Roots Of Rubia Cordifolia Research Articles

Rubia-Inspired biogenic Synthesis of Cu-ZnO Nanocomposites: Dual-modelling of visible light Photocatalytic Degradation and Antibacterial Assessment

Cu-doped ZnO nanoparticles (NPs) were synthesised using Rubia cordifolia root extract and their photocatalytic degradation and antimicrobial properties were evaluated. Among all dopant concentrations, UV-VIS analysis of 5% Cu-ZnO NPs revealed a clean shift towards the visible range with a reduction in the band gap from 3.2 eV for pristine ZnO to 2.98 eV. Formed NPs were identified as wurtzite crystal structure (size of 16.67 nm) having a functional group of ZnO, using XRD and FTIR analysis. Highest photocatalytic degradation efficiencies of both Alizarine Red (AZ) (80%) and Rhodamine B (RhB) (82%) dyes were by 5% Cu-ZnO NPs. Statistical modelling and optimization were conducted using Response Surface Methodology (RSM) and Adaptive Neuro-Fuzzy Inference System (ANFIS), resulting in development of models having >90% predictive accuracy. Furthermore, the biogenic Cu-ZnO nanoparticles exhibits effective antimicrobial properties against both gram-positive (S. aureus) and gram-negative (E. coli) bacteria. The biogenic synthesis approach demonstrated enhanced photocatalytic efficiency and antimicrobial properties, suggesting its potential for environmentally friendly applications.

Structures of bicyclic hexapeptides RA-XXVII and RA-XXVIII from Rubia cordifolia L.

Two bicyclic hexapeptides RA-XXVII and RA-XXVIII, featuring a phenylpropanoid unit attached to the aromatic ring of the Tyr-6 residue of deoxybouvardin, were isolated from the roots of Rubia cordifolia L. Their structures were determined on the basis of spectroscopic data and X-ray crystallography of the 4-O-methyl derivative of RA-XXVII, and the semisynthesis from deoxybouvardin and coniferyl alcohol. RA-XXVII and RA-XXVIII exhibited cytotoxic activity with IC50 values of 0.051 and 0.18 μM, respectively, against the HL-60 cell line, and 0.18 and 0.78 μM, respectively, against the HCT-116 cell line.

Effects of geographical, soil and climatic factors on the two marker secondary metabolites contents in the roots of Rubia cordifolia L.

The growth and quality of medicinal plants depend heavily on environmental variables. The quality of Rubia cordifolia, an important medicinal plant, is determined by the two main secondary metabolites of the root, purpurin and mollugin. However, their relationship with environmental factors has not been studied. In this study, the purpurin and mollugin contents of R. cordifolia roots from different sampling sites in China were measured using ultra-high-performance liquid chromatography, and the correlations between the two secondary metabolites and environmental variables were analyzed. The results showed that there were significant differences in the contents of purpurin and mollugin in the roots of R. cordifolia at different sampling points. The content of purpurin ranged from 0.00 to 3.03 mg g-1, while the content of mollugin ranged from 0.03 to 10.09 mg g-1. The quality of R. cordifolia in Shanxi, Shaanxi and Henan border areas and southeastern Liaoning was higher. Liaoning is expected to become a R. cordifolia planting area in Northeast China. Correlation and regression analysis revealed that the two secondary metabolites were affected by different environmental factors, the two secondary metabolites contents were positively correlated with longitude and latitude, and negatively correlated with soil nutrients. In addition, higher temperature and shorter sunshine duration facilitated the synthesis of purpurin. Annual precipitation might be the main factor limiting the quality of R. cordifolia because it had opposite effects on the synthesis of two major secondary metabolites. Therefore, this study is of great significance for the selection of R. cordifolia planting areas and the improvement of field planting quality.

Optimization of conditions to achieve a high content of alizarin and purpurin in the adventitious roots of Rubia cordifolia L.

