Biological activities, identification, method development, and validation for analysis of polyphenolic compounds in Nymphaea rubra flowers and leaves by UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS.

INTRODUCTION: Nymphaea rubra belongs to the Nymphaea family and is regarded as a vegetable used in traditional medicine to cure several ailments. These species are rich in phenolic acid, flavonoids, and hydrolysable tannin. OBJECTIVE: This study aimed to assess the biological activities of Nymphaea rubra flowers (NRF) and leaves (NRL) by identifying and quantifying their polyphenolic compounds using ultra-performance liquid chromatography coupled to quadrupole cyclic ion mobility time-of-flight mass spectrometry (UHPLC-Q-cIM-TOF-MS) and triple quadrupole mass spectrometry (UHPLC-TQ-MS). METHODOLOGY: NRF and NRL powder was extracted with methanol and fractionated using hexane, ethylacetate, and water. Antioxidant and α-glucosidase, and tyrosinase enzyme inhibitory activities were evaluated. The polyphenolic components of NRF and NRL were identified and quantified using UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS. The method was validated using linearity, precision, accuracy, limit of detection (LOD), and lower limit of quantification (LLOQ). RESULTS: Bioactive substances and antioxidants were highest in the ethylacetate fraction of flowers and leaves. Principal component analysis showed how solvent and plant components affect N. rubra's bioactivity and bioactive compound extraction. A total of 67 compounds were identified, and among them 21 significant polyphenols were quantified. Each calibration curve had R2 > 0.998. The LOD and LLOQ varied from 0.007 to 0.09 µg/mL and from 0.01 to 0.1 µg/mL, respectively. NRF contained a significant amount of gallic acid (10.1 mg/g), while NRL contained abundant pentagalloylglucose (2.8 mg/g). CONCLUSION: The developed method is simple, rapid, and selective for the identification and quantification of bioactive molecules. These findings provide a scientific basis for N. rubra's well-documented biological effects.

Maternal choline supplementation protects against age-associated cholinergic and GABAergic basal forebrain neuron degeneration in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Down syndrome (DS) is a genetic disorder caused by triplication of human chromosome 21. In addition to intellectual disability, DS is defined by a premature aging phenotype and Alzheimer's disease (AD) neuropathology, including septohippocampal circuit vulnerability and degeneration of basal forebrain cholinergic neurons (BFCNs). The Ts65Dn mouse model recapitulates key aspects of DS/AD pathology, namely age-associated atrophy of BFCNs and cognitive decline in septohippocampal-dependent behavioral tasks. We investigated whether maternal choline supplementation (MCS), a well-tolerated treatment modality, protects vulnerable BFCNs from age- and genotype-associated degeneration in trisomic offspring. We also examined the effect of trisomy, and MCS, on GABAergic basal forebrain parvalbumin neurons (BFPNs), an unexplored neuronal population in this DS model. Unbiased stereological analyses of choline acetyltransferase (ChAT)-immunoreactive BFCNs and parvalbumin-immunoreactive BFPNs were conducted using confocal z-stacks of the medial septal nucleus and the vertical limb of the diagonal band (MSN/VDB) in Ts65Dn mice and disomic (2N) littermates at 3-4 and 10-12 months of age. MCS trisomic offspring displayed significant increases in ChAT-immunoreactive neuron number and density compared to unsupplemented counterparts, as well as increases in the area of the MSN/VDB occupied by ChAT-immunoreactive neuropil. MCS also rescued BFPN number and density in Ts65Dn offspring, a novel rescue of a non-cholinergic cell population. Furthermore, MCS prevented age-associated loss of BFCNs and MSN/VDB regional area in 2N offspring, indicating genotype-independent neuroprotective benefits. These findings demonstrate MCS provides neuroprotection of vulnerable BFCNs and non-cholinergic septohippocampal BFPNs, indicating this modality has translational value as an early life therapy for DS, as well as extending benefits to the aging population at large.

