Phytochemical analysis of baby corn silk extracts

BackgroundBaby corn silk extract can be used as an antioxidant dietary supplement. However, insufficient data exists for this extract to guarantee its quality, efficacy and safety.ObjectiveTo determine phytochemical constituents, contents of phenolics and flavonoids, antioxidant activities, heavy metal concentrations, and microbial contamination of baby corn silk extracts.Material and methodsBaby corn silks including Pacific 271 and Zeba SG 17 hybrids were individually extracted with 40% v/v ethanol and distilled water to obtain Pacific 271 ethanol extract (PE), Zeba SG 17 ethanol extract (ZE), Pacific 271 aqueous extract (PA), and Zeba SG 17 aqueous extract (ZA). The analysis of phytochemical constituents was carried out using phytochemical tests, TLC screening, UV-visible, FTIR, and 1H NMR experiments. The contents of phenolics and flavonoids were determined using the modified Folin-Ciocalteu and aluminium chloride colorimetric procedures, respectively. Antioxidant activities were investigated using DPPH and FRAP assays. The concentrations of heavy metals were analyzed by ICP-MS. Microbial enumeration tests were carried out according to the United States Pharmacopeia (USP) 41.ResultsPE and ZE were composed of flavonoids, tannins, terpenoids, and steroids while PA and ZA contained flavonoids and tannins. PE and ZE exhibited higher total phenolic and flavonoid contents and significantly stronger antioxidant activities than PA and ZA. All extracts conformed to the microbiological and heavy metal requirements according to Association of South East Asian Nations (ASEAN) guidelines.ConclusionPE and ZE were considered appropriate to use as natural extracts of phenolics and flavonoids with antioxidant activities and safety.

Effect of Corn Silk on Adipose Tissues in Type 2 Diabetic Rats Based on GC-MS / 中国实验方剂学杂志

Objective:To evaluate the regulation effect of corn silk on fatty acid compositions in adipose tissues of rats with type 2 diabetes mellitus（T2DM） based on gas chromatography-mass spectrometry （GC-MS）， and explore the mechanism of corn silk water decoction for lipid metabolism disorder in . Method:Rat model of T2DM was established by high-sugar and high-fat diet combined with intraperitoneal injection of 35 mg·kg-1 streptozocin （STZ）. They were randomly divided into model group，metformin group，and low，medium and high dose groups（5.4，10.8，21.6 g·kg-1） of corn silk decoction， with administration of 4 weeks. Serum was taken from the abdominal aorta for the determination of free fatty acids （FFAs），blood lipids ［total cholesterol（TC），triglyceride（TG），high-density lipoprotein（HDL-C），low density lipoprotein（LDL-C）］，and adipose tissue was taken for pathological section analysis. At the same time，GC-MS technology and multivariate statistical analysis methods were adopted to investigate the fatty acid compositions in adipose tissue. Result:After treatment with corn silk decoction，the contents of FFAs，TC，TG，HDLC and LDLC in T2DM rats were all reversed. As compared with the model group，the morphology of rat adipocytes，macrophage infiltration，vascular congestion and other phenomena were restored after administration. GC-MS analysis showed that the contents of palmitic acid and stearic acid in the adipose tissue of T2DM rats were significantly increased，while the contents of tetradecanoic acid，pentadecanoic acid，9-octadecenoic acid，9-hexadecenoic acid and 5，8，11，14-eicosatetraenoic acid were decreased significantly，and all the dose groups of corn silk had a reversing effect on differentially expressed fatty acids. Conclusion:Corn silk can be able to reverse the fatty acid content in adipose tissue and restore the morphology of adipose tissue，with a regulating effect on the lipid metabolism disorder in T2DM rats.

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.

Study on action mechanism of corn silk in treating type II diabetic rats based on urine metabonomics / 中国药理学通报

Aim: To observe the interference of corn water decoction on endogenous metabolites in urine of rats with type 2 diabetes mellitus (T2DM), and to investigate the hypoglycemic mechanism of corn silk in metabonomics. Methods: Wistar rats were fed with high-sugar and high-fat diet for four weeks, and a small dose of streptozotocin was intraperitoneally injected to replicate the T2DM model. The modeled rats were divided into model control group and corn silk group. The corn silk group was given water to the corn water decoction(10. 8 g · kg-1) for four weeks. The state of the rats was observed during the administration, and blood glucose levels were monitored every two weeks. After treatment, the fasted 12 h urine samples were collected and the changes analyzed by UPLC/Q-TOF-MS combined with principal component analysis and orthogonal partial least squares-discriminant analysis methods. Results: Maize water decoction could significantly reduce blood glucose levels and improve symptoms in diabetic rats. In the positive and negative ion modes, a total of 12 differential markers were screened. These differential markers include chenodeoxycholic acid, glycocholic acid, argininosuccinic acid, etc. Conclusions: The hypoglycemic mechanism of corn decoction may be related to the metabolism of tricarboxylic acid, biosynthesis of bile acids, metabolism of color amino acid, etc. It also suggests that it may play a protective role in liver and kidney function.

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.

Survey of ear flies (Diptera, Ulidiidae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskal in Brazil

Survey of ear flies (Diptera, Ulidiidae) in maize (Zea mays L.) and a new record of Euxesta mazorca Steyskalin Brazil. Species of Euxesta (Diptera, Ulidiidae), known as silk flies or ear flies, are becoming increasingly important as maize insect pests in South America, although very little is known about them in Brazil. The larvae of some species of this genus initially damage female reproductive tissues, and then the developing kernels on the ear. As a result of feeding, fermentation and associated odors cause complete loss of the grain because it is no longer fit for human or livestock consumption. The main objective of this work was to evaluate the incidence of Euxesta spp. in Brazilian maize fields and to determine the most prevalent species using two different hydrolyzed protein foods attractants, BioAnastrepha® (hydrolyzed maize protein) and Torula, placed inside McPhail traps. The two species identified were E. eluta Loew and E. mazorca Steyskal, the latter being a new record from Brazil. Between the two species, E. eluta was the more abundant in maize fields. Both attractants were efficient in capturing the two species. However, BioAnastrepha® captured significantly more insects than Torula.

Levantamento de mosca-da-espiga (Diptera: Ulidiidae) em milho (Zea mays L.) e primeiro relato de ocorrência de Euxesta mazorca Steyskal no Brasil. Espécies de Euxesta (Diptera, Ulidiidae), conhecidas como moscas do cabelo ou moscas da espiga estão aumentando em importância nas culturas de milho em diferentes países, embora muito pouco se conheça sobre elas no Brasil. As larvas das espécies representativas de Ulidiidae inicialmente danificam a parte reprodutiva feminina da planta e depois os grãos em desenvolvimento. Como resultado da alimentação das larvas ocorre fermentação e odor forte tornando a espiga inapropriada para o consumo humano ou animal. O principal objetivo deste trabalho foi avaliar a incidência de espécies de Euxesta em áreas de produção de milho e identificar as espécies predominantes usando dois atraentes alimentares diferentes à base de proteínas hidrolisáveis, BioAnastrepha® (proteína hidrolisável de milho) e Torula, colocados no interior de armadilha McPhail. As duas espécies identificadas foram E. eluta Loew and E. mazorca Steyskal, registrada pela primeira vez no Brasil. Entre as espécies, E. eluta foi predominante no milho. Ambos os atraentes foram eficientes na captura das duas espécies. No entanto, as armadilhas com BioAnastrepha® capturaram significativamente mais insetos do que aquelas com Torula.