Therapeutic propensity of ginsenosides Rg1 and Rg3 in rhabdomyolysis-induced acute kidney injury and renohepatic crosstalk in rats.

BACKGROUND: Ginseng is a traditional herbal medicine used for thousands of years in Southeast Asian countries because of its medicinal properties. Ginsenosides Rg1 and Rg3 have demonstrated therapeutic properties against a broad spectrum of diseases. PURPOSE: Here in this study, we investigated the therapeutic efficacy of Rg1 and Rg3 in alleviating glycerol-induced acute kidney injury, also known as rhabdomyolysis-induced acute kidney injury (RAKI). METHODS: AKI was induced in male Wistar rats through intramuscular injection of 10 mL/kg glycerol and simultaneous oral treatment of ginsenosides Rg1 and Rg3 for 3 days. We also evaluated the therapeutic potential of Rg1 and Rg3 on human embryonic kidney epithelial (HEK-293). Cell viability and LDH assay were performed on HEK-293 cells to evaluate the toxicity of Rg1 and Rg3. Evaluation of important kidney damage markers such as creatinine and blood urea nitrogen (BUN) was carried out at different time points from the rat serum. Histopathological analysis was performed on kidney tissues. We also performed experiments such as ELISA assay, immunohistochemistry, immunofluorescence staining, COMET assay, western blotting, TUNEL assay, and flow cytometry to obtain results. RESULTS: Rg1 and Rg3 significantly downregulated the expression of kidney damage markers such as creatinine and BUN in a dose-dependent manner. Histopathological analysis revealed damage across the glomerulus, tubules, and collecting duct rendering the kidney dysfunctional in glycerol treatment groups. However, Rg1 and Rg3 treated groups showed a significant reduction in tubular necrosis at both 10 and 20 mg/kg. There was also a sharp downregulation of oxidative and ER stress markers. Additionally, we observed nuclear translocation of Nrf2 which were more prominent in kidney tissues. Rg1 and Rg3 were also able to mitigate apoptotic cell death in vitro and in vivo evaluated through immunofluorescence staining for p53, TUNEL assay, flow cytometry, and immunoblotting for intrinsic apoptosis markers. CONCLUSION: In summary, we conclude that Rg1 and Rg3 exhibited natural therapeutic remedy against AKI.

Ultraviolet B-irradiated mushroom supplementation increased the Ca++ uptake and ameliorated the LPS-induced inflammatory responses in zebrafish larvae.

The harmful effects of excessive ultraviolet (UV) exposure are well known. However, moderate exposure to UV radiation is beneficial and required for active vitamin D synthesis in our body. People living in the coldest regions on the earth are unable to expose their skin to the solar UV radiation and, therefore, additional supplementation of Vitamin D2 is recommended. Mushrooms are one such consumable macrofungi, which has high vitamin content and therefore used in various traditional medicines. Particularly, UVB-irradiated mushrooms are rich in active vitamin D content and that is why recommended to include in the daily diets for the patients suffering from the problems associated with bone mineralization. In the present study, we evaluated the cytotoxic effect of mushroom extract (UVB-ME) (Lentinus edodes) treatment against MG-63 cells, HepG2 cells, and CCD 841 CoN cells. Furthermore, we elucidated the potential of UVB-ME on Ca++ uptake in osteoblast-like MG-63 cells. Next, we validated the response of Ca++ uptake on the growth and development of zebrafish larvae. In addition, the anti-inflammatory and immunomodulatory potential of UVB-ME treatment against lipopolysaccharide-induced inflammatory response was also analyzed in vivo. Collectively, the study suggested that dietary supplementation of UVB-irradiated mushroom is beneficial for bone calcification and could modulate the host immune system.

Bamboo leave extract ameliorated 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ear inflammation by reducing MAP kinase levels and NF-κB activation in mice model.

