Boswellia serrata Extract, 5-Loxin®, Prevents Joint Pain and Cartilage Degeneration in a Rat Model of Osteoarthritis through Inhibition of Inflammatory Responses and Restoration of Matrix Homeostasis.

Osteoarthritis (OA) is a chronic, progressive joint disease associated with pain, functional impairment, and diminished quality of life in affected individuals. At a societal level, it also has a high economic burden. Boswellia serrata has been reported to have potent anti-inflammatory, antiarthritic, and analgesic effects. The aim of this study was to explore the therapeutic potential and possible underlying mechanism of 5-Loxin®, a standardized Boswellia serrata extract, in a rat model of OA. The OA model was established by the intra-articular injection of 50 µL of monosodium iodoacetate (MIA) (60 mg/mL). 5-Loxin® was administered orally, and efficacy was evaluated through serum analysis, real-time polymerase chain reaction (PCR), histologic staining, and micro-computed tomography (micro-CT). Results indicated that administration of 5-Loxin® can relieve OA joint pain through inhibition of both inflammatory processes and cartilage degeneration. In the group of rats treated with 5-Loxin®, the suppression of inflammatory enzymes such as cyclooxygenase (COX)-2 and 5-lipoxygenase (LOX) resulted in a significant reduction in the prostaglandin (PG) E2 and leukotriene (LT) B4 levels. Moreover, 5-Loxin® ameliorated the deterioration of the main components of the articular extracellular matrix (ECM), such as glycosaminoglycans (GAGs) and aggrecan, through the downregulation of matrix metalloproteinases (MMPs). These findings suggest that 5-Loxin® may be a potential therapeutic agent for the treatment of OA.

Antiobesity Effect of a Novel Herbal Formulation LI85008F in High-Fat Diet-Induced Obese Mice.

A variety of natural products have been explored for their antiobesity potential and widely used to develop dietary supplements for the prevention of weight gain from excess body fat. In an attempt to find a natural antiobesity agent, this study was designed to evaluate the antiobesity activity of a novel herbal formulation LI85008F composed of extracts from three medicinal plants in high-fat diet- (HFD-) induced obese mice. After the thirteen-week oral administration of the test materials to mice, the body weight gain, whole-body fat mass, adipose tissue weight, and the expression levels of obesity-related proteins were measured. Our results indicated that LI85008F can suppress body weight gain and lower whole-body fat mass in HFD-induced obese mice. Significant decreases in epididymal and retroperitoneal fat mass were observed in LI85008F-treated groups compared with the HFD-fed control group (p < 0.05). Furthermore, the oral administration of LI85008F caused significant decreases in the expression level of adipogenic (C/EBPα and PPARγ) and lipogenic (ACC) markers and notable increases in the production level of thermogenetic (AMPKα, PGC1α and UCP1) and lipolytic (HSL) proteins. These findings suggest that LI85008F holds great promise for a novel herbal formulation with antiobesity activities, preventing body fat accumulation and altering lipid metabolism.

Selenium utilization in thioredoxin and catalytic advantage provided by selenocysteine.

Thioredoxin (Trx) is a major thiol-disulfide reductase that plays a role in many biological processes, including DNA replication and redox signaling. Although selenocysteine (Sec)-containing Trxs have been identified in certain bacteria, their enzymatic properties have not been characterized. In this study, we expressed a selenoprotein Trx from Treponema denticola, an oral spirochete, in Escherichia coli and characterized this selenoenzyme and its natural cysteine (Cys) homologue using E. coli Trx1 as a positive control. (75)Se metabolic labeling and mutation analyses showed that the SECIS (Sec insertion sequence) of T. denticola selenoprotein Trx is functional in the E. coli Sec insertion system with specific selenium incorporation into the Sec residue. The selenoprotein Trx exhibited approximately 10-fold higher catalytic activity than the Sec-to-Cys version and natural Cys homologue and E. coli Trx1, suggesting that Sec confers higher catalytic activity on this thiol-disulfide reductase. Kinetic analysis also showed that the selenoprotein Trx had a 30-fold higher Km than Cys-containing homologues, suggesting that this selenoenzyme is adapted to work efficiently with high concentrations of substrate. Collectively, the results of this study support the hypothesis that selenium utilization in oxidoreductase systems is primarily due to the catalytic advantage provided by the rare amino acid, Sec.

Inhibitory effects of (-)-loliolide on cellular senescence in human dermal fibroblasts.

