Rosmarinic Acid Methyl Ester Research Articles

Rosmarinic acid and its derivative’s duel as antitubercular agents: insights from computational prediction to functional response in vitro

Tuberculosis is one of the most dreadful infectious diseases, afflicting global populations with anguish. With the emergence of multi-drug resistant strains of mycobacteria, the imperative for new anti-tuberculosis drugs has grown exponentially. Thus, the current study delves into evaluating the impact of Perovskia abrotanoides and its active metabolites-namely, rosmarinic acid and its derivatives-against strains of Mycobacterium tuberculosis (Mtb). Through the use of the CRI assay, the antimycobacterial potential of the high-altitude medicinal plant P. abrotanoides was gauged, while docking and molecular dynamics simulations unveiled plausible targets. Of these, the peak antimycobacterial effectiveness was observed in the P. abrotanoides ethyl acetate extract with 125 µg/mL as minimum inhibitory concentration against various strains of M. tuberculosis, encompassing H37Rv and strains resistant to multiple drugs. Following bioassay-guided fractionation and isolation, rosmarinic acid and rosmarinic acid methyl ester emerged as potent molecules against H37Rv and multidrug-resistant M. tuberculosis strains; minimum inhibitory concentration ranging from 15 to 32 µg/mL. Additionally, out of 22 targets explored, Mtb lipoamide dehydrogenase (PDB: 3II4) and Rv2623 (PDB: 3CIS) were forecasted as potential Mtb targets for rosmarinic acid and rosmarinic acid methyl ester, respectively, a supposition further affirmed by molecular simulations (100 ns). The stability of both complexes throughout the simulation was measured by protein backbone root-mean-square deviation, substantiating their roles as respective targets for antimycobacterial activities. Communicated by Ramaswamy H. Sarma

Potential antithrombotic effect of two new phenylpropanoid sucrose esters and other secondary metabolites of Canna indica L. rhizome

Canna indica L. has been traditionally used to treat various diseases. Based on previously reported antithrombotic effect for this plant, two new phenylpropanoid sucrose esters (canindicoside A (1) and canindicoside B (2)) and seven known compounds: nepetoidin B (3), caffeic acid (4), ferulic acid (5), (R)-(+)-rosmarinic acid (6), isorinic acid (7), (S)-(-)-rosmarinic acid (8) and (S)-(-)-rosmarinic acid methyl ester (9) were isolated from the ethyl acetate extract. Compounds were elucidated by NMR and MS spectroscopic methods. The antiplatelet effect was evaluated using turbidimetric method. Anticoagulant activity was examined by measuring activated partial thromboplastine time (APTT), prothrombin time, and thrombine time (TT). It was shown for the first time that both new phenylpropanoid sucrose esters 1 and 2, 7 and 9 displayed dose-dependent antiplatelet effects. 2 and 9 had the highest inhibitory activity on both adenosine diphosphate (ADP)- and collagen-induced platelet aggregation. Moreover, 1, 7 and 9 also exhibited anticoagulant activity. At 0.4 mg/mL, both 1 and 7 prolonged APTT compared to the negative control (p < 0.05), suggesting the possible inhibitory impact on the intrinsic coagulation pathway. Moreover, 9 at 0.4 mg/mL exerted higher TT values than the negative control (p < 0.05). C. indica and its bioactive phytochemicals are potential candidates for development of anti-thrombosis therapy.

Application of Rosmarinic Acid with Its Derivatives in the Treatment of Microbial Pathogens.

The emergence of the antimicrobial resistance phenomena on and the harmful consequences of the use of antibiotics motivate the necessity of innovative antimicrobial therapies, while natural substances are considered a promising alternative. Rosmarin is an original plant compound listed among the hydroxycinnamic acids. This substance has been widely used to fight microbial pathology and chronic infections from microorganisms like bacteria, fungi and viruses. Also, various derivatives of rosmarinic acid, such as the propyl ester of rosmarinic acid, rosmarinic acid methyl ester or the hexyl ester of rosmarinic acid, have been synthesized chemically, which have been isolated as natural antimicrobial agents. Rosmarinic acid and its derivatives were combined with antibiotics to obtain a synergistic effect. This review reports on the antimicrobial effects of rosmarinic acid and its associated derivatives, both in their free form and in combination with other microbial pathogens, and mechanisms of action.

