Wnt signaling by silymarin still remains unanswered. Thus, we investigated whether silymarin affects Wnt signaling in human colorectal cancer cells to elucidate the additional anti-cancer mechanism of silymarin. Transient transfection with a TOP and FOP FLASH luciferase construct indicated that silymarin suppressed the transcriptional activity of ß-catenin/TCF. Silymarin treatment resulted in a decrease of intracellular ß-catenin protein but not mRNA. The inhibition of proteasome by MG132 and GSK3ß inhibition by SB216763 blocked silymarin-mediated downregulation of ß-catenin. In addition, silymarin increased phosphorylation of ß-catenin and a point mutation of S33Y attenuated silymarin-mediated ß-catenin downregulation. In addition, silymarin decreased TCF4 and increased Axin expression in both protein and mRNA level. From these results, we suggest that silymarin-mediated downregulation of ß-catenin and TCF4 may result in the inhibition of Wnt signaling in human colorectal cancer cells.

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Phlorofucofuroeckol A (PFF-A), one of the phlorotannins found in brown algae, has been reported to exert anti-cancer property. However, the molecular mechanism for the anti-cancer effect of PFF-A has not been known. Activating transcription factor 3 (ATF3) has been reported to be associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which PFF-A stimulates ATF3 expression and apoptosis in human colorectal cancer cells. PFF-A decreased cell viability through apoptosis of human colorectal cancer cells. PFF-A increased ATF3 expression through regulating transcriptional activity. The responsible cis-element for ATF3 transcriptional activation by PFF-A was cAMP response element binding protein (CREB), located between positions -147 and -85 of the ATF3 promoter. Inhibition of p38, c-Jun N-terminal kinases (JNK), glycogen synthase kinase (GSK) 3ß, and IκB kinase (IKK)-α blocked PFF-A-mediated ATF3 expression. ATF3 knockdown by ATF3 siRNA attenuated the cleavage of poly (ADP-ribose) polymerase (PARP) by PFF-A, while ATF3 overexpression increased PFF-A-mediated cleaved PARP. These results suggest that PFF-A may exert anti-cancer property through inducing apoptosis via the ATF3-mediated pathway in human colorectal cancer cells.

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BACKGROUND: Mulberry root bark was shown to induce cyclin D1 proteasomal degradation in the human colorectal cancer cells. Still, the molecular mechanisms whereby mulberry root bark induces cyclin D1 proteasomal degradation remain largely unknown. PURPOSE: In this study, the inhibitory effect of mulberry root bark (MRB) on the proliferation of human colorectal cancer cells and the mechanism of action were examined to evaluate its anti-cancer activity. METHODS: Anti-proliferative effect was determined by MTT assay. RT-PCR and Western blotting were used to assess the mRNA and protein expression of related proteins. RESULTS: MRB inhibited markedly the proliferation of human colorectal cancer cells (HCT116, SW480 and LoVo). In addition, the proliferation of human breast cancer cells (MDA-MB-231 and MCF-7) was suppressed by MRB treatment. However, MRB did not affect the growth of HepG-2 cells as a human hepatocellular carcinoma cell line. MRB effectively decreased cyclin D1 protein level in human colorectal cancer cells and breast cancer cells, but not in hepatocellular carcinoma cells. Contrast to protein levels, cyclin D1 mRNA level did not be changed by MRB treatment. Inhibition of proteasomal degradation by MG132 attenuated MRB-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with MRB. In addition, MRB increased phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine attenuated MRB-mediated cyclin D1 degradation. Inhibition of GSK3ß by LiCl suppressed cyclin D1 phosphorylation and downregulation by MRB. MRB decreased the nuclear level of cyclin D1 and the inhibition of nuclear export by LMB attenuated MRB-mediated cyclin D1 degradation. CONCLUSION: MRB has anti-cancer activity by inducing cyclin D1 proteasomal degradation through cyclin D1 nuclear export via GSK3ß-dependent threonine-286 phosphorylation. These findings suggest that possibly its extract could be used for treating colorectal cancer.

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Naringenin (NAR) as one of the flavonoidsobserved in grapefruit has been reported to exhibit an anti-cancer activity. Activating transcription factor 3 (ATF3) is associated with apoptosis in human colon cancer cells. This study was performed to investigate the molecular mechanism by which NAR stimulates ATF3 expression and apoptosis in human colon cancer cells. NAR reduced the cell viability and induced an apoptosis in human colon cancer cells. ATF3 overexpression increased NAR-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by NAR. NAR increased ATF3 expression in both protein and mRNA level, and increased the luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by NAR is located between -317 and -148 of ATF3 promoter. p38 inhibition blocked NAR-mediated ATF3 expression, its promoter activation and apoptosis. The results suggest that NAR induces apoptosis through p38-dependent ATF3 activation in human colon cancer cells.

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Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells.