• Nutrition Research and Practice
• /
• 제17권4호
• /
• pp.616-630
• /
• 2023

BACKGROUND/OBJECTIVES: Indole-3-propionic acid (IPA) is a tryptophan-derived microbial metabolite that has been associated with protective effects against inflammatory and metabolic diseases. However, there is a lack of knowledge regarding the effects of IPA under physiological conditions and at the intestinal level. MATERIALS/METHODS: Human intestinal epithelial Caco-2 cells were treated for 2, 24, and/or 72 h with IPA or its precursors - indole, tryptophan, and propionate - at 1, 10, 100, 250, or 500 μM to assess cell viability, integrity, differentiation, and proliferation. RESULTS: IPA induced cell proliferation and this effect was associated with a higher expression of extracellular signal-regulated kinase 2 (ERK2) and a lower expression of c-Jun. Although indole and propionate also induced cell proliferation, this involved ERK2 and c-Jun independent mechanisms. On the other hand, both tryptophan and propionate increased cell integrity and reduced the expression of claudin-1, whereas propionate decreased cell differentiation. CONCLUSIONS: In conclusion, these findings suggested that IPA and its precursors distinctly contribute to the proliferation, differentiation, and barrier function properties of human intestinal epithelial cells. Moreover, the pro-proliferative effect of IPA in intestinal epithelial cells was not explained by its precursors and is rather related to its whole chemical structure. Maintaining IPA at physiological levels, e.g., through IPA-producing commensal bacteria, may be important to preserve the integrity of the intestinal barrier and play an integral role in maintaining metabolic homeostasis.

• Journal of Life Science
• /
• 제29권1호
• /
• pp.60-68
• /
• 2019

Limonium tetragonum, an edible halophyte that grows on salt marshes in Korea, is thought to possess various health benefits (e.g., antioxidant, antitumor, and hepatoprotective). In the present study, different solvent partitioned subfractions, water ($H_2O$), buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and hexane (n-hexane), from crude extract of L. tetragonum were tested for their ability to prevent adipogenesis in differentiating 3T3-L1 preadipocytes. The treatment of differentiating 3T3-L1 preadipocytes with L. tetragonum subfractions (LTFs) resulted in suppressed adipogenesis and reduced expression of adipogenesis-related transcription factors such as peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), CCAATT/enhancer-binding protein alpha ($C/EBP{\alpha}$), and sterol regulatory element-binding protein 1c (SREBP-1c) at both mRNA and protein levels. In addition, the LTF treatment notably decreased the levels of phosphorylated p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) pathway in association with $PPAR{\gamma}$-linked adipogenesis. Among all the tested LTFs, $H_2O$ and n-hexane were the most effective in lowering lipid accumulation and regulating the adipocyte differentiation via $PPAR{\gamma}$ pathway. Taken together, the results indicated that the $H_2O$ and n-hexane LTFs contain bioactive compounds that may exhibit significant antiadipogenesis activity by downregulation of the $PPAR{\gamma}$ pathway and inactivation of the MAPK signal pathway in 3T3-L1 preadipocytes.

• Journal of the Korean Society of Food Science and Nutrition
• /
• 제46권6호
• /
• pp.671-680
• /
• 2017

This study was conducted to examine the effects and potential mechanisms of action of black soybean extracts and fermented black soybean extracts by Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animals subsp. lactis BB-12 (BB-12) on proliferation of human follicle dermal papilla cells (HFDPC). We examined changes in pH, total polyphenol, sugar, and reducing sugar contents according to fermentation period of black soybean extracts. Assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was performed to determine cell toxicity levels of the four black soybean extracts [black soybean water extract (BWE), black soybean ethanol extract (BEE), fermented BWE (F-BEW), and fermented BEE (F-BEE)]. Changes in mRNA expression levels of hair growth promoting factors and hair growth inhibiting factors by the four black soybean extracts were measured by real-time PCR. In addition, phosphorylation levels of mitogen-activated protein kinase family proteins were measured by western blot analysis. As a result, fermentation of black soybeans significantly reduced pH, total polyphenols, and sugar/reducing sugar contents. All four black soybean extracts showed no cellular toxicity in HFDPC. In fact, BEE significantly enhanced cell viability of HFDPC at $100{\mu}g/mL$ compared to control. BWE, BEE, and BWE-F significantly increased mRNA expression of vascular endothelial growth factor, and all four extracts increased mRNA expression of fibroblast growth factor. However, mRNA expression levels of apoptosis-related genes were not affected by black soybean extracts in HFDPC. Furthermore, BWE, BEE, and BWE-F significantly increased phosphorylation levels of extracellular signal-regulated kinase compared to control. Taken together, we demonstrated that black soybean extracts enhanced proliferation of human follicle dermal papilla cells partially via activation of hair growth promoting factors, although no particular significant effects on proliferation were observed by fermentation of black soybeans.

