Villareal Myra

The harsh environment that plants in the semi-arid and arid regions are exposed to induced the plants to adapt in order to survive, and in the process, produce numerous bioactive compounds with therapeutic or medicinal properties. Extracts of arid land plants Cymbopogon schoenanthus, Crithmum maritimum, and Rhanterium suaveolens were evaluated for their effects on immediate-type allergy and melanin biosynthesis using RBL- 2H3 basophilic cells and B16 murine melanoma cells, respectively. MTT assay done to evaluate the cytotoxicity of the extracts revealed non-cytotoxic effects at low concentrations. β-hexosaminidase release inhibition assay revealed that the extracts significantly inhibited mas cell degranulation while melanin assay results showed significant melanin biosynthesis regulatory effects in B16 cells. This is a preliminary study to evaluate the bioactivities of arid plants C. schoenanthus, C. maritimum, and R. suaveolens. Futher studies are being undertaken to understand the mechanism underlying the observed effects.

α-Linolenic acid (ALA), a major fatty acid in flaxseed oil, has multiple functionalities such as anti-cardiovascular and anti-hypertensive activities. In this study, we investigated the effects of ALA on lipid metabolism and studied the possible mechanisms of its action in differentiated 3T3-L1 adipocytes using DNA microarray analysis. From a total of 34,325 genes in the DNA chip, 87 genes were down-regulated and 185 genes were up-regulated at least twofold in differentiated 3T3-L1 adipocyte cells treated with 300 μM ALA for a week, 5-12 days after induction of cell differentiation, compared to ALA-untreated 3T3-L1 adipocytes (control). From the Reactome analysis results, eight lipid metabolism-related genes involved in cholesterol and triacylglycerol biosynthesis pathway and lipid transport were significantly down-regulated by ALA treatment. Furthermore, ALA significantly decreased the mRNA expressions of sterol regulatory element binding protein (SREBP)-2, SREBP-1a, SREBP-1c and fatty acid synthase (FAS) in 3T3-L1 adipocyte cells. On the other hand, the average levels of the gene expressions of carnitine palmitoyltransferase 1a (CPT-1a) and leptin in 300 μM ALA treatment were increased by 1.7- and 2.9-fold, respectively, followed by an increase in the intracellular ATP content. These results show that ALA is likely to inhibit cholesterol and fatty acid biosynthesis pathway by suppressing the expression of transcriptional factor SREBPs. Furthermore, ALA promotes fatty acid oxidation in 3T3-L1 adipocytes, thereby increasing its health benefits. © 2012 Springer Science+Business Media Dordrecht.

The effects of caffeoylquinic acid (CQA)-rich purple sweet potato (PSP) extract, with (PSPEa) or without (PSPEb) anthocyanin, on the improvement of spatial learning and memory of senescence-accelerated prone mouse strain (SAMP) 8 was determined. SAMP8 was treated with 20 mg/kg/day of PSPEa or PSPEb for 30 days. The effect on spatial learning and memory and the molecular mechanism of this effect were determined in vivo (SAMP8) and in vitro (SH-SY5Y cells). PSPEa or PSPEb reduced the escape latency time of SAMP8 by 17.0 ± 8.0 and 14.2 ± 5.8 s (P &lt 0.01), respectively. PSPEa administration induced an overexpression of antioxidant-, energy metabolism-, and neuronal plasticity-related proteins in the brain of SAMP8. Additionally, PSPEa and PSPEb increased the cell viability by 141.6 and 133% as compared to Aβ1-42-treated cells. These findings suggest that PSP rich in CQA derivatives with or without anthocyanidine had a neuroprotective effect on mouse brain and can improve the spatial learning and memory of SAMP8. © 2013 American Chemical Society.

Hypopigmentation diseases are usually managed using UVB light which increases the patients' risk for skin cancer. Here, we evaluated the melanogenesis stimulatory effects of leaf extracts of Erica multiflora, a medicinal plant from the Mediterranean region, and its active component, lup-20 (29)-en-3-one, as possible therapeutic agents to address hypopigmentation disorders. B16 murine melanoma cells were treated with E. multiflora extracts or its active component lupenone to evaluate their effects on melanin biosynthesis. The mechanism underlying the observed effects was also determined. Bioactivity-guided fractionation of fifteen ethyl acetate fractions identified fraction 2 to have melanogenesis stimulatory effects due to its ability to decrease mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 activation. Preparative TLC of ethyl acetate fraction 2 revealed the presence of lup-20(29)-en-3-one as the major bioactive component. B16 cells treated with lup-20(29)-en-3-one increased melanin content without cytotoxicity. To determine the mechanism for the observed effects of lup-20(29)-en-3-one, the tyrosinase enzyme activity, the tyrosinase protein expression, and the activation of phosphorylated extracellular signal-regulated kinases 1 and 2 were determined. In addition, the expression of the tyrosinase mRNA was quantified using real-time PCR. Results showed that lup-20(29)-en-3-one has no effect on the tyrosinase enzyme activity but can increase tyrosinase expression at both the transcriptional and translational levels. The increase in the tyrosinase mRNA expression was most likely due to the inhibited mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 activation. We report for the first time that E. multiflora ethyl acetate extract and its active compound lup-20(29)-en-3-one stimulate melanogenesis by increasing the tyrosinase enzyme expression via mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 phosphorylation inhibition, making it a possible treatment for hypopigmentation diseases.