Natural Products from Leaves of the Ancient Iranian Medicinal Plant Echium amoenum Fisch. &amp; C. A. Mey.

For several millennia, leaves of Echium amoenum Fisch. & C. A. Mey., an important Iranian medicinal plant with nutritional value as nutraceutical, have been used as tea for the treatment of several conditions, including inflammation. The nutritional value of intake of E. amoenum tea has mainly been correlated to its rich content of mainly water-soluble antioxidants. Although the entire plant is utilized, only natural products of the flowers have previously been thoroughly investigated. The rare natural products bis(3-(3,4-dihydroxyphenyl)-1-methoxy-1-oxopropan-2-yl)-1-(3,4-dihydroxyphenyl)-6,7-dihydroxy-1,2-dihydronaphthalene-2,3-dicarboxylate, 4-Oxy-(E)-caffeoyl-2,3-dihydroxybutanoic acid methyl ester and 4-Oxy-(Z)-caffeoyl-2,3-dihydroxybutanoic acid methyl ester, in addition to the widely distributed compounds rosmarinic acid methyl ester and (E)-caffeic acid, were purified and characterized from leaves of Echium amoenum. The structures were determined by a combination of several 2D NMR spectroscopic techniques, circular dichroism spectroscopy and high-resolution mass spectrometry. The fact that bis(3-(3,4-dihydroxyphenyl)-1-methoxy-1-oxopropan-2-yl)-1-(3,4-dihydroxyphenyl)-6,7-dihydroxy-1,2-dihydronaphthalene-2,3-dicarboxylate belongs to a rare group of natural products which have previously been patented for their significant anti-inflammatory activity may rationalize the traditional treatment of inflammations with E. amoenum.

Rosmarinic Acid Methyl Ester Regulates Ovarian Cancer Cell Migration and Reverses Cisplatin Resistance by Inhibiting the Expression of Forkhead Box M1

Rosmarinic acid methyl ester (RAME), a derivative of rosmarinic acid (RA), is reported to have several therapeutic effects, including anti-tumor effects against cervical cancer. However, its anti-tumor effects in ovarian cancer is unclear. In this study, we studied the molecular pathways associated with the anti-tumor effects of RAME in ovarian cancer. To identify the effects of RAME in ovarian cancer, RNA sequencing was performed in RAME-treated ovarian cancer cells; we found that RAME treatment downregulated the genes closely involved with the target genes of the transcription factor Forkhead box M1 (FOXM1). It was reported that FOXM1 is overexpressed in a variety of cancer cells and is associated with cell proliferation and tumorigenesis. Therefore, we hypothesized that FOXM1 is a key target of RAME; this could result in its anti-tumor effects. Treatment of ovarian cancer cells with RAME-inhibited cell migration and invasion, as shown by wound healing and transwell migration assays. To examine whether RAME represses the action of FOXM1, we performed quantitative RT-PCR and ChIP-qPCR. Treatment of ovarian cancer cells with RAME decreased the mRNA expression of FOXM1 target genes and the binding of FOXM1 to its target genes. Moreover, FOXM1 expression was increased in cisplatin-resistant ovarian cancer cells, and combination treatment with RAME and cisplatin sensitized the cisplatin-resistant ovarian cancer cells, which was likely due to FOXM1 inhibition. Our research suggests that RAME is a promising option in treating ovarian cancer patients, as it revealed a novel molecular pathway underlying its anti-tumor effects.

Identification of a novel S6K1 inhibitor, rosmarinic acid methyl ester, for treating cisplatin-resistant cervical cancer