Rubia cordifolia L. (Indian madder) is a valuable medicinal plant known for its natural dye content, notably alizarin and purpurin, with applications in textiles and cosmetics. This study aims to optimize the concentrations of auxin, salicylic acid, elicitors, and precursors to maximize the production of alizarin and purpurin in adventitious roots. Various concentrations and combinations of auxins were systematically tested to explore their effects on the yield of adventitious root formation and dye compounds. Nodal explants cultivated in MS media supplemented with IAA + IBA + NAA (1.5 + 0.5 + 0.75 mg/L) at a pH of 5.7 exhibited the highest adventitious root production. Post-establishment of root cultures, the impact of salicylic acid, L-phenylalanine, elicitors (yeast extract, pectin, and Xylan), and the precursor α-ketoglutaric acid on the production of anthraquinones (AQ) was evaluated. High-performance liquid Chromatography (HPLC) analysis revealed enriched alizarin, purpurin, and total AQ content. The maximum amount of AQ (64.65 mg/g), alizarin (17.59 mg/g), and purpurin (19.61 mg/g) was observed when cultured on 30 mg/L of α-ketoglutaric acid, compared to other elicitors and precursors. This optimized condition provides valuable insights for the sustainable cultivation and utilization of R. cordifolia as a prominent source of natural dyes. It offers practical implications for the dye industry and its production.

Rubia cordifolia L. Attenuates Diabetic Neuropathy by Inhibiting Apoptosis and Oxidative Stress in Rats.

Diabetic neuropathy is a debilitating manifestation of long-term diabetes mellitus. The present study explored the effects of the roots of Rubia cordifolia L. (R. cordifolia L.) in the Wistar rat model for diabetic neuropathy and possible neuroprotective, antidiabetic, and analgesic mechanisms underlying this effect. Rats were divided into five experimental groups. An amount of 0.25% carboxy methyl cellulose (CMC) in saline and streptozotocin (STZ) (60 mg/kg) was given to group 1 and group 2, respectively. Group 3 was treated with STZ and glibenclamide simultaneously while groups 4 and 5 were simultaneously treated with STZ and hydroalcoholic extract of the root of R. cordifolia, respectively. Hot plate and cold allodynias were used to evaluate the pain threshold. The antioxidant effects of R. cordifolia were assessed by measuring Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). At the end of the study, sciatic nerve and brain tissues were collected for histopathological study. Bcl-2 proteins, cleaved caspase-3, and Bax were assessed through the Western blot method. R. cordifolia significantly attenuated paw withdrawal and tail flick latency in diabetic neuropathic rats. R. cordifolia significantly (p < 0.01) improved the levels of oxidative stress. It was found to decrease blood glucose levels and to increase animal weight in R. cordifolia-treated groups. Treatment with R. cordifolia suppressed the cleaved caspase-3 and reduced the Bax:Bcl2 ratio in sciatic nerve and brain tissue compared to the diabetic group. Histopathological analysis also revealed a marked improvement in architecture and loss of axons in brain and sciatic nerve tissues at a higher dose of R. cordifolia (400 mg/kg). R. cordifolia attenuated diabetic neuropathy through its antidiabetic and analgesic properties by ameliorating apoptosis and oxidative stress.

Biogenic synthesis of ZnO from Rubia cordifolia root extract: A study on sono-photocatalytic dye degradation and anti-bacterial assay

ZnO is a semiconductor metal oxide with unique antibacterial and photocatalytic properties. Green synthesis of nanoparticle is environmentally friendly procedure, imparting multiple properties to the nanoparticles (NPs). This study reports Rubia cordifolia root extract mediated ZnO NP synthesis. Synthesised NPs were analysed for antibacterial properties and sonication assisted photocatalytic dye degradation experiments were performed. Synthesised ZnO NPs were characterized employing UV-VIS spectroscopy, X-Ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) followed by energy dispersive X-ray spectroscopy (EDX) analysis and was compared with commercial grade ZnO. UV-VIS adsorption peak of NPs was found at 375 nm with a bandgap of 3.2 eV. The NPs reveals to have a crystalline size of 17.54 nm with a hexagonal wurtzite structure and clustered flakes with rose petal morphology were identified through XRD and SEM analysis respectively. The green ZnO possesses good antibacterial properties against both gram positive (Staphyllococcus aureus) and gram negative bacteria (E.coli). Study on the effectiveness of synthesised ZnO for ultrasound sonication-assisted photocatalysis over normal photocatalytic degradation were carried out through response surface methodology with face central composite design. The regression models (R2adj > 90 % and R2pred > 90 %) were confirmed by analysis of variance (ANOVA), and optimization was performed. The green ZnO nanoparticle was capable of degrading alizarine red up to 92.89 % and rhodamine B up to 89.95 % under optimal conditions and were also compared with commercial ZnO NPs. Reusability of the photocatalyst was confirmed by conducting 4 cycles of experiments at optimum condition.

