Rosmarinic acid induces melanogenesis through protein kinase A activation signaling

Rosemary extract and rosmarinic acid accelerate elastic fiber formation by increasing the expression of elastic fiber components in dermal fibroblasts

Ultraviolet (UV)-induced skin photoaging is caused by qualitative and quantitative degradation of dermal extracellular matrix components such as collagen and elastic fibers. Elastic fibers are important for maintaining cutaneous elasticity, despite their small amount in the skin. Previously, microfibril-associated protein 4 (MFAP-4), which is downregulated in photoaging dermis, has been found to be essential for elastic fiber formation by interaction with both fibrillin-1 and elastin, which are core components of elastic fiber. In addition, enhanced cutaneous MFAP-4 expression in a human skin-xenografted murine photoaging model protects against UV-induced photodamage accompanied by the prevention of elastic fiber degradation and aggravated elasticity. We therefore hypothesized that the upregulation of MFAP-4 in dermal fibroblasts may more efficiently accelerate elastic fiber formation. We screened botanical extracts for MFAP-4 expression-promoting activity in normal human dermal fibroblasts (NHDFs). We found that rosemary extract markedly promotes early microfibril formation and mature elastic fiber formation along with a significant upregulation of not only MFAP-4 but also fibrillin-1 and elastin in NHDFs. Furthermore, rosmarinic acid, which is abundant in rosemary extract, accelerated elastic fiber formation via upregulation of transforming growth factor β-1. This was achieved by the induction of cAMP response element-binding protein phosphorylation, demonstrating that rosmarinic acid represents one of the active ingredients in rosemary extract. Based on the findings in this study, we conclude that rosemary extract and rosmarinic acid represent promising materials that exert a preventive or ameliorative effect on skin photoaging by accelerating elastic fiber formation.

Rosmarinic acid enhances CHO cell productivity and proliferation through activation of the unfolded protein response and the mTOR pathway

Rosmarinic acid (RA) has gained attraction in bioprocessing as a media supplement to improve cellular proliferation and protein production. Here, we observe up to a two-fold increase in antibody production with RA-supplementation, and a concentration-dependent effect of RA on cell proliferation for fed-batch Chinese hamster ovary (CHO) cell cultures. Contrary to previously reported antioxidant activity, RA increased the reactive oxygen species (ROS) levels, stimulated endoplasmic reticulum (ER) stress, activated the unfolded protein response (UPR), and elicited DNA damage. Despite such stressful events, RA appeared to maintained cell health via mammalian target of rapamycin (mTOR) pathway activation; both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) were stimulated in RA-supplemented cultures. By reversing such mTOR pathway activity through either chemical inhibitor addition or siRNA knockdown of genes regulating the mTORC1 and mTORC2 complexes, antibody production, UPR signaling, and stress-induced DNA damage were reduced. Further, the proliferative effect of RA appeared to be regulated selectively by mTORC2 activation and have reproduced this observation by using the mTORC2 stimulator SC-79. Analogously, knockdown of mTORC2 strongly reduced X-box binding protein 1 (XBP1) splicing, which would be expected to reduce antibody folding and secretion, sugging that reduced mTORC2 would correlate with reduced antibody levels. The crosstalk between mTOR activation and UPR upregulation may thus be related directly to the enhanced productivity. Our results show the importance of the mTOR and UPR pathways in increasing antibody productivity, and suggest that RA supplementation may obviate the need for labor-intensive genetic engineering by directly activating pathways favorable to cell culture performance.

Insights into the interaction mechanism of acid phosphatase from Lateolabrax japonicus livers and rosmarinic acid using multispectroscopy and molecular docking

Acid phosphatase (ACP) is a key enzyme that hydrolyzes inosinic acid. The mechanisms underlying the interaction between rosmarinic acid (RA) and ACP and the inhibition of the enzyme were investigated using inhibition kinetics, UV-visible and fluorescence spectroscopy, circular dichroism, and molecular docking. The results showed that RA was a reversible inhibitor of ACP and that the inhibition mechanism was uncompetitive. The ACP fluorescence was quenched by RA, and the quenching mode was static. The interaction of ACP with RA was driven by H bonds and van der Waals forces. The addition of RA increased the α-helix content and decreased the β-sheet, β-turn, and random coil contents in ACP, thereby altering the secondary structure of the enzyme. This study enriched our understanding of inhibitory and interaction mechanisms involving ACP and RA.

Research Progress of Small Molecules as Anti-vitiligo Agents

Vitiligo is a disease characterized by skin discoloration, and no safe and effective drugs have been developed until now. New drug research and development are imminent. This article reviews the research on small-molecule drugs for vitiligo from 1990 to 2021 at home and abroad. They are classified according to their structures and mechanisms of action, including natural products and derivatives, anti-oxidative stress drugs, immunosuppressants, prostaglandins, etc. The research on their anti-vitiligo activity, structural modification, new dosage forms, clinical trials, and the development trend in new anti-vitiligo drugs are reviewed, which provides important references for the development of new drugs.

Drug delivery of natural products through nano-carriers for effective vitiligo therapy: A compendia review

BACKGROUND

Vitiligo is a depigmenting illness that causes white areas on the skin. Vitiligo's pathogenetic genesis is based on the melanocyte's autoimmune destruction, in which oxidative stress causes melanocyte molecular, organelle, and exposure of antigen, as well as melanocyte cell death, and so plays a role in vitiligo progression. Natural compounds have recently shown a wide range of therapeutic bioactivities against a number of skin disorders.

AIM

The aim of this work is drug delivery of natural products through nano-carriers for effective vitiligo therapy: A compendia review.

METHODS & MATERIALS

An online literature analysis was guided for vitiligo therapy, nanotechnology, phytochemical composition, and, types of vitiligo, types of nanomedicine. Appropriate information were taken from different electronic scientific databases such as Web of Science, Science Direct, Elsevier, Google Scholar, Springer, PubMed, and scripts.

RESULTS

Nano-carriers-based natural compounds provide a great relationship for the enhancement in the efficacy and safety of pharmacotherapeutic agents for the treatment of vitiligo.

DISCUSSION

In this study focuses on natural compounds' effects and processes on vitiligo models. Although topical therapy plays an important role in vitiligo treatment, its utility and patient compliance are hampered by adverse effects or inadequate efficacy. Novel drug delivery techniques can help improve topical medication delivery by improving epidermal localization, reducing side effects, and increasing effectiveness.

CONCLUSION

This paper covers the significant potential of herbal-derived active compounds as anti-vitiligo drugs, as well as new drug delivery as a viable carrier and future possibilities to investigate.

