Phospho-Chitooligosaccharides below 1 kDa Inhibit HIV-1 Entry In Vitro.

Despite present antiviral agents that can effectively work against HIV-1 replication, side effects and drug resistance have pushed researchers toward novel approaches. In this context, there is a continued focus on discovering new and more effective antiviral compounds, particularly those that have a natural origin. Polysaccharides are known for their numerous bioactivities, including inhibiting HIV-1 infection and replication. In the present study, phosphorylated chitosan oligosaccharides (PCOSs) were evaluated for their anti-HIV-1 potential in vitro. Treatment with PCOSs effectively protected cells from HIV-1-induced lytic effects and suppressed the production of HIV-1 p24 protein. In addition, results show that PCOSs lost their protective effect upon post-infection treatment. According to the results of ELISA, PCOSs notably disrupted the binding of HIV-1 gp120 protein to T cell surface receptor CD4, which is required for HIV-1 entry. Overall, the results point out that PCOSs might prevent HIV-1 infection at the entry stage, possibly via blocking the viral entry through disruption of virus-cell fusion. Nevertheless, the current results only present the potential of PCOSs, and further studies to elucidate its action mechanism in detail are needed to employ phosphorylation of COSs as a method to develop novel antiviral agents.

Inhibitory Effects of Sesquiterpenoids Isolated from Artemisia scoparia on Adipogenic Differentiation of 3T3-L1 Preadipocytes.

Obesity and related complications are significant health issues in modern society, largely attributed to a sedentary lifestyle and a carbohydrate-rich diet. Since anti-obesity drugs often come with severe side effects, preventative measures are being sought globally, including dietary changes and functional foods that can counteract weight gain. In this context, plant-based metabolites are extensively studied for their advantageous biological effects against obesity. Several plants within the Artemisia genus have been reported to possess anti-adipogenic properties, preventing adipocytes from maturing and accumulating lipids. The present study investigated the anti-adipogenic potential of two sesquiterpenoids, reynosin and santamarine, isolated from A. scoparia in adipose-induced 3T3-L1 preadipocytes. Differentiating 3T3-L1 adipocytes treated with these isolated compounds displayed fewer adipogenic characteristics compared to untreated mature adipocytes. The results indicated that cells treated with reynosin and santamarine accumulated 55.0% and 52.5% fewer intracellular lipids compared to untreated control adipocytes, respectively. Additionally, the mRNA expression of the key adipogenic marker, transcription factor PPARγ, was suppressed by 87.2% and 91.7% following 60 µM reynosin and santamarine treatment, respectively, in differentiated adipocytes. Protein expression was also suppressed in a similar manner, at 92.7% and 82.5% by 60 µM reynosin and santamarine treatment, respectively. Likewise, SERBP1c and C/EBPα were also downregulated at both gene and protein levels in adipocytes treated with samples during differentiation. Further analysis suggested that the anti-adipogenic effect of the compounds might be a result of AMPK activation and the subsequent suppression of MAPK phosphorylation. Overall, the present study suggested that sesquiterpenoids, reynosin, and santamarine were two potential bioactive compounds with anti-adipogenic properties. Further research is needed to explore other bioactive agents within A. scoparia and elucidate the in vivo action mechanisms of reynosin and santamarine.

Quercetin 3-O-Galactoside Isolated from Limonium tetragonum Inhibits Melanogenesis by Regulating PKA/MITF Signaling and ERK Activation.

Quercetin 3-O-galactoside (Q3G) is a common dietary flavanol that has been shown to possess several bioactivities, including anti-melanogenesis. However, how Q3G exerts its anti-melanogenic effect has not been studied. The current study, therefore aimed to investigate the anti-melanogenesis potential of Q3G and elucidate the underlying action mechanism in α-melanocyte-stimulating hormone (α-MSH)-induced hyperpigmentation model of B16F10 murine melanoma cells. Results showed that α-MSH stimulation significantly increased tyrosinase (TYR) and melanin production, which were significantly downregulated by Q3G treatment. The treatment with Q3G suppressed the transcriptional and protein expressions of melanogenesis-related enzymes TYR, tyrosinase related protein-1 (TRP-1), and TRP-2, along with the melanogenic transcription factor microphthalmia-associated transcription factor (MITF) in B16F10 cells. It was shown that Q3G downregulated MITF expression and suppressed its transcriptional activity by inhibiting the cAMP-dependent protein kinase A (PKA)-mediated activation of CREB and GSK3ß. In addition, MAPK-regulated MITF activation signaling was also involved in the inhibition of melanin production by Q3G. The results suggest that the anti-melanogenic properties of Q3G rationalize further studies in vivo to confirm its action mechanism and consequent utilization as a cosmetic ingredient against hyperpigmentation.