Antioxidant, Tyrosinase, α-Glucosidase, and Elastase Enzyme Inhibition Activities of Optimized Unripe Ajwa Date Pulp (Phoenix dactylifera) Extracts by Response Surface Methodology.

The Ajwa date (Phoenix dactylifera L., Arecaceae family) is a popular edible fruit consumed all over the world. The profiling of the polyphenolic compounds of optimized unripe Ajwa date pulp (URADP) extracts is scarce. The aim of this study was to extract polyphenols from URADP as effectively as possible by using response surface methodology (RSM). A central composite design (CCD) was used to optimize the extraction conditions with respect to ethanol concentration, extraction time, and temperature and to achieve the maximum amount of polyphenolic compounds. High-resolution mass spectrometry was used to identify the URADP's polyphenolic compounds. The DPPH-, ABTS-radical scavenging, α-glucosidase, elastase and tyrosinase enzyme inhibition of optimized extracts of URADP was also evaluated. According to RSM, the highest amounts of TPC (24.25 ± 1.02 mgGAE/g) and TFC (23.98 ± 0.65 mgCAE/g) were obtained at 52% ethanol, 81 min time, and 63 °C. Seventy (70) secondary metabolites, including phenolic, flavonoids, fatty acids, and sugar, were discovered using high-resolution mass spectrometry. In addition, twelve (12) new phytoconstituents were identified for the first time in this plant. Optimized URADP extract showed inhibition of DPPH-radical (IC50 = 87.56 mg/mL), ABTS-radical (IC50 = 172.36 mg/mL), α-glucosidase (IC50 = 221.59 mg/mL), elastase (IC50 = 372.25 mg/mL) and tyrosinase (IC50 = 59.53 mg/mL) enzymes. The results revealed a significant amount of phytoconstituents, making it an excellent contender for the pharmaceutical and food industries.

Metabolite profiling of Nymphaea rubra (Burm. f.) flower extracts using cyclic ion mobility-mass spectrometry and their associated biological activities.

Nymphaea rubra flowers (NRF) are widely used as a food and in folk medicine throughout the subtropical regions due to their health-promoting characteristics. This study characterized the phytochemical composition of various extracts/fractions of NRF by establishing a quadrupole-cyclic ion mobility-time-of-flight (Q-cIM-TOF) mass spectrometry method in both positive and negative electrospray ionization modes. Over 100 phytoconstituents were tentatively identified, among which 53 phytochemicals belonging to phenolic acids, tannins, flavonoids, terpenoids, alkaloids, xanthones, and naphthopyrones have never been documented in NRF before. Moreover, the ethyl acetate fraction of NRF demonstrated strong antioxidant potential (IC50: 9.21 ± 0.47 µg/mL in DPPH assay and 13.65 ± 0.03 µg/mL in ABTS assay) and tyrosinase, α-glucosidase, and elastase inhibition (IC50: 10.58 ± 0.20, 2.48 ± 0.02, and 38.15 ± 0.25 µg/mL, respectively). The findings highlight the value of NRF as a source of functional components and broaden its potential applications in the food and nutraceutical industries.

Optimization of the extraction conditions of Nypa fruticans Wurmb. using response surface methodology and artificial neural network.

In this study, we conducted response surface methodology (RSM) and artificial neural network (ANN) to predict and estimate the optimized extraction condition of Nypa fruticans Wurmb. (NF). The effect of ethanol concentration (X1; 0-100%), extraction time (X2; 6-24 h), and extraction temperature (X3; 40-60 °C) on the antioxidant potential was confirmed. The optimal conditions (57.6% ethanol, 19.0 h extraction time, and 51.3 °C extraction temperature) of 2,2-diphenyl-1-1picrylhydrazyl (DPPH) scavenging activity, cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and total flavonoid contents (TFC) resulted in a maximum value of 62.5%, 41.95 and 48.39 µM, 143.6 mg GAE/g, and 166.8 CAE/g, respectively. High-resolution mass spectroscopic technique was performed to profile phenolic and flavonoid compounds. Upon analyzing, total 48 compounds were identified in NF. Altogether, our findings can provide a practical approach for utilizing NF in various bioindustries.