Quantification of rosmarinic acid from different plant species of lower Himalayan region and expression analysis of underlying L-Phenylalanine pathway

This study adopts a very effective high-performance liquid chromatography (HPLC) technique for the quantitative determination of rosmarinic acid (RA) and PCR-based amplification of biosynthetic key regulators in Isodon rugosus, Daphne mucronata, and Viburnum grandiflorum from the lower Himalayan regions. Rosmarinic acid is engaged in a variety of biological processes and has significant industrial significance. In this study, it was identified from crude methanolic extract using thin-layer chromatography with a standard, and its content was quantified using HPLC without interrupting spikes using a mixture of methanol and deionized water containing acetonitrile (70:30 v/v) and acetic acid (0.1% v/v) at UV 310 nm absorption. We used RT-PCR to identify cDNAs encoding PAL, C4H, and RAS, and Image J's semi-quantitative analysis to quantify the expression levels of genes involved in RA production from chosen plant material. The highest levels of PAL, C4H, and RAS were detected, by band intensity, in the leaves and flowers of I. rugosus, which also exhibited a substantial quantity of RA. However, in V. grandiflorum and D. mucronata the transcript of the given genes was low. The concentration of RA ranged from 187.7 to 21.2 mg g^-1 for I. rugosus, 17.42 to 5.42 mg g^-1 for V. grandiflorum, and 15.19 mg g^-1 for D. mucronata. This study demonstrated that the method for quantifying RA from a crude methanolic extract was effective, indicating that I. rugosus might be used as an indigenous alternative source of RA.

Dietary Supplements and the Skin: Focus on Photoprotection and Antioxidant Activity—A Review

Skin health is not only significantly affected by ageing, but also by other lifestyle-related factors, such as sun exposure, exercise and eating habits, smoking or alcohol intake. It is known that the cutaneous tissue can exhibit visible signs of senescence, in the form of, for example, dull complexion, loss of firmness, or changes in pigmentation. Consumers attempt to improve skin health and appearance not only by cosmetic products, but also with the consumption of food supplements. Recently, there has been an increase in the amount of food supplements with claims that are related to skin and hair health. Nevertheless, the literature is still scarce in evidence of the efficacy of this type of products. Considering this scenario, we aim in this review to assemble studies and methodologies that are directed at the substantiation of the cutaneous health claims of food supplements. For example, we reviewed those that were indicative of antioxidant properties, improvement in pigmentation disorders, increased hydration or protection against the damages caused by ultraviolet radiation.

Prospecting In Vitro Antioxidant and Photoprotective Properties of Rosmarinic Acid in a Sunscreen System Developed by QbD Containing Octyl p-Methoxycinnamate and Bemotrizinol

Progressively growing diagnoses of skin cancer trigger public health concerns about excessive sun exposure, awareness of the deleterious effects of ultraviolet (UV) radiation on the skin, and the proper use of sunscreens. Studies show that bioactive molecules, such as rosmarinic acid (RA), may potentiate the photoprotective and antioxidant activity of topical formulations. This research presents the application of the concepts of quality by design (QbD) to evaluate the critical parameters of quality and the development of an optimized cosmetic formulation with RA by means of an understanding of product design space. Samples were developed using design of experiments (DoE) and they were evaluated for in vitro antioxidant activity and photoprotective efficacy, as well as for photostability through artificial irradiation. We were able to achieve the RA performance regarding antioxidant and SPF properties through in vitro experiments. We obtained the equations for predicting the in vitro antioxidant activity and SPF. Considering our sunscreen system, developed with octyl p-methoxycinnamate and bemotrizinol, the presence of RA increased its antioxidant capacity; however, the in vitro SPF was reduced when both UV filters were used. The development of multifunctional sunscreens is of utmost importance; moreover, there is a need for the rational development of formulations that ensure representative statistical tests of the effects and interactions among the components of a formulation on the desired critical quality attributes, including efficacy.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.

Rosmarinic acid inhibits proliferation and migration, promotes apoptosis and enhances cisplatin sensitivity of melanoma cells through inhibiting ADAM17/EGFR/AKT/GSK3β axis

Rosmarinic acid (RA), a naturally occurring polyphenolic compound, exerts multiple biological properties including anti-cancer. The metalloprotease, a disintegrin and metalloproteinase 17 (ADAM17), can activate ligands of the epidermal growth factor receptor (EGFR) and contribute to tumor progression. We aimed to investigate whether RA could exhibit anti-cancer effects in melanoma cells through down-regulating ADAM17. The human melanoma A375 cells were exposed to RA, then cell viability, migration, invasion, apoptosis, melanin content and the expression of ADAM17/EGFR/AKT/GSK3β were evaluated. The viability of cells exposed to RA in the presence of cisplatin (Cis) was measured by CCK-8. Cells were overexpressed with ADAM17 in the absence or presence of RA and ADAM17 inhibitor (TACE prodomain; TPD) co-treatment, then the above cellular processes were also observed. Results showed that A375 cells treated with RA showed significant lower cell viability, proliferation, migrative and invasive abilities, melanin content and expression of related proteins including MMP2 and MMP9, compared with normal cells. RA enhanced the ratio of TUINEL-positive cells, the expression of pro-apoptotic proteins, but reduced Bcl-2 expression. RA co-treatment increased the inhibitory effect of Cis on cell viability. RA inhibited the expression of ADAM17/EGFR/AKT/GSK3β, which was further suppressed by TPD. Moreover, ADAM17 overexpression blocked all the effects of RA whereas TPD treatment generated an opposite function. In conclusion, RA exerted obvious inhibitory effect on melanoma cell proliferation, migration and invasion, but promotive effect on cells apoptosis. Addition, the showing of this characteristic of RA may rely on inhibiting the expression of ADAM17/EGFR/AKT/GSK3β axis.