BackgroundThe mTOR/S6K1 signaling pathway is often activated in cervical cancer, and thus considered a molecular target for cervical cancer therapies. Inhibiting mTOR is cytotoxic to cervical cancer cells and creates a synergistic anti-tumor effect with conventional chemotherapy agents. In this study, we identified a novel S6K1 inhibitor, rosmarinic acid methyl ester (RAME) for the use of therapeutic agent against cervical cancer.MethodsCombined structure- and ligand-based virtual screening was employed to identify novel S6K1 inhibitors among the in house natural product library. In vitro kinase assay and immunoblot assay was used to examine the effects of RAME on S6K1 signaling pathway. Lipidation of LC3 and mRNA levels of ATG genes were observed to investigate RAME-mediated autophagy. PARP cleavage, mRNA levels of apoptotic genes, and cell survival was measured to examine RAME-mediated apoptosis.ResultsRAME was identified as a novel S6K1 inhibitor through the virtual screening. RAME, not rosmarinic acid, effectively reduced mTOR-mediated S6K1 activation and the kinase activity of S6K1 by blocking the interaction between S6K1 and mTOR. Treatment of cervical cancer cells with RAME promoted autophagy and apoptosis, decreasing cell survival rate. Furthermore, we observed that combination treatment with RAME and cisplatin greatly enhanced the anti-tumor effect in cisplatin-resistant cervical cancer cells, which was likely due to mTOR/S6K1 inhibition-mediated autophagy and apoptosis.ConclusionsOur findings suggest that inhibition of S6K1 by RAME can induce autophagy and apoptosis in cervical cancer cells, and provide a potential option for cervical cancer treatment, particularly when combined with cisplatin.

Effect of LED illumination and amino acid supplementation on phenolic compounds profile in Agastache rugosa in vitro cultures

Agastache rugosa (Fischer & C.A.Meyer) O.Kuntze (Lamiaceae) is an East Asian medicinal and aromatic plant. It is rich in polyphenolic compounds such as rosmarinic, chlorogenic, ferulic acids and apigenin glycosides. in vitro shoot cultures were used to study influence of various factors on polyphenol profile using Ultra Performance Liquid Chromatography coupled to high resolution mass spectrometry (UPLC-ESI-qTOF-MS). Large differences in the morphology and polyphenol profile were observed in experiments with various illumination (white fluorescent lamps or white and photosynthetically active radiation LEDs) and supplementation with plant growth regulators and amino acids. Shoots were cultured on the MS basal agar medium with or without plant growth regulators (6-benzylaminopurine - BA, indole-3-acetic acid – IAA), or supplemented with different concentrations of phenylpropanoid biosynthesis precursor - l-phenylalanine or an amino acid mixture (casein hydrolysate). The composition of polyphenols in methanolic extracts was analyzed using UPLC-DAD-qTOF-MS. Three phenolic acids: cryptochlorogenic acid, feruloyl-quinic acid, rosmarinic acid, a rosmarinic acid methyl ester and two isomeric ferulic acid glucosides, as well as one flavonoid – an apigenin derivative were detected. Rosmarinic acid (RA) was the most abundant compound found in the analyzed plant material. Supplementation with amino acids resulted in highest content of RA in shoots cultured for 196 days on media containing either low concentration (1 mg/L) of l-phenylalanine or two of the highest - 20, 50 mg/L. The effect of casein hydrolysate supplementation was noticed from the beginning of shoot culture and reached maximum of 23.3 mg/g on 140 day. On the other hand, shoots that were growing under different illumination produced over 20 mg/g dw of RA after 70 days of culture. In conclusion, the production of phenolic compounds in A. rugosa in vitro shoots was influenced by the age of the shoot cultures, illumination regime and amino acids supplementation.

Isolation, identification of secondary metabolites from Salvia absconditiflora and evaluation of their antioxidative properties

Salvia absconditiflora Greuter & Burdet (Synonym Salvia cryptantha Montbret & Aucher ex Benth) has been used extensively for traditional medicine. The aerial of plant material was boiled in water then filtrated. The filtrate was partitioned with ethyl acetate and n-butanol sequentially to yield the ethyl acetate and n-butanol extract. A sample of water was lyophilized to yield the water extract. Ethyl acetate extract revealed the highest antioxidant activity and included the most phenolic compounds among the extracts. Hence, ethyl acetate extract was subjected to chromatographic techniques. Ursolic acid (1), crismaritin (2), luteolin (3), rosmarinic acid methyl ester (4), 3,4-dihydroxyl benzaldehyde (protocatechuic aldehyde) (5), caffeic acid (6), apigenin-7-O-β-glucoside (7), rosmarinic acid (8) and luteolin-7-O-β-glucoside (9) were isolated and the structures were elucidated by spectroscopic methods including 1D, 2D NMR, and LC-TOF/MS. Cirsimaritin (2), luteolin (3), rosmarinic acid methyl ester (4), rosmarinic acid (8), luteolin-7-O-β-glucoside (9) displayed the considerable antioxidant activity.