Adiponectin Modulation by Genotype and Maternal Choline Supplementation in a Mouse Model of Down Syndrome and Alzheimer's Disease.

Down syndrome (DS) is a genetic disorder caused by the triplication of human chromosome 21, which results in neurological and physiological pathologies. These deficits increase during aging and are exacerbated by cognitive decline and increase of Alzheimer's disease (AD) neuropathology. A nontoxic, noninvasive treatment, maternal choline supplementation (MCS) attenuates cognitive decline in mouse models of DS and AD. To evaluate potential underlying mechanisms, laser capture microdissection of individual neuronal populations of MCS offspring was performed, followed by RNA sequencing and bioinformatic inquiry. Results at ~6 months of age (MO) revealed DS mice (the well-established Ts65Dn model) have significant dysregulation of select genes within the Type 2 Diabetes Mellitus (T2DM) signaling pathway relative to normal disomic (2N) littermates. Accordingly, we interrogated key T2DM protein hormones by ELISA assay in addition to gene and encoded protein levels in the brain. We found dysregulation of adiponectin (APN) protein levels in the frontal cortex of ~6 MO trisomic mice, which was attenuated by MCS. APN receptors also displayed expression level changes in response to MCS. APN is a potential biomarker for AD pathology and may be relevant in DS. We posit that changes in APN signaling may be an early marker of cognitive decline and neurodegeneration.

Lablab Purpureus Protects HaCaT Cells from Oxidative Stress-Induced Cell Death through Nrf2-Mediated Heme Oxygenase-1 Expression via the Activation of p38 and ERK1/2.

Ultraviolet B (UV-B) radiation induces the extreme production of either reactive oxygen species (ROS) or inflammatory mediators. The aim of this study was to evaluate the antioxidant activities of 70% ethanolic extract of Lablab purpureus (LPE) and the underlying mechanisms using HaCaT cells exposed to UV-B. High-performance liquid chromatography (HPLC) confirmed the presence of gallic acid, catechin, and epicatechin in LPE. LPE was shown to have a very potent capacity to scavenge free radicals. The results showed that LPE prevented DNA damage and inhibited the generation of ROS in HaCaT cells without causing any toxicity. LPE increased the expression of endogenous antioxidant enzymes such as superoxide dismutase-1 and catalase. Furthermore, LPE treatment facilitates the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf-2), boosting the phase II detoxifying enzyme heme oxygenase-1 (HO-1) leading to the combatting of oxidative stress. However, pretreatment of LPE also caused the phosphorylation of mitogen-activated protein kinases (MAPK kinase) (p38 kinase) and extracellular signal-regulated kinase (ERK), whereas treatment with p38 and ERK inhibitors substantially suppressed LPE-induced Nrf2 and heme oxygenase (HO)-1 expression. These findings suggest that LPE exhibits antioxidant activity via Nrf-2-mediated HO-1 signaling through the activation of p38 and ERK, indicating that LPE can potentially be used as a remedy to combat oxidative stress-induced disorder.

Attenuation of Inflammatory Symptoms by Icariside B2 in Carrageenan and LPS-Induced Inflammation Models via Regulation of MAPK/NF-κB Signaling Cascades.