On the Role of ROS and Glutathione in the Mode of Action Underlying Nrf2 Activation by the Hydroxyanthraquinone Purpurin.

Purpurin is a major anthraquinone present in the roots of Rubia cordifolia (madder). Purpurin is known to activate Nrf2 (Nuclear transcription factor erythroid 2-related factor 2) EpRE (electrophile responsive element) mediated gene expression as a potential beneficial effect. This study aimed to elucidate the balance between the electrophilicity or pro-oxidant activity of purpurin underlying the Nrf2 induction. For this, Nrf2 activation with modified intracellular glutathione (GSH) levels was measured in an Nrf2 CALUX reporter gene assay. In addition, both cell-free and intracellular ROS formation of purpurin with modified (intracellular) GSH levels at different pH were quantified using the DCF-DA assay. GSH adduct formation was evaluated by UPLC and LC-TOF-MS analysis. GSH and GSSG levels following purpurin incubations were quantified by LC-MS/MS. We show that Nrf2 induction by purpurin was significantly increased in cells with buthionine sulfoximine depleted GSH levels, while Nrf2 induction was decreased upon incubation of the cells with N-acetylcysteine being a precursor of GSH. In cell-free incubations, ROS formation increased with increasing pH pointing at a role for the deprotonated form of purpurin. Upon incubations of purpurin with GSH at physiological pH, GSH adduct formation appeared negligible (<1.5% of the added purpurin). The addition of GSH resulted in conversion of GSH to GSSG and significantly reduced the ROS formation. Together these results demonstrate that Nrf2 induction by purpurin originates from intracellular ROS formation and not from its electrophilicity, which becomes especially relevant when intracellular GSH levels can no longer scavenge the ROS. The present study demonstrated that the efficiency of intracellular Nrf2 activation by purpurin and related anthraquinones will depend on (i) their pKa and level of deprotonation at the intracellular pH, (ii) the oxidation potential of their deprotonated form and (iii) the intracellular GSH levels. Thus, the Nrf2 induction by purpurin depends on its pro-oxidant activity and not on its electrophilicity.

Formulation and Evaluation of an Anti-inflammatory Topical Polyherbal Gel

Inflammation is currently treated with NSAIDs. Unfortunately, these drugs increase the risk of blood clots, heart attacks, and strokes. Therefore, the development of potent anti-inflammatory drugs from natural products is currently being investigated. Natural products made from medicinal plants play an important role in curing many diseases associated with inflammation. Conventional anti-inflammatory drug available in the market has various side effects. Because of these side effects, there is a need to look for newer drugs with fewer or no side effects. The objective of the present study was to develop polyherbal gel containing hydroalcoholic extract of Berberis aristata root, Rubia cordifolia root and Boswellia serrata gum by using Carbopol 934 and Propylene glycol. The 32 factorial design was constructed using concentration of polymer (carbopol 934) and penetration enhancer (Propylene glycol) as independent variables while Viscosity (m.Pas), % in vitro release of Berberine, Rubiadin and AKBA as dependent variables, total 9 possible experimental runs formulate and evaluate. The optimized gel was selected by design of expert employing the overlay plot with desirability approach. Optimized gel showed 39568 m.Pas viscosity, drug content of Berberine 0.48 mg, Rubiadin 0.42 mg and AKBA 0.51 mg. In vivo and histopathology study revealed that prepared gel showed good anti-inflammatory activity.

Functionalization of silk with chitosan and Rubia cordifolia L. dye extract for enhanced antimicrobial and ultraviolet protective properties

Natural dyes have attained the interest of scientists over the last decade due to their functional activities in addition to their primary role of color impartation on textile materials. This study is the first report on the functionalization of silk with antimicrobial and ultraviolet protective properties using a dye extract from the roots of Rubia cordifolia L. in conjunction with chitosan as a bio-mordant. Alum mordant was also used in the dyeing process alongside chitosan for comparison purposes. Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were utilized to determine the anthraquinone-based components of the dye extract. Furthermore, the structure and surface morphology of silk fibers before and after dyeing were investigated. The dyed silk samples exhibited good fastness against washing, rubbing, and lighting. The chitosan mordanted-dyed silk presented remarkable antimicrobial properties with maximum inhibitions of 96.71% and 99.08% against Escherichia coli and Staphylococcus aureus, respectively, and only 2.3% spore germination of white mold ( Aspergillus spp.). Likewise, an excellent ultraviolet protection factor was achieved in the chitosan modified-dyed silk. The findings of this study demonstrated the potential of the Rubia cordifolia L. extract as a functional dye, as well as the advanced properties of chitosan in increasing the fastness and functional performance for the dyed silk compared to alum mordant.