Oleracone C from Portulaca oleracea attenuates UVB-induced changes in matrix metalloproteinase and type I procollagen production via MAPK and TGF-ß/Smad pathways in human keratinocytes.

BACKGROUND: Chronic exposure to ultraviolet (UV) radiation induces photo-oxidation, which in turn causes the overproduction of matrix metalloproteinases (MMPs) and collagen degradation. These symptoms are referred to as photoaging, which is characterized by skin thickness, irregular pigmentation, elastosis and coarse wrinkles. In this study, the protective effects of oleracone C isolated from Portulaca olerace against UVB-induced changes in MMPs and type I procollagen production were investigated in human keratinocytes. METHODS: Human immortalized keratinocytes have been used as an in vitro cell model to study the abnormal skin barrier development such as in photoaging. The effects of the compound on cell viability were determined by colorimetric MTT assay. This study also measured ROS production using DCFH-DA assay. Releases of MMPs and type Iα1 procollagen were analysed by ELISA. RT-PCR and Western blot were carried out to test the expressions of mRNA and proteins related to MMPs and type I procollagen biosynthesis. RESULT: Effect of oleracone C against UVB-mediated oxidative stress was evaluated measuring its ability to eliminate UVB-induced activation of reactive oxygen species (ROS). Treatment of oleracone C hindered the production of intracellular ROS. UVB exposure increased MMPs (MMP-1, MMP-2 and MMP-9) release from keratinocytes and decreased the release of type I procollagen. Treatment with oleracone C reversed these effects of UVB exposure. Oleracone C treatment also diminished the intracellular expression of MMP-1, MMP-2 and MMP-9 and elevated the type I procollagen. Oleracone C suppressed the UVB irradiation-dependent upregulation phosphorylation of p38 and ERK1/2 in the mitogen-activated protein kinase (MAPK) pathway. Furthermore, oleracone C stimulated collagen production through the TGF-ß signalling pathway, which activates collagen synthesis in UVB-irradiated keratinocytes. CONCLUSION: These findings reasonably suggest ameliorating the potential of oleracone C against the UVB-induced photoaging of the human keratinocytes.

RÉSUMÉ: CONTEXTE: L'exposition chronique aux rayons ultraviolets (UV) induit la photo-oxydation, qui à son tour entraîne la surproduction de métalloprotéases matricielles (MMP) et la dégradation du collagène. Ces symptômes sont appelés photovieillissement, qui se caractérise par une épaisseur de la peau, une pigmentation irrégulière, une élastose et des rides grossières. Dans cette étude, les effets protecteurs de l'oléracone C isolée à partir du pourpier potager contre les changements induits par les UVB dans les MMP et la production de procollagène de type I ont été étudiés dans les kératinocytes humains. MÉTHODES: Les kératinocytes humains immortalisés ont été utilisés comme modèle cellulaire in vitro pour étudier le développement anormal de la barrière cutanée, comme c'est le cas dans le photovieillissement. Les effets du composé sur la viabilité cellulaire ont été déterminés par test colorimétrique au MTT. Cette étude a également mesuré la production de DRO à l'aide du dosage DCFH-DA. Les productions de MMP et de procollagène de type Iα1 ont été analysées par la méthode ELISA. La RT-PCR et le Western blot ont été réalisés pour tester les expressions de l'ARNm, et des protéines liées aux MMP et à la biosynthèse du procollagène de type I. RÉSULTAT: L'effet de l'oléracone C contre le stress oxydatif médié par les UVB a été évalué en mesurant sa capacité à éliminer l'activation induite par les UVB des dérivés réactifs de l'oxygène (DRO). Le traitement par oléracone C a empêché la production de DRO intracellulaires. L'exposition aux UVB a augmenté la production de MMP (MMP-1, MMP-2 et MMP-9) par les kératinocytes et a diminué la production de procollagène de type I. Le traitement par oléracone C a inversé ces effets de l'exposition aux UVB. Le traitement par oléracone C a également diminué l'expression intracellulaire de MMP-1, MMP-2 et MMP-9, et a augmenté le taux de procollagène de type I. L'oléracone C a supprimé la phosphorylation de régulation à la hausse dépendante de l'exposition aux UVB de p38 et ERK1/2 dans la voie de la protéine kinase activée par des agents mitogènes (Mitogen-Activated Protein Kinase, MAPK). En outre, l'oléracone C a stimulé la production de collagène par la voie de signalisation de TGF-ß, qui active la synthèse du collagène dans les kératinocytes exposés aux UVB. CONCLUSION: Ces résultats indiquent raisonnablement une amélioration du potentiel de l'oléracone C contre le photovieillissement induit par les UVB des kératinocytes humains.