: Prolonged inflammatory responses can lead to the development of several chronic diseases, such as autoimmune disorders and the development of natural therapeutic agents is required. A murine model was used to assess the anti-inflammatory effects of the megastigmane glucoside, icariside B2 (ICSB), and the assessment was carried out in vitro, and in vivo. The in vitro anti-inflammatory effects of ICSB were tested using LPS-stimulated BV2 cells, and the protein expression levels of inflammatory genes and cytokines were assessed. Mice were subcutaneously injected with 1% carrageenan (CA) to induce acute phase inflammation in the paw. Inflammation was assessed by measuring paw volumes hourly; subsequently, the mice were euthanized and the right hind paw skin was expunged and processed for reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analyses. ICSB inhibits LPS-stimulated nitric oxide (NO) and prostaglandin E2 (PGE2) generation by reducing the expression of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2). ICSB also inhibits the COX-2 enzyme with an IC50 value of 7.80±0.26 µM. Molecular docking analysis revealed that ICSB had a strong binding affinity with both murine and human COX-2 proteins with binding energies of -8 kcal/mol and -7.4 kcal/mol, respectively. ICSB also reduces the manifestation of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1ß, at their transcriptional and translational level. ICSB hinders inhibitory protein κBα (IκBα) phosphorylation, thereby terminating the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) nuclear translocation. ICSB also represses the mitogen-activated protein kinases (MAPKs) signaling pathways. ICSB (50 mg/kg) showed an anti-edema effect in CA-induced mice and suppressed the CA-induced increases in iNOS and COX-2 protein levels. ICSB attenuated inflammatory responses by downregulating NF-κB expression through interference with extracellular signal-regulated kinase (ERK) and p38 phosphorylation, and by modulating the expression levels of iNOS, COX-2, TNF-α, IL-1ß, and IL-6.

Protection against UVB-Induced Photoaging by Nypa fruticans via Inhibition of MAPK/AP-1/MMP-1 Signaling.

Ultraviolet B (UVB) irradiation is major causative factor in skin aging. The aim of the present study was to investigate the protective effect of a 50% ethanol extract from Nypa fruticans (NF50E) against UVB-induced skin aging. The results indicated that NF50E exerted potent antioxidant activity (IC50 = 17.55 ± 1.63 and 10.78 ± 0.63 µg/mL for DPPH and ABTS-radical scavenging activity, respectively) in a dose-dependent manner. High-performance liquid chromatography revealed that pengxianencin A, protocatechuic acid, catechin, chlorogenic acid, epicatechin, and kaempferol were components of the extract. In addition, the extract exhibited elastase inhibitory activity (IC50 = 17.96 ± 0.39 µg/mL). NF50E protected against UVB-induced HaCaT cell death and strongly suppressed UVB-stimulated cellular reactive oxygen species generation without cellular toxicity. Moreover, topical application of NF50E mitigated UVB-induced photoaging lesions including skin erythema and skin thickness in BALB/C mice. NF50E treatment inhibited UVB-induced collagen degradation as well as MMP-1 and IL-1ß expressions and significantly stimulated SIRT1 expression. Furthermore, the extract treatment markedly suppressed the activation of NF-κB and AP-1 (p-c-Jun) by deactivating the p38 and JNK proteins. Taken together, current data suggest that NF50E exhibits potent antioxidant potential and protection against photoaging by attenuating MMP-1 activity and collagen degradation possibly through the downregulation of MAPK/NF-κB/AP-1 signaling and SIRT1 activation.

Microbial assessment of medicinal herbs (Cnidii Rhizoma and Alismatis Rhizoma), effects of electron beam irradiation and detection characteristics.

Medicinal herbs comprise of heavy microbial contaminations. This study aimed to assess microbial hazards including foodborne pathogens in 20 commercial medicinal herbs, Cnidii Rhizoma (C1-C10) and Alismatis Rhizoma (T1-T10) as well as to evaluate irradiation effects of E-beam on microbial load and detection chracteristics. Four samples (C5, C10, T1, T8) from both herbs with higher microbial load were selected for evaluating the irradiation effect of E-beam (up to 10 kGy) on microbial load and radiation-induced changes in detection markers by standard methods (Codex, Korean Food Code), such as direct epifluorescent filter technique/aerobic plate count (DEFT/APC), photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR). DEFT/APC revealed non-evidence of pre-sterilization of all samples. PSL differentiated irradiated samples (1, 5, and 10 kGy) of both herbs from non-irradiated (control: 0 kGy). Both TL and ESR methods validated PSL screening results by detecting radiation-induced markers from E-beam irradiated medicinal herbs.

Effect of E-Beam Irradiation on Microbial Load, Stability of Active Components, and Anti-Inflammatory Activity of Cnidii Rhizoma and Alismatis Rhizoma.

