Sung-Min Moon

Licochalcone-A induces intrinsic and extrinsic apoptosis via ERK1/2 and p38 phosphorylation-mediated TRAIL expression in head and neck squamous carcinoma FaDu cells.

We investigated Licochalcone-A (Lico-A)-induced apoptosis and the pathway underlying its activity in a pharyngeal squamous carcinoma FaDu cell line. Lico-A purified from root of Glycyrrhiza inflata had cytotoxic effects, significantly increasing cell death in FaDu cells. Using a cell viability assay, we determined that the IC50 value of Lico-A in FaDu cells was approximately 100 µM. Chromatin condensation was observed in FaDu cells treated with Lico-A for 24 h. Consistent with this finding, the number of apoptotic cells increased in a time-dependent manner when FaDu cells were treated with Lico-A. TRAIL was significantly up-regulated in Lico-A-treated FaDu cells in a dose-dependent manner. Apoptotic factors such as caspases and PARP were subsequently activated in a caspase-dependent manner. In addition, levels of pro-apoptotic factors increased significantly in response to Lico-A treatment, while levels of anti-apoptotic factors decreased. Lico-A-induced TRAIL expression was mediated in part by a MAPK signaling pathway involving ERK1/2 and p38. In xenograft mouse model, Lico-A treatment effectively suppressed the growth of FaDu cell xenografts by activating caspase-3, without affecting the body weight of mice. Taken together, these data suggest that Lico-A has potential chemopreventive effects and should therefore be developed as a chemotherapeutic agent for pharyngeal squamous carcinoma.

Purification and characterization of a novel fibrinolytic α chymotrypsin like serine metalloprotease from the edible mushroom, Lyophyllum shimeji.

A novel fibrinolytic enzyme was purified from Lyophyllum shimeji, a popular edible mushroom in Asia. The enzyme was purified using combination of anion exchange chromatography on a Mono Q 5/5 column and size exclusion gel filtration chromatography on Superdex 200 100/300 column. This purification protocol resulted 80.9-fold purification of the enzyme and a final yield of 5.7%. The molecular weight of the purified enzyme was estimated to be 21 kDa by SDS-PAGE and size exclusion gel filtration. The N-terminal amino acid sequence was found to be ITFQSASP, which is dissimilar from that of known fibrinolytic enzymes. The purified enzyme was a neutral protease with an optimal reaction pH and temperature of 8.0 and 37°C, respectively. Enzymatic activity was inhibited by Cu(2+) and Co(2+). It was also significantly inhibited by PMSF and TPCK. Furthermore, it was found to exhibit a higher specificity for S-7388, a well-known chymotrypsin chromogenic substrate, indicating chymotrypsin like serine metalloprotease. The relative fibrinolytic activity of 5 μg purified enzyme have two fold more activity than 1 unit/ml of plasmin on fibrin plate. Furthermore, purified enzyme preferentially hydrolyzed the Aα-chain followed by the Bβ- and γ-chain of fibrinogen, which is precursor of fibrin. Therefore, these data suggests that the fibrinolytic enzyme derived from edible mushroom, L. shimeji, might be useful for thrombolytic therapy and preventing thrombotic disease.

Berberine induces FasL-related apoptosis through p38 activation in KB human oral cancer cells

In the present study, we examined the anticancer properties of berberine in KB oral cancer cells with a specific focus on its cellular mechanism. Berberine did not affect the cell viability of the primary human normal oral keratinocytes that were used as a control. However, the viability of KB cells was found to decrease significantly in the presence of berberine in a dose-dependent manner. Furthermore, in KB cells, berberine induced the fragmentation of genomic DNA, changes in cell morphology, and nuclear condensation. In addition, caspase-3 and -7 activation, and an increase in apoptosis were observed. Berberine was also found to upregulate significantly the expression of the death receptor ligand, FasL. In turn, this upregulation triggered the activation of pro-apoptotic factors such as caspase-8, -9 and -3 and poly(ADP-ribose) polymerase (PARP). Furthermore, pro-apoptotic factors such as Bax, Bad and Apaf-1 were also significantly upregulated by berberine. Anti-apoptotic factors such as Bcl-2 and Bcl-xL were downregulated. Z-VAD-FMK, a cell-permeable pan-caspase inhibitor, suppressed the activation of caspase-3 and PARP. These results clearly indicate that berberine-induced cell death of KB oral cancer cells was mediated by both extrinsic death receptor-dependent and intrinsic mitochondrial-dependent apoptotic signaling pathways. In addition, berberine-induced upregulation of FasL was shown to be mediated by the p38 MAPK signaling pathway. We also found that berberine-induced migration suppression was mediated by downregulation of MMP-2 and MMP-9 through phosphorylation of p38 MAPK. In summary, berberine has the potential to be used as a chemotherapeutic agent, with limited side-effects, for the management of oral cancer.