Association of Genetic Structure and Diversity in Iranian Wild Germplasms of Mentha longifolia L. Based on Phenotypical, Biochemical, and Molecular Markers

Mentha longifolia L. is well-known to be one of the most pervasive wild-growing species of the Lamiaceae family, which has extensive beneficial properties in the fields of pharmacology and biological products. In the present study, the correlation between Inter-simple sequence repeat (ISSR) markers and morpho-chemical parameters of twenty different M. longifolia accessions (MLACs) were assessed. The geographic information system (GIS) has been employed to interpret the original habitat of the accessions in Iran. ISSR analysis indicated a remarkable difference in the studied accessions, segregated them into three main groups, constructed by an unweighted pair-group method with arithmetic (UPGMA) and principal coordinate analysis (PCoA). A total of 89 bands were generated by 12 ISSR primers, among which 82 (91.97 %) of them were polymorphic. The cluster analysis based on agro-morphological data scattered MLACs into two main groups. The essential oils (EOs) were analyzed through GC/FID/MS, and four chemotypes were characterized according to the major constituents. Pulegone ranged from 0.17 to 69.50 % was the main oil constituent with the highest content. Also, HPLC-PDA was employed to identify and to quantify the phenolic compounds in the MeOH extracts of MLACs. Heatmap cluster based on phenolic compounds produced three main categories of accessions. The components identified in the extracts were rosmarinic acid, rutin, vanillic acid, ferulic acid, chlorogenic acid, caffeic acid, 3,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, and p-coumaric acid, which among them rosmarinic acid (RA) varied from 39.16 to 261.55 mg/100 g (DW) as a predominant constituent. Subsequently, multiple regression analyses between ISSR fragments and morpho-chemical data illustrated considerable relationships in the plant materials. The high variation and correlation observed in metabolic and phenotypic traits of MLACs establish an adequate source to conduct reserves conservation programs.

Effect of Rosmarinic Acid and Ionizing Radiation on Glutathione in Melanoma B16F10 Cells: A Translational Opportunity

To explain a paradoxical radiosensitizing effect of rosmarinic acid (RA) on the melanoma B16F10 cells, we analyzed the glutathione (GSH) intracellular production on this cell (traditionally considered radioresistant) in comparison with human prostate epithelial cells (PNT2) (considered to be radiosensitive). In PNT2 cells, the administration of RA increased the total GSH content during the first 3 h (p < 0.01) as well as increased the GSH/oxidized glutathione (GSSG) ratio in all irradiated cultures during all periods studied (1h and 3h) (p < 0.001), portraying an increase in the radioprotective capacity. However, in B16F10 cells, administration of RA had no effect on the total intracellular GSH levels, decreasing the GSH/GSSG ratio (p < 0.01); in addition, it caused a significant reduction in the GSH/GSSG ratio in irradiated cells (p < 0.001), an expression of radioinduced cell damage. In B16F10 cells, the administration of RA possibly activates the metabolic pathway of eumelanin synthesis that would consume intracellular GSH, thereby reducing its possible use as a protector against oxidative stress. The administration of this type of substance during radiotherapy could potentially protect healthy cells for which RA is a powerful radioprotector, and at the same time, cause significant damage to melanoma cells for which it could act as a radiosensitive agent.

Insight into Mechanistic Action of Thymoquinone Induced Melanogenesis in Cultured Melanocytes

BACKGROUND

Melanin plays a crucial role in camouflage, social communication and protection against harmful ultraviolet radiations. Melanin is synthesized by melanocytes through melanogenesis and several intrinsic and extrinsic factors are involved during the process. Any change occuring in the normal melanogenesis process can cause severe pigmentation problems of hypopigmentation or hyperpigmentation.

OBJECTIVE

The present study is based on the evaluation of the effect of thymoquinone on melanogenesis and their possible mechanism of action using the B16F10 melanoma cell line for the production via blocking signaling pathways.

METHODS

Phase contrast microscopy, cell viability, tyrosinase activity, melanin content and western blot analysis were used in the present study.

RESULTS

In the present investigation, cultured melanocytes exhibit that the stimulation of melanin synthesis when treated with thymoquinone. Tyrosinase activity and melanin production in B16F10 melanoma cell line was increased in doze-dependent manner. In western blot, we investigated the involvement of the cAMP/PKA pathway in thymoquinone induced melanogenesis. It was observed protein kinase inhibitors PKA, PKC, PKB and MEK1 decreased the stimulatory effects of thymoquinone from 11.45- fold value to 8.312, 6.631, 4.51, and 7.211-fold value, respectively. However, the results also prove that thymoquinone may partially induce tyrosinase expression via PKA, PKB, PKC and MEK1 signaling pathways.

CONCLUSION

The present finding proposed that thymoquinone is a protective challenger for melanogenesis and it might be useful for the treatment of hypopigmentary disorders.

Rosmarinic acid improves hypertension and skeletal muscle glucose transport in angiotensin II-treated rats

BACKGROUND

Rosmarinic acid (RA) is a natural pure compound from herbs belonging to the Lamiaceae family, such as rosemary, sage, basil, and mint. The antioxidant, angiotensin-converting enzyme inhibitory, and vasodilatory effects of RA have been revealed. Angiotensin II (ANG II) is a potent agent that generates hypertension and oxidative stress. Hypertension and skeletal muscle insulin resistance are strongly related. The aim of this study was to evaluate the effects of acute and chronic RA treatment on blood pressure and skeletal muscle glucose transport in ANG II-induced hypertensive rats.

METHODS

Eight-week-old male Sprague Dawley rats were separated into SHAM and ANG II-infused (250 ng/kg/min) groups. ANG II rats were treated with or without acute or chronic RA at 10, 20, or 40 mg/kg. At the end of the experiment, body weight, liver and heart weights, oral glucose tolerance, skeletal muscle glucose transport activity, and signaling proteins were evaluated.

RESULTS

Both acute and chronic RA treatment decreased systolic, diastolic, and mean arterial blood pressure. Only acute RA at 40 mg/kg resulted in a reduction of fasting plasma glucose levels and an induction of skeletal muscle glucose transport activity. These effects might involve increased ERK activity in skeletal muscle. Meanwhile, chronic RA treatment with 10, 20, and 40 mg/kg prevented ANG II-induced hyperglycemia.

CONCLUSIONS

Both acute and chronic RA treatment attenuated ANG II-induced cardiometabolic abnormalities in rats. Therefore, RA would be an alternative strategy for improving skeletal muscle glucose transport and protecting against ANG II-induced hypertension and hyperglycemia.

Functional characterization of the extranasal OR2A4/7 expressed in human melanocytes

Olfactory receptors (ORs) were first described as specialized chemoreceptors in the nasal epithelium. In the last two decades, ORs have also been detected to be functionally expressed and active in different nonolfactory tissues of the human body, because they used to react to specific odour stimuli. In this study, we conducted a characterization of the extranasal OR2A4/7 expressed in primary human melanocytes and sections of the human skin. OR2A4/7 expression could be demonstrated at the transcript and protein level. We uncovered elevated intracellular cAMP and Ca²⁺ levels accompanied by elevated p38 and reduced p42/44 MAPK phosphorylation following odourant (cyclohexyl salicylate; CHS) stimulation of melanocytes. These results were associated with enhanced melanin biosynthesis in conjunction with the growth inhibition and differentiation of melanocytes. Our findings highlight the participation of OR2A4/7 in human primary melanocyte physiology and suggest an alternate mechanism that regulates melanogenesis.

