Hypoglycemic activity of Gymnema sylvestre extracts on oxidative stress and antioxidant status in diabetic rats

Diabetes mellitus, which is associated with oxidative damage, has a significant impact on health, quality of life, and life expectancy. An ethanol extract of Gymnema sylvestre leaf was examined in vitro and in vivo to investigate the role of antioxidants in diabetic rats. The extract exhibited strong antioxidant activity in the assays, including TBA (56%), SOD-like (92%), and ABTS (54%). Blood glucose levels in the diabetic rats fed G. sylvestre extract decreased to normal levels. The presence of the antihyperglycemic compounds gymnemagenin and gymnemic acids in G. sylvestre extract was detected by LC/MS analysis. Lipid peroxidation levels were decreased by 31.7% in serum, 9.9% in liver, and 9.1% in kidney in the diabetic rats fed the extract. Feeding G. sylvestre extract to the diabetic rats decreased the activity of glutathione peroxidase in cytosolic liver and glutamate pyruvate transaminase in serum to normal levels.     

Flavonoids with potent antioxidant activity found in young green barley leaves

Saponarin, a flavonoid found in young green barley leaves, possesses potent antioxidant activities, which are determined by its inhibition of malonaldehyde (MA) formation from various lipids oxidized by UV light or Fenton's reagent. Lipids used were squalene, ethyl linoleate, ethyl linolenate, ethyl arachidonate, octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), cod liver oil, lecithin I, lecithin II, and blood plasma. The addition of saponarin inhibited the formation of MA from squalene upon UV irradiation at the level of 2 μmol/mL by almost 100%, whereas BHT inhibited its formation by 75% at the same level. Saponarin showed potent antioxidant activity toward fatty acid ethyl esters at levels >100 μg/mL. Saponarin inhibited MA formation in ODTA by 60%, in EPA by 50%, and in DHA by 43% at the level of 15 μmol/mL. Saponarin exhibited strong antioxidant activities with dose-response levels toward cod liver oil and lipoproteins (lecithins I and II), higher than those of α-tocopherol. A mixture of saponarin/lutonarin (4.5:1, w/w) inhibited MA formation appreciably from all lipids tested with dose response. This mixture exhibited highest effect toward cod liver oil (86%), followed by DHA, lecithin II, blood plasma, EPA, and lecithin I. Supplementation of young green barley leaves containing saponarin should be beneficial to health and may prevent diseases caused by oxidative damage such as various cancers, inflammations, and cardiovascular diseases.     

Characterization of spheres derived from canine mammary gland adenocarcinoma cell lines

There is increasing evidence for the presence of cancer stem cells in several solid tumors, and these cancer stem cells have a potential role in tumor initiation, aggression, and recurrence. The stem cell-like properties of spheres derived from canine mammary tumors remain largely elusive. We attempted to induce sphere formation using four cell lines of canine mammary adenocarcinoma, and characterized the spheres derived from a CHMp line in vitro and in vivo. The CHMp-derived spheres showed predominantly CD44⁺CD24⁻ population, higher expression of stem cell-related genes, such as CD133, Notch3 and MDR, and higher resistance to doxorubicin compared with the CHMp-derived adherent cells. Xenograft transplantations in nude mice demonstrated that only 1 × 10⁴ sphere cells were sufficient for tumor formation. Use of the sphere assay on these sphere-derived tumors showed that sphere-forming cells were present in the tumors, and were maintained in serial transplantation. We propose that spheres derived from canine mammary adenocarcinoma cell lines possess a potential characteristic of cancer stem cells. Spheres derived from canine mammary tumors could be a powerful tool with which to investigate novel therapeutic drugs and to elucidate the molecular and cellular mechanisms that underlie tumorigenesis.     