Cellular senescence influences tumor suppression and progress, tissue repair and regeneration, tissue and organismal aging, and age-related diseases. Aging intervention might be an advantageous target for prevention and treatment of diverse age-related diseases. In this study, we investigated whether (-)-loliolide purified from the crude extract of Polygonum aviculare exerted inhibitory activity against cellular senescence in human dermal fibroblasts (HDFs). (-)-Loliolide diminished senescence-associated ß-galactosidase activity (SA-ß-gal), the level of p21 protein, and the level of reactive oxygen species in senescent cells induced by adriamycin treatment. (-)-Loliolide also attenuated SA-ß-gal activity in HDFs under replicative senescence. These findings imply that (-)-loliolide rescues cellular senescence in HDFs and might be useful for the development of dietary supplements or cosmetics that ameliorate tissue aging or age-associated diseases.

Quercetin-3-O-ß-D-glucuronide isolated from Polygonum aviculare inhibits cellular senescence in human primary cells.

Cellular senescence is known to contribute to tissue aging, a variety of age-related diseases, tissue regeneration, and cancer. Therefore, aging intervention might be useful for prevention of aging as well as age-related disease. In this study, we investigated compounds from Polygonum aviculare to determine if they inhibited cellular senescence in human primary cells, human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs). Ten compounds from P. aviculare were purified and their inhibitory effects on adriamycin-induced cellular senescence were measured by observing senescence-associated ß-galactosidase (SA-ß-gal) activity and reactive oxygen species. Among them, compound 9 (quercetin-3-O-ß-D-glucuronide) showed inhibitory effects against cellular senescence in HDFs and HUVECs treated with adriamycin. Additionally, compound 9 rescued replicative senescence in HDFs and HUVECs. These data imply that compound 9 represses cellular senescence in human primary cells and might be useful for the development of dietary supplements or cosmetics that ameliorate tissue aging or aging-associated diseases.

Inhibitory effects of juglanin on cellular senescence in human dermal fibroblasts.

Cellular senescence contributes to tissue and organismal aging, tumor suppression and progress, tissue repair and regeneration, and age-related diseases. Thus, aging intervention might be a promising target for treatment and prevention of diverse age-related diseases. In the present study, we investigated whether juglanin purified from the crude extract of Polygonum aviculare exerted inhibitory activity against cellular senescence in human dermal fibroblasts (HDFs). Juglanin decreased senescence-associated ß-galactosidase activity (SA-ß-gal) and the level of reactive oxygen species in senescent cells induced by adriamycin treatment. Juglanin also repressed SA-ß-gal activity in HDFs under replicative senescence. These results suggest that juglanin represses cellular senescence in HDFs and might be useful for the development of dietary supplements or cosmetics that alleviate tissue aging or age-related diseases.

Risk factors for low vitamin D status in Korean adolescents: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009.

OBJECTIVE: To evaluate the prevalence of vitamin D deficiency and predictors for low vitamin D status in Korean adolescents living between latitudes 33° and 39° N. DESIGN: A descriptive cross-sectional study. SETTING: Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009. SUBJECTS: A total of 1510 healthy adolescents aged 12-18 years (806 male, mean age 14.7 years) participated. Possible predictors for low vitamin D status (log-transformed 25-hydroxyvitamin D (25(OH)D) concentrations) were evaluated. RESULTS: The prevalence of vitamin D deficiency (25(OH)D<20 ng/ml) was 89.1% in spring, 53.7% in summer, 63.9% in autumn and 90.5% in winter. Winter season, older age, higher education level reached, being female, being obese, a lack of vitamin D supplementation, lower milk consumption (0-<200 ml/d) and a lack of physical activity were unadjusted predictors (all P < 0.05). Multiple linear regression analysis showed that winter season (P < 0.001), higher education level (P < 0.001) and a lack of vitamin D supplementation (P = 0.012) were independent predictors for low vitamin D status. The modifying effect of season on the association between vitamin D supplement use and vitamin D status was significant (P < 0.001). CONCLUSIONS: Vitamin D deficiency was highly prevalent in Korean adolescents, especially those in higher school grades. Vitamin D supplementation may contribute to maintain a better vitamin D status with lower seasonal variation. Further studies are required to determine optimal vitamin D intakes to maintain sufficient vitamin D status for Korean adolescents.

The methionine sulfoxide reduction system: selenium utilization and methionine sulfoxide reductase enzymes and their functions.