Bioactive Phenolic Compounds from the Roots of Danshen (Salvia miltiorrhiza)

Danshen ( Salvia miltiorrhiza Bunge) is one of the most used medicinal plants in the Oriental medicine and has been well studied for application in modern medicine. In our continuing study on chemical constituents of danshen cultivated in Vietnam, using chromatography separation resulted in the isolation of six phenolic compounds including a benzophenone, iriflophenone 2- O- α-L-rhamnopyranoside (1), and five phenolic acids including rosmarinic acid (2), rosmarinic acid methyl ester (3), rosmarinic acid ethyl ester (4), salvianolic acid A methyl ester (5) and salvianolic acid A ethyl ester (6) from the butanol portion of the danshen crude extract. Beside the typically main phenolic acid components, to our knowledge, iriflophenone 2- O- α-L-rhamnopyranoside (1) was first isolated from salvia sp. On biological testing, compound 1 showed strong antiproliferative activity on HL-60 leukemia cells with the IC50 of 8.9 μM; compounds 1 and 3–6 inhibited markedly nitric oxide production in lipopolysaccharide-treated RAW 264.7 cells.

Molecular Docking Studies Of Natural Phenolic Compound and Derivates With Phospholipase A2

The enzyme phospholipase A2 (PLA2) catalyzes the conversion of membrane phospholipids in the inflammatory mediators, such as prostaglandins and leukotrienes. Because of this role, substances with inhibitory activity of PLA2 enzyme, has gained prominence in the scientific community like possible anti-inflammatory. Several studies have shown that phenolic compounds such as flavonoids, phenolic acids and other, has, among various biological activities, anti-inflammatory activity by inhibition of the enzyme PLA2. Based on this context, this study aimed to conduct a molecular docking study of various natural phenolic compounds and some of their derivatives forward to the enzyme PLA2. The crystallographic structure of PLA 2 was obtained from Target Database Protein Data Bank [PDB ID: 1KPM] and the ligands were obtained from PubChem Database. The docking was performed using the AutoDock 4.0 software. It was observed that among the phenolic compounds included in the study, those with better interaction with the enzyme were rosmarinic acid 3'-O-beta-glucoside, 4-nerolidylcatechol, rosmarinic acid methyl ester, quercetin 3-O-malonylglucoside, quercetin pentaacetate and rosmarinic acid, respectively. The present study provides a better understanding of the inhibition of PLA2 by phenolic compounds, which may contribute to the development of new anti-inflammatories. DOI: http://dx.doi.org/10.17807/orbital.v10i6.981

Constituents of Mediterranean Spices Counteracting Vascular Smooth Muscle Cell Proliferation: Identification and Characterization of Rosmarinic Acid Methyl Ester as a Novel Inhibitor.

Aberrant vascular smooth muscle cell (VSMC) proliferation is involved in atherosclerotic plaque formation and restenosis. Mediterranean spices have been reported to confer cardioprotection, but their direct influence on VSMCs has largely not been investigated. This study aims at examining rosmarinic acid (RA) and 11 related constituents for inhibition of VSMC proliferation in vitro, and at characterizing the most promising compound for their mode of action and influence on neointima formation in vivo. RA, rosmarinic acid methyl ester (RAME), and caffeic acid methyl ester inhibit VSMC proliferation in a resazurin conversion assay with IC50 s of 5.79, 3.12, and 6.78µm, respectively. RAME significantly reduced neointima formation in vivo in a mouse femoral artery cuff model. Accordingly, RAME leads to an accumulation of VSMCs in the G0 /G1 cell-cycle phase, as indicated by blunted retinoblastoma protein phosphorylation upon mitogen stimulation and inhibition of cyclin-dependent kinase 2 in vitro. RAME represses PDGF-induced VSMC proliferation in vitro and reduces neointima formation in vivo. These results recommend RAME as an interesting compound with VSMC-inhibiting potential. Future metabolism and pharmacokinetics studies might help to further evaluate the potential relevance of RAME and other spice-derived polyphenolics for vasoprotection.