Sasa coreana Nakai (SCN) is a medicinal plant commonly used against inflammation. However, the underlined mechanisms against skin inflammation is poorly understood. The present study investigated the effects of SCN leave extract on ear inflammation. To this aim, six-week-old male ICR mice was subjected to 12-O-tetradecanoyl-phorbol-13-acetate induce ear edema, which were then topically treated with the leave extract of SCN. Ear thickness, weight, and morphological changes were recorded to ensure the induction of ear edema. Further, histological analysis and protein expression for inflammatory markers were also recorded to validate the study. Topical treatment with SCN repressed TPA-induced ear edema in a dose-dependent manner. Further, SCN treatment significantly antagonized the protein expression of MAP kinase signaling pathway and reduced the effect of TPA-induced NF-κB activation, sequentially, deactivated its transcriptional targets in a dose-dependent manner. Collectively, the study suggested that SCN could be a useful therapeutic agent against skin inflammation.

Comparative study on the chemical composition and biological activities of the essential oils of three Lagochilus species collected from Uzbekistan.

Lagochilus species are mainly distributed in Central Asia and widely used in folk medicine as a sedative and haemostatic. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three Lagochilus species (L. gypsaceus, L. inebrians and L. setulosus) essential oils from Uzbekistan. The chemical composition of these essential oils was determined by GC-MS. The results showed that the studied essential oils are made up mainly of linalool (11.97%), ß-ionone (11.75%), trans-chrysanthenyl acetate (7.15%), α-terpineol (7.40%) for L. gypsaceus; trans-chrysanthenyl acetate (9.40%), eugenol (7.01%), trans-verbenol (3.85%), bicyclo[3.1.1]hept-3-en-2-one (3.76%), pinocarvone (3.43%) for L. inebrians; and finally 2,4-bis(1,1-dimethylethyl)phenol (19.78%), bicyclo[3.1.1]hept-2-en-4-ol (5.43%), hexadecanoic acid (5.39%), limonene (5.19%), 2-hexenal (5.03%) for L. setulosus. The best antioxidant and tyrosinase inhibitory activity was observed for the essential oil of L. inebrians. However, L. setulosus essential oil exhibited the strongest inhibitory effect against amylase.

Phorbol 12-Myristate 13-Acetate Induced Toxicity Study and the Role of Tangeretin in Abrogating HIF-1α-NF-κB Crosstalk In Vitro and In Vivo.

Phorbol 12-myristate 13-acetate (PMA) is a potent tumor promoter and highly inflammatory in nature. Here, we investigated the toxic effects of PMA on different model system. PMA (10 µg) caused chromosomal aberrations on the Allium cepa root tip and induced mitotic dysfunction. Similarly, PMA caused embryonic and larval deformities and a plummeted survivability rate on zebrafish embryo in a dose-dependent manner. Persistently, PMA treatment on immortalized human keratinocyte human keratinocyte (HaCaT) cells caused massive inflammatory rush at 4 h and a drop in cell survivability at 24 h. Concomitantly, we replicated a cutaneous inflammation similar to human psoriasis induced by PMA. Herein, we used tangeretin (TAN), as an antagonist to counteract the inflammatory response. Results from an in vivo experiment indicated that TAN (10 and 30 mg/kg) significantly inhibited PMA stimulated epidermal hyperplasia and intra-epidermal neutrophilic abscesses. In addition, its treatment effectively neutralized PMA induced elevated reactive oxygen species (ROS) generation on in vitro and in vivo systems, promoting antioxidant response. The association of hypoxia-inducible factor 1-alpha (HIF-1α)-nuclear factor kappa-light-chain-enhancer of activated b cells (NF-κB) crosstalk triggered by PMA enhanced PKCα-ERK1/2-NF-κB pathway; its activation was also significantly counteracted after TAN treatment. Conclusively, we demonstrated TAN inhibited the nuclear translocation of HIF-1α and NF-κB p65. Collectively, TAN treatment ameliorated PMA incited malignant inflammatory response by remodeling the cutaneous microenvironment.

Genotypic, phenotypic, and pathogenic characterization of the soil isolated Acinetobacter courvalinii.