Aqueous extract of Codium fragile suppressed inflammatory responses in lipopolysaccharide-stimulated RAW264.7 cells and carrageenan-induced rats

Codium fragile (Suringar) Hariot has been used in Oriental medicine for the treatment of enterobiasis, dropsy, and dysuria and has been shown to have various biological effects. In this study, we evaluated the anti-inflammatory effects of aqueous extract of C. fragile (AECF) using in vitro and in vivo models. Nitric oxide (NO), prostaglandin E2 (PGE2), inflammatory-related mRNAs, and proteins were determined using the Griess assay, enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and western blotting, respectively. Our results indicate that pretreatment of cells with AECF (50, 100 and 200μg/mL) significantly inhibited LPS-induced secretion of NO and PGE2 in RAW264.7 cells without cytotoxicity. We also found that AECF (100 and 200μg/mL) inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 expression in a dose-dependent manner. Additionally, pretreatment of cells with AECF (100 and 200μg/mL) inhibited LPS-induced production of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. It also prevented the nuclear translocation of nuclear factor (NF)-κB by suppressing the phosphorylation and degradation of inhibitor of NF-κB (IκB)-α. Furthermore, AECF (100 and 200μg/mL) inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase (ERK) 1/2, c-Jun N-terminal kinase (JNK), and p38. In addition, orally administered 50, 100, and 200mg/kg body weight of AECF dose-dependently suppressed carrageenan-induced rat paw edema thickness by 6%, 31%, and 50% respectively, after 4h. Furthermore, the anti-inflammatory effect was comparable to that observed in animals treated with the standard drug diclofenac sodium (56%) in vivo. Collectively, our results suggest that AECF exerts potential anti-inflammatory effects by suppressing NF-κB activation and MAPKs pathways in vitro, as well as inhibiting carrageenan-induced rat paw edema thickness in vivo. These findings indicate that AECF could be further developed as an anti-inflammatory drug.

NRSF/REST regulates the mTOR signaling pathway in oral cancer cells

The neuron-restrictive silencer factor/repressor element 1-silencing transcription factor (NRSF/REST) was originally discovered as a transcriptional repressor of neuronal genes in non-neuronal cells. However, it was recently reported to be abundantly expressed in several types of aggressive cancer cells, as well as in mature neurons. In the present study, the role of NRSF/REST in the human oral squamous cell carcinoma (SCC) KB cell line was evaluated. NRSF/REST was expressed at a higher level in KB cells when compared with that in normal human oral keratinocytes (NHOKs). Knockdown of NRSF/REST by siRNA reduced cell viability only in KB cells in a time-dependent manner, and this effect was due to the activation of apoptosis components and DNA fragmentation. In addition, knockdown of NRSF/REST disrupted the mTOR signaling pathway which is a key survival factor in many types of cancer cells. For example, the phosphorylation of elF4G, elF4E and 4E-BP1 was significantly reduced in the KΒ cells upon NRSF/REST knockdown. These results imply that NRSF/REST plays an important role in the survival of oral cancer cells by regulating the mTOR signaling pathway.

