Corrigendum: Anti-growth Effects of Imatinib and GNF5 via Regulation of Skp2 in Human Hepatocellular Carcinoma Cells

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Antimicrobial Activity of Korean Propolis Extracts on Oral Pathogenic Microorganisms / 치위생과학회지

Propolis has been used as a natural remedy in folk medicine worldwide. The antibacterial, antiviral, antifungal, and antiprotozoal aspects of its antimicrobial properties have been widely investigated. However, few studies focused on its applications in dentistry. Many dental diseases are related to various microorganisms in the oral cavity. In this study, we assessed the antimicrobial activity of Korean propolis extract, collected from 6 different regions, on oral pathogenic microorganisms. The propolis samples, collected from 6 different regions (P1: Uijeongbu, P2: Ansan, P3: Hongcheon, P4: Iksan, P5: Gwangju, and P6: Sangju), were dissolved in ethanol at two different concentrations (10 and 50 mg/ml). Three oral bacteria (Streptococcus mutans, Staphylococcus aureus, and Enterococcus faecalis) and one fungus (Candida albicans) were activated in general broth for 24 hours. Microorganisms were diluted and spread onto agar plates, onto which sterilized 6 mm filter papers with or without each propolis sample were placed. After 24 hours of incubation, clear zones of inhibition were observed. All tests were performed in triplicate. The propolis samples showed significant antibacterial and antifungal activity on oral pathogenic microorganisms; in addition, low-concentration groups showed outstanding antimicrobial efficacy on the 4 different microorganisms. Among the samples, P6 had significantly higher antibacterial activity than that of the others against three different bacteria. In particular, a high concentration of P6 showed a significant antifungal effect. In conclusion, we confirmed that Korean propolis has an inhibitory effect on oral pathogenic bacteria and fungi. Therefore, we suggest the possibility of developing oral medicine and oral care products based on Korean propolis.

Anti-growth Effects of Imatinib and GNF5 via Regulation of Skp2 in Human Hepatocellular Carcinoma Cells

BACKGROUND: Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells. METHODS: Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated. RESULTS: Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5. CONCLUSIONS: These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

Protective Effect of White-fleshed Peach (Prunus persica (L.) Batsch) on Chronic Nicotine-induced Toxicity

BACKGROUND: Nicotine is a major toxic component of tobacco smoke and has been recognized as a risk factor to induce oxidative tissue damage, which is a precursor to cardiovascular diseases, lung-related diseases, and cancers. Peaches (Prunus persica) have been used for the treatment of degenerative disorders, such as hypermenorrhea, dysmenorrhea, and infertility in Asian countries. In this study, we investigated the effects of white-fleshed peach on the excretion of nicotine metabolites and 1-hydroxypyrene in smokers and chronic nicotine-induced tissue damages in mice. METHODS: The concentrations of cotinine and 1-hydroxypyrene were measured in urine of smokers before or after intake of white-fleshed peaches. In addition, ICR mice were injected with nicotine (5 mg/kg body weight) and then orally administered with white-fleshed peach extracts (WFPE) (250 or 500 mg/kg body weight) for 36 days. The oxidative stress parameters and the activities of antioxidant enzymes were measured in liver and kidney tissues. Also, histological changes and nitrotyrosine expression were assessed. RESULTS: Intake of white-fleshed peaches increased the urinary concentration of nicotine metabolites and 1-hydroxypyrene in 91.67% and 83.33% of smokers, respectively. WFPE decreased the malondialdehyde levels and recovered the activities of antioxidant enzymes in nicotine-injected mice. In addition, WFPE inhibited nitrotyrosine expression and inflammatory responses in the liver, kidney, and lung tissues of nicotine-treated mice. CONCLUSIONS: White-fleshed peaches may increase the metabolism of toxic components in tobacco smoke in smokers and protect normal tissues against nicotine toxicity in mice. Therefore, supplementation of white-fleshed peaches might be beneficial to smokers.

Isoliquiritigenin Inhibits Metastatic Breast Cancer Cell-induced Receptor Activator of Nuclear Factor Kappa-B Ligand/Osteoprotegerin Ratio in Human Osteoblastic Cells

Bone destruction induced by the metastasis of breast cancer cells is a frequent complication that is caused by the interaction between cancer cells and bone cells. Receptor activator of nuclear factor kappa-B ligand (RANKL) and the endogenous soluble RANKL inhibitor, osteoprotegerin (OPG), directly play critical roles in the differentiation, activity, and survival of osteoclasts. In patients with bone metastases, osteoclastic bone resorption promotes the majority of skeletal-related events and propagates bone metastases. Therefore, blocking osteoclast activity and differentiation via RANKL inhibition can be a promising therapeutic approach for cancer-associated bone diseases. We investigated the potential of isoliquiritigenin (ISL), which has anti-proliferative, anti-angiogenic, and anti-invasive effects, as a preventive and therapeutic agent for breast cancer cell-induced bone destruction. ISL at non-toxicity concentrations significantly inhibited the RANKL/OPG ratio by reducing the production of RANKL and restoring OPG production to control levels in hFOB1.19 cells stimulated with conditioned medium (CM) of MDA-MB-231 cells. In addition, ISL reduced the expression of cyclooxygenase-2 in hFOB1.19 cells stimulated by CM of MDA-MB-231 cells. Therefore, ISL may have inhibitory potential on breast cancer-induced bone destruction.

Patterns of Voiding Dysfunction of Stroke Patients during Rehabilitation

OBJECTIVE: The purpose of this study is to evaluate the patterns of voiding dysfunction of stroke patients during rehabilitation. METHOD: We evaluated 53 patients with complaints of voiding dysfunction following the strokes. After the comprehensive history and physical examination, all patients underwent cystometric study and males underwent the transrectal ultrasound. RESULTS: The incidences of detrusor hyperreflexia, detrusor areflexia, and normal finding on the cystometry were 50.9%, 32.1%, and 17.0%, respectively (p<0.05). There was a significantly high incidence of detrusor hyperreflexia in the groups of subcortical lesion, large lesion, and the over 3 months after stroke (p<0.05). However, there was no statistical difference on cystometric findings according to the other characteristics of the stroke such as the age, sex, type of stroke, cognition, aphasia, and diabetes mellitus. The incidences of irritative, obstructive, and mixed symptoms according to the presenting voiding complaints were 49.1%, 32.1%, and 18.9%, respectively (p<0.05). There was no significant statistical difference on the cystometric findings according to the 3 voiding symptom groups as well as none of significant statistical difference on prostate enlargement in males in according to the 3 voiding symptom groups. CONCLUSION: Only with the pattern of voiding, we could not predict the cystometric finding or the presence of bladder outlet obstruction. Thus, we recommend the further studies including cystometry and evaluation of the bladder outlet obstruction for the treatment of voiding dysfunction of stroke patients during rehabilitation.