Most of the human gene homologs are found in Caenorhabditis elegans. As a wide variety of micro-organisms present in the environment is pathogens, so, C. elegans could be a useful model to track future infectious disease. With this knowledge, in this study, we isolated Acinetobacter courvalinii from the soil and characterized its pathogenicity for the first time. For the isolation, we used Glucose-Yeast extract-Ethanol-Calcium carbonate medium. To this aim, we evaluated the resistivity of bacteria against several stressful microenvironments. As we observed, A. courvalinii JP_A1001 shown highly tolerance against the acidic environment (pH 3-7), resistant against up to 0.2% of phenol content, and survived in the medium supplemented with 0.3% of bile salt. In addition, the bacteria were also resistant against several antibiotics showing the property of multidrug-resistant bacteria. Moreover, the isolated bacteria have shown the biofilm formation ability within 60 h. Further, we found that incubation of C. elegans with A. courvalinii JP_A1001 decreased the body movement and increased the free radical generation which remarkably influenced the life expectancy of C. elegans compared to E. coli OP50. Therefore, we concluded that A. courvalinii JP_A1001 found in the soil could be a future threat as a pathogen to public health.

Aflatoxin B1 induces reactive oxygen species-dependent caspase-mediated apoptosis in normal human cells, inhibits Allium cepa root cell division, and triggers inflammatory response in zebrafish larvae.

Mycotoxin contamination of food and water is a serious global concern. Aflatoxin B1 (AFB1) is a deadly mycotoxin that contaminates both food and water bodies in the environment. AFB1 is reported to cause severe health issues, including hepatotoxicity, teratogenicity, and immunotoxicity in humans; however, the mechanistic effects on plant and aquatic animals are not fully understood. To obtain a clear understanding of the effects of AFB1 on the ecosystem, we examined the influence of AFB1 exposure on different model systems corresponding to various habitats. In the current study, AFB1 contamination consequences were studied on a human normal cell lines (HaCaT, CCD 841 CoN), meristematic Allium cepa (onion) root cells, and zebrafish embryonic development. Our results clearly indicate that concentrations of AFB1 >10 µM are toxic to HaCaT cells. Morphological changes of HaCaT and CCD 841 CoN cells were clearly observed after exposure to AFB1. Particularly in HaCaT cells, treatment with 50 µM and 100 µM AFB1induces oxidative stress by excessive endogenous free-radical production such as ROS and NO generation. These consequences accelerate the ROS-dependent DNA damage events, which subsequently result in caspase mediated programmed cell death. Exposure of A. cepa root cells to AFB1 for 24 h resulted in abnormal cell division. A. cepa root cells subjected to AFB1 treatment showed a significant concentration-dependent increase in metaphase arrest. Exposure of zebrafish embryos to AFB1 also revealed that AFB1 contamination restricts the larval growth and development, resulting in a remarkably increased zebrafish mortality rate. Collectively, results of the current study indicate that AFB1 contamination triggers the programmed cell death machinery, subsequently affecting the ecosystem.

Inhibitory insights of strawberry (Fragaria × ananassa var. Seolhyang) root extract on tyrosinase activity using computational and in vitro analysis.

The strawberry (Fragaria × ananassa var. seolhyang) is commonly used as fruit but medicinal importance for the non-edible roots which contained a pool of bioactive compounds are not yet studied against tyrosinase inhibition. This study demonstrates the potential of bioactive compounds in root and rhizome of strawberry against tyrosinase inhibition using in silico and in vitro approaches. ADMET profiling and molecular docking analysis show druglikeness for the major bioactive compounds in strawberry root extract (SRE), i.e. procyanidin, procyanidin trimer, kaempferol 3-O-(4-O-p-coumaroyl)-glucoside, neochlorogenic acid, procyanidin tetramer, and quercetin-3-O-pentoside, and docking score between -7.8 to -6.3 kcal/mol with tyrosinase, respectively. Also, these docked complexes exhibit substantial stability contributed by strong hydrogen bonding, hydrophobic interactions, and polar interactions in 100 ns molecular dynamics simulation; further supported by essential dynamics and dynamic cross-correlation matrix analysis. Also, in vitro functional assays support in silico predicted results in terms of substantial cytoprotective and cellular antioxidant potential in Raw 264.7 macrophages challenged by H2O2 as well as non-significant toxicity in zebrafish. SRE exhibits the lowest (5.8%) and highest (42.8%) inhibition of tyrosinase at 100 and 500 µg/ml concentrations, respectively. These results advocated functional properties and tyrosinase inhibition potential of SRE; and hence, SRE can be used in medicinal or cosmetic applications.