Nutritional profiles, phenolics, and DNA damage protective effect of Lycopus lucidus Turcz. root at different harvest times

ABSTRACTLycopus lucidus root, harvested from two sites at three different times, was analysed for nutritional profiles; phenolics by HPLC-MS and NMR; enzymatic activity of phenylalanine ammonia-lyase (PAL), tyrosine aminotransferase (TAT), cinnamic acid 4-hydroxylase (C4H), and polyphenol oxidase (PPO); and DNA damage protective effect. The results showed that the moisture first increased and then decreased, and the crude fat and crude fibre increased continuously during the harvesting period. Sucrose and fructose were the predominant sugars with different changing patterns. Linolelaidic, linoleic, palmitic, and stearic acids were the predominant fatty acids. No significant difference was observed of vitamin B2 accompany with an increase of vitamin C with the harvest time delayed among the three harvest times investigated. Caffeic, rosmarinic, and protocatechuic acid; rosmarinic acid methylester; protocatechualdehyde; Danshensu; 3, 4-dihydroxyphenyl caffeate; and N-trans-feruloyl tyramine were identified in L. lucidus root and their variations were discrepant in the period of harvest. There was no significant correlation between phenolics and enzymatic activity except for insoluble cell-wall-bound phenolics (ICP) and C4H, as well as protocatechualdehyde and TAT. The FP exhibited higher DNA damage protective activity than ICP.

Anti-inflammatory activity of caffeic acid derivatives isolated from the roots of Salvia miltiorrhiza Bunge.

Ten caffeic acid derivatives (1-10) were isolated from the roots of Salvia miltiorrhiza by using various chromatographic methods and their chemical structures were spectroscopically elucidated. The absolute configurations of chiral centers were determined by comparison with reported coupling constants, optical rotation values, and CD techniques. Anti-inflammatory activities were evaluated using nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 inhibition assays, and by determining the expression of heme oxygenase (HO)-1. Two new caffeic acid derivatives, 8-epiblechnic acid 9-methyl ester (4) and 8-epiblechnic acid 9'-methyl ester (5), and eight known derivatives, caffeic acid methyl ester (1), shimobashiric acid B (2), rosmarinic acid methyl ester (3), salvianolic acid C (6), methyl salvianolate C (7), lithospermic acid monomethyl ester (8), lithospermic acid dimethyl ester (9), and dimethyl lithospermate B (10), were isolated from the ethyl acetate fraction of S. miltiorrhiza. All caffeic acid derivatives were evaluated for their inhibitory effect on NO production. Compounds 2 and 3 inhibited NO production with IC50 values of 1.4 and 0.6μM, respectively. These compounds also strongly inhibited the production of iNOS and COX-2. In addition, compound 3 induced the expression HO-1 in a concentration-dependent manner at 0.1, 0.3, and 1.0μM.

Antiviral activities of compounds from aerial parts of Salvia plebeia R. Br

Ethnopharmacological relevanceSalvia plebeia R. Br. is an edible plant widely spread in many countries. It has been used as a traditional medicine to treat common cold, flu, cough, hepatitis, hemorrhoids, etc. The purpose of the study is to explicate antiviral compounds responsible for its traditional use for the common cold or flu. Materials and methodsThe methanolic extract of the aerial parts of S. plebeia was extracted with CHCl3, EtOAc, and n-BuOH, successively. The EtOAc and CHCl3 fractions were subjected to a successive of chromatographic method, which led to the isolation of fourteen compounds. Inhibition activities of the isolated compounds were evaluated against influenza A (H1N1) neuraminidase. ResultsChemical investigation of the methanolic extracts of S. plebeia resulted in the isolation of two novel benzoylated monoterpene glycosides, named as plebeiosides A (1) and B (2), together with twelve known compounds including four flavonoids (4–5, 7, 10), two sesquiterpenoids (8, 12), four phenolics (9–10, 13–14), a steroid (6), and a triterpenoid (3). Their chemical structures were elucidated based on spectroscopic data and absolute stereochemistries of 1 and 2 were determined by comparison of optical rotations of their hydrolysates with literature values. Compounds 5, 7, 9, and 11 exhibited potent enzymatic inhibition against H1N1 neuraminidase (IC50 values ranging from 11.18±1.73 to 19.83±2.28μM). Furthermore, two flavonoids (5 and 7) and one rosmarinic acid methyl ester (9) reduced cytopathic effects of the H1N1 virus during replication. ConclusionsThe antiviral activities of the flavonoids and phenolics isolated from the extracts of S. plebeia supported the traditional application of this medicine on common cold or flu. In this study, benzoylated monoterpene glycosides were first found to exist in this species. Moreover, the present study suggested potential of three compounds (5, 7, and 9) to be new lead structures for the development of new neuraminidase inhibitors in the future.

