We previously reported that TIP49a is a novel mammalian DNA helicase showing structural similarity with the bacterial recombination factor RuvB. In this study, we isolated a new TIP49a-related gene, termed TIP49b, from human and yeast cells. TIP49b also resembled RuvB, thus suggesting that TIP49a and TIP49b are included in a gene family. Like TIP49a, TIP49b was abundantly expressed in the testis and thymus. Enzyme assays revealed that TIP49b was an single-stranded DNAstimulated ATPase and ATP-dependent DNA helicase. Most of the enzymatic properties of TIP49b were the same as those of TIP49a, whereas the polarity of TIP49b DNA helicase activity (5 to 3) was the opposite to that of TIP49a. TIP49b and TIP49a bound to each other and were included in the same complex of ϳ700 kDa in a cell. We found that TIP49b was an essential gene for the growth of Saccharomyces cerevisiae, as is the TIP49a gene, suggesting that TIP49b does not complement the TIP49a function and vice versa. From these observations, we suggest that TIP49b plays an essential role in the cellular processes involved in DNA metabolism.

Pantoea agglomerans (P. agglomerans) is a Gram-negative bacterium that grows symbiotically with various edible plants, and the oral or sublingual administration of lipopolysaccharide derived from P. agglomerans (LPSp) have been suggested to contribute to prevention of immune-related diseases. Our previous study indicated that orally administered LPSp was shown to exhibit an LDL-lowering effect in hyperlipidemic volunteers; however, a preventive effect of LPSp on atherosclerosis is unclear. The present study attempted to evaluate the anti-atherosclerotic effect by LPSp in a mouse model of high-fat diet (HFD)-induced atherosclerosis. For 16 weeks, apoE-deficient mice were fed an HFD and received drinking water containing LPSp (0.3 or 1 mg/kg body weight/day). The results showed that the orally administered LPSp decreased body weight. A significant reduction in atherosclerotic plaque deposition was observed even with the lower dose of LPSp. The biochemical analyses showed that LPSp markedly improved glucose tolerance and reduced plasma LDL and oxidized LDL levels. In addition, LPSp significantly reduced the production of pro-inflammatory mediators including MCP-1 (in the plasma), TNF-α and IL-6 (in the colon), and decreased the oxidative burst activities in the peripheral blood sample. Taken together, these results suggest the possibility that oral administration of LPSp can effectively ameliorate HFD-induced hyperlipidemia and inflammatory/oxidative responses to prevent atherosclerosis and related metabolic disorders.

3,4,5-Tricaffeoylquinic acid (TCQA) that is not found in intact plant of lettuce leaves was isolated from the cultured cells. The intact plant produced chicoric acid (dicaffeoyl tartaric acid: L-CCA) as well as chlorogenic acid (3-caffeoylquinic acid: 3-CQA) as the major metabolites. After subculturing of the cells for 40 days, the amount of 3,4,5-TCQA reached to 0.14 mg/g fresh weight. The inhibitory effect of 3,4,5-TCQA for human immunodeficiency virus (HIV) Type 1 integrase was assayed. Anti-HIV activity using HIV and MT-2 cells was 1.15 microM and IC(50) against HIV integrase was 0.063 microM whereas cell toxicity of this chemical was expressed as 5% death of all living cells to be 18.4 microM. The HIV inhibitory effect of 3,4,5-TCQA was the highest in values among L-CCA, and other dicaffeoylquinic acids. This data will provide a new possibility for creating a new drug design for HIV.