Anticancer potential of rosmarinic acid and its improved production through biotechnological interventions and functional genomics

Rosmarinic acid (RA) is a highly valued natural phenolic compound that is very commonly found in plants of the families Lamiaceae and Boraginaceae, including Coleus blumei, Heliotropium foertherianum, Rosmarinus officinalis, Perilla frutescens, and Salvia officinalis. RA is also found in other members of higher plant families and in some fern and horned liverwort species. The biosynthesis of RA is catalyzed by the enzymes phenylalanine ammonia lyase and cytochrome P450-dependent hydroxylase using the amino acids tyrosine and phenylalanine. Chemically, RA can be produced via methods involving the esterification of 3,4-dihydroxyphenyllactic acid and caffeic acid. Some of the derivatives of RA include melitric acid, salvianolic acid, lithospermic acid, and yunnaneic acid. In plants, RA is known to have growth-promoting and defensive roles. Studies have elucidated the varied pharmacological potential of RA and its derived molecules, including anticancer, antiangiogenic, anti-inflammatory, antioxidant, and antimicrobial activities. The demand for RA is therefore, very high in the pharmaceutical industry, but this demand cannot be met by plants alone because RA content in plant organs is very low. Further, many plants that synthesize RA are under threat and near extinction owing to biodiversity loss caused by unscientific harvesting, over-collection, environmental changes, and other inherent features. Moreover, the chemical synthesis of RA is complicated and expensive. Alternative approaches using biotechnological methodologies could overcome these problems. This review provides the state of the art information on the chemistry, sources, and biosynthetic pathways of RA, as well as its anticancer properties against different cancer types. Biotechnological methods are also discussed for producing RA using plant cell, tissue, and organ cultures and hairy-root cultures using flasks and bioreactors. The recent developments and applications of the functional genomics approach and heterologous production of RA in microbes are also highlighted. This chapter will be of benefit to readers aiming to design studies on RA and its applicability as an anticancer agent.

Rosmarinic acid attenuates cardiac fibrosis following long-term pressure overload via AMPKα/Smad3 signaling

Agonists of peroxisome proliferator-activated receptor gamma (PPAR-γ) can activate 5' AMP-activated protein kinase alpha (AMPKα) and exert cardioprotective effects. A previous study has demonstrated that rosmarinic acid (RA) can activate PPAR-γ, but its effect on cardiac remodeling remains largely unknown. Our study aimed to investigate the effect of RA on cardiac remodeling and to clarify the underlying mechanism. Mice were subjected to aortic banding to generate pressure overload induced cardiac remodeling and then were orally administered RA (100 mg/kg/day) for 7 weeks beginning 1 week after surgery. The morphological examination, echocardiography, and molecular markers were used to evaluate the effects of RA. To ascertain whether the beneficial effect of RA on cardiac fibrosis was mediated by AMPKα, AMPKα2 knockout mice were used. Neonatal rat cardiomyocytes and fibroblasts were separated and cultured to validate the protective effect of RA in vitro. RA-treated mice exhibited a similar hypertrophic response as mice without RA treatment, but had an attenuated fibrotic response and improved cardiac function after pressure overload. Activated AMPKα was essential for the anti-fibrotic effect of RA via inhibiting the phosphorylation and nuclear translocation of Smad3 in vivo and in vitro, and AMPKα deficiency abolished RA-mediated protective effects. Small interfering RNA against Ppar-γ (siPpar-γ) and GW9662, a specific antagonist of PPAR-γ, abolished RA-mediated AMPKα phosphorylation and alleviation of fibrotic response in vitro. RA attenuated cardiac fibrosis following long-term pressure overload via AMPKα/Smad3 signaling and PPAR-γ was required for the activation of AMPKα. RA might be a promising therapeutic agent against cardiac fibrosis.

Upregulation of Melanogenesis and Tyrosinase Activity: Potential Agents for Vitiligo

Melanin, the compound primarily responsible in humans for hair, eye and skin pigmentation, is produced by melanocytes through a complicated process called melanogenesis that is catalyzed by tyrosinase and other tyrosinase-related proteins. The abnormal loss of melanin causes dermatological problems such as vitiligo. Hence the regulation of melanogenesis and tyrosinase activity is very important for treating hypopigmentary disorders. Many melanogenesis stimulators have been discovered during the past decade. This article reviews recent advances in research on extracts and active ingredients of plants, synthesized compounds with stimulating effect on melanin synthesis and tyrosinase activity, as well as their influence on the expression of related proteins and possible signaling pathways for the design and development of novel anti-vitiligo agents.

Salvia fruticosa Modulates mRNA Expressions and Activity Levels of Xenobiotic Metabolizing CYP1A2, CYP2E1, NQO1, GPx, and GST Enzymes in Human Colorectal Adenocarcinoma HT-29 Cells

Natural products have gained considerable interests because of their use in some industrial areas including nutrition, cosmetic, pharmacy, and medicine. Salvia fruticosa M. (Lamiaceae) is known for its antioxidant, antimicrobial, and antiproliferative activities. Phase I xenobiotic metabolizing enzymes, CYP1A2 and CYP2E1, produce reactive metabolites which are eliminated by the action of phase II enzymes, NQO1, GPx, and glutathione S-transferases (GSTs). In this study, in vitro modulatory effects of S. fruticosa and its major phenolic compound rosmarinic acid (RA) on CYP1A2, CYP2E1, NQO1, GPx, and GSTm1 mRNA expressions and enzyme activities of GPx and GSTs were investigated in HT-29 cells. An mRNA expression analysis revealed that CYP1A2 and CYP2E1 levels were decreased while those of NQO1, GPx, and GSTm1 increased after S. fruticosa and RA treatments. In parallel to gene expressions, enzyme activities of GPx and GSTs by S. fruticosa increased 1.68- and 1.48-fold, respectively. Moreover, RA increased GPx and GSTs activities 1.67- and 1.94-fold, respectively. The results of this preliminary study show that metabolism of xenobiotics may be altered due to changes in the expression and activity of the investigated enzymes by S. fruticosa.