Libanoridin Isolated from Corydalis heterocarpa Inhibits Adipogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells.

Bone marrow adiposity is a complication in osteoporotic patients. It is a result of the imbalance between adipogenic and osteogenic differentiation of bone marrow cells. Phytochemicals can alleviate osteoporotic complications by hindering bone loss and decreasing bone marrow adiposity. Corydalis heterocarpa is a biennial halophyte with reported bioactivities, and it is a source of different coumarin derivatives. Libanoridin is a coumarin isolated from C. heterocarpa, and the effect of libanoridin on adipogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) was evaluated in the present study. Cells were induced to undergo adipogenesis, and their intracellular lipid accumulation and expression of adipogenic markers were observed under libanoridin treatment. Results showed that 10 µM libanoridin-treated adipocytes accumulated 44.94% less lipid compared to untreated adipocytes. In addition, mRNA levels of PPARγ, C/EBPα, and SREBP1c were dose-dependently suppressed with libanoridin treatment, whereas only protein levels of PPARγ were decreased in the presence of libanoridin. Fluorescence staining of adipocytes also revealed that cells treated with 10 µM libanoridin expressed less PPARγ compared to untreated adipocytes. Protein levels of perilipin and leptin, markers of mature adipocytes, were also suppressed in adipocytes treated with 10 µM libanoridin. Analysis of MAPK phosphorylation levels showed that treatment with libanoridin inhibited the activation of p38 and JNK MAPKs observed by decreased levels of phosphorylated p38 and JNK protein. It was suggested that libanoridin inhibited adipogenic differentiation of hBM-MSCs via suppressing MAPK-mediated PPARγ signaling. Future studies revealing the anti-adipogenic effects of libanoridin in vivo and elucidating its action mechanism will pave the way for libanoridin to be utilized as a nutraceutical with anti-osteoporotic properties.

Dracunculin Inhibits Adipogenesis in Human Bone Marrow-Derived Mesenchymal Stromal Cells by Activating AMPK and Wnt/ß-Catenin Signaling.

Increased bone marrow adiposity is widely observed in patients with obesity and osteoporosis and reported to have deleterious effects on bone formation. Dracunculin (DCC) is a coumarin isolated from Artemisia spp. but, until now, has not been studied for its bioactive potential except antitrypanosomal activity. In this context, current study has reported the anti-adipogenic effect of DCC in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). DCC dose-dependently inhibited the lipid accumulation and expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) in hBM-MSCs induced to undergo adipogenesis. To elucidate its action mechanism, the effect of DCC on Wnt/ß-catenin and AMPK pathways was examined. Results showed that DCC treatment activated Wnt/ß-catenin signaling pathway via AMPK evidenced by increased levels of AMPK phosphorylation and Wnt10b expression after DCC treatment. In addition, DCC treated adipo-induced hBM-MSCs exhibited significantly increased nuclear levels of ß-catenin compared with diminished nuclear PPARγ levels. In conclusion, DCC was shown to be able to hinder adipogenesis by activating the ß-catenin via AMPK, providing potential utilization of DCC as a nutraceutical against bone marrow adiposity.