Carvacrol inhibits cytochrome P450 and protects against binge alcohol-induced liver toxicity.

Alcoholism is a serious addiction that can lead to various health complications such as liver fibrosis, steatosis, and cirrhosis. Carvacrol is present in many plant-based essential oils and used as a preservative in the food industry. In this study, we have investigated the hepatoprotective role of carvacrol against ethanol-induced liver toxicity in mice. To determine the effect of carvacrol on liver injury parameters, 5 doses of 50% ethanol (10 mL/kg body weight) were orally administered every 12 h for inducing the hepatotoxicity in experimental mice. Interestingly, carvacrol pre-treatment (50 and 100 mg/kg) reversed the ethanol-induced effects on liver function, antioxidant markers, matrix metalloproteinases activities, and histological changes. Moreover, carvacrol binds to the active pocket of cytochrome P450 (Cyt P450) and inhibits its expression. Thus, our finding suggests carvacrol can be used as an adjuvant for the amelioration of alcohol-induced hepatotoxicity.

Thymol attenuates the worsening of atopic dermatitis induced by Staphylococcus aureus membrane vesicles.

Staphylococcus aureus membrane vesicles (MVs) aggravate atopic dermatitis (AD) through the delivery of bacterial effector molecules to host cells and the stimulation of inflammatory responses. This study investigated the inhibitory effect of thymol, a phenolic monoterpene found in essential oils derived from plants, on the worsening of AD induced by S. aureus MVs both in vitro and in vivo. The sub-minimal inhibitory concentrations of thymol disrupted S. aureus MVs. Intact S. aureus MVs induced the expression of pro-inflammatory cytokine (interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α) and chemokine (IL-8 and monocyte chemoattractant protein-1) genes in cultured keratinocytes, whereas thymol-treated S. aureus MVs did not stimulate the expression of these genes. Topical application of thymol-treated S. aureus MVs or treatment with thymol after intact S. aureus MVs to AD-like skin lesions diminished the pathology of AD. This included decreases in epidermal/dermal thickness and infiltration of eosinophils/mast cells, and inhibited expression of pro-inflammatory cytokine and chemokine genes in mouse AD model. Moreover, thymol significantly suppressed the Th1, Th2, and Th17-mediated inflammatory responses in AD-like skin lesions induced by S. aureus MVs, and reduced the serum levels of immunoglobulin (Ig) G2a, mite-specific IgE, and total IgE. In summary, thymol disrupts S. aureus MVs and suppresses inflammatory responses in AD-like skin lesions aggravated by S. aureus MVs. Our results suggest that thymol is a possible candidate for the management of AD aggravation induced by S. aureus colonization or infection in the lesions.

In vitro and in vivo antitumor potential of carvacrol nanoemulsion against human lung adenocarcinoma A549 cells via mitochondrial mediated apoptosis.

Carvacrol is present abundantly in the essential oils of many medicinal plants and well known for its numerous biological activities. Since partial solubility in water and physicochemical instability limits its industrial uses, the present study was performed to prepare a carvacrol nanoemulsion (CANE) using an ultrasonication technique and further evaluation of its anticancer potential against human lung adenocarcinoma A549 cells. The nanoemulsion formulation was optimized by varying carvacrol and polysorbate 80 ratios and characterized by dynamic light scattering (DLS), which revealed a negative surface charge with a mean droplet size between 105.5 ± 3.4 to 169.8 ± 4.9 nm. The CANE induced reactive oxygen species (ROS) production in A549 cells, leading to activation of key regulators of apoptosis such as p-JNK, Bax and Bcl2 as well as release of cytochrome C, and activation of the caspase cascade. Suppression of mitochondrial ROS using Mito-TEMPO reversed the apoptotic potential of CANE signifying involvement of mitochondrial ROS in cell death. Beside, CANE displayed a strong antitumor potential in vivo using an athymic nude mice model. The results strongly support that CANE induced apoptosis in A549 cells by induction of ROS and could be a promising candidate for lung cancer therapy.