Melanin performs a crucial role in protecting the skin against harmful ultraviolet light. However, hyperpigmentation may lead to aesthetic problems and disorders such as solar lentigines (SL), melasma, postinflammatory hyperpigmentation and even melanoma. Arthrophytum scoparium grows in the desert in the North African region, and given this type of environment, A. scoparium exhibits adaptations for storing water and produces useful bioactive factors. In this study, the effect of A. scoparium ethanol extract (ASEE) on melanogenesis regulation in B16 murine melanoma cells was investigated. Cells treated with 0.017% (w/v) ASEE showed a significant inhibition of melanin biosynthesis in a time-dependent manner without cytotoxicity. To clarify the mechanism behind the ASEE-treated melanogenesis regulation, the expressions of tyrosinase enzyme and melanogenesis-related genes were determined. Results showed that the expression of tyrosinase enzyme was significantly decreased and Tyr, Trp-1, Mitf and Mc1R mRNA expressions were significantly down-regulated. LC-ESI-TOF-MS analysis of the extract identified the presence of six phenolic compounds: coumaric acid, cinnamic acid, chrysoeriol, cyanidin, catechol and caffeoylquinic acid. The melanogenesis inhibitory effect of ASEE may therefore be attributed to its catechol and tetrahydroisoquinoline derivative content. We report here that ASEE can inhibit melanogenesis in a time-dependent manner by decreasing the tyrosinase protein and Tyr, Trp-1, Mitf and Mc1R mRNA expressions. This is the first report on the antimelanogenesis effect of A. scoparium and on its potential as a whitening agent. © 2013 John Wiley &amp Sons A/S.

Argan (Argania spinosa L.) oil has been used for centuries in Morocco as cosmetic oil to maintain a fair complexion and to cure skin pimples and chicken pox pustules scars. Although it is popular, the scientific basis for its effect on the skin has not yet been established. Here, the melanogenesis regulatory effect of argan oil was evaluated using B16 murine melanoma cells. Results of melanin assay using B16 cells treated with different concentrations of argan oil showed a dose-dependent decrease in melanin content. Western blot results showed that the expression levels of tyrosinase (TYR), tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase (DCT) proteins were decreased. In addition, there was an increase in the activation of MITF and ERK1/2. Real-time PCR results revealed a downregulation of Tyr, Trp1, Dct, and Mitf mRNA expressions. Argan oil treatment causes MITF phosphorylation which subsequently inhibited the transcription of melanogenic enzymes, TYR and DCT. The inhibitory effect of argan oil on melanin biosynthesis may be attributed to tocopherols as well as the synergistic effect of its components. The results of this study provide the scientific basis for the traditionally established benefits of argan oil and present its therapeutic potential against hyperpigmentation disorders. © 2013 Myra O. Villareal et al.