To reduce microbial loads in medicinal herbs, Cnidii Rhizoma and Alismatis Rhizoma were subjected to electron-beam (e-beam) irradiation at doses (≤10 kGy) as permitted by the Korean Food Code. The effects of e-beam irradiation on the microbial load, stability of the active components, and anti-inflammatory activity of medicinal herbs were determined. We observed that the total aerobic bacteria (TAB; 4.0-7.0 log CFU/g), yeasts and molds (Y&M; 3.3-6.8 log CFU/g), and coliform counts (CC; 3.2-3.8 log CFU/g) in both herb samples were effectively reduced in a dose-dependent manner, resulting in acceptable levels of <3.0 log CFU/g in TAB and Y&M and negative in CC at 10 kGy irradiation. The concentration of the active components (0.87-4.22 mg/g) of Cnidii Rhizoma, including z-ligustilide, chlorogenic acid, senkyunolide A, and ferulic acid, in order of prevalence and those (0.86-2.76 mg/g) of Alismatis Rhizoma, including Alisol B acetate and Alisol B, were not changed at irradiation doses of ≤10 kGy. The extracts of e-beam irradiated Cnidii Rhizoma and Alismatis Rhizoma showed a reduced production of inflammation-related factors, such as nitric oxide, prostaglandin E2, interleukin (IL)-1ß, and IL-6, in a concentration-dependent manner, which was induced by lipopolysaccharide in RAW 264.7 cell. However, there was no significant difference observed at e-beam irradiation doses of 0, 1, 5, and 10 kGy. Thus, we confirm that e-beam irradiation up to 10 kGy was effective for the control of microbial load in Cnidii Rhizoma and Alismatis Rhizoma without causing considerable changes in their major active components and anti-inflammatory activity. The results show the potential of e-beam application for sanitization of medicinal herbs.

Protopine attenuates inflammation stimulated by carrageenan and LPS via the MAPK/NF-κB pathway.

We investigated the anti-inflammatory activity of protopine (PTP) and sought to determine its mechanism of action in LPS-stimulated BV2 cells and a carrageenan (CA)-induced mouse model. Treatment with PTP (5, 10, and 20 µM) significantly suppresses the secretion of NO and PGE2 in a concentration-dependent manner without affecting cell viability by downregulating iNOS and COX-2 expression in LPS-induced BV2 cells. PTP also attenuates the production of pro-inflammatory chemokines, such as MCP-1, and cytokines, including TNF-α, IL-1ß and IL-6, and augments the expression of the anti-inflammatory cytokine IL-10. In addition, PTP suppresses the nuclear translocation of NF-κB by hindering the degradation of IκB and downregulating the expression of mitogen-activated protein kinases (MAPKs), including p38, ERK1/2 and JNK protein. Furthermore, PTP treatment significantly suppresses CA-induced paw oedema in mice compared to that seen in untreated mice. Expression of iNOS and COX-2 proteins is also abrogated by PTP (50 mg/kg) treatment in CA-induced mice. PTP treatment also abolishes IκB phosphorylation, which hinders the activation of NF-κB. Collectively, these results suggest PTP has potential for attenuating CA- and LPS-induced inflammatory symptoms through modulation of MAPKs/NF-κB signaling cascades.

Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Choline is critical for normative function of 3 major pathways in the brain, including acetylcholine biosynthesis, being a key mediator of epigenetic regulation, and serving as the primary substrate for the phosphatidylethanolamine N-methyltransferase pathway. Sufficient intake of dietary choline is critical for proper brain function and neurodevelopment. This is especially important for brain development during the perinatal period. Current dietary recommendations for choline intake were undertaken without critical evaluation of maternal choline levels. As such, recommended levels may be insufficient for both mother and fetus. Herein, we examined the impact of perinatal maternal choline supplementation (MCS) in a mouse model of Down syndrome and Alzheimer's disease, the Ts65Dn mouse relative to normal disomic littermates, to examine the effects on gene expression within adult offspring at ∼6 and 11 mo of age. We found MCS produces significant changes in offspring gene expression levels that supersede age-related and genotypic gene expression changes. Alterations due to MCS impact every gene ontology category queried, including GABAergic neurotransmission, the endosomal-lysosomal pathway and autophagy, and neurotrophins, highlighting the importance of proper choline intake during the perinatal period, especially when the fetus is known to have a neurodevelopmental disorder such as trisomy.-Alldred, M. J., Chao, H. M., Lee, S. H., Beilin, J., Powers, B. E., Petkova, E., Strupp, B. J., Ginsberg, S. D. Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Attenuation of UVB-Induced Photo-Aging by Polyphenolic-Rich Spatholobus Suberectus Stem Extract Via Modulation of MAPK/AP-1/MMPs Signaling in Human Keratinocytes.