Thymol Elicits HCT-116 Colorectal Carcinoma Cell Death Through Induction of Oxidative Stress.

BACKGROUND: Colon cancer is one of the most deadly and common carcinomas occurring worldwide and there have been many attempts to treat this cancer. The present work was designed in order to evaluate thymol as a potent drug against colon cancer. MATERIALS AND METHODS: Cytotoxicity of thymol at different concentrations was evaluated against a human colon carcinoma cell line (HCT-116 cells). Fluorescent staining was carried out to evaluate the level of ROS as well as mitochondrial and DNA fragmentation and immunoblot analysis were performed to confirm apoptosis and mitoptosis. RESULTS AND CONCLUSION: Results of the study demonstrated that thymol efficiently created an oxidative stress environment inside HCT-116 cells, a colorectal carcinoma cell line, through induction of ROS production along with intense damage to DNA and mitochondria, as observed through Hoechst and rhodamine 123 staining, respectively. Moreover, expression of PARP-1, p-JNK, cytochrome-C and caspase-3 proteins was up-regulated, suggesting HCT-116 cells underwent mitoptotic cell death. Therefore, thymol could be used as a potent drug against colon cancer due to its lower toxicity and prevalence in natural medicinal plants.

Potential effect of compounds isolated from Coffea arabica against UV-B induced skin damage by protecting fibroblast cells.

Ultraviolet (UV) radiation has adverse effects on extracellular matrix (ECM) proteins, leading to formation of wrinkles a hallmark of premature skin aging. The adverse effects of UV radiation are associated with induction of matrix metalloproteinases (MMPs) expression and degradation of collagen and elastin. The present study investigated anti-wrinkle effects of chlorogenic acid (CGA), pyrocatechol (PC) and 3,4,5-tricaffeoyl quinic acid (TCQ), isolated from beans of Coffea arabica, against UV-B stimulated mouse fibroblast cells (CCRF) by measuring expression levels of MMP-1, 3, 9, and type-I procollagen. The three compounds were isolated and purified from coffee grounds using column chromatography and structural examination was evaluated by nuclear magnetic resonance (NMR) analysis. Among the three isolated compounds, CGA effectively suppressed the expression of the MMP-1, 3, and 9 and increased synthesis of type-I procollagen as compared UV-B-stimulated CCRF cells. In addition, CGA dose-dependently inhibited intracellular reactive oxygen species (ROS) production in CCRF cells stimulated by UV radiation. Moreover, CGA displayed a good sun protection factor (SPF) and in vitro DNA damage protection together with inhibition of enzyme xanthine oxidase. The enzyme inhibitory kinetic behavior of CGA was determined by Lineweaver-Burk plot, displayed a mixed type enzyme inhibition with 260.3±4.5µM, Ki value. The results indicate that CGA has potential to be used as a preventive agent against premature skin aging induced by UV radiation.

Apoptotic Activity of Lactobacillus plantarum DGK-17-Fermented Soybean Seed Extract in Human Colon Cancer Cells via ROS-JNK Signaling Pathway.

Fermented food has been always possesses upper hand compared to normal food due to its antibacterial, antioxidant, and anticancer properties. Soybeans, which have high nutritional value, are widely consumed in Korea. In this study, soybean seed powder fermented with Lactobacillus plantarum DGK-17, which was previously isolated from kimchi, showed anticancer potential. Fermented soybean extract (FSE) resulted in morphological changes, reduction of cancer cell colony formation and apoptotic cell death of HCT-116 colon cancer cells in a dose-dependent manner, and IC50 value of 111 µg. FSE treatment caused reduction of cell growth in a dose-dependent manner via release of lactate dehydrogenase. FSE treatment induced HCT-116 apoptotic cell death as confirmed by the presence of fragmented nuclei, oxidative burst, and reduced mitochondrial membrane potential (ΔΨm ). Further, FSE treatment sensitized cells to ER stress via IRE1-α induction. FSE treatment also resulted in JNK activation, subsequently causing activation of Bax and downregulation of BCl2. Weakened mitochondrial membrane potential (ΔΨm ) also caused release of Cyto C, further activating caspase-mediated cell death. Therefore, this study reveals the apoptotic role of DGK-17-fermented soybean seed extract in human colon cancer HCT-116 cells.