Formation of carcinogenic 4(5)-methylimidazole in Maillard reaction systems

4(5)-Methylimidazole has received the attention of federal and state regulatory agencies because of its carcinogenicity and common presence in foods and beverages. In the present study, the formation of 4(5)-methylimidazole in Maillard reaction model systems consisting of D-glucose/NH(3), L-rhamnose/NH(3), methylglyoxal/NH(3), and methylglyoxal/formaldehyde/NH(3) was investigated. 4(5)-Methylimidazole was formed at levels ranging from 0.49 to 0.71 mg/mL in the d-glucose/NH(3) model system. The formation of 4(5)-methylimidazole was slightly higher in the L-rhamnose/NH(3) system (0.91 mg/mL) than in the d-glucose/NH(3) system (0.71 mg/mL) under the conditions used in the present study. A methylglyoxal/NH(3) system produced significantly higher levels of 4(5)-methylimidazole (5.70 mg/mL), suggesting that methylglyoxal is an important precursor of 4(5)-methylimidazole. Ammonolysis of methylglyoxal, which is one of the glucose degradation products, was proposed to form formamide, which subsequently reacted with 2-aminopropanal (α-aminocarbonyl intermediate) formed from methylglyoxal to give 4- or 5-methylimidazole. The levels of 4(5)-methylimidazole found in commercial cola soft drinks range from 0.30 μg/mL (brand 3) to 0.36 μg/mL (brands 1 and 5).     

High levels of sugars and fructan in mature seed of sweet wheat lacking GBSSI and SSIIa enzymes

Sweet wheat (SW), which lacks functional granule-bound starch synthase I (GBSSI) and starch synthase IIa (SSIIa), accumulates high levels of free sugars in immature seeds. Here, we examined the effects of the lack of these two enzymes on mature kernel composition. Whole grain flour of SW had higher levels of sugars, particularly maltose, slightly higher ash and protein content, approximately two to three times higher lipid levels, and about twice as much total dietary fiber as parental or wild-type lines. Considerably higher levels of low-molecular-weight soluble dietary fiber (LMW-SDF), largely consisting of fructan, were also detected in SW. Although there were no differences in total amino acid levels, the free amino acid content of SW was approximately 4-fold higher than that of wild type, and the levels of certain free amino acids such as proline were particularly high. Thus, we were able to clearly demonstrate that the lack of GBSSI and SSIIa caused dramatic changes in mature seed composition in SW. These compositional changes suggest that SW flour may provide health benefits when used as a food ingredient.     

Palatability and physicochemical properties of sausages prepared via lactic acid fermentation and drying at low temperature

The present study aimed to assess the palatability of sausages undergoing low‐temperature fermentation and drying process. Lactobacillus sakei D‐1001 or Lactobacillus salivarius A001 were used as starter cultures for fermentation, and the following properties of the sausages were investigated: colony‐forming units of lactic acid bacteria; concentrations of lactic acid, protein, peptides, and free amino acids; distribution of protein; composition of free amino acids; and physical properties and taste. Alterations in the composition of proteins, peptides, and free amino acids as well as in various physical properties were caused by fermentation by lactic acid bacteria. A sensory test indicated that the palatability of the fermented sausages was greater than that of the non‐fermented sausages, particularly in terms of hardness and juiciness. This was considered to be due to protein degeneration and changes in the physical properties of the sausages as a result of fermentation by lactic acid bacteria. However, the taste of the fermented sausages was sourer than that of the non‐fermented sausages, and therefore, inferior. Our study revealed that the palatability of the sausages in terms of hardness and juiciness were increased by low‐temperature fermentation by lactic acid bacteria and the drying process.     

Combining pre-transplanting phosphorus application and green manure incorporation: a trial for reducing fertilizer input

Pre-transplanting phosphorus application is a fertilization method that can reduce phosphorus (P) fertilization of the field and increase P use efficiency. We investigated whether P use efficiency can be increased further by combining pre-transplanting phosphorus application and the green manure practice, using cabbage as a test plant in a field experiment performed from 2006 to 2008. The pre-transplanting phosphorus application successfully reduced P fertilization of the field to half without any yield losses in 2006 and 2008. However, growth and yield could not be maintained with the pre-transplanting phosphorus application when P fertilization was halved in 2007. Differences among seasons and discrepancies in the results compared to previous studies may have arisen from the differences in the field management and the nursery soil used. No benefits of green manure in terms of the subsequent cabbage yield were detected. Consequently, there was no positive effect of the combination of pre-transplanting phosphorus application and incorporation of green manure. Studies with mycorrhizal plants as test plants may be necessary to verify the mechanism of enhanced P supply by the incorporation of green manure, and to examine any potential benefit of combining green manure and pre-transplanting phosphorus application practices.     