Oleamide suppresses inflammatory responses in LPS-induced RAW264.7 murine macrophages and alleviates paw edema in a carrageenan-induced inflammatory rat model

&NA; Oleamide compounds purified from green algae have been used for the prevention and treatment of atherosclerosis, thrombosis, arthritis, and cancer. They function through their metabolic conversion into prostaglandins, thromboxanes, and leukotrienes. However, the actual mechanism of action has not been well characterized. To investigate the underlying anti‐inflammatory activity and associated mechanisms, oleamide purified from Codium fragile was studied using RAW264.7 murine macrophages and a carrageenan‐induced inflammatory rat model. Our results indicate that pre‐treatment of RAW264.7 cells with oleamide significantly suppressed LPS‐induced nitrite production and PGE2 secretion. Oleamide inhibited LPS‐induced iNOS and COX‐2 mRNA and protein expression. It also inhibited the LPS‐induced production of inflammatory cytokines such as tumor necrosis factor‐&agr; (TNF‐&agr;), interleukin (IL)‐1&bgr;, and IL‐6. In addition, oleamide prevented the nuclear translocation of NF‐&kgr;B by suppressing the phosphorylation of the inhibitor of kappa B (I&kgr;B)‐&agr;. Oleamide also suppressed the phosphorylation of mitogen‐activated protein kinases such as ERK1/2 and JNK. Furthermore, inhibition of paw swelling (%) was suppressed 2 h after the intraperitoneal injection of oleamide (20 mg/kg, body weight) in a carrageen‐induced rat model. Therefore, our results suggest that oleamide can be used as a single ingredient treatment for inflammatory diseases.

Aqueous extract of Codium fragile alleviates osteoarthritis through the MAPK/NF-κB pathways in IL-1β-induced rat primary chondrocytes and a rat osteoarthritis model

BACKGROUND Codium fragile (Suringar) Hariot has been used as a potential remedy in traditional medicine because of its anti-inflammatory and anti-oxidant effects. Osteoarthritis is a chronic progressive joint disease, characterized by complex mechanisms related to inflammation and degeneration of articular cartilage. In this study, we aimed to evaluate the cartilage protective effect of an aqueous extract of Codium fragile (AECF) using rat primary chondrocytes and the osteoarthritis animal model induced by destabilization of the medial meniscus (DMM). METHODS In vitro, rat primary cultured chondrocytes were pre-treated with AECF (0.5, 1, and 2mg/mL) for 1h and then incubated with interleukin-1β (10ng/mL) for 24h. Nitrite production was detected by the Griess reagent. Alteration of the protein levels of iNOS, MMP-13, ADAMTS-4, ADAMTS-5, mitogen-activated protein kinases (MAPKs), and nuclear factor-κB (NF-κB) was detected by western blotting. In vivo, osteoarthritis was induced by DMM of Sprague Dawley (SD) rats. The rats subjected to destabilization of the medial meniscus (DMM) surgery were orally administered with AECF (50, 100, and 200mg/kg bodyweight) or distilled water for 8w. The severity of cartilage lesions was evaluated by safranin O staining and the Osteoarthritis Research Society International (OARSI) score. RESULTS These results demonstrated that AECF significantly inhibited nitrite production and inhibited the levels of iNOS, MMP-13, ADAMTS-4, and ADAMTS-5 in interleukin-1β-induced rat primary cultured chondrocytes. Moreover, AECF suppressed interleukin-1β-induced NF-κB activation in the nucleus and phosphorylation of ERK1/2 and JNK in the cytosol. In vivo, the cartilage lesions in AECF-treated osteoarthritis rats exhibited less proteoglycan loss and lower OARSI scores. CONCLUSIONS These results suggested that AECF is a potential therapeutic agent for the alleviation of osteoarthritis progression.

Transcriptional regulation of the neuropeptide VGF by the neuron-restrictive silencer factor/neuron-restrictive silencer element.

The neurotrophin-inducible gene VGF plays an important role in the maintenance of organismal energy balance and in the mediation of hippocampal synaptic activity. The regulatory mechanism of VGF transcription is not fully understood. The neuron-restrictive silencer factor (NRSF) binds with the neuron-restrictive silencer element (NRSE), thereby suppressing the transcription of NRSE-containing genes. In this study, we show that the NRSE sequence of the VGF gene critically regulates the repression of VGF expression in NMB cells. Sequence analysis also establishes the presence of two putative NRSEs (NRSE-1 and NRSE-2) in the promoter region of the VGF gene. In reporter gene experiments, a more than eight-fold increase in the promoter activity was observed when both NRSE-1 and NRSE-2 were deleted. Deletion of NRSE-2 alone did not affect the promoter activity, thus indicating that NRSE-1 could be solely responsible for the repression of VGF gene expression. Mutations in the NRSE-1 sequence increased promoter activity. However, no change in activity was observed when NRSE-1 was coexpressed with dominant-negative NRSF, thereby suggesting that endogenous NRSF interacts with NRSE-1. Binding of NRSF to NRSE in a sequence-specific manner was confirmed with chromatin immunoprecipitation assays, respectively. Furthermore, the overexpressed NRSF in PC12 cells significantly suppressed the VGF gene expression by interacting with the NRSE located in the VGF promoter region. Our results indicate that NRSF plays an important role as a repressor of VGF gene regulation in NMB cells through a mechanism that is dependent on VGF-NRSE.

