Preventive effect of Kaempferia parviflora ethyl acetate extract and its major components polymethoxyflavonoid on metabolic diseases

Previously, we reported that rhizome powder of Kaempferia parviflora Wall. Ex. Baker prevented obesity and a range of metabolic diseases. In this study, to clarify which molecular mechanisms and active ingredients of K. parviflora have an anti-obesity effect, we investigated the effect of ethyl acetate extract of K. parviflora (KPE) on TSOD mice, a spontaneously obese Type II diabetes model, and on pancreatic lipase. In the TSOD groups, KPE showed a suppressive effect on body weight increase and visceral fat accumulation and also showed preventive effects on symptoms related to insulin resistance, hypertension and fatty liver. In addition, KPE also suppressed body weight increase and food intake in TSNO mice groups, which served as reference animals, at an early stage of administration. Searching for the ingredients in KPE revealed that KPE contains at least 12 kinds of polymethoxyflavonoid (PMF). Furthermore, KPE and its component PMFs showed an inhibitory effect on pancreatic lipase. The above results suggest that KPE has a preventive effect on obesity and various metabolic diseases. The mechanisms of action probably involve inhibition of pancreatic lipase by the PMFs in KPE.     

Annual variation of natural 15N abundance in tea leaves and its practicality as an organic tea indicator

To obtain basic knowledge about the relationship between the application of organic fertilizers and the δ15N values of leaves of organically grown tea plants, annual variations in the δ15N values of the tea leaves were investigated. Although variations did not immediately arise after the application of organic fertilizers, differences in the δ15N values between organic and conventional cultivations appeared basically after three years from the beginning of the organic cultivation except when an organic fertilizer with a low δ15N value was applied, and the variation depended on the δ15N values of the fertilizers. In addition, the effectiveness of the δ15N values as a practical indicator of organic teas was examined. The tea leaves collected from organic farms did not always have higher δ15N values than the commercially available nonorganic teas. This result demonstrates that it is not easy to discriminate organic teas from nonorganic teas simply by their δ15N values.     

Experimental infection of ducks with Mycoplasma gallisepticum

Specific-pathogen-free ducks 24 and 180 days old were inoculated intranasally with the S6 strain of Mycoplasma gallisepticum (MG). No significant gross lesions were found in trachea, lung or air sacs at 7 or 28 days postinfection (PI). MG was recovered from the infraorbital sinus and trachea but not from the air sacs 7 and 28 days PI. A few ducks responded serologically by developing agglutinating antibody. MG multiplied in embryonated duck eggs but to lower titers than in embryonated chicken eggs.     

Immunohistochemical examination of PDGF-AB, TGF-beta and their receptors in the hemocytes of a tick, Ornithodoros moubata (Acari: Argasidae)

Growth factors, Platelet Derived Growth Factor (PDGF) and Transforming Growth Factor (TGF)-beta, were demonstrated in vertebrate and invertebrate immmunocytes. It is generally known that the growth factors are important in various biological processes, such as the regulation of cell differentiation, development and wound healing. In the present study, the presence of TGF-beta1 and PDGF-receptor-alpha in plasmatocytes and PDGF-AB in granulocytes of a soft tick, Ornithodoros moubata, was confirmed immunohistochemically. The tick midgut might be damaged by intracellular digestion and penetration of protozoa. Therefore, it is considered that PDGF from granulocytes may affect the PDGF-receptor-alpha in plasmatocytes and TGF-beta from plasmatocytes may function to repair the midgut. The results obtained here add to the elucidation of the functions of tick hemocytes.     

Spontaneous uterine leiomyosarcoma in a golden hamster (Mesocrietus auratus)

Uterine leiomyosarcoma occurring spontaneously in a domestic golden hamster was examined histologically and immunohistochemically. The histological findings for this tumour were similar to those for leiomyosarcomas described in other species. Immunohistochemical examination demonstrated the positivity of neoplastic cells with alpha-smooth muscle actin and desmin. From the results mentioned above, the tumour of this case was revealed to be of smooth muscle origin. To our knowledge, this is the first report of a uterine leiomyosarcoma in domestic golden hamsters.     

Functional degeneration of the resistance gene nsv against Melon necrotic spot virus at low temperature

The single recessive gene, nsv, which confers resistance against Melon necrotic spot virus (MNSV), has recently been used to develop virus-resistant melon cultivars in Japan. However, the Chiba isolate of MNSV, a common isolate in Japan, infected resistant cultivars when inoculated melon plants were grown at 15°C. Viral RNAs accumulated in protoplasts from resistant cultivars at both 15 and 20°C. Mechanical inoculation of the cotyledons caused MNSV to spread throughout the leaves at 15°C, but not at 20°C. These results support our novel hypothesis that a temperature-sensitive inactivation of disease resistance genes occurs at the nsv locus in melon cultivars with the resistance gene grown at temperatures below 20°C. The first and second authors contributed equally to this research.     

Risk assessment of ozone impact on the carbon absorption of Japanese representative conifers

A risk assessment of ozone (O₃) impact on the annual carbon absorption (ACA) of Japanese representative conifers was conducted based on the results of an experimental study, monitoring data of oxidant concentrations and vegetation surveys. The areas with high O₃-induced reduction in ACA did not necessarily correspond to the areas with relatively high O₃-exposure. Widespread distribution of O₃-sensitive tree species such as Pinus densiflora and Larix kaempferi, and high ACA were important factors that induced a high risk of O₃ impact on the ACA. Therefore, we concluded that not only the accumulated O₃-exposure but also the variety of tree habitat, the tree sensitivity to O₃ and the ACA among the tree species must be taken into account to assess the risk of O₃ impact on the ACA of Japanese conifers. The O₃-induced reduction in the total ACA of the three tree species in Japan was estimated to be 0.8%.     

Comparison of the glucosinolate-myrosinase systems among daikon (Raphanus sativus, Japanese white radish) varieties

Myrosinase is a cytosolic plant enzyme present in daikon ( Raphanus sativus, Japanese white radish) roots that hydrolyzes 4-methylthio-3-butenyl glucosinolate (MTBGLS) into the natural pungent agent 4-methylthio-3-butenyl isothiocyanate (MTBITC), which possesses antimicrobial, antimutagenic, and anticarcinogenic properties. The concentration of MTBGLS, myrosinase activity, and production of MTBITC in seven daikon varieties (one conventional and six heirlooms) were determined to rank the activity of the glucosinolate-myrosinase system and identify critical factors influencing the production of MTBITC. The six heirloom varieties produced 2.0-11.5 times higher levels of MTBITC as compared to the conventional variety, Aokubi, which is consumed by the present Japanese population. The myrosinase was located exclusively in the outer epidermal layer in Aokubi, and MTBGLS was widely distributed throughout the root tissue. Although the skin is a potentially rich source of myrosinase in Aokubi, the skin is usually peeled off in the current practice of preparing daikon for cooking. New practices are therefore proposed for the preparation of daikon tubers that eliminate the peeling of the skin to avoid removing the enzyme needed to convert MTBGLS to the health-beneficial MTBITC. It is also concluded that the consumption of heirloom daikon varieties in addition to changes in food preparation will optimize the health benefits of daikon.