The pathogenesis of Alzheimer’s disease (AD) remains unclear, but an imbalance between the production and clearance of amyloid-β (Aβ) peptides is known to play a critical role in AD progression. A promising preventative approach is to enhance the normal Aβ clearance activity of brain phagocytes such as microglia. In mice, the intraperitoneal injection of Toll-like receptor 4 agonist was shown to enhance Aβ clearance and exhibit a preventative effect on AD-related pathology. Our previous clinical study demonstrated that orally administered Pantoea agglomerans-derived lipopolysaccharide (LPSp) exhibited an LDL (low-density lipoprotein)-lowering effect in human volunteers with hyperlipidemia, a known risk factor for AD. In vitro studies have shown that LPSp treatment increases Aβ phagocytosis by microglial cells; however it is still unclear whether orally administered LPSp exhibits a preventive effect on AD progression. We show here that in senescence-accelerated prone 8 (SAMP8) mice fed a high-fat diet, oral administration of LPSp at 0.3 or 1 mg/kg body weight·day for 18 weeks significantly improved glucose metabolism and lipid profiles. The LPSp treatment also reduced pro-inflammatory cytokine expression and oxidative-burst activity in the peripheral blood. Moreover, LPSp significantly reduced brain Aβ burden and memory impairment as seen in the water maze test, although we could not confirm a significant enhancement of Aβ phagocytosis in microglia isolated from the brains after treatment. Taken together, our results show that LPSp holds promise as a preventative therapy for AD or AD-related diseases induced by impairment of metabolic functions.

Two antitumor promoters against tumor promoter-induced Epstein-Barr virus activation were isolated from the leaves of jute (Corchorus capsularis L.). The antitumor-promoting activity was examined by an immunoblotting analysis. Their active components were identified as phytol (3,7,11,15-tetramethyl-2-hexadecen-1-ol) and monogalactosyldiacylglycerol (1,2-di-O-␣-linolenoyl-3-O-␤-D-galactopyranosyl-sn-glycerol) by spectroscopic data and chemical and enzymatic reactions. The content of the latter in four cultivars of C. capsularis L. and C. olitorius L. was found to vary with the cultivar. The detectable amount of each active component increased by treatment of the leaves with hot water.Keywords: Corchorus capsularis L., Corchorus olitorius L., jute, phytol, monogalactosyldiacylglycerol, antitumor promoter, cancer chemoprevention Recent epidemiological investigations have been providing increasing evidence that a high consumption of vegetables and fruits could be associated with a reduced risk of cancer, especially that in the gastrointestinal tract (Steinmetz & Potter, 1991a, 1991bBlock et al., 1992;Ziegler, 1991). These epidemiological predictions suggest that vegetables and fruits contain anticancer or antitumor-promoting components. Thus the physiologically functional components in vegetables could be good sources of chemopreventive agents with low-toxicity available in our daily food supply.Jute (white jute, Corchorus capsularis L.; nalta jute or tossa jute, C. olitorius L.; Tiliaceae family), known as a fiber plant, is a time-honored medicinal vegetable in North Africa, the Middle and Near East and Southeast Asia. The young leaves of C. olitorius that have been introduced into Japan as a healthy vegetable, moroheiya, are rich in vitamins, carotenoids, calcium, potassium and dietary fiber (Resources Council, Science and Technology Agency, Japan, 2000).During our investigation of edible plants as sources of functional constituents, we found that jute leaves contain two active components against tumor promoter-induced Epstein-Barr virus (EBV) activation in Raji cells. We report herein the identification of the active components (phytol and monogalactosyldiacylglycerol), variation of their contents among four cultivars of jute and change in their detectable amounts by treatment with hot water. Materials and MethodsGeneral procedure NMR spectra were recorded with a JEOL A400 FT NMR spectrometer at 400 MHz for Plant materials Several cultivars of Corchorus capsularis L. were cultivated in a field on our faculty farm in 1998, and the leaves were used for isolation of the active components.The seeds of C. olitorius L., tentatively called cultivar M, were purchased from Ubagai Seed Co. (Ehime), and the other seeds of C. capsularis L. (cultivars A-38 and C-443) and C. olitorius L.(O-9897) were provided from the Bangladesh Institute of Nuclear Agriculture, Bangladesh. Four of the cultivars were grown in the same field in 2000. Two months after sowing the seeds, the leaves were harvested, freeze-dried and powdered; these ...