It is well known that ultraviolet light activates mitogen-activated protein (MAP) kinase by increasing the reactive oxygen species (ROS) in the body, enhancing activating protein 1(AP-1) complexes (c-Jun and c-Fos), increasing matrix metalloproteinases (MMPs) and degrading collagen and elastin. In this study, we confirmed that polyphenolic rich Spatholobus suberectus (SS) stem extracts suppressed ultraviolet (UV)-induced photo-aging. The major active components of SS stem extracts were identified as gallic acid, catechin, vanillic acid, syringic acid and epicatechin. The aqueous and ethanolic extracts of the stem of SS (SSW and SSE, respectively) significantly reduced the elastase enzyme activity. Moreover, both extracts were suppressed the ROS generation and cellular damage induced by UVB in HaCaT cells. Our results also revealed that SSE could regulate the expression of MMPs, tissue inhibitor of matrix metalloproteinase (TIMP)-1, collagen type I alpha 1 (COL1A1), elastin (ELN) and hyaluronan synthase 2 (HAS2) at their transcriptional and translational level. Furthermore, SSE was blocked the UVB-induced phosphorylation of mitogen-activated protein kinases (MAPKs), nuclear factor-kappa B (NF-κB) and c-Jun. Moreover, combination of syringic acid, epicatechin and vanillic acid showed strong synergistic effects on elastase inhibition activity, in which the combination index (CI) was 0.28. Overall, these results strongly suggest that the polyphenolics of SSE exert anti-ageing potential as a natural biomaterial to inhibit UVB-induced photo-aging.

Gossypol from Cottonseeds Ameliorates Glucose Uptake by Mimicking Insulin Signaling and Improves Glucose Homeostasis in Mice with Streptozotocin-Induced Diabetes.

Glucose absorption from the gut and glucose uptake into muscles are vital for the regulation of glucose homeostasis. In the current study, we determined if gossypol (GSP) reduces postprandial hyperglycemia or enhances glucose uptake; we also investigated the molecular mechanisms underlying those processes in vitro and in vivo. GSP strongly and concentration dependently inhibited α-glucosidase by functioning as a competitive inhibitor with IC50 value of 0.67 ± 0.44. GSP activated the insulin receptor substrate 1 (IRS-1)/protein kinase B (Akt) signaling pathways and enhanced glucose uptake through the translocation of glucose transporter 4 (GLUT4) into plasma membrane in C2C12 myotubes. Pretreatment with a specific inhibitor attenuated the in vitro effects of GSP. We used a streptozotocin-induced diabetic mouse model to assess the antidiabetic potential of GSP. Consistent with the in vitro study, a higher dose of GSP (2.5 mg/kg-1) dramatically decreased the postprandial blood glucose levels associated with the upregulated expressions of GLUT4 and the IRS-1/Akt-mediated signaling cascade in skeletal muscle. GSP treatment also significantly boosted antioxidant enzyme expression and mitigated gluconeogenesis in the liver. Collectively, these data imply that GSP has the potential in managing and preventing diabetes by ameliorating glucose uptake and improving glucose homeostasis.

Inhibition of Migration and Invasion in Melanoma Cells by ß-Escin via the ERK/NF-κB Signaling Pathway.