Background: We have previously reported that hirsein A inhibits melanogenesis in B16 melanoma cells by downregulating the Mitf gene expression. Objective: In this study, microarray was employed to determine the transcriptional response of B16 cells to hirsein A (HA) treatment and to find out the mechanism underlying Mitf downregulation. Methods: DNA microarray, spotted with 265 genes for melanogenesis and signal transduction, was performed using the total RNA isolated from B16 cells treated with HA. Validation of the results was done using real-time PCR. In addition, real-time PCR using primers for Mda-7 gene and F-actin staining were performed. Transfection experiments were performed to knockdown the expression of the Mc1r gene to evaluate its role in the cell morphological change observed. Results: As expected, the expressions of the Mitf-regulated melanosome transport genes and the Mc1r gene were downregulated. Furthermore, the expressions of the MAPK pathway intermediates were either up- or downregulated. Genes associated with cell differentiation, such as Gadd45b, were upregulated and prompted us to determine the expression of the Il-24 (Mda-7) gene using real-time PCR. There was an increase in the Mda-7 mRNA expression in B16 and HMV-II melanoma cells, and in human melanocytes. To better visualize the cell morphology, F-actin staining was performed and the results showed an increase in the dendrite outgrowth in HA-treated cells. Silencing the Mc1r gene did not cause a change in the 816 cell morphology observed in cells treated with HA. Conclusion: This study demonstrated that HA downregulates Mitf gene expression by regulating the expressions of the MAPK signaling pathway intermediates. In addition, the inhibited Mc1r gene expression also contributed to the overall Mitf downregulation but does not play a role in the observed change in B16 cell morphology. HA surprisingly can regulate genes associated with differentiating cells (Mda-7) suggesting a role for HA in the melanoma cell differentiation induction. While the exact molecular mechanism by which HA promotes cell differentiation remain to be determined, it is clear that HA can downregulate Mitf expression and promote cell differentiation and has the potential to be used in the development of therapy for melanoma. (C) 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Fulvic acid (FA) is class of compounds of humic substances formed through the degradation of organic substances by chemical and biological processes. FA has been utilized in traditional Chinese medicine and possesses various pharmacological properties. Previously, we reported that FA extracted from solubilized excess sludge (SS-FA) had an inhibitory effect on β-hexosaminidase release in human leukemia basophilic (KU812) cells. In this study, we investigated the effects of SS-FA on the immediate-type allergic reaction and studied its possible mechanisms of action in KU812 cells following activation with phorbol myristate acetate (20 nmol L-1) plus calcium ionophore A23187 (1 μmol L-1) (PMACI). The inhibitory effect of SS-FA on degranulation in PMACI-stimulated KU812 cells was examined using histamine release assay. SS-FA significantly decreased the histamine release in KU812 cells at concentrations of 0.1-10.0 μg mL-1. To gain more information regarding the mechanism of the suppression of degranulation following SS-FA treatment, microarray was conducted to determine which genes were differentially expressed in response to SS-FA in PMACI-activated KU812 cells. From a total of 201 genes in the DNA chip, 28 genes were up-regulated and 173 genes were down-regulated in cells pretreated with SS-FA for 15 min and stimulated with PMACI. From the 71 genes that showed more than two fold change in expression, 16 genes were significantly down-regulated that were subjected to hierarchical clustering. SS-FA affected the expression of genes that were involved in the following pathways: signal transduction, cytokine-cytokine receptor interaction, immune response, cell adhesion molecules and IgE receptor β subunit response. © 2011 Springer Science+Business Media B.V.

Previously, we reported that Thymelaea hirsuta extract has antimelanogenesis effect on B16 murine melanoma cells. The extract was subjected to fractionation, and hirsein A (HA) and hirsein B (HB) were discovered and tested for their ability to regulate melanogenesis in B16 cells. Western blot (WB) analysis was carried out to determine the expression of tyrosinase. Moreover, to elucidate the possible mechanism behind melanogenesis regulation, real-time PCR using primers for Mitf, Tyr, Trp1 and Dct genes, and protein kinase C (PKC) activity assay were carried out. Results clearly show that 0.1 mu m HA and HB significantly reduced the melanin content. This reduction in melanin content was accompanied by reduced tyrosinase expression as detected by WB analysis. There was also a significant decrease in the expression level of Mitf gene in HA- and HB-treated cells. HA down-regulated the expressions of Tyr, Trp1 and Dct, whereas HB down-regulated only those of Trp1 and Dct. Interestingly, HB-treated cells had lower kinase activity than HA-treated cells indicating a possible difference in the activities of the compounds but with the same mechanism of melanogenesis regulation. We report for the first time that HA and HB can down-regulate melanogenesis by down-regulating Mitf gene expression, leading to reduced expressions of Tyr, Trp1 and Dct. The hirseins were also able to reduce the kinase activity, suggesting the possible involvement of PKC in the overall ability of the hirseins to down-regulate melanogenesis.

The effect of Tunisian Capparis spinosa L. aromatic plant extract on melanogenesis regulation in B16 murine melanoma cells was investigated. B16 cells were treated with 0.0005, 0.005, and 0.05% (w/v) C. spinosa extract after which the melanin content and cell viability were measured. To clarify the mechanism behind melanogenesis regulation, the expression of tyrosinase was determined. Results showed that the extract had a significant stimulative effect on melanogenesis in B16 cells in a dose-dependent manner without cytotoxicity. Western blot analysis showed that expression of tyrosinase in cells treated with 0.03% (w/v) C. spinosa extract increased by 12.5- and 20-fold after 24 and 48 h of incubation, respectively, compared with untreated cells. HPLC analysis of the extract revealed the presence of 1% quercetin, a known melanogenesis stimulator, indicating that our findings may be attributed to quercetin however, other compounds present in the extract may also have an effect on the overall ability of the extract to stimulate melanogenesis. We report here that Tunisian C. spinosa leaf extract can stimulate melanogenesis in a dose-dependent manner without cytotoxicity by increasing tyrosinase protein expression and has the potential to be used as a possible tanning agent or as a treatment for hair depigmentation. © 2009 The Japanese Society of Pharmacognosy and Springer.