Anticancer activity of Saussurea lappa extract by apoptotic pathway in KB human oral cancer cells

Abstract Context: Saussurea lappa Dence (Compositae) is used as a traditional herbal medicine to treat abdominal pain and tenesmus in East Asia. Current studies have shown that S. lappa has anticancer activity in divergent of cancer cells. However, the effects of S. lappa on oral cancer and its mechanisms of action have yet to be elucidated. Objective: To explore its potential chemotherapeutic effects and mechanism of cell growth inhibition on human oral cancer cells. Materials and methods: The dried roots of S. lappa were used in this study. Cell viability of KB cells was evaluated by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay after treatment with 30 µg/ml of methanol extract from the dried roots of S. lappa. To understand whether its effect on cell death is related with apoptosis pathway, we performed DNA fragmentation assay, western blot, caspase activity assay and fluorescence-activated cell sorting (FACS) analysis. Results: Treatment of S. lappa extract onto KB cells reduced cell viability significantly with an IC50 value of 30 µg/ml. The formation of a DNA ladder was observed starting at the 24 h treatment. In western blotting analysis, the S. lappa extract induced the proteolytic processing of caspase-3, -9 and poly (ADP-ribose) polymerase, a significant increase of Bax and marked reduction of Bcl-2. We also confirmed the activation of caspase-3/-7 in living KB cells by fluorescence microscopy. Conclusion: These results suggested that S. lappa extract inhibited cell proliferation through the apoptosis pathway in KB human oral cancer cells.

Chondroprotective effects of aqueous extract of Anthriscus sylvestris leaves on osteoarthritis in vitro and in vivo through MAPKs and NF-κB signaling inhibition

Osteoarthritis (OA) is a common degenerative joint disease, characterized by cartilage degradation and inflammation, in the elderly population. Anthriscus sylvestris has been used in Korean traditional medicine and contains many polyphenolic compounds such as cynaroside and chlorogenic acid, which are major active components responsible for its antioxidant effect. In this study, we aimed to evaluate the chondroprotective effect of an aqueous extract of A. sylvestris leaves (AE-ASL) on OA, both in vitro and in vivo. Rat primary chondrocytes were pretreated with AE-ASL for 1 h before interleukin-1β (20 ng/mL) stimulation. The production of nitrite, PGE2, aggrecan, and collagen type II were detected by Griess reagent and ELISAs. The mRNA levels of iNOS, COX-2, MMP-3, and MMP-13 were measured by RT-PCR. In addition, protein levels of iNOS, COX-2, MMP-3, MMP-13, ADAMTS-4, MAPKs, and NF-κB p65 subunit were measured by western blot analysis. Sulfated glycosaminoglycan (sGAGs) were detected by dimethylmethylene blue (DMMB) assay. During in vivo study, the effects of AE-ASL were evaluated for 8 weeks in a rat model of destabilization of the medial meniscus (DMM) surgery-induced OA. AE-ASL significantly inhibited expression of nitrite, iNOS, PGE2, COX-2, MMP-3, MMP-13, and ADAMTS-4 in IL-1β-stimulated chondrocytes. Moreover, it decreased the IL-1β-induced degradation of aggrecan, collagen type II, and proteoglycan. In addition, AE-ASL suppressed IL-1β-induced phosphorylation of MAPKs and NF-κB p65 subunit translocation to nucleus. In vivo, AE-ASL inhibited DMM surgery-induced cartilage destruction and proteoglycan loss. Taken together, these results suggest that AE-ASL may be a potential therapeutic agent for the alleviation of OA progression.