The Phenolic Fraction of Mentha haplocalyx and Its Constituent Linarin Ameliorate Inflammatory Response through Inactivation of NF-κB and MAPKs in Lipopolysaccharide-Induced RAW264.7 Cells

Mentha haplocalyx has been widely used for its flavoring and medicinal properties and as a traditional Chinese medicine with its anti-inflammation properties. The present study was designed to investigate the anti-inflammatory effects and potential molecular mechanisms of the phenolic fraction of M. haplocalyx (MHP) and its constituent linarin in lipopolysaccharide (LPS)-induced RAW264.7 cells. The high-performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometry (HPLC-LTQ-Orbitrap MS) was used to analyze the chemical composition of MHP. Using the enzyme-linked immunosorbent assay (ELISA) and quantitative realtime polymerase chain reaction (qRT-PCR), the expression of pro-inflammatory meditators and cytokines was measured at the transcriptional and translational levels. Western blot analysis was used to further investigate changes in the nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and Akt signaling pathways. Fourteen phenolic constituents were identified from MHP based on the data of the mass spectrometry (MS)/MS analysis. MHP and linarin decreased the production of NO, tumor necrosis factor-α (TNF-α), interlenkin-1β (IL-1β), and IL-6. The messenger ribonucleic acid (mRNA) expression levels of inducible NO synthase (iNOS), TNF-α, IL-1β, and IL-6 were also suppressed by MHP and linarin. Further investigation showed that MHP and linarin down-regulated LPS-induced phosphorylation content of NF-κB p65, inhibitor kappa B α (IκBα), extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK), and p38. However, MHP and linarin showed no inhibitory effect on the phosphorylated Akt. These results suggested that MHP and linarin exerted a potent inhibitory effect on pro-inflammatory meditator and cytokines production via the inactivation of NF-κB and MAPKs, and they may serve as potential modulatory agents for the prevention and treatment of inflammatory diseases.

Lactoferrin inhibits melanogenesis by down-regulating MITF in melanoma cells and normal melanocytes

The aim of this study was to evaluate the effect of bovine lactoferrin (bLf) on melanin-producing cells and to elucidate its mechanism of action. We tested the anti-melanogenic effect of bLf on a 3-dimensional cultured pigmentation skin model and confirmed a 20% reduction in pigmentation, suggesting that bLf was transdermally absorbed and it suppressed melanin production. Treatment of human melanoma cells with bLf resulted in a significant, dose-dependent suppression of melanin production. Apo-bLf and holo-bLf suppressed melanogenesis to the same degree as bLf. The key feature behind this anti-melanogenic effect of bLf was the down-regulation of the microphthalmia-associated transcription factor (MITF), leading to the suppression of tyrosinase activity. Treatment with bLf resulted in both decreased expression of MITF mRNA and enhanced degradation of MITF protein. However, the primary effector was enhanced phosphorylation of extracellular signal-regulated kinase (ERK), leading to the phosphorylation and degradation of MITF. Our finding that bLf suppresses melanin production in melanocytes indicates that bLf is a possible candidate for application as a skin-whitening agent.

Anticancer Effects of Rosemary (Rosmarinus officinalis L.) Extract and Rosemary Extract Polyphenols

Cancer cells display enhanced growth rates and a resistance to apoptosis. The ability of cancer cells to evade homeostasis and proliferate uncontrollably while avoiding programmed cell death/apoptosis is acquired through mutations to key signaling molecules, which regulate pathways involved in cell proliferation and survival. Compounds of plant origin, including food components, have attracted scientific attention for use as agents for cancer prevention and treatment. The exploration into natural products offers great opportunity to evaluate new anticancer agents as well as understand novel and potentially relevant mechanisms of action. Rosemary extract has been reported to have antioxidant, anti-inflammatory, antidiabetic and anticancer properties. Rosemary extract contains many polyphenols with carnosic acid and rosmarinic acid found in highest concentrations. The present review summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of rosemary extract and the rosemary extract polyphenols carnosic acid and rosmarinic acid, and their effects on key signaling molecules.

Lemon balm extract (Melissa officinalis, L.) promotes melanogenesis and prevents UVB-induced oxidative stress and DNA damage in a skin cell model

BACKGROUND

Solar ultraviolet (UV) radiation is one of the main causes of a variety of cutaneous disorders, including photoaging and skin cancer. Its UVB component (280-315nm) leads to oxidative stress and causes inflammation, DNA damage, p53 induction and lipid and protein oxidation. Recently, an increase in the use of plant polyphenols with antioxidant and anti-inflammatory properties has emerged to protect human skin against the deleterious effects of sunlight.

OBJECTIVE

This study evaluates the protective effects of lemon balm extract (LBE) (Melissa Officinalis, L) and its main phenolic compound rosmarinic acid (RA) against UVB-induced damage in human keratinocytes.

METHODS

The LBE composition was determined by HPLC analysis coupled to photodiode array detector and ion trap mass spectrometry with electrospray ionization (HPLC-DAD-ESI-IT-MS/MS). Cell survival, ROS generation and DNA damage were determined upon UVB irradiation in the presence of LBE. The melanogenic capacity of LBE was also determined.

RESULTS

RA and salvianolic acid derivatives were the major compounds, but caffeic acid and luteolin glucuronide were also found in LBE. LBE and RA significantly increased the survival of human keratinocytes upon UVB radiation, but LBE showed a stronger effect. LBE significantly decreased UVB-induced intracellular ROS production. Moreover, LBE reduced UV-induced DNA damage and the DNA damage response (DDR), which were measured as DNA strand breaks in the comet assay and histone H2AX activation, respectively. Finally, LBE promoted melanogenesis in the cell model.

CONCLUSIONS

These results suggest that LBE may be considered as a candidate for the development of oral/topical photoprotective ingredients against UVB-induced skin damage.

Effect of Purified Mushroom Tyrosinase on Melanin Content and Melanogenic Protein Expression

In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocytes showed that the stimulation of melanogenesis by purified tyrosinase is due to increased tyrosinase absorption. Cellular tyrosinase activity and melanin content in B16F10 melanocytes were increased by purified tyrosinase in a dose-dependent manner. Western blot analysis revealed that cellular tyrosinase levels were enhanced after treatment with purified tyrosinase for 48 hours. Furthermore, tyrosinase induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner. The purified tyrosinase-mediated increase of tyrosinase activity was significantly attenuated by H89, LY294002, Ro-32-0432, and PD98059, cAMP-dependent protein kinase inhibitors. The results indicate that purified tyrosinase can be used as contestant for the treatment of vitiligous skin conditions.

The Osmanthus fragrans flower phenylethanoid glycoside-rich extract: Acute and subchronic toxicity studies

ETHNOPHARMACOLOGICAL RELEVANCE

Osmanthus fragrans var. thunbergii (O. fragrans) flower has been consumed as folk medicine for thousands of years. O. fragrans flower extract is a well-characterized phenylethanoid glycoside-rich extract, which has been used as a natural anti-oxidant. The aim of this study was to evaluate the safety of O. fragrans flower phenylethanoid glycoside-rich extract (OFFE).

