The Effect of Saccharin on the Gene Expression of NF-κB and Inflammatory Cytokines in LPS-Stimulated SW480 Colon Cancer Cells

There have been no published studies concerning the anti-inflammatory effects of corn silk on colon cancer cells. Thus, this study was conducted to investigate the effect of corn silk extract containing high levels of maysin on inflammation and its mechanism of action in colon cancer cells. SW 480 human colon cancer cells were treated with 1 µg/mL of lipopolysaccharide (LPS) to induce inflammation, and next they were treated with different concentrations of corn silk extract (0, 5, 10 and 15 µg/mL). The concentrations of nitric oxide (NO) were determined. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6), were determined. Western blot analysis was performed to determine the protein expressions of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases, and the latter consists of extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 MAP kinase (p38). The concentration of NO and the mRNA expression of iNOS were significantly and dose-dependently decreased in the corn silk-treated groups (P<0.05). The mRNA expression of TNF-α, IL-1β and IL-6 were significantly increased in the LPS-treated group (P<0.05), but these expressions were significantly and dose-dependently decreased in the corn silk treated groups (P<0.05). The protein expressions of NF-κB (in a dose-dependent fashion), ERK (at 10 and 15 µg/mL), JNK (at 15 µg/mL) and p38 (at 10 and 15 µg/mL) were significantly decreased with corn silk treatments (P<0.05). In conclusion, corn silk extract containing high levels of maysin seems to inhibit the LPS-induced inflammatory responses in SW480 colon cancer cells via the NF-κB pathway.

Corn silk extract improves benign prostatic hyperplasia in experimental rat model

BACKGROUND/OBJECTIVES: This study was conducted to investigate the effect of a corn silk extract on improving benign prostatic hyperplasia (BPH). MATERIALS/METHODS: The experimental animals, 6-week-old male Wistar rats, were divided into sham-operated control (Sham) and experimental groups. The experimental group, which underwent orchiectomy and received subcutaneous injection of 10 mg/kg of testosterone propionate to induce BPH, was divided into a Testo Only group that received only testosterone, a Testo+Fina group that received testosterone and 5 mg/kg finasteride, a Testo+CSE10 group that received testosterone and 10 mg/kg of corn silk extract, and a Testo+CSE100 group that received testosterone and 100 mg/kg of corn silk extract. Prostate weight and concentrations of dihydrotestosterone (DHT), 5α-reductase 2 (5α-R2), and prostate specific antigen (PSA) in serum or prostate tissue were determined. The mRNA expressions of 5α-R2 and proliferating cell nuclear antigen (PCNA) in prostate tissue were also measured. RESULTS: Compared to the Sham group, prostate weight was significantly higher in the Testo Only group and decreased significantly in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups (P < 0.05), results that were consistent with those for serum DHT concentrations. The concentrations of 5α-R2 in serum and prostate as well as the mRNA expression of 5α-R2 in prostate were significantly lower in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups than that in the Testo Only group (P < 0.05). Similarly, the concentrations of PSA in serum and prostate were significantly lower in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups (P < 0.05) than in the Testo Only group. The mRNA expression of PCNA in prostate dose-independently decreased in the Testo+CSE-treated groups (P < 0.05). CONCLUSIONS: BPH was induced through injection of testosterone, and corn silk extract treatment improved BPH symptoms by inhibiting the mRNA expression of 5α-R2 and decreasing the amount of 5α-R2, DHT, and PSA in serum and prostate tissue.

High maysin corn silk extract reduces body weight and fat deposition in C57BL/6J mice fed high-fat diets

BACKGROUNG/OBJECTIVES: The study was performed to investigate the effects and mechanisms of action of high maysin corn silk extract on body weight and fat deposition in experimental animals. MATERIALS/METHODS: A total of 30 male C57BL/6J mice, 4-weeks-old, were purchased and divided into three groups by weight using a randomized block design. The normal-fat (NF) group received 7% fat (diet weight basis), the high-fat (HF) group received 25% fat and 0.5% cholesterol, and the high-fat corn silk (HFCS) group received high-fat diet and high maysin corn silk extract at 100 mg/kg body weight through daily oral administration. Body weight and body fat were measured, and mRNA expression levels of proteins involved in adipocyte differentiation, fat accumulation, fat synthesis, lipolysis, and fat oxidation in adipose tissue and the liver were measured. RESULTS: After experimental diet intake for 8 weeks, body weight was significantly lower in the HFCS group compared to the HF group (P < 0.05), and kidney fat and epididymal fat pad weights were significantly lower in the HFCS group compared to the HF group (P < 0.05). In the HFCS group, CCAAT/enhancer binding protein-β, peroxisome proliferator-activated receptor-γ1 (PPAR-γ1), and PPAR-γ2 mRNA expression levels were significantly reduced (P < 0.05) in the epididymal fat pad, whereas cluster of differentiation 36, lipoprotein lipase, acetyl-CoA carboxylase-1, sterol regulatory element binding protein-1c, pyruvate dehydrogenase kinase, isozyme-4, glucose-6-phosphate dehydrogenase, and stearoyl-CoA desaturase-1 mRNA expression levels were significantly decreased in liver and adipose tissues (P < 0.05). In the HFCS group, mRNA expression levels of AMP-activated protein kinase, hormone-sensitive lipase, and carnitine palmitoyltransferase-1 were elevated (P < 0.05). CONCLUSIONS: It can be concluded that high maysin corn silk extract inhibits expression of genes involved in adipocyte differentiation, fat accumulation, and fat synthesis as well as promotes expression of genes involved in lipolysis and fat oxidation, further inhibiting body fat accumulation and body weight elevation in experimental animals.

Corn silk extract improves cholesterol metabolism in C57BL/6J mouse fed high-fat diets

BACKGROUND/OBJECTIVES: Corn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets. MATERIALS/METHODS: Normal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor α were determined. RESULTS: Oral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different. CONCLUSIONS: CS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.