Santamarine Shows Anti-Photoaging Properties via Inhibition of MAPK/AP-1 and Stimulation of TGF-ß/Smad Signaling in UVA-Irradiated HDFs.

Chronic UVA exposure results in elevated reactive oxygen species in skin which leads to photoaging characterized as upregulated matrix metalloproteinase (MMP)-1 and loss of collagen. Therefore, natural antioxidants are hailed as promising agents to be utilized against photoaging. In the current study, reynosin and santamarine, two known sesquiterpene lactones isolated from Artemisia scoparia, were analyzed for their anti-photoaging properties in UVA-irradiated human dermal fibroblasts (HDFs). Results showed that UVA irradiation (8 J/cm2) upregulated the MMP-1 secretion and expression, and suppressed collagen production, which were significantly reverted by santamarine treatment (10 µM). Although both reynosin and santamarine exhibited ROS scavenging abilities, reynosin failed to significantly diminish UVA-stimulated MMP-1 release. UVA-irradiated HDFs showed increased collagen production when treated with santamarine. As a mechanism to suppress MMP-1, santamarine significantly suppressed the UVA-induced phosphorylation of p38 and JNK and nuclear translocation of p-c-Fos and p-c-Jun. Santamarine promoted collagen I production via relieving the UVA-induced suppression on TGF-ß and its downstream activator Smad2/3 complex. Antioxidant properties of santamarine were also shown to arise from stimulating Nrf2-dependent expression of antioxidant enzymes SOD-1 and HO-1 in UVA-irradiated HDFs. In conclusion, santamarine was found to be a promising natural antioxidant with anti-photoaging properties against UVA-induced damages in HDFs.

Antiphotoaging Effect of 3,5-Dicaffeoyl-epi-quinic Acid against UVA-Induced Skin Damage by Protecting Human Dermal Fibroblasts In Vitro.

Cutaneous aging is divided into intrinsic and exogenous aging correspondingly contributing to the complex biological phenomenon in skin. Intrinsic aging is also termed chronological aging, which is the accumulation of inevitable changes over time and is largely genetically determined. Superimposed on this intrinsic process, exogenous aging is associated with environmental exposure, mainly to ultraviolet (UV) radiation and more commonly termed as photoaging. UV-induced skin aging induces increased expression of matrix metalloproteinases (MMPs) which in turn causes the collagen degradation. Therefore, MMP inhibitors of natural origin are regarded as a primary approach to prevent or treat photoaging. This study investigated the effects of 3,5-dicaffeoyl-epi-quinic acid (DEQA) on photoaging and elucidated its molecular mechanisms in UVA-irradiated human dermal fibroblasts (HDFs). The results show that treatment with DEQA decreases MMP-1 production and increases type I collagen production in UVA-damaged HDFs. In addition, treatment of UVA-irradiated HDFs with DEQA downregulates MMP-1, MMP-3 and MMP-9 expression via blocking MAPK-cascade-regulated AP-1 transcriptional activity in UVA-irradiated HDFs. Furthermore, DEQA relieves the UVA-mediated suppression of type I procollagen and collagen expression through stimulating TGF-ß/Smad signaling, leading to activation of the Smad 2/3 and Smad 4 nuclear translocation. These results suggest that DEQA could be a potential cosmetic agent for prevention and treatment of skin photoaging.

Effect of Quercetin 3-O-ß-D-Galactopyranoside on the Adipogenic and Osteoblastogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stromal Cells.

