Joon-Ho Hwang

Fermented guava leaf extract inhibits LPS-induced COX-2 and iNOS expression in Mouse macrophage cells by inhibition of transcription factor NF-κB

The goal of this study was to elucidate the antiinflammatory activities of Psidium guajava L. (guava) leaf. To improve the functionality of guava leaf, it was fermented with Phellinus linteus mycelia, Lactobacillus plantarum and Saccharomyces cerevisiae. The ethanol extract from fermented guava leaf inhibited lipopolysaccharide (LPS)‐induced nitric oxide (NO) and prostaglandin E2 (PGE2) production. Western blot analysis showed that fermented guava leaf extract decreased LPS‐induced inducible nitric oxide synthase (iNOS) and the cyclooxygenase‐2 (COX‐2) protein level in RAW 264.7 cells. To investigate the mechanism involved, the study examined the effect of fermented guava leaf extract on LPS‐induced nuclear factor‐κB (NF‐κB) activation. Fermented guava leaf extract significantly inhibited LPS‐induced NF‐κB transcriptional activity. Immunochemical analysis revealed that fermented guava leaf extract suppressed LPS‐induced degradation of I‐κBα. Taken together, the data indicate that fermented guava leaf extract is involved in the inhibition of iNOS and COX‐2 via the down‐regulation of NF‐κB pathway, revealing a partial molecular basis for the antiinflammatory properties of fermented guava leaf extract. Copyright

Petalonia improves glucose homeostasis in streptozotocin-induced diabetic mice

The anti-diabetic potential of Petalonia binghamiae extract (PBE) was evaluated in vivo. Dietary administration of PBE to streptozotocin (STZ)-induced diabetic mice significantly lowered blood glucose levels and improved glucose tolerance. The mode of action by which PBE attenuated diabetes was investigated in vitro using 3T3-L1 cells. PBE treatment stimulated 3T3-L1 adipocyte differentiation as evidenced by increased triglyceride accumulation. At the molecular level, peroxisome proliferator-activated receptor gamma (PPARgamma) and terminal marker protein aP2, as well as the mRNA of GLUT4 were up-regulated by PBE. In mature adipocytes, PBE significantly stimulated the uptake of glucose and the expression of insulin receptor substrate-1 (IRS-1). Furthermore, PBE increased PPARgamma luciferase reporter gene activity in COS-1 cells. Taken together, these results suggest that the in vivo anti-diabetic effect of PBE is mediated by both insulin-like and insulin-sensitizing actions in adipocytes.

Antioxidant and anticancer activities of broccoli by-products from different cultivars and maturity stages at harvest.

Many studies on broccoli have analyzed the functional components and their functionality in terms of antioxidant and anticancer activities; however, these studies have focused on the florets of different varieties. Investigation of the functionality of broccoli by-products such as leaves, stems, and leaf stems from different cultivars and harvest dates might be valuable for utilizing waste materials as useful food components. Total phenolics and sulforaphane contents, and antioxidant and anticancer activities were measured in the leaves, leaf stems, and stems of early-maturing (Kyoyoshi), middle-maturing (Myeongil 96), and late-maturing broccoli (SK3-085) at different harvest dates. Total phenolics in the leaves of Kyoyoshi were about 1.8-fold to 12.1-fold higher than those in all of the other cultivars and parts. The sulforaphane content of Kyoyoshi was 2.8-fold higher in the stems than in the florets. Antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorbance capacity were highest in Kyoyoshi, followed by Myeongil 96 and SK3-085, most notably in the leaves harvested at the immature stage. Inhibition activity of cell growth against the NCI-H1299 cell lines was highest in the leaves of all cultivars in decreasing order of florets, leaf stems, and stems. The leaves harvested in October (nonflowering stage) had the highest inhibition activity, while those harvested in January (mature broccoli) showed the lowest. The results of this study demonstrate that broccoli leaves and stems contain high levels of total phenolics, and high antioxidant and anticancer activities and can provide opportunities for early-maturing broccoli as functional fresh raw vegetables.

Antioxidant and Anti-inflammatory Activities of Broccoli Florets in LPS-stimulated RAW 264.7 Cells

Broccoli (Brassica oleracea var. italia) florets were extracted with 80% methanol and the extract was sequentially fractionated with n-hexane, ethyl acetate, n-butanol, and distilled water. The extract and the fractions were evaluated for total phenolic content, sulforaphane content, antioxidant activity, and anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The total phenolic content and sulforaphane content of the ethyl acetate fraction (EF) were 35.5 mg gallic acid equivalents/g and 620.2 μg/g, respectively. These values were higher than those of the 80% methanol extract and organic solvent fractions. The oxygen radical absorbance capacity of the EF [1,588.7 μM Trolox equivalents (TE)/mg] was 11-fold higher than that of the distilled water fraction (143.7 μM TE/mg). The EF inhibited nitric oxide release from LPS-stimulated RAW 264.7 cells in a dose-dependent manner and inhibited IκB-α degradation and nuclear factor-κB activation in LPS-stimulated RAW 264.7 cells. In conclusion, the EF of broccoli florets exerted potent antioxidant and anti-inflammatory effects.

Anti-inflammatory activities of some brown marine algae in LPS-stimulated RAW 264.7 cells

The antioxidant and anti-inflammatory activities of methanol extracts of Undaria pinnatifida from Jeju, Wando, and Gijang were measured by the oxygen radical absorbance capacity and inhibition of nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 cells. The U. pinnatifida methanol extract (UPME) from Jeju exhibited the highest antioxidant activity by 208.1 μmol TE/100 μg, followed by Gijang (112.8 μmol TE/100 μg) and Wando (94.8 μmol TE/100 μg). The antiinflammatory activity of the UPME from Jeju was high with an IC50 value of 78.5 μg/mL as compared with those from Wando and Gijang at 250.2 and 219.1 μg/mL, respectively. The UPME from Jeju inhibited iNOS and COX-2 expression in a dose-dependent manner. A 20-min treatment with the UPME from Jeju inhibited IκB-α degradation and phosphorylation. It also inhibited the nuclear translocation of NF-κB at 30-min treatment and reduced NF-κB transcriptional activity in a dose-dependent manner. It was concluded that the UPME from Jeju inhibited the production of inflammatory factors by inhibiting the phosphorylation and degradation of IκB-α in LPS-induced RAW 264.7 cells.

Antioxidant and Anti-Inflammatory Activities of Sasa quelpaertensis Leaf Extracts

Oxidative stress plays a critical role in the pathogenesis of inflammation (Winrow et al., 1993), which is a physiological response that protects the body from stimuli including infections and tissue injury. The magnitude of the inflammatory response is crucial, and insufficient responses result in immunodeficiency, which can lead to infection and cancer. Excessive responses cause morbidity and mortality from diseases such as rheumatoid arthritis, Crohn’s disease, atherosclerosis, diabetes, Alzheimer’s disease, multiple sclerosis, and cerebral and myocardial ischemia (Tracey, 2002). Inflammation is associated with a wide range of inflammatory mediators that initiate inflammatory responses, recruit and activate other cells to the site of inflammation, and subsequently resolve the inflammation (Gallin & Snyderman, 1999). The expression of pro-inflammatory mediators such as cytokines, chemokines, adhesion molecules, iNOS, and COX-2 involves nuclear factor-κB (NF-κB) (Baeuerle & Baltimore, 1996; Hayden & Ghosh, 2004). Mitogen-activated protein kinases (MAPKs) pathways are also reportedly stimulated by inflammatory mediators (Guha & Mackman, 2001).