Evaluation of antidepressant properties of ethanolic extract of root of in Swiss albino mice

Mental health has always been given a prime importance along with physical health by the World Health Organization (WHO). Depression contributes to significant disease burden at global level and is ranked by WHO as the single largest contributor to global disability. Oxidative stress plays an important role in the pathogenesis of many neurological conditions such as depression. is known to possess antioxidant properties; hence, this study has been conducted to evaluate the antidepressant activity of Rubia cordifolia root extract in rodent models. Ethanolic extract of root powder (EERC) was used for evaluating the antidepressant activity in Swiss albino mice. EERC was used in two doses – 50 mg/kg and 100 mg/kg. Antidepressant activity was evaluated by performing Forced swim test and Tail suspension test with Imipramine (10mg/kg) as the standard drug. The data was analyzed using one way ANOVA (analysis of variance) followed by Tukey Krammer test. P value &amp;#60;0.05 was considered as statistically significant. Forced swim test and tail suspension test showed significant decrease in the period of immobility by EERC treated groups indicating its antidepressant property. There is no significant difference observed between the two doses of the extract i.e.; 50 mg/kg and 100 mg/kg (inter-group comparison). The period of immobility and period of mobility were not significantly different from the standard group. This study shows that ethanolic extract of root powder possess significant antidepressant properties. However, this is just a preliminary study. Further studies have to be carried out to find out the exact mechanism responsible for antidepressant activity by isolating the active constituents and performing neurotransmitter studies.

Alizarin as a New Activator of the Aryl Hydrocarbon Receptor Signaling Pathway

Alizarin (1,2-dihydroxyanthraquinone) is a natural red dye extracted from the roots of Rubia cordifolia L. (family Rubiaceae). Alizarin has been used as a biological red stain for calcium. The aryl hydrocarbon receptor (AhR) has critical roles in multiple physiological pathways. This study aimed to determine whether alizarin is an unreported ligand of AhR. In the present study, we investigated the effects on cytochrome P450 (CYP) 1A1 mRNA, protein expression, AhR nuclear translocation, aryl hydrocarbon response element (AHRE) reporter activity, and AhR-specific antagonist following alizarin treatment of cells of the human hepatoma cell line, HepG2, and murine hepatoma cell line, Hepa-1c1c7. Alizarin induced CYP1A1 mRNA and protein expression in HepG2 and Hep-1c1c7 cells. Such induction was not present in C4 (B13NBii1) cells, which are AhR signal deficient, C12 (B15ECiii2) cells, which reduce AhR protein levels. The alizarin-induced responses were blocked by CH-223191, which is an AhR antagonist. Alizarin, the same as with the AhR ligand, induced the nuclear localization of AhR, as well as stimulated the transcriptional activity of AHRE. The results of this study suggest that alizarin is an AhR agonist.

Purpurin ameliorates alcohol-induced hepatotoxicity by reducing ROS generation and promoting Nrf2 expression