Natural products, especially phenols, are promising therapeutic agents with beneficial effects against aging-related complications such as osteoporosis. This study aimed to investigate the effect of quercetin 3-O-ß-D-galactopyranoside (Q3G), a glycoside of a common bioactive phytochemical quercetin, on osteogenic and adipogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). hBM-MSCs were induced to differentiate into osteoblasts and adipocytes in the presence or absence of Q3G and the differentiation markers were analyzed to observe the effect. Q3G treatment stimulated the osteoblastogenesis markers: cell proliferation, alkaline phosphatase (ALP) activity and extracellular mineralization. In addition, it upregulated the expression of RUNX2 and osteocalcin protein as osteoblastogenesis regulating transcription factors. Moreover, Q3G treatment increased the activation of osteoblastogenesis-related Wnt and bone morphogenetic protein (BMP) signaling displayed as elevated levels of phosphorylated ß-catenin and Smad1/5 in nuclear fractions of osteo-induced hBM-MSCs. The presence of quercetin in adipo-induced hBM-MSC culture inhibited the adipogenic differentiation depicted as suppressed lipid accumulation and expression of adipogenesis markers such as PPARγ, SREBP1c and C/EBPα. In conclusion, Q3G supplementation stimulated osteoblast differentiation and inhibited adipocyte differentiation in hBM-MSCs via Wnt/BMP and PPARγ pathways, respectively. This study provided useful information of the therapeutic potential of Q3G against osteoporosis mediated via regulation of MSC differentiation.

Syringaresinol Inhibits UVA-Induced MMP-1 Expression by Suppression of MAPK/AP-1 Signaling in HaCaT Keratinocytes and Human Dermal Fibroblasts.

Ultraviolet (UV) irradiation induces detrimental changes in human skin which result in photoaging. UV-induced intracellular changes cause degradation of extracellular matrix (ECM). UV-stimulated cleavage of collagen in ECM occurs via matrix metalloproteinases (MMPs). (±)-syringaresinol (SYR), a phytochemical which belongs to the lignan group of polyphenols, was investigated for its ability to reverse the UVA-induced changes in human HaCaT keratinocytes and dermal fibroblasts (HDFs) in vitro. Effect of SYR on UVA-induced changes was investigated by production and activation of MMPs and its transcriptional upstream effectors; mitogen-activated protein kinases (MAPKs) and pro-inflammatory mediators. Levels of expression were determined using ELISA, RT-PCR and immunoblotting. UVA irradiation stimulated the production of MMP-1 and inhibited collagen production. SYR treatment suppressed MMP-1 and enhanced collagen production in UVA-irradiated HaCaT keratinocytes and HDFs. SYR repressed the UV-induced phosphorylation of p38, ERK and JNK MAPKs in HaCaT keratinocytes while only suppressing JNK phosphorylation in HDFs. In addition, SYR was able to inhibit UVA-induced production of inflammatory cytokines; TNF-α, COX-2, IL-1ß and IL-6. Moreover, SYR suppressed the activator protein-1 (AP-1), a heterodimer of phosphorylated transcription factors c-Jun and c-Fos. SYR-treatment decreased nuclear levels of activated c-Fos and c-Jun as a mechanism to inhibit UVA-induced transcriptional activities leading to MMP-1 production. In conclusion, current results demonstrated that SYR could inhibit UVA-induced upregulation of MMP-1 by suppressing MAPK/AP-1 signaling in HaCaT keratinocytes and HDFs. Therefore, SYR was suggested as a potential compound with antiphotoaging properties against UVA-induced skin aging.

Anticatabolic and Anti-Inflammatory Effects of Myricetin 3-O-ß-d-Galactopyranoside in UVA-Irradiated Dermal Cells via Repression of MAPK/AP-1 and Activation of TGFß/Smad.