ß-Escin, a natural triterpene saponin was extracted from Aesculus hippocastanum seeds, which have been widely used to treat inflammation in traditional medicine. In an effort to study the possible anti-tumor effects of ß-escin, we performed wound healing, invasion, and adhesion assays to examine the effects of ß-escin on cell migration, invasion, and angiogenesis. Our results revealed that ß-escin inhibits cell migration as well as motility in B16F10 and SK-MEL5 cells in a dose-dependent manner. RT-PCR and Western blot analysis showed that ß-escin increased TIMP-1, -2 while significantly downregulated phosphorylated extracellular signal-regulated kinase (p-ERK) expression, and suppressing nuclear factor-kappa B (NF-κB) and inhibitor of nuclear factor-kappa B (IκB) expression. Overall, the data from the current study suggest that ß-escin has the potential for inhibiting both metastatic and angiogenic activities, and are the earliest evidence for the involvement of the NF-κB/IκB signaling in ß-escin-induced anti-tumor effects.

Attenuation of melanogenesis by Nymphaea nouchali (Burm. f) flower extract through the regulation of cAMP/CREB/MAPKs/MITF and proteasomal degradation of tyrosinase.

Medicinal plants have been used to treat diseases from time immemorial. We aimed to examine the efficacy of the ethyl acetate fraction of Nymphaea nouchali flower extract (NNFE) against melanogenesis process, and the underlying mechanisms in vitro and in vivo. Paper spray ionisation mass spectroscopy and (+) mode electrospray ionisation revealed the presence of seven flavonoids, two spermidine alkaloids, 3,4,8,9,10-pentahydroxy-dibenzo[b,d]pyran-6-one, and shoyuflavone C in NNFE. NNFE (100 µg/mL) significantly inhibited the monophenolase and diphenolase activities of mushroom tyrosinase at 94.90 ± 0.003% and 93.034 ± 0.003%, respectively. NNFE significantly suppressed cellular tyrosinase activity and melanin synthesis in vitro in melan-a cells and in vivo in HRM2 hairless mice. Furthermore, NNFE inhibited tyrosinase (TYR), tyrosinase-related protein (TYRP)-1, TYRP-2, and microphthalmia-associated transcription factor (MITF) expression, thereby blocking melanin synthesis. In particular, NNFE suppressed cAMP production with subsequent downregulation of CREB phosphorylation. Additionally, it stimulated MAP kinase phosphorylation (p38, JNK, and ERK1/2) and the proteasomal debasement pathway, leading to degradation of tyrosinase and MITF and the suppression of melanin production. Moreover, selective inhibitors of ERK1/2, JNK, and p38 attenuated NNFE inhibitory effects on melanogenesis, and MG-132 (a proteasome inhibitor) prevented the NNFE-induced decline in tyrosinase protein levels. In conclusion, these findings indicate that NNFE is a potential therapy for hyperpigmentation.

Cytotoxic properties of the anthraquinone derivatives isolated from the roots of Rubia philippinensis.

BACKGROUND: Cancer is one of the most frequently occurring diseases and is the second leading cause of death worldwide. In this study, anthraquinone derivatives (Compounds 1-5) were evaluated for their anti-cancer potential against various skin and breast cancer cell lines to assess whether these anthraquinone derivatives may serve as a lead for the augmentation of anti-cancer drug. METHODS: Anthraquinone derivatives, 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone-3-O-(6'-O-acetyl)-α-rhamnosyl(1 → 2)-ß-glucoside (Comp 1), 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone (Comp 2), and alizarin (Comp 3) were isolated from the dichloromethane fraction of the roots of Rubia philippinensis., whereas ethyl acetate fraction yielded xanthopurpurin (Comp 4) and lucidin-ω-methyl ether (Comp 5). Structures of all the isolated compounds were determined by spectral data analysis. All isolated compounds (Comp 1-5) were assessed for cytotoxicity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against four different cancer cell lines, i.e. human melanoma (SK-MEL-5), murine melanoma (B16F10), and human breast adenocarcinoma (MCF7 and MDA-MB-231). RESULTS: Significant activity of the compounds 4 and 5 was observed against the breast cancer cell line MDA-MB-231 with IC50 values of 14.65 ± 1.45 and 13.03 ± 0.33 µM, respectively. Encouragingly, IC50 values of 67.89 ± 1.02 and 79.01 ± 0.03 µM against normal kidney epithelial cells (MDCK) were also obtained for compounds 4 and 5, respectively, which indicated very low toxicity and favorable selectivity indices for compounds 4 and 5 in the range of 1.85 to 3.95 and 2.11 to 6.06 against skin cancer cell lines (SK-MEL-5, and B16F10), and breast cancer cell lines (MCF7 and MDA-MB-231), respectively. CONCLUSION: Our results suggested that the compounds 4 (xanthopurpurin) and 5 (lucidin-ω-methyl ether) showed high selective toxicity towards breast cancer cells at lower concentrations without showing toxicity towards normal cells, thus could be of potential as new lead molecules in cancer treatment.