Anti-inflammatory Potential of Quercetin-3-O-ß-D-("2"-galloyl)-glucopyranoside and Quercetin Isolated from Diospyros kaki calyx via Suppression of MAP Signaling Molecules in LPS-induced RAW 264.7 Macrophages.

Diospyros kaki (DK) contains an abundance of flavonoids and has been used in folk medicine in Korea for centuries. Here, we report for the first time the anti-inflammatory activities of Quercetin (QCT) and Quercetin 3-O-ß-("2"-galloyl)-glucopyranoside (Q32G) isolated from DK. We have determine the no cytotoxicity of Q32G and QCT against RAW 264.7 cells up to concentration of 50 µM. QCT and Q32G demonstrated potent anti-inflammatory activities by reducing expression of nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 inducible NO synthase (iNOS), cyclooxygenase (COX)-2, and mitogen-activated protein kinase (MAPKs) in mouse RAW 264.7 macrophages activated with lipopolysaccharide (LPS). Both QCT or Q32G could decrease cellular protein levels of COX-2 and iNOS as well as secreted protein levels of NO, PGE2 , and cytokines (TNF-α, IL-1ß, and IL-6) in culture medium of LPS-stimulated RAW 264.7 macrophages. Immunoblot analysis showed that QCT and Q32G suppressed LPS-induced MAP kinase pathway proteins p-p38, ERK, and JNK. This study revealed that QCT and Q32G have anti-inflammatory potential, however Q32G possess comparable activity as that of QCT and could be use as adjuvant to treat inflammatory diseases.

Antiviral potential of a diterpenoid compound sugiol from Metasequoia glyptostroboides.

This research reports first time antiviral activity of sugiol, a diterpenoid isolated from Metasequoia glyptostroboides in terms of its ability to inhibit in vitro growth of H1N1 influenza virus. Antiviral potential of sugiol was evaluated through hcytopathogenic reduction assay using Madin-Darby canine kidney (MDCK) cell line. Sugiol (500 µg/ml) was found to exhibit considerable anti-cytopathic effect on MDCK cell line confirming its antiviral efficacy against H1N1 influenza virus. These findings strongly reinforce the suggestion that sugiol could be a candidate of choice in combinational regimen with potential antiviral efficacy.

Protective effect of heat-treated cucumber (Cucumis sativus L.) juice on alcohol detoxification in experimental rats.

In this study, heat-treated cucumber juice was assessed for its protective effect on blood alcohol levels and hepatic alcohol metabolic enzyme system in experimental rats. Initially, during detoxification of alcohol, all groups were orally dosed to 22% alcohol (6ml/kg body weight) along with different concentrations of heat-treated cucumber juice (10, 100 and 500mg/kg) and commercial goods for hangover-removal on sale (2ml/kg). Cucumber juice was dosed before 30 min, and simultaneously after 30min of alcohol administration, and its hepatoprotective effect on blood alcohol levels and hepatic alcohol metabolic enzyme system in experimental rats was evaluated. As a result, after 7h, remarkable reduction was found in the blood alcohol levels for all concentrations of cucumber juice treatment. Treatment with cucumber juice resulted in increasing dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) enzymatic activities in rat liver at 9h after alcohol administration thereby stimulated blood alcohol metabolism as compared with control group. The effect of heat-treated cucumber juice on alcohol detoxification was observed only in the rats treated before 30min from alcohol administration. These findings indicate that heat-treated cucumber juice has significant protective effect on alcohol detoxification in experimental rats, suggesting its usefulness in the treatment of liver injury caused by alcohol consumption.