UV irradiation is one of the main causes of extrinsic skin aging. UV-mediated skin aging, also known as photoaging, causes excessive breakdown of extracellular matrix which leads skin to lose its elasticity and strength. Several phytochemicals are known to exert anti-photoaging effects via different mechanisms, partly due to their antioxidant properties. The current study has been carried out to determine the potential anti-photoaging properties of myricetin 3-O-ß-d-galacto-pyranoside (M3G), a flavonol glycoside isolated from L. tetragonum, in UVA-irradiated in vitro models; HaCaT keratinocytes and human dermal fibroblasts (HDFs). UVA-induced changes in MMP-1 and collagen production have been observed in HaCaT keratinocytes and HDFs. Further, UVA-induced activation of MAPK signaling, and pro-inflammatory cytokine production have been investigated. TGFß/Smad pathway has also been analyzed in UVA-irradiated HDFs. Treatment with M3G reversed the UVA-induced changes in MMP-1 and collagen production both in HaCaT keratinocytes and HDFs. UVA-mediated activation of p38, ERK and JNK MAPK activation was also inhibited by M3G treatment in HaCaT keratinocytes. In HDFs, M3G was able to upregulate the TGFß/Smad pathway activation. In addition, M3G downregulated the UVA-induced pro-inflammatory cytokines in keratinocytes and HDFs. It has been suggested that the M3G has exerted potential antiphotoaging properties in vitro, by attenuating UVA-induced changes in MMP-1 and collagen production in keratinocytes and dermal fibroblasts.

Phlorofucofuroeckol A from Edible Brown Alga Ecklonia Cava Enhances Osteoblastogenesis in Bone Marrow-Derived Human Mesenchymal Stem Cells.

The deterioration of bone formation is a leading cause of age-related bone disorders. Lack of bone formation is induced by decreased osteoblastogenesis. In this study, osteoblastogenesis promoting effects of algal phlorotannin, phlorofucofuroeckol A (PFF-A), were evaluated. PFF-A was isolated from brown alga Ecklonia cava. The ability of PFF-A to enhance osteoblast differentiation was observed in murine pre-osteoblast cell line MC3T3-E1 and human bone marrow-derived mesenchymal stem cells (huBM-MSCs). Proliferation and alkaline phosphatase (ALP) activity of osteoblasts during differentiation was assayed following PFF-A treatment along extracellular mineralization. In addition, effect of PFF-A on osteoblast maturation pathways such as Runx2 and Smads was analyzed. Treatment of PFF-A was able to enhance the proliferation of differentiating osteoblasts. Also, ALP activity was observed to be increased. Osteoblasts showed increased extracellular mineralization, observed by Alizarin Red staining, following PFF-A treatment. In addition, expression levels of critical proteins in osteoblastogenesis such as ALP, bone morphogenetic protein-2 (BMP-2), osteocalcin and ß-catenin were stimulated after the introduction of PFF-A. In conclusion, PFF-A was suggested to be a potential natural product with osteoblastogenesis enhancing effects which can be utilized against bone-remodeling imbalances and osteoporosis-related complications.

Evaluation of MMP Inhibitors Isolated from Ligustrum japonicum Fructus.

The current study investigated the ability of two secoiridoids, GL-3 (1) and oleonuezhenide (2), isolated from the fruits of Ligustrum japonicum to inhibit MMP-2 and -9 activity in phorbol 12-myristate 13-acetate (PMA)-induced HT-1080 human fibrosarcoma cells. Both compounds 1 and 2 were able to exert lowered gelatin digestion activity for MMP-2 and -9 tested by gelatin zymography via suppressing the release of MMPs to culture medium according to ELISA results. Treatment with compounds was also able to suppress the expression of both mRNA and protein levels of MMP-2 and -9. Action mechanism behind the MMP inhibitory effect of the compounds was suggested to be via MAPK pathway indicated by decreased levels of phosphorylated p38, ERK and JNK proteins evaluated employing immunoblotting. Compound 1 was shown to be slightly more active to inhibit MMP-2 and -9, however, compound 2 showed more regular dose-dependency during inhibition. In conclusion, this study suggested that GL-3 and oleonuezhenide were notable natural origin potent MMP inhibitors and could serve as lead compounds for development of anti-invasive MMP inhibitors against tumor metastasis.

Effect of the Arctic terrestrial plant Ranunculus hyperboreus on LPS-induced inflammatory response via MAPK pathways.