MATERIALS AND METHODS

The OFFE was extracted by 80% (v/v) aqueous ethanol with 0.01% sodium isoascorbate (w/v) from the O. fragrans flower and purified on HPD300 resins. The total phenylethanoid glycosides content and individual phenylethanoid glycosides was determined by photocolorimetric method and reversed phase UPLC respectively. An acute oral toxicity study, reverse mutation test, bone marrow cell micronucleus test, and sperm abnormality test as well as a 90-day oral toxicity study were performed on experimental animals.

RESULTS

The total content of phenylethanoid glycosides in OFFE was 73.4g acteoside equivalent per 100g of extract, include acteoside (52.5g per 100g of extract), salidroside (13.8g per 100g of extract), and isoacteoside (2.6g per 100g of extract) and so on. No acute lethal effect at the maximal tested OFFE dose of 10g/kg body weight (bw) in either rats or mice was observed, suggesting that OFFE can be considered nontoxic. No evidence for mutagenicity was detected in any of the three mutagenic tests. Administration at levels of 0.50, 1.00, and 2.00g/kg bw to rats for 90 days failed to induce any significant hematological, clinical, chemical, or histopathological changes. The no-observed adverse-effect-level for OFFE was >2.00g/kg bw for the study on subchronic toxicity.

CONCLUSION

The results showed that consuming OFFE has no adverse effects and poses no health risk in the acute oral toxicity study, subchronic oral toxicity study, and in the micronucleus test, which may provide supportive evidence for the safety of OFFE powder that has been used in medicine as well as in functional foods, and dietary supplements.

Quantitatively metabolic profiles of salvianolic acids in rats after gastric-administration of Salvia miltiorrhiza extract

Salvianolic acids, the well-known active components in Salvia miltiorrhiza, have been shown to possess markedly pharmacological activities. However, due to the complex in vivo course after administration, the pharmacologically active forms are still poorly understood. In present study, we evaluated the stability of eight major salvianolic acids from Danshen extract under different chemical and physiological conditions. We also quantitatively explained the absorption, metabolism and excretion of these salvianolic acids in rats after gastric-administration, which was carried out by simultaneously determining the amounts of salvianolic acids and their metabolites in the rat gastrointestinal contents, gastrointestinal mucosa, plasma, bile and urine. We found that: 1) protocatechuic aldehyde (PAL) was much stable whether in acidic environment (pH4.0) or in alkaline environment (pH8.0), while other salvianolic acids were stable in acidic environment and instable in alkaline environment; 2) PAL, salvianoli acid A (SAA) and salvianolic acid B (SAB) were instable whether in rat stomach or in small intestine, while other salvianolic acids were stable in rat stomach and instable in small intestine; 3) after gastric-administration, except PAL and Danshensu (DSS), other phenolic acids would be metabolized into DSS and caffeic acid (CA) in the rat gastrointestinal tract before absorption, and only free and glucuronidated PAL, CA and DSS were detected in rat plasma, bile and urine. In conclusion, it was the free and glucuronidated PAL, CA and DSS rather than the prototypes of other salvianolic acids that were present in plasma with considerable concentrations after gastric-administration.

Vasoactive intestinal peptide stimulates melanogenesis in B16F10 mouse melanoma cells via CREB/MITF/tyrosinase signaling

Vasoactive intestinal peptide (VIP), one of the major skin neuropeptides, has been suggested to have active roles in the pathogenesis of inflammatory skin disorders such as atopic dermatitis and psoriasis, which can commonly cause post-inflammatory hyperpigmentation. However, the effect of VIP on melanogenesis remains unknown. In this study, we showed that the melanin contents, tyrosinase activity, and gene expression of tyrosinase and microphthalmia-associated transcription factor (MITF) were significantly increased by treatment with VIP in B16F10 mouse melanoma cells and the stimulatory melanogenic effect was further examined in human epidermal melanocytes (HEMns). In addition, phosphorylated levels of CRE-binding protein (CREB) and protein kinase A (PKA) were markedly increased after VIP treatment, but not p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), or Akt, indicating the possible PKA-CREB signaling pathway involved in VIP-induced melanogenesis. This result was further verified by the fact that VIP induced increased melanin synthesis, and protein levels of phosphorylated CREB, MITF, tyrosinase were significantly attenuated by H89 (a specific PKA inhibitor). These data suggest that VIP-induced upregulation of tyrosinase through the CREB-MITF signaling pathway plays an important role in finding new treatment strategy for skin inflammatory diseases related pigmentation disorders.

Functional Characterization of the Odorant Receptor 51E2 in Human Melanocytes

Olfactory receptors, which belong to the family of G-protein-coupled receptors, are found to be ectopically expressed in non-sensory tissues mediating a variety of cellular functions. In this study we detected the olfactory receptor OR51E2 at the transcript and the protein level in human epidermal melanocytes. Stimulation of primary melanocytes with the OR51E2 ligand β-ionone significantly inhibited melanocyte proliferation. Our results further showed that β-ionone stimulates melanogenesis and dendritogenesis. Using RNA silencing and receptor antagonists, we demonstrated that OR51E2 activation elevated cytosolic Ca(2+) and cAMP, which could mediate the observed increase in melanin synthesis. Co-immunocytochemical stainings using a specific OR51E2 antibody revealed subcellular localization of the receptor in early endosomes associated with EEA-1 (early endosome antigen 1). Plasma membrane preparations showed that OR51E2 protein is present at the melanocyte cell surface. Our findings thus suggest that activation of olfactory receptor signaling by external compounds can influence melanocyte homeostasis.

(E)-4-(3,4-Dimethoxyphenyl)but-3-en-1-ol Enhances Melanogenesis through Increasing Upstream Stimulating Factor-1-Mediated Tyrosinase Expression

We investigated the potential melanogenic effect of compounds from Zingiber cassumunar Roxb. Our data revealed that chloroform-soluble extract of Z. cassumunar enhanced melanin synthesis in B16F10 melanoma cells. Among the components of the chloroform extract, (E)-4-(3,4-dimethoxyphenyl)but-3-en-1-ol (DMPB) increased melanogenesis in both B16F10 cells and human primary melanocytes. In B16F10 cells, DMPB enhanced the activation of ERK and p38, and the level of tyrosinase. Although the level of microphthalmia-associated transcription factor was unchanged in DMPB-treated B16F10 cells, DMPB increased levels and nuclear localization of upstream stimulating factor-1 (USF1). Consistently, DMPB-mediated melanin synthesis was diminished in USF1-knockdown cells. Furthermore, DMPB induced hyperpigmentation in brown guinea pigs in vivo. Together, these data suggest that DMPB may promote melanin synthesis via USF1 dependent fashion and could be used as a clinical therapeutic agent against hypopigmentation-associated diseases.