Introduction and aimPurpurin, a naturally occurring anthraquinone isolated from the roots of Rubia cordifolia, exhibits anti-cancer, anti-genotoxic, anti-microbial, neuromodulatory and photodynamic activity. However, purpurin's in vivo and in vitro antioxidant mechanism remains unexplored. The present study explores the anti-oxidative mechanism of purpurin under the influence of alcohol using in vivo and in vitro test systems. MethodsMice hepatocytes and alcohol-induced liver toxicity model were used to evaluate the effect of purpurin. The non-enzymatic and enzymatic oxidative stress markers were estimated by the colorimetric method. The reactive oxygen species (ROS) were quantified in mitochondria and cells using flow cytometer. Real-time PCR and western blotting were used to quantify cytochrome 450 subtype 2E1 (CYP2E1) and Nrf2 expression in the liver tissue of mice. In silico studies were performed through receptor-ligand binding interaction. Key findingsPurpurin effectively reduced total cellular and mitochondrial ROS in primary hepatocytes and WRL-68 cells. It prevented alcohol-induced ROS-dependent biochemical and cellular insults observed by analysing the serum glutamic pyruvic transaminase (SGPT), glutamic-oxaloacetic transaminase (SGOT) levels and CYP2E1 expression in liver tissue of alcohol-administered mice. Moreover, it also restored the activity of antioxidant enzymes. Its antioxidant effect was established by glutathione and ROS-dependent mechanisms using buthionine sulfoximine and N-acetyl cysteine. Along with alcohol, purpurin up-regulated Nrf2 expression in hepatocytes. SignificanceThis work confirmed the ameliorative effect of purpurin for alcohol-induced hepatotoxicity by drabbing free radicals and curbing oxidative stress via activation of antioxidant signalling pathways.

Rubia cordifolia (Manjishtha): A review based upon its Ayurvedic and Medicinal uses

Medicinal herbs have a rich history of their utilization for variety of ailments. India is categorized among those countries which have produced vast variety of medicinal plants. India is also called as “Botanical garden of the world”. Medicinal plants are the source of discovery of new drugs across the world. Most of the drugs available today have some herbal content of plants in them. Rubia Cordifolia (Manjishtha) is a climber herb having small flowers of greenish white colour which are grouped around the purplish fleshy fruits. The roots of Rubia cordifolia imparts red colour from where dye is obtained which is due to the presence of brownish red bark. This plant is mainly cultivated in the hilly areas. Manjishtha has a very significant place in Ayurveda which is one of the most ancient health care systems of the world. Charaka categorized this medicinal herb as varnya (for the enhancement of skin complexion), jvarahara (anti-pyretic), visaghna (a detoxifier) and a rasayana (rejuvenator). While it is categorized as pittasamsamana (one which maintains the pitta dosha of the body i.e. the fire component of the body) by Acharya Sushrut. Manjishtha has potential to pacifiy the pitta dosha. The phytochemical constituents of Rubia Cordifolia (Manjishtha) are associated with wide range of therapeutic properties. In this review, summary of its phytochemistry, its uses in different medicinal systems like Ayurveda and folk system and its scientific therapeutic properties are reported.

Chemical constituents from Melodinus cochinchinensis (Lour.) Merr. and their chemotaxonomic significance

A phytochemical investigation on the twigs and leaves of Melodinus cochinchinensis (Lour.) Merr. resulted in the isolation and identification of 22 compounds, including seven sesamin-type lignans (1–7), three pentacyclic triterpenes (8–10), one anthraquinone (11), one flavanone (12), two phenolic compounds (13 and 14), five aspidosperma-type indole alkaloids (15–19), and three eburnan-type indole alkaloids (20–22). The structures of these compounds were elucidated by means of spectroscopic analysis, including HREIMS together with 1D and 2D NMR experiments, and comparison with reported data. Among them, compounds 1/4, 2/5, and 3/6 are three pairs epimers at C-7''. Compounds 1–6, 8 and 11 were firstly isolated from the family Apocynaceae, whereas 17 was isolated from Melodinus species for the first time. Compound 8 was only found in Juglans hopeiensis, while 11 was only found in roots of Rubia cordifolia. Compounds 1–6, 8, 11 and 15–22 could be considered as chemotaxonomic markers for M. cochinchinensis. Furthermore, the chemotaxonomic significance and distribution of these isolates in Melodinus genus are discussed in detail.

Purpurin: A natural anthraquinone with multifaceted pharmacological activities.

Purpurin is a naturally occurring anthraquinone isolated from the roots of Rubia cordifolia. Historically, it has been used as a red dye. However, its photosensitizing property and biological effects have deciphered its novel application. Purpurin shows antigenotoxic, anticancer, neuromodulatory, and antimicrobial potential associated with antioxidant action in in vivo and in vitro experiments. A robust antioxidant nature of purpurin is responsible for the majority of its pharmacological effects. It produces anti-inflammatory activity by reducing oxidative stress, which is a fundamental property to target diseases involving endoplasmic reticulum and mitochondrial stress. It can cross the blood-brain barrier and produce neuroprotective effects, including antidepressant and anti-Alzheimer action. It shows antimutagenic property via inhibiting essential CYP-450 enzymes. Interestingly, it gets photosensitized by UV-light and produces target-specific ROS-dependent apoptosis in cancer cells. Therefore, it owns cell killing and cell survival potential subject to the influence of external conditions. Hitherto, limited research studies are performed with purpurin to understand its therapeutic potential. Hence, this review describes and discusses different in vivo, in vitro, and in silico studies performed using purpurin. It also covers physicochemical, pharmacokinetics, and toxicology aspects of purpurin. Moreover, in the end, the prospect of purpurin in the management of cancer has also been proposed.