• Journal of Life Science
• /
• 제33권3호
• /
• pp.234-241
• /
• 2023

At present, many countries around the world are legalizing cannabis and its products, and research on various treatments using cannabis is being actively conducted. However, the cannabis plant contains other compounds whose biological effects have not yet been established. We investigated the effect of cannabidiol (CBD) on hair growth in human dermal papilla cells (HDPCs). 2,2'-Azino-bis (3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays were performed to determine the antioxidant activity of CBD. The HDPCs viability of CBD was examined via water-soluble tetrazolium salt (WST-1) assay. The expression of hair-loss-related markers in HDPCs by CBD treatment was analyzed by real-time PCR and western blotting. The DPPH, ABTS radical scavenging activity assay showed that CBD had superior antioxidant activities. In HDPCs, CBD increased cellular proliferation at concentrations without cytotoxicity. It also increased the expressions of fibroblast growth factor 1 (FGF1), fibroblast growth factor 7 (FGF7), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). These results correlated with a decrease in the expression of inhibition-related factors, such as androgen receptor (AR) and transforming growth factor beta 1 (TGF-B1). Moreover, CBD resulted in a significant increase in the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). Therefore, it is suggested that CBD may be a potential remedy for the treatment of alopecia.

• Microbiology and Biotechnology Letters
• /
• 제47권1호
• /
• pp.148-157
• /
• 2019

A 70% ethanol extract of Erigeron annuus (L.) Pers. was investigated for its whitening activity for application as a functional ingredient in cosmetic products. At the E. annuus extract concentration of $100{\mu}g/ml$, the electron-donating ability was found to be 67.83%, the tyrosinase inhibitory effect (related to skin-whitening) was 69%, the elastase inhibitory effect (related to skin-wrinkling) was 69%, and the astringent effect was 80%. The $ABTS^+$ radical-scavenging ability was 87% at the $500{\mu}g/ml$ concentration. In the cell viability test measured on melanoma cells, 96% of the cells treated with $100{\mu}g/ml$ of the extract were viable. According to the western blot results, the protein expression of the microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 was decreased by 60.22%, 47.83%, 54.79%, and 67.88%, respectively, at the extract concentration of $100{\mu}g/ml$. The protein expression of phosphorylated extracellular signal regulated kinase (p-ERK) and phosphorylated cAMP response element-binding protein (p-CREB) was decreased with increasing concentrations of the extract. Reverse transcription-polymerase chain reaction of the extract showed that the mRNA expression of MITF, tyrosinase, TRP-1, and TRP-2 was decreased by 86.51%, 85.22%, 74.26%, and 66.66%, respectively, at $100{\mu}g/ml$ extract concentration. The findings suggest that the 70% ethanol extract from E. annuus (L.) Pers. has potential as a cosmeceutical ingredient with whitening effect.

