Kang-Hyun Chung

Hederagenin Supplementation Alleviates the Pro-Inflammatory and Apoptotic Response to Alcohol in Rats

In this study, we determined the effects of hederagenin isolated from Akebia quinata fruit on alcohol-induced hepatotoxicity in rats. Specifically, we investigated the hepatoprotective, anti-inflammatory, and anti-apoptotic effects of hederagenin, as well as the role of AKT and mitogen-activated protein kinase (MAPK) signaling pathways in ethanol-induced liver injury. Experimental animals were randomly divided into three groups: normal (sham), 25% ethanol, and 25% ethanol + hederagenin (50 mg/kg/day). Each group was orally administered the respective treatments once per day for 21 days. Acetaldehyde dehydrogenase-2 mRNA expression was higher and alcohol dehydrogenase mRNA expression was lower in the ethanol + hederagenin group than those in the ethanol group. Pro-inflammatory cytokines, including TNF-α, IL-6, and cyclooxygenase-2, significantly increased in the ethanol group, but these increases were attenuated by hederagenin. Moreover, Western blot analysis showed increased expression of the apoptosis-associated protein, Bcl-2, and decreased expression of Bax and p53 after treatment with hederagenin. Hederagenin treatment attenuated ethanol-induced increases in activated p38 MAPK and increased the levels of phosphorylated AKT and ERK. Hederagenin alleviated ethanol-induced liver damage through anti-inflammatory and anti-apoptotic activities. These results suggest that hederagenin is a potential candidate for preventing alcoholic liver injury.

Physicochemical Characteristics and Biological Activities of Makgeolli Supplemented with the Fruit of Akebia quinata during Fermentation

We investigated the characteristics and biological activity of makgeolli supplemented with different levels (0%, 1%, 3%, 5%, and 7%) of Akebia quinata fruit during fermentation. Our results showed that supplementation with Akebia quinata fruit led to an increase in the acidity level, amino acid concentration, alcohol content, and total sugar level. Makgeolli supplemented with 7% Akebia quinata fruit showed the highest total sensory score. Supplementation with Akebia quinata fruit resulted in a significant increase in the antioxidant activity and nitric oxide inhibitory activity. Further, makgeolli supplemented with Akebia quinata fruit showed anticancer activity against DU145, HeLa, MCF-7, and U87cells, and significantly enhanced antibacterial activity against Shigella flexneri. Our results indicate that Akebia quinata fruit represents an effective natural additive for enhancing the biological activities of makgeolli.

Calcium Supplement Derived from Gallus gallus domesticus Promotes BMP-2/RUNX2/SMAD5 and Suppresses TRAP/RANK Expression through MAPK Signaling Activation

The present study evaluated the effects of a calcium (Ca) supplement derived from Gallus gallus domesticus (GD) on breaking force, microarchitecture, osteogenic differentiation and osteoclast differentiation factor expression in vivo in Ca-deficient ovariectomized (OVX) rats. One percent of Ca supplement significantly improved Ca content and bone strength of the tibia. In micro-computed tomography analysis, 1% Ca supplement attenuated OVX- and low Ca-associated changes in bone mineral density, trabecular thickness, spacing and number. Moreover, 1% Ca-supplemented diet increased the expression of osteoblast differentiation marker genes, such as bone morphogenetic protein-2, Wnt3a, small mothers against decapentaplegic 1/5/8, runt-related transcription factor 2, osteocalcin and collagenase-1, while it decreased the expression of osteoclast differentiation genes, such as thrombospondin-related anonymous protein, cathepsin K and receptor activator of nuclear factor kappa B. Furthermore, 1% Ca-supplemented diet increased the levels of phosphorylated extracellular signal-regulated kinase and c-Jun N-terminal kinase. The increased expression of osteoblast differentiation marker genes and activation of mitogen-activated protein kinase signaling were associated with significant increases in trabecular bone volume, which plays an important role in the overall skeletal strength. Our results demonstrated that 1% Ca supplement inhibited osteoclastogenesis, stimulated osteoblastogenesis and restored bone loss in OVX rats.

Melanin extract from Gallus gallus domesticus promotes proliferation and differentiation of osteoblastic MG-63 cells via bone morphogenetic protein-2 signaling

BACKGROUND/OBJECTIVES Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of 50-250 µg/mL. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to 250 µg/mL and were 149% and 129% at 250 µg/mL concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of 500 µg/mL. CONCLUSIONS This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.

Akebia quinata Extract Combined with Korean Traditional Juice Activates Antioxidant Enzymes and Reduces Apoptosis and Inflammation

In this study, we investigated the effects of Akebia quinata ethanol extract (AE), Akebia quinata sikhye (AS), and Akebia quinata water extract (AW) on alcohol-induced liver injury in rats. The hepatoprotective, anti-inflammatory, anti-apoptotic, and antioxidant effects of AE, AS, and AW were examined. Experimental animals were randomly divided into five groups: normal, ethanol, AE (10 mL/kg), AS (10 mL/kg), and AW (10 mL/kg). Each group was administered the respective treatment orally once per day for 21 days. CYP2E1 mRNA expression was significantly lower in the AE, AS, and AW groups than that in the ethanol group. Pro-inflammatory cytokines including cyclooxygenase-2, IL6, and TNF-α increased significantly in the ethanol group but these increases were ameliorated with AE, AS, and AW treatment. Moreover, the expression of the apoptosis-associated proteins Bax, p53, procaspase-3, and PARP decreased after treatment with AE, AS, and AW. The expression of antioxidant enzymes including BCL-2, SOD, and GST slightly decreased in the ethanol group, but AE, AS, and AW treatment augmented their activities. AQ extracts and AS attenuated ethanol-induced increases in the levels of phosphorylated p-AKT, p-ERK, and p-JNK. These results demonstrate that AQ is a competence indicator for inhibiting alcoholic liver injury.