Dioscin Derived from Solanum melongena L. "Usukawamarunasu" Attenuates α-MSH-Induced Melanogenesis in B16 Murine Melanoma Cells via Downregulation of Phospho-CREB and MITF

This study aimed to chemically isolate and explore an antimelanogenesis inducer in extracts of Solanum melongena L. "Usukawamarunasu" eggplant. We successfully identified dioscin ([25R]-Spirost-5-en-3β-yl) 2-O-(6-deoxy-α-L-mannopyranosyl) - 4-O-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranoside] in the plant, and examined the effects of α-melanocyte-stimulating hormone (MSH)-induced melanogenesis in B16 murine melanoma cells by this plant-derived dioscin. Immunoblot analysis suggested that dioscin reduced the expression of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, resulting in inhibition of intracellular production of melanin. In addition, dioscin caused reduction of phosphorylated cAMP-responsive element binding protein 1 transcription factors (CREB), which led to a reduction of microphthalmia-related transcription factor (MITF) in α-MSH-stimulated cells, but did not affect phosphorylation of extracellular signal-regulated kinase. Furthermore, dioscin significantly downregulated the expression of tyrosinase, TRP-1, and TRP-2, which led to the reduction of α-MSH-induced melanogenesis in B16 cells. These results suggest that dioscin may decrease the level of MITF via inhibition of phosphorylation of CREB in α-MSH-induced melanogenesis in B16 cells.

Antagonizing Effects of Aspartic Acid against Ultraviolet A-Induced Downregulation of the Stemness of Human Adipose Tissue-Derived Mesenchymal Stem Cells

Ultraviolet A (UVA) irradiation is responsible for a variety of changes in cell biology. The purpose of this study was to investigate effects of aspartic acid on UVA irradiation-induced damages in the stemness properties of human adipose tissue-derived mesenchymal stem cells (hAMSCs). Furthermore, we elucidated the UVA-antagonizing mechanisms of aspartic acid. The results of this study showed that aspartic acid attenuated the UVA-induced reduction of the proliferative potential and stemness of hAMSCs, as evidenced by increased proliferative activity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and upregulation of stemness-related genes OCT4, NANOG, and SOX2 in response to the aspartic acid treatment. UVA-induced reduction in the mRNA level of hypoxia-inducible factor (HIF)-1α was also significantly recovered by aspartic acid. In addition, the antagonizing effects of aspartic acid against the UVA effects were found to be mediated by reduced production of PGE2 through the inhibition of JNK and p42/44 MAPK. Taken together, these findings show that aspartic acid improves reduced stemness of hAMSCs induced by UVA and its effects are mediated by upregulation of HIF-1α via the inhibition of PGE2-cAMP signaling. In addition, aspartic acid may be used as an antagonizing agent to mitigate the effects of UVA.

Differential Effects of Methoxylated p-Coumaric Acids on Melanoma in B16/F10 Cells

As an approach to search for chemopreventive agents, we tested p-coumaric acid, 3-methoxy-p-coumaric acid (ferulic acid), and 3,5-dimethoxy-p-coumaric acid (sinapic acid) in B16/F10 melanoma cells. Intracellular melanin contents were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cytotoxicity of the compounds were examined by lactate dehydrogenase (LDH) release. p-Coumaric acid showed inhibitory effect on melanogenesis, but ferulic acid increased melanin content, and sinapic acid had almost no effect on melanogenesis. Treatment with ferulic acid resulted in a 2 to 3 fold elevation in the production of melanin. Correlatively, cell viability decreased in a dose-dependent manner when treated with ferulic acid. However, ferulic acid did not affect the LDH release from the cells. Treatment with sinapic acid resulted in a 50~60% elevation in the release of LDH when treated with a 200 μg/mL concentration and showed neither cytostasis nor increase of melanin synthesis in a dose-dependent manner. Taken together, p-coumaric acid inhibits melanogenesis, ferulic acid induces melanogenesis, and sinapic acid exerts cytotoxic effects in B16/F10 murine melanoma cells. The results indicate that the addition of methoxy groups to p-coumaric acid shows the melanogenic or cytotoxic effects in melanoma cells compared to the original compound. Therefore, this study suggests the possibility that methoxylated p-coumaric acid, ferulic acid can be used as a chemopreventive agent.

In vitro evaluation of anti-herpes simplex-1 activity of three standardized medicinal plants from Lamiaceae

BACKGROUND

Rosmarinic acid (RA) is a phenolic acid with antioxidant and anti-viral effects. We have studied anti-herpes simplex virus type 1 (HSV-1) effect of three medicinal plants from Lamiaceae family which have been standardized on the basis of RA content.

MATERIALS AND METHODS

Methanolic extract of Teucrium polium, Ziziphora clinopoides, and Salvia rhytidea was prepared by maceration method and RA content of the plants was determined using a spectrophotometric method. Maximum nontoxic concentration (MNTC) of the extracts was determined using neutral red method. Serial dilutions of extracts up to MNTC were examined on Vero cells for anti-HSV-1 effect by plaque assay in comparison to acyclovir as a positive control.

RESULTS

Among the tested extracts, T. polium contained the highest percentage of RA (1.8%w/w) and exhibited the least toxicity (MNTC = 1000 μg/ml). The greatest anti-HSV-1 was shown by T. polium and Z. clinopoides extracts which exhibited both time and concentration-dependent plaque inhibition.

CONCLUSION

Considering the low toxicity and significant anti-viral effect of T. polium extract, this plant would prove valuable as an active anti-viral drug.