Antioxidant mechanism of polyphenol-rich Nymphaea nouchali leaf extract protecting DNA damage and attenuating oxidative stress-induced cell death via Nrf2-mediated heme-oxygenase-1 induction coupled with ERK/p38 signaling pathway.

This study investigates the polyphenolic composition and antioxidant mechanism of an ethyl acetate fraction of Nymphaea nouchali leaves (NNLE). Various in vitro assays were performed using RAW 264.7 cells to assess the antioxidant effects of NNLE and to understand the underlying molecular mechanism. High-performance liquid chromatography analysis revealed the presence of gallic acid, catechin, epigallocatechin, epicatechin gallate, caffeic acid, luteolin, and kaempferol as the key polyphenolic composition of NNLE. NNLE had a potent ability to scavenge numerous free radicals through hydrogen atom transfer and/or electron donation. In addition, NNLE prevented the damage of DNA and quenched t-BHP induced generation of ROS without showing toxicity. NNLE was found to combat oxidative stress by enhancing the transcription and translation of both primary antioxidant enzymes and phase-II detoxifying enzymes, especially heme-oxygenase-1 (HO-1). NNLE treatment enhanced Nrf2 accumulation in the nucleus and post-translational phosphorylation level of p38 kinase and extracellular signal-regulated kinase (ERK) in RAW 264.7 cells. Treatment with p38 and ERK inhibitors completely suppressed NNLE-induced Nrf2 and HO-1 expression. We also found that p38 and ERK inhibitors significantly antagonized the increase in cell viability and cellular ROS scavenging activity induced by NNLE. The findings of this study provide scientific evidence on the potential of NNLE as a cost-effective and readily available source of natural phytochemicals, along with the strategy to prevent diseases associated with oxidative stress through attenuating disease progression.

Antimelanogenic Effect of an Oroxylum indicum Seed Extract by Suppression of MITF Expression through Activation of MAPK Signaling Protein.

In this study, the antimelanogenic effect of an ethyl acetate fraction of Oroxylum indicum Vent. seeds (OISEA) and its underlying mechanisms in melan-a cells were investigated. Antimelanogenesis activity was confirmed by assessing inhibition of tyrosinase activity and melanin content in the cells. Both transcriptional and translational expression of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase related protein-1 and 2 (TYRP-1 and TYRP-2), were also examined. The results depicted that pretreatment of OISEA significantly inhibits not only tyrosinase activity, but melanin production and intracellular tyrosinase activity. By repressing the expression of tyrosinase, TYRP-1, TYRP-2, and MITF, OISEA interrupted melanin production. Additionally, OISEA interfered with the phosphorylation of p38, extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK), with the reversal of OISEA-induced melanogenesis inhibition after treatment with the specific inhibitors SB239063, U0126, and SP600125. Overall, these results suggest that OISEA can stimulate p38, ERK1/2, JNK phosphorylation, and subsequent suppression of melanin, leading to the inhibition of melanogenic enzymes and melanin production, possibly owing to the presence of polyphenolic compounds.