Study of the antioxidant activity of Thymus sibthorpii Bentham (Lamiaceae)

From the aerial parts of Thymus sibthorpii Bentham (Lamiaceae), five flavonoids apigenin (1), 7-methoxy-apigenin (2), naringenin (3), eriodictyol (4) and eriodictyol-7-glucoside (5), have been isolated together with caffeic acid methyl ester (6), rosmarinic acid (7) and rosmarinic acid methyl ester (8). The structures of the isolated compounds were established by spectroscopic methods. The extracts and the isolated compounds were tested for their free radical scavenging activity using the following in vitro assays: (i) interaction with the free stable radical of DPPH (1,1-diphenyl-2-picrylhydrazyl), (ii) inhibition of linoleic acid lipid peroxidation induced by the dihydrochloric acid of 2,2-azobis-2-amidinepropane (AAPH) and (iii) the scavenging activity of enzymatically produced superoxide anion. Their inhibitory activity toward soybean lipoxygenase was evaluated in vitro, using linoleic acid as a substrate. The antioxidant results of the extracts are discussed in terms of their constitution in phenolic compounds, which were determined following the Folin–Ciocalteu method.

Rosmarinic Acid Methyl Ester Inhibits LPS-Induced NO Production via Suppression of MyD88- Dependent and -Independent Pathways and Induction of HO-1 in RAW 264.7 Cells.

In this study, we investigated the anti-inflammatory effect of rosmarinic acid methyl ester (RAME) isolated from a mutant cultivar of Perilla frutescens (L.) Britton. We found that RAME inhibits lipopolysaccharide (LPS)-induced nitric oxide (NO) production, with an IC50 of 14.25 µM, in RAW 264.7 cells. RAME inhibited the LPS-induced expression of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, monocyte chemoattractant protein-1, interferon-β, and inducible nitric oxide synthase (iNOS). Moreover, RAME suppressed the activation of nuclear factor kappa B. These results suggest that the downregulation of iNOS expression by RAME was due to myeloid differentiation primary response gene 88 (MyD88)-dependent and -independent pathways. Furthermore, RAME induced the expression of heme oxygenase-1 (HO-1) through activation of nuclear factor-erythroid 2-related factor 2. Treatment with tin protoporphyrin, an inhibitor of HO-1, reversed the RAME-induced suppression of NO production. Taken together, RAME isolated from P. frutescens inhibited NO production in LPS-treated RAW 264.7 cells through simultaneous induction of HO-1 and inhibition of MyD88-dependent and -independent pathways.

Erratum to: Evaluation of antioxidant potential of ethyl acetate fraction of Rosmarinus officinalis L. and its major components

The solvent fractions of rosemary methanol extract were obtained by successive extraction with n-hexane, chloroform, ethyl acetate, butanol, and water. The ethyl acetate fraction (EAF) contained a remarkable amount of polyphenol and flavonoid as well as high levels of alkyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity. The activity guided fractionation and repeated chromatographic separations over silica gel, RP C18, and Sephadex LH-20 led to isolation of six compounds from the EAF. 1H NMR, 13C NMR, 2D NMR, MS, and IR spectroscopies determined the compounds to be caffeic acid (1), rosmarinic acid (2), rosmarinic acid methyl ester (3), luteolin (4), apigenin (5), and hispidulin (6), and high-performance liquid chromatography quantification was used to determine concentrations in EAF. Among the six isolated compounds, rosmarinic acid methyl ester showed the highest scavenging activities against di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium, alkyl and ABTS radicals. The EAF mixture, but not individual isolated compounds, shielded dermal fibroblast cells from H2O2-induced cytotoxicity at concentrations that encompass the SC50 of alkyl and ABTS radical. Therefore, our findings suggested for the first time that antioxidant capacity of the EAF mixture result in a synergistic effect on the antioxidant action.