SIGNIFICANCE: Selenium is utilized in the methionine sulfoxide reduction system that occurs in most organisms. Methionine sulfoxide reductases (Msrs), MsrA and MsrB, are the enzymes responsible for this system. Msrs repair oxidatively damaged proteins, protect against oxidative stress, and regulate protein function, and have also been implicated in the aging process. Selenoprotein forms of Msrs containing selenocysteine (Sec) at the catalytic site are found in bacteria, algae, and animals. RECENT ADVANCES: A selenoprotein MsrB1 knockout mouse has been developed. Significant progress in the biochemistry of Msrs has been made, which includes findings of a novel reducing system for Msrs and of an interesting reason for the use of Sec in the Msr system. The effects of mammalian MsrBs, including selenoprotein MsrB1 on fruit fly aging, have been investigated. Furthermore, it is evident that Msrs are involved in methionine metabolism and regulation of the trans-sulfuration pathway. CRITICAL ISSUES: This article presents recent progress in the Msr field while focusing on the physiological roles of mammalian Msrs, functions of selenoprotein forms of Msrs, and their biochemistry. FUTURE DIRECTIONS: A deeper understanding of the roles of Msrs in redox signaling, the aging process, and metabolism will be achieved. The identity of selenoproteome of Msrs will be sought along with characterization of the identified selenoprotein forms. Exploring new cellular targets and new functions of Msrs is also warranted.

Analyses of fruit flies that do not express selenoproteins or express the mouse selenoprotein, methionine sulfoxide reductase B1, reveal a role of selenoproteins in stress resistance.

Selenoproteins are essential in vertebrates because of their crucial role in cellular redox homeostasis, but some invertebrates that lack selenoproteins have recently been identified. Genetic disruption of selenoprotein biosynthesis had no effect on lifespan and oxidative stress resistance of Drosophila melanogaster. In the current study, fruit flies with knock-out of the selenocysteine-specific elongation factor were metabolically labeled with (75)Se; they did not incorporate selenium into proteins and had the same lifespan on a chemically defined diet with or without selenium supplementation. These flies were, however, more susceptible to starvation than controls, and this effect could be ascribed to the function of selenoprotein K. We further expressed mouse methionine sulfoxide reductase B1 (MsrB1), a selenoenzyme that catalyzes the reduction of oxidized methionine residues and has protein repair function, in the whole body or the nervous system of fruit flies. This exogenous selenoprotein could only be expressed when the Drosophila selenocysteine insertion sequence element was used, whereas the corresponding mouse element did not support selenoprotein synthesis. Ectopic expression of MsrB1 in the nervous system led to an increase in the resistance against oxidative stress and starvation, but did not affect lifespan and reproduction, whereas ubiquitous MsrB1 expression had no effect. Dietary selenium did not influence lifespan of MsrB1-expressing flies. Thus, in contrast to vertebrates, fruit flies preserve only three selenoproteins, which are not essential and play a role only under certain stress conditions, thereby limiting the use of the micronutrient selenium by these organisms.

Regulation of selenoproteins and methionine sulfoxide reductases A and B1 by age, calorie restriction, and dietary selenium in mice.

Methionine residues are susceptible to oxidation, but this damage may be reversed by methionine sulfoxide reductases MsrA and MsrB. Mammals contain one MsrA and three MsrBs, including a selenoprotein MsrB1. Here, we show that MsrB1 is the major methionine sulfoxide reductase in liver of mice and it is among the proteins that are most easily regulated by dietary selenium. MsrB1, but not MsrA activities, were reduced with age, and the selenium regulation of MsrB1 was preserved in the aging liver, suggesting that MsrB1 could account for the impaired methionine sulfoxide reduction in aging animals. We also examined regulation of Msr and selenoprotein expression by a combination of dietary selenium and calorie restriction and found that, under calorie restriction conditions, selenium regulation was preserved. In addition, mice overexpressing a mutant form of selenocysteine tRNA reduced MsrB1 activity to the level observed in selenium deficiency, whereas MsrA activity was elevated in these animals. Finally, we show that selenium regulation in inbred mouse strains is preserved in an outbred aging model. Taken together, these findings better define dietary regulation of methionine sulfoxide reduction and selenoprotein expression in mice with regard to age, calorie restriction, dietary Se, and a combination of these factors.

MsrB1 (methionine-R-sulfoxide reductase 1) knock-out mice: roles of MsrB1 in redox regulation and identification of a novel selenoprotein form.