The Arctic flora hosts a limited number of species due to its extreme environmental conditions which also yield novel and unique secondary metabolites from withstanding plants. Considering a lack of research on bioactivity potential of Arctic flora, Ranunculus hyperboreus, an Arctic plant, was studied for its anti-inflammatory potential as a part of ongoing research on discovering novel natural bioactive products. Solvent-based fractions (H2O, n-BuOH, 85% aq. MeOH, n-hexane) from R. hyperboreus extract were observed to decrease the elevated nitrate amount during the inflammatory response of lipopolysaccharide-induced mouse macrophage RAW264.7 cells. To some extent, treatment with fractions was able to regulate the expression and protein levels of inflammation-related enzymes, iNOS and COX-2, and pro-inflammatory cytokines, TNF-α, IL-1ß, and IL-6. The most active fractions, H2O and 85% aq. MeOH, were suggested to exert their effect through suppressed activation of MAPK pathways, especially JNK. Based on the studies of same species, phenolic glycosides were suggested to be the main active ingredients. To our knowledge, this is the first report of any bioactivity of R. hyperboreus which could be a valuable source of natural bioactive agents against inflammation.

Anti-Melanogenic Effects of Flavonoid Glycosides from Limonium tetragonum (Thunb.) Bullock via Inhibition of Tyrosinase and Tyrosinase-Related Proteins.

Overproduction and stimulation of tyrosinase result in increased melanogenesis of which several skin disorders such as freckles, spots, and hyperpigmentation appear as complications. Limonium tetragonum is a halophyte well-known for its antioxidative properties. This study investigated the anti-melanogenic effects of solvent-partitioned L. tetragonum extracts (LTEs) and its bioactive constituents, two isolated flavonoid glycosides. Current study followed a set of experiments on B16-F10 mouse melanoma cell model with a focus on tyrosinase activity and production. The anti-melanogenic capacity of LTEs was confirmed by their tyrosinase inhibitory effects, prevention of DOPA oxidation, and suppression of melanin production. The inhibition of tyrosinase and DOPA oxidation by LTEs was suggested to be related with the downregulation of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2, verified with mRNA and protein expression levels. Among all tested LTEs, 85% aq. MeOH and n-BuOH were found to be the most active fractions which later yielded the two known compounds, myricetin 3-galactoside and quercetin 3-O-ß-galactopyronaside. The anti-melanogenic potential of the compounds were confirmed by their tyrosinase inhibitory effects. These results suggested that L. tetragonum may serve as a potential source of bioactive substances with effective anti-melanogenesis properties.

Dioxinodehydroeckol Enhances the Differentiation of Osteoblasts by Regulating the Expression of Phospho-Smad1/5/8.

Lack of bone formation-related health problems are a major problem for the aging population in the modern world. As a part of the ongoing trend of developing natural substances that attenuate osteoporotic bone loss conditions, dioxinodehydroeckol (DHE) from edible brown alga Ecklonia cava was tested for its effects on osteoblastogenic differentiation in MC3T3-E1 pre-osteoblasts. DHE was observed to successfully enhance osteoblast differentiation, as indicated by elevated cell proliferation, alkaline phosphatase activity, intracellular cell mineralization, along with raised levels of osteoblastogenesis indicators at the concentration of 20 µM. Results suggested a possible intervening of DHE on the bone morphogenetic protein (BMP) signaling pathway, according to elevated protein levels of BMP-2, collagen-I, and Smads. In addition, the presence of DHE was also able to raise the phosphorylated extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) levels which are also activated by the BMP signaling pathway. In conclusion, DHE is suggested to be a potential bioactive compound against bone loss that could enhance osteoblastogenesis with a suggested BMP pathway interaction.

Bioactive quinone derivatives from the marine brown alga Sargassum thunbergii induce anti-adipogenic and pro-osteoblastogenic activities.