The relationship of readily decomposable organic matter of the paddy soil to its colloidal complexes

The soil nitrogen of paddy soil is found to exist in the form of organic and inorganic nitrogen. In general, the content of inorganic nitrogen is so low that it is mainly occupied by organic nitrogen. Such soil organic nitrogen is characterized by large resistance to decomposition by soil microorganisms, and so its mineralization occurs to a small extent in most cases. However, as revealed by M. Shioiri¹⁾ and T. Harada et al. ^2,3), by some appropriate treatment of paddy soil, a part of soil organic nitrogen becomes decomposed by microorganisms and mineralized under flooded condition. Among various treatment, for example, are Presented the followings: (1) air-drying of soil Prior to flooding; (2) raising the soil temperature during the flooded condition; (3) raising the soil reaction (pH 9.0) by addition of weak alkali solution; (4) the addition of neutral salts such as Nafiuoride, Na-phosphate, Na-oxalate etc., which make soil humus peptizable.     

Dry heat popping of amaranth seed might damage some of its essential amino acids

Amaranth was a major crop among the Aztecs. In Mexico the seed is popped and eaten with brown sugar. The crude protein content of the seed is 14±2% but its contents of lysine and tryptophan are 6.2 and 1.6 g/16 g N respectively. We developed a popping method based on a fluid bed system (FBS) whereas the traditional method (TM) is just to pop the seeds manually in a hot plate. Assays carried out were evaluation of racemization of the amaranth protein due to heat treatment, amino acid composition of the raw and heat treated seeds and a biological experiment testing whether leucine was the most limiting amino acid of amaranth protein. Male rats were fed both popped amaranths and roasted amaranth. Parboiled amaranth and casein were controls. The results were: (a) Lys, Arg and Cys were damaged in the heat treated seeds; (b) Asp, Met, Glu, Ala and Phe were racemized in that decreasing order in the seeds popped and roasted by the TM; (c) the estimated net protein retention (NPR) and estimated net protein utilization (NPU) of popped amaranths by either method were not different, but were lower than for the parboiled amaranth. The parboiled amaranth was not different from casein; (d) Leu was not the most limiting amino acid in any of the amaranth seeds tested. After Lys, sulfur amino acids appear to be the next most limiting in severely heat treated amaranth. The FBS seems to be a promising method for popping amaranth at industrial level.     

Model-based forecasting of twig canker incidence of bacterial spot of peach in Fukushima Prefecture

Bacterial spot caused by Xanthomonas arboricola pv. pruni (Xap) is the most important disease that affects peach production. A disease-forecasting model was developed to help growers decide when to apply bactericides and remove diseased, last-year twigs. To predict the incidence of “spring cankers”, peach twigs damaged by Xap, we used 12 years (2009–2020) of data from Fukushima Prefecture to develop a forecasting system using a hierarchical Bayesian model (HBM). The model included the number of fields with a bacterial spot incidence (BSI) on leaves?≥?10% in late September of the previous season and the number of days with rain (≥?10 mm/day) and maximum wind speed (≥?5 m/s) during the previous October as predictors. Using a best-fit cutoff value based on a receiver operating characteristic (ROC) curve, the model achieved a 0.836 accuracy, 0.804 sensitivity, 0.847 specificity, 0.847 precision, and 0.712 F-measure. The model was validated using a fourfold cross-validation (CV) procedure and achieved an average accuracy of 0.847. Thus, the model explained 65.7% of the variability compared to observed frequencies with predicted probabilities of twig canker incidence (TCI)?≥?2% from April to May 2009 to 2020 in Fukushima Prefecture. These results suggest that this disease-forecasting model using HBM based on 12 years of historical data can be used to predict the risk of twig cankers of bacterial spot of peach.