Protein oxidation has been linked to accelerated aging and is a contributing factor to many diseases. Methionine residues are particularly susceptible to oxidation, but the resulting mixture of methionine R-sulfoxide (Met-RO) and methionine S-sulfoxide (Met-SO) can be repaired by thioredoxin-dependent enzymes MsrB and MsrA, respectively. Here, we describe a knock-out mouse deficient in selenoprotein MsrB1, the main mammalian MsrB located in the cytosol and nucleus. In these mice, in addition to the deletion of 14-kDa MsrB1, a 5-kDa selenoprotein form was specifically removed. Further studies revealed that the 5-kDa protein occurred in both mouse tissues and human HEK 293 cells; was down-regulated by MsrB1 small interfering RNA, selenium deficiency, and selenocysteine tRNA mutations; and was immunoprecipitated and recognized by MsrB1 antibodies. Specific labeling with (75)Se and mass spectrometry analyses revealed that the 5-kDa selenoprotein corresponded to the C-terminal sequence of MsrB1. The MsrB1 knock-out mice lacked both 5- and 14-kDa MsrB1 forms and showed reduced MsrB activity, with the strongest effect seen in liver and kidney. In addition, MsrA activity was decreased by MsrB1 deficiency. Liver and kidney of the MsrB1 knock-out mice also showed increased levels of malondialdehyde, protein carbonyls, protein methionine sulfoxide, and oxidized glutathione as well as reduced levels of free and protein thiols, whereas these parameters were little changed in other organs examined. Overall, this study established an important contribution of MsrB1 to the redox control in mouse liver and kidney and identified a novel form of this protein.

Saengshik, a formulated health food, prevents liver damage in CCl4-induced mice and increases antioxidant activity in elderly women.

Saengshik is a Korean noncooked food made with of more than 30 different whole gains, vegetables, fruits, mushrooms, and seaweeds. All of these ingredients are frozen and dried to minimize the loss of nutrients. Saengshik has become popular among health-conscious people in the Republic of Korea. The study aims to investigate antioxidant effects of Saengshik by in vivo and human experiments. In in vivo tests, mice were fed Saengshik for 4 weeks, and oxidative damage was induced by CCl(4). Then the effects of Saengshik on oxidative damage were examined. It was found that plasma lipid hydroperoxide and protein oxidative damages were significantly suppressed and antioxidants, glutathione, and thiol groups were increased. The activity of the antioxidant enzyme superoxide dismutase was increased, and the level of glutamate pyruvate transaminase was decreased. In a human study, elderly people were given Saengshik for 24 weeks, and changes in antioxidant defense of the body were examined. Antioxidant activities in plasma were enhanced, although the difference was not significant. Therefore, it is expected that Saengshik is effective at removing oxidants from body tissues, preventing oxidative damage, and eventually boosting the antioxidant capacity of the body.

A polysaccharide extracted from rice bran fermented with Lentinus edodes enhances natural killer cell activity and exhibits anticancer effects.

The objective of this study was to investigate the activation of natural killer (NK) cells and anticancer effects of exo-biopolymer from rice bran cultured with Lentinus edodes [rice bran exo-biopolymer (RBEP)]. Oral administration of RBEP induced the activation of NK cells in a dose-dependent manner. RBEP also prolonged the life spans of mice transplanted with Sarcoma-180 cells and inhibited growing Sarcoma-180 cells in intraperitoneum. Solid tumor growth was also suppressed by oral administration of RBEP in C57/Bl6 mice transplanted with B16/Bl6 melanoma. Intraperitoneal injection of RBEP was more effective than oral administration at the same dosage in mice with transplanted tumor cells. According to this result, when RBEP directly contacts immune cells, the anticancer activity is higher than by indirectly inducing an immune response through oral administration. Therefore, we suggest that the administration of RBEP may be effective for preventing and/or treating cancer through NK cell activation. However, further studies are needed to elucidate the possible mechanisms of the anticancer activity and to investigate the other beneficial effects of RBEP for the development of a new biological response modifier.

Antiproliferative crude soy saponin extract modulates the expression of IkappaBalpha, protein kinase C, and cyclooxygenase-2 in human colon cancer cells.

Frequent consumption of soy and soy-based products is associated with reduced cancer incidence particularly for breast, colon, and prostate cancer. In this study, we examined the effect of crude soy saponin extract on PMA (phorbol 12-myristate 13-acetate)-induced inflammatory responses. Human adenocarcinoma cells (HT-29) were treated with various concentrations of saponin extract for 72 h. Cell growth was measured at 24, 48 and 72 h of incubation, and the PMA-induced expressions of cyclooxygenase-2 (COX-2), protein kinase C (PKC), and IkappaBalpha were determined. The results indicate that crude saponin extract decreased cell growth in a dose- and time-dependent manner. Crude soy saponin extract suppressed the degradation of IkappaBalpha in PMA-stimulated cells, while COX-2 and PKC expressions were significantly down-regulated. These findings support the hypothesis that the soy saponins reduce the risk of colon tumorigenesis possibly by suppressing inflammatory responses.