Quercetin-3-O-ß-d-glucopyranosyl-(1 → 6)-ß-d-glucopyranoside suppresses melanin synthesis by augmenting p38 MAPK and CREB signaling pathways and subsequent cAMP down-regulation in murine melanoma cells.

In this study, the effect of purified quercetin-3-O-ß-d-glucopyranosyl-(1 â†’ 6)-ß-d-glucopyranosid (QCGG) on melanogenesis was investigated. QCGG was isolated from the calyx of a traditional Korean medicinal herb, Persimmon (Diospyros kaki). The hypopigmentation effects of QCGG were determined by examination of cellular melanin contents, tyrosinase activity assay, cAMP assay, and Western blotting of α-MSH-stimulated B16F10 mouse melanoma cells. Our results showed that QCGG inhibited both melanin synthesis and tyrosinase activity in a concentration-dependent manner as well as significantly reduced the expression of melanogenic proteins such as microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1, tyrosinase-related protein-2, and tyrosinase. Moreover, QCGG inhibited intracellular cAMP levels, cAMP response element-binding protein (CREB), and p38 MAPK expression in α-MSH-stimulated B16F10 cells. Taken together, the suppressive effects of QCGG on melanogenesis may involve down-regulation of MITF and its downstream signaling pathway via phosphorylation of p38 MAPK and CREB along with reduced cAMP levels. These results indicate that QCGG reduced melanin synthesis by reducing expression of tyrosine and tyrosine-related proteins via extracellular signal-related protein kinase (ERK) activation, followed by down-regulation of CREB, p38, and MITF.

α-Glucosidase and tyrosinase inhibitory effects of an abietane type diterpenoid taxoquinone from Metasequoia glyptostroboides.

BACKGROUND: Nowadays plant derived natural compounds have gained huge amount of research attention especially in food and medicine industries due to their multitude of biological and therapeutic properties as alternative medicines. METHODS: In this study, a diterpenoid compound taxoquinone, isolated from Metasequoia glyptostroboides was evaluated for its α-glucosidase and tyrosinase inhibitory efficacy in terms of its potent anti-diabetic and depigmentation potential, respectively. RESULTS: As a result, taxoquinone at the concentration range of 100-3,000 µg/mL and 200-1,000 µg/mL showed potent efficacy on inhibiting α-glucosidase and tyrosinase enzymes by 9.24-51.32% and 11.14-52.32%, respectively. CONCLUSIONS: The findings of this study clearly evident potent therapeutic efficacy of an abietane diterpenoid taxoquinone isolated from M. glyptostroboides with a possibility for using it as a novel candidate in food and medicine industry as a natural alternative medicine to prevent diabetes mellitus type-2 related disorders and as a depigmentation agent.

Anti-listerial synergism of leaf essential oil of Metasequoia glyptostroboides with nisin in whole, low and skim milks.

OBJECTIVE: To examine the individual and synergistic anti-listerial effect of nisin and leaf essential oil of Metasequoia glyptostroboides (M. glyptostroboides) against one of the leading foodborne pathogens Listeria monocytogenes (L. monocytogenes) ATCC 19116 in milk samples. METHODS: The whole (8%), low (1%) and skim (no fat content) milk samples were inoculated with L. monocytogenes ATCC 19116 along with leaf essential oil of M. glyptostroboides or nisin alone as well in combinations. RESULTS: In this study, the leaf essential oil at the concentrations of 2% and 5% revealed strong anti-listerial effect against L. monocytogenes ATCC 19116 in all categories of milk samples. Nisin at the concentrations of 250 and 500 IU/mL displayed a strong inhibitory effect against ATCC 19116 as compared to the control group. Additionally, synergistic combinations of leaf essential oil (1%) and nisin (62.5, 125, 250 and 500 IU/mL) also had a remarkable anti-listerial synergism in all the tested milk samples including whole, low and skim milk after 14 days. CONCLUSIONS: As a major finding, the leaf essential oil of M. glyptostroboides might be a useful candidate for using in food industry to control the growth of foodborne pathogenic bacteria as confirmed by its potent anti-listerial synergistic effect with nisin against L. monocytogenes ATCC 19116 in different milk samples.