BACKGROUND: Health problems related to the lack of bone formation are a major problem for ageing populations in the modern world. As a part of the ongoing trend to develop natural substances that attenuate bone loss in osteoporosis, the effects of the edible brown alga Sargassum thunbergii and its active contents on adipogenic differentiation in 3T3-L1 fibroblasts and osteoblast differentiation in MC3T3-E1 pre-osteoblasts were evaluated. RESULTS: Treatment with S. thunbergii significantly reduced lipid accumulation and expression of adipogenic differentiation markers such as peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α and sterol regulatory element binding protein 1c. In addition, S. thunbergii successfully enhanced osteoblast differentiation as indicated by increased alkaline phosphatase activity along raised levels of osteoblastogenesis indicators, namely bone morphogenetic protein-2, osteocalcin and collagen type I. Two compounds, sargaquinoic and sargahydroquinoic acid, were isolated from active extract and shown to be active by means of osteogenesis inducement. CONCLUSION: S. thunbergii could be a source for functional food ingredients for improved treatment of osteoporosis and obesity.

Anti-HIV-1 activity of phlorotannin derivative 8,4‴-dieckol from Korean brown alga Ecklonia cava.

8,4‴-dieckol is a natural product which has been isolated from brown alga, Ecklonia cava. This polyphenolic compound is a phlorotannin derivative with a broad range of bioactivities. Its inhibitory activity on human immunodeficiency virus type-1 (HIV-1) was tested and the results indicated that 8,4‴-dieckol inhibited HIV-1 induced syncytia formation, lytic effects, and viral p24 antigen production at noncytotoxic concentrations. Furthermore, it was found that 8,4‴-dieckol selectively inhibited the activity of HIV-1 reverse trancriptase (RT) enzyme with 91% inhibition ratio at the concentration of 50 µM. HIV-1 entry was also inhibited by 8,4‴-dieckol. According to data from this study, 8,4‴-dieckol is an effective compound against HIV-1 with high potential for further studies. These results suggest that it might be used as a drug candidate for the development of new generation therapeutic agents, although further studies on the mechanism of inhibition should be addressed.

Effect of Salicornia herbacea on osteoblastogenesis and adipogenesis in vitro.

Bone-related complications are among the highest concerning metabolic diseases in the modern world. Bone fragility and susceptibility to fracture increase with age and diseases like osteoporosis. Elevated adipogenesis in bone results in osteoporosis and loss of bone mass when coupled with lack of osteoblastogenesis. In this study the potential effect of Salicornia herbacea extract against osteoporotic conditions was evaluated. Adipogenesis inhibitory effect of S. herbacea has been evidenced by decreased lipid accumulation of differentiating cells and expression levels of crucial adipogenesis markers in 3T3-L1 pre-adipocytes. S. herbacea treatment reduced the lipid accumulation by 25% of the control. In addition, mRNA expression of peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein (C/EBP)α and sterol regulatory element binding protein (SREBP)1c were inhibited by the presence of S. herbacea. Bone formation enhancement effect of S. herbacea was also confirmed in MC3T3-E1 pre-osteoblasts. The presence of S. herbacea significantly elevated the alkaline phosphatase (ALP) activity by 120% at a concentration of 100 µg/mL in differentiating osteoblasts. S. herbacea also significantly increased the expression of osteoblastogenesis indicators, ALP, bone morphogenetic protein (BMP)-2, osteocalcin and collagen type I (collagen-I). In conclusion, S. herbacea possess potential to be utilized as a source of anti-osteoporotic agent that can inhibit adipogenesis while promoting osteoblastogenesis.

Radical scavenging and anti-inflammatory effects of the halophyte Spergularia marina Griseb.

As a part of ongoing research to develop antioxidant and anti-inflammatory nutraceuticals, an ethanolic extract of Spergularia marina Griseb. was tested for its ability to scavenge radicals and suppress inflammation. The extract was able to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals, respectively, in cell-free environments as well as intracellular radicals in H2O2-stimulated mouse macrophages. Inflammation in mouse macrophages induced by lipopolysaccharides was suppressed by S. marina according to the measurement of nitric oxide generation and expression of inflammatory cytokines, i.e. tumour necrosis factor-α (TNFα), interleukin (IL)-1ß, and IL-6. The anti-inflammatory effect of S. marina was substantiated by the finding that the expression of the inflammatory modulators, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), was significantly decreased. The chemical composition of S. marina was evaluated by FT-IR analysis of the extract indicating the presence of polyphenols and flavonoids. In conclusion, S. marina is suggested as a novel source for antioxidant and anti-inflammatory agents.