• Journal of Life Science
• /
• 제21권7호
• /
• pp.985-991
• /
• 2011

The purpose of this study was to investigate the biological effect of obesity-induced oxidative damage on neurogenesis and early protein expression. Obesity was induced I thirty 4-week old male Sprague-Dawley rats through a high fat diet for 15 weeks. After one week of environmental adaptation, the rats were divided into 2 groups: high fat diet sedentary group (HDS, n=15) and high fat diet training group (HDT, n=15). Exercise training was performed 5 times a week for 8 weeks, with mild-intensity treadmill running for weeks 1-4 and moderate-intensity treadmill running for weeks 5-8. After the 8 week training period, we analyzed lipid profiles, serum 8-hydroxyguanosine (8-OHdG), liver tissue malondialdehyde (MDA) related to oxidative damage factors, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), c-fos, c-jun, and extracellular signal regulated kinase (Erk) in the hippocampus. The results of this study are as follows. There were differences between HDS and HDT in triglyceride (TG) and total cholesterol (TC) (p<0.05). In high density lipoprotein (HDL-c), the HDT was higher than HDS after treadmill training (p<0.05). In 8-OHdG, the HDT was lower than HDS after treadmill training (p<0.05). Genetic expressions of c-jun, BDNF and MDA in the HDT were higher than in the HDS after treadmill training in hippocampus (p<0.05). Therefore, we conclude that 8 weeks of treadmill training can improve imbalanced lipid profiles, reduce oxidative damage, and activate neurogenesis in obese rats.

• Journal of Life Science
• /
• 제32권8호
• /
• pp.601-610
• /
• 2022

P. tenebrifer (PT) belongs to the Diptera order and Stratiomyidae family. Recently, insect industry have been focused as food, animal feed and environmental advantages. γ-aminobutyric acid (GABA) and melatonin have been associated with regulating sleep and depression. GABA is the primary inhibitory neurotransmitter and is synthesized via biotransformation of monosodium glutamate (MSG) to GABA by lactic acid bacteria. In this study, we first used a GABA-enhanced PT extract, wherein GABA was enhanced by feeding MSG to PT. The underlying mechanisms preventing stress and insomnia were investigated in a corticosterone (CORT)-induced endoplasmic reticulum (ER) stress and chronic restraint stress (CRS)-exposed mouse model, as well as in pentobarbital (45 mg/kg)-induced sleep behaviors in mice. In the present study, the GABA peak was detected in high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) analysis and showed in Ptecticus tenebrifer water extract (PTW) but not in non-PTW extract. The results showed that PTW and Ptecticus tenebrifer with 70% ethanol extract (PTE) exerted neuroprotective effects by protecting against CORT-induced downregulation of phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) and cAMP-response element binding protein (CREB) expression. In addition, PTW (300 mg/kg) significantly reduced CORT levels in CRS-exposed mice. Furthermore, PTW (100 and 300 mg/kg) significantly reduced sleep latency and increased total sleep duration in pentobarbital (45 mg/kg)-induced sleeping behaviors, which was related to serum melatonin levels. In conclusion, our results suggest that PTW exerts anti-stress and sleep-enhancing effects by regulating serum CORT and melatonin levels.

• Journal of Life Science
• /
• 제30권12호
• /
• pp.1092-1100
• /
• 2020

The six-transmembrane epithelial antigen of prostate 4 (Steap4) is a metalloreductase that plays a role in intracellular iron and cupper homeostasis, inflammatory response, and glucose and lipid metabolism. Previously, Steap4 has been reported to stimulate adipocyte differentiation; however, the underlying mechanisms of this action remain unexplored. In the present study, we investigated the molecular mechanisms involved in Steap4-induced adipocyte differentiation using 3T3-L1 cells, immortalized brown adipocyte (iBA) cells, and mouse embryonic fibroblast C3H10T1/2 cells. The knockdown of Steap4 using adenovirus-containing shRNA attenuated mitotic clonal expansion (MCE), as evidenced by the impaired proliferation of 3T3-L1 cells, iBA cells, and C3H10T1/2 cells within 48 hr after adding the differentiation medium. Steap4 knockdown downregulated G1/S phase transition-related cell cycle regulators (including cyclin A and cyclin D) and upregulated cell cycle inhibitors (including p21 and p27). Furthermore, Steap4 knockdown inhibited the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and Akt. Moreover, Steap4 knockdown repressed the expression of early adipogenic activators, such as CCAAT-enhancer-binding protein β (C/EBPβ) and Kruppel-like factor family factor 4 (KLF4). On the other hand, Steap4 knockdown stimulated the expression of adipogenic inhibitors, including KLF2, KLF3, and GATA2. The overexpression of Steap4 using an adenovirus removed the repressive histone marks H3K9me2 and H3K9me3 on the promoter of C/EBPβ. These results indicate that Stepa4 stimulates adipocyte differentiation through the induction of MCE and the modulation of early adipogenic transcription factors, including C/EBPβ, during the early phase of adipocyte differentiation.