Evaluation of antioxidant potential of ethyl acetate fraction of Rosmarinus officinalis L. and its major components

The solvent fractions of rosemary methanol extract were obtained by successive extraction with n-hexane, chloroform, ethyl acetate, butanol, and water. The ethyl acetate fraction (EAF) contained a remarkable amount of polyphenol and flavonoid as well as high levels of alkyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity. The activity guided fractionation and repeated chromatographic separations over silica gel, RP C18, and Sephadex LH-20 led to isolation of six compounds from the EAF. 1H NMR, 13C NMR, 2D NMR, MS, and IR spectroscopies determined the compounds to be caffeic acid (1), rosmarinic acid (2), rosmarinic acid methyl ester (3), luteolin (4), apigenin (5), and hispidulin (6), and high-performance liquid chromatography quantification was used to determine concentrations in EAF. Among the six isolated compounds, rosmarinic acid methyl ester showed the highest scavenging activities against di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium, alkyl and ABTS radicals. The EAF mixture, but not individual isolated compounds, shielded dermal fibroblast cells from H2O2-induced cytotoxicity at concentrations that encompass the SC50 of alkyl and ABTS radical. Therefore, our findings suggested for the first time that antioxidant capacity of the EAF mixture result in a synergistic effect on the antioxidant action.

Lipophilic modification enhances anti-colitic properties of rosmarinic acid by potentiating its HIF-prolyl hydroxylases inhibitory activity

Inhibition of hypoxia inducible factor-prolyl hydroxylase-2 (HPH), leading to activation of hypoxia inducible factor (HIF)-1 is a potential therapeutic strategy for the treatment of colitis. Rosmarinic acid (RA), an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid is a naturally occurring polyphenolic compound with two catechols, a or inhibition of HPH. To improve accessibility of highly hydrophilic RA to HPH, an intracellular target, RA was chemically modified to decrease hydrophilicity. Of the less-hydrophilic derivatives, rosmarinic acid methyl ester (RAME) most potently inhibited HPH. Accordingly, RAME prevented hydroxylation of HIF-1α and consequently stabilized HIF-1α protein in cells. RAME inhibition of HPH and induction of HIF-1α were diminished by elevated doses of the required factors of HPH, 2-ketoglutarate and ascorbate. RAME induction of HIF-1α led to activation of an ulcer healing pathway, HIF-1-vascular endothelial growth factor (VEGF), in human colon carcinoma cells. RAME administered rectally ameliorated TNBS-induced rat colitis and substantially decreased the levels of pro-inflammatory mediators in the inflamed colonic tissue. In parallel with the cellular effects of RAME, RAME up-regulated HIF-1α and VEGF in the inflamed colonic tissue. Thus, lipophilic modification of RA improves its ability to inhibit HPH, leading to activation of the HIF-1-VEGF pathway. RAME, a lipophilic RA derivative, may exert anti-colitic effects via activation of the ulcer healing pathway.

Structural characterisation and antioxidant activity evaluation of phenolic compounds from cold-pressed Perilla frutescens var. arguta seed flour

A total of 11 phenolic compounds, as well as sucrose (12) and tryptophan (13), were isolated from cold-pressed Perilla frutescens var. arguta seed flour using column chromatography, and their chemical structures were identified as 3′-dehydroxyl-rosmarinic acid-3-o-glucoside (1), rosmarinic acid-3-o-glucoside (2), rosmarinic acid (3), rosmarinic acid methyl ester (4), luteolin (5), luteolin-5-o-glucoside (6), apigenin (7), caffeic acid (8), caffeic acid-3-o-glucoside (9), vanillic acid (10) and cimidahurinine (11) using NMR and time-of-flight mass spectrometry. Of these components, compound 1 is novel, and this is the first report of compounds 10 and 11 in perilla seeds. HPLC quantification combined with antioxidant activity evaluation revealed that rosmarinic acid and rosmarinic acid-3-o-glucoside were the dominant phenolic antioxidants with strong antioxidant activities.