Ultraviolet A regulates the stemness of human adipose tissue-derived mesenchymal stem cells through downregulation of the HIF-1α via activation of PGE(2)-cAMP signaling

Ultraviolet A (UVA) irradiation is responsible for a variety of changes in cell biology. The purpose of this study was to investigate the effects of UVA irradiation on the stemness properties of human adipose tissue-derived mesenchymal stem cells (hAMSCs). Furthermore, we examined the UVA-antagonizing effects of L-cysteine ethylester hydrochloride (ethylcysteine) and elucidated its action mechanisms. The results of this study showed that UVA reduced the proliferative potential and stemness of hAMSCs, as evidenced by reduced proliferative activity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and downregulation of OCT4, NANOG, and SOX2, stemness-related genes. The mRNA level of hypoxia-inducible factor (HIF)-1α, but not HIF-2α was reduced by UVA. Moreover, the knockdown of HIF-1α using small interfering RNA (siRNA) for HIF-1α was found to downregulate stemness genes, suggesting that UVA reduces the stemness through downregulation of HIF-1α. In addition, we examined the mechanisms underlying the UVA-mediated effects and found that UVA induced production of prostaglandin (PG) E2 and 3'-5'-cyclic adenosine monophosphate (cAMP), and that this effect was mediated through activation of activating protein-1 (AP-1) and nuclear factor-κB (NF-κB). The UVA effects were antagonized by ethylcysteine, and the effects were found to be mediated by reduced production of PGE2 through the inhibition of JNK and p42/44 MAPK. Taken together, these findings show for the first time that UVA regulates the stemness of hAMSCs and its effects are mediated by downregulation of HIF-1α via the activation of PGE(2)-cAMP signaling. In addition, ethylcysteine may be used as an antagonizing agent to mitigate the effects of UVA.

Anti herpes simplex-1 activity of a standard extract of Zataria multiflora Boiss

In Rosmarinic Acid (RA) is a phenolic acid which has many biological activities such as antioxidant, anti inflammatory and anti viral effects. In the present study, we have studied the anti Herpes simplex type 1 (HSV-1) effect of methanolic extract of Zataria multiflora which has been standardized on the basis of RA content. Methanolic extract of Zatria multiflora was prepared by maceration method. RA content of plant extract was measured by spectrophotometry method using the calibration curve of RA. Maximum non Toxic Concentration (MNTC) of the plant was determined by neutral red method. MNTC and lower serial dilutions of extract were examined in vitro on vero cells for their effect against HSV-1 using a plaque reduction assay. Acyclovir was used as positive control. Time-dependent antiviral effect of Z. multiflora was studied by adding the extract to HSV-1 infected vero cells at different stages of infection. The percentage of RA was determined as 2.2% in Z. multiflora. This plant was effective in all used concentrations and significantly reduced plaque formation up to 100% at concentrations of 800 and 1000 microg mL(-1). Clearly Z. multiflora revealed both a time and concentration inhibition. It seems that the presence of rosmarinic acid would be a determining factor for anti HSV activity of Z. multiflora.

Rosmarinic acid from eelgrass shows nematicidal and antibacterial activities against pine wood nematode and its carrying bacteria

Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA). RosA showed effective nematicidal activity, of which the LC₅₀ (50% lethal concentration) to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L₉ (3⁴) orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v). The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight). The crude extracts of Zostera marina (10 mg/mL) and RosA (1 mg/mL) also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina.

Comparative study of rosmarinic acid content in some plants of Labiatae family

BACKGROUND

Plants of Labiatae are used in traditional medicine and phytotherapy. Rosmarinic acid (RA) is a phenolic compound which is found in many genus of Labiatae and exhibits important biological activities.

MATERIALS AND METHODS

In this investigation, RA contents of 29 species of Labiatae named Salvia officinalis, Salvia limbata, Salvia virgata, Salvia hypoleuca, Salvia macrosiphon, Salvia choloroleuca, Melissa officinalis, Origanum vulgare, Lavandula angustifolia, Rosmarinus officinalis, Thymus daenensis, Thymus citriodorous, Thymus pubescens, Thymus vulgaris, Zataria multiflora, Mentha piperita, Mentha pulegium, Mentha longifolia, Mentha spicata, Mentha aquatica, Mentha crispa, Perovskia artemisoides, Zhumeria majdae, Satureja hortensis, Satureja khuzistanica, Satureja bachtiarica, Satureja atropatana, Satureja mutica and Satureja macrantha were determined by using high-performance liquid chromatographic method.

RESULTS

The results showed that RA content in different species of Labiatae was 0.0-58.5 mg g(-1) of dried plants. The highest amount of RA was found in Mentha species especially M. spicata.

CONCLUSION

M. spicata can be considered as a new source of rosmarinic acid .

Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma

ETHNOPHARMACOLOGICAL RELEVANCE

Pyrostegia venusta is a native Brazilian plant which has a variety of uses in traditional folk medicine including the treatment of vitiligo. However, its effectiveness on melanogenesis is not yet elucidated.

AIM OF THE STUDY

This study aimed to investigate the melanogenic activity of hydroalcoholic extracts from the leaves and flowers of P. venusta on murine B16F10 melanoma cells.

MATERIALS AND METHODS

Different concentrations of the hydroalcoholic extracts of flowers and leaves of P. venusta were evaluated in trials of spontaneous melanin content (4 days), and cell viability by the MTT assay in murine B16F10 cells, and in the mushroom tyrosinase activity in vitro.

RESULTS

Both extracts, leaves (0.1; 0.3; 1 and 3 μg/mL) and flowers (0.03 and 0.1 μg/mL) increased the melanin content in a concentration dependent manner after 4 days of incubation on melanoma cells. Leaves extract promoted enhancement of melanogenesis with maximum effect of 33.3±3% (3 μg/mL), and the flower extract increased in 23.4±3% (0.1 μg/mL). The cell viability test using MTT showed that in the same tested concentrations of both extracts no cell death was detected. Actually, either extract was not able to cause any change in the tyrosinase activity. HPLC analysis of P. venusta extracts found 0.09% and 1.08% of allantoin on leaves and flowers extracts, respectively.

CONCLUSIONS

The leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo.

Stability studies on trans-rosmarinic acid and GC-MS analysis of its degradation product

The stability of trans-rosmarinic acid (trans-RA, an important phenolic compound with anti-oxidant, anti-inflammatory, anti-bacterial, and anti-viral properties) exposed to different stress conditions (daylight, higher temperatures, different solvents, and humidity) was investigated. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the degraded samples, and structural identification of degradation products was assigned based upon MS fragmentation pattern. The GC-MS method was validated in terms of linearity, precision as repeatability, accuracy, limit of detection (LOD), limit of quantitation (LOQ) and recovery. The stability experiments were performed on pure trans-RA and on trans-RA present in commercially available rosemary extract. The cis-isomer of RA was the only degradation product. The results showed that trans-RA was readily isomerized into its cis-form within a few hours when dissolved in ethanol, methanol or tetrahydrofuran, and exposed to darkness or daylight at different temperatures. Isomerization took place to a greater extent in protic than in aprotic solvents. Trans-RA in the solid state was found to be stable for up to three months under all tested conditions. The described GC-MS method was also applied to the determination of trans-RA in eight different species of Lamiaceae family.