Revealing the mechanisms and the material basis of Rubia cordifolia L. on abnormal uterine bleeding with uniting simultaneous determination of four components and systematic pharmacology approach-experimental validation

The roots of Rubia cordifolia L. (RCL) have become an important medicine for abnormal uterine bleeding (AUB) and hemorrhage syndrome in Traditional Asian medicine. However, the underlying mechanism and the material basis of RCL for treating AUB has not been fully elucidated. In this study, quantitative evaluation of quinones, systematic pharmacology and experimental verification were adopted. Firstly, the Disease-Ingredient-Target network was established by Cytoscape, which was consistent with 23 compounds and 47 target genes. The hub targets were discovered by Maximal Clique Centrality (MCC) method with Cytohubba plugins of Cytoscape, and top 20 nodes were ranked by MCC. It was assumed that mollugin is the main ingredient of RCL for treating AUB. Pathways on which RCL acted were obtained from observation of its biological functions, KEGG pathways and Reactome pathway enrichment analysis. The possible mechanism of RCL for treating AUB was revealed for improvment of the blood clotting system, blood circulation, arachidonic acid metabolism and inflammation. Then, a novel method for evaluating the quality of RCL was established, and the content of mollugin in RCL was the higher than others. Finally, pharmacologic experiments confirmed that RCL could improve the inflammation by inhibiting the activity of COX-2 and cPLA2 enzyme, ameliorate blood hypercoagulability by affecting coagulation cascade and fibrinolytic system. It was found that RCL inhibited the expression COX-2 and PAI-1 by reducing HIF-1α expression. The trend of each index of mollugin was consistent with that of RCL, indicating that it played an important role in RCL for treating AUB. The above results could provide a novel method for the quality evaluation of RCL and was expected to give us more important information regarding the use of RCL as a promising drug candidate for AUB, offering a fertility preserving medical, non-hormonal treatment choose for women with AUB.

Development of A Method of Quantitative Determination of Rhizome and Roots of Rubia cordifolium

This paper discusses the current aspects of improving the standardization method of medicinal plant raw materials of Rubia cordifolia L. New approaches for quantitative analysis of rhizome with roots of Rubia cordifolia were introduced, which consist in using of the method of Spectrophotometry at an analytical wavelength of 520 nm and the use of ultrasound for the maximum output of anthracen derivatives from raw materials. At present, the basis of the technology for extracting of medicinal substances from animal and plant tissues is most often the inefficient and lengthy process of extraction. Low-frequency ultrasound significantly reduces the extraction time. During the passage of ultrasound through a molecule, its light part will oscillate in resonance with the frequency of the wave, and the heavy part will lag behind. As a result, there will be zones of tension, considerable friction forces, superior to the forces of chemical bonding, a rupture of the whole substance molecule will occur. This topic is relevant today, as the development and application of ultrasound technology now opens up new perspectives. Using the improved technique, we found that the content of the total anthracen derivatives in samples of medicinal plant raw materials of Rubia tinctorum varies from 0, 56% to 1, 37% (calculated on ruberythric acid).The results indicate the maximum yield of anthracen derivatives from medicinal plant raw materials of Rubia cordifolia and the feasibility of further research in the development of new drugs.

RA-XXV and RA-XXVI, Bicyclic Hexapeptides from Rubia cordifolia L.: Structure, Synthesis, and Conformation.

Two RA-series bicyclic hexapeptides, RA-XXV (4) and RA-XXVI (5), which have no N-methyl group at Tyr-5, were isolated from the roots of Rubia cordifolia L. Their amino acid compositions and sequences were determined by interpretation of MS, and 1D and 2D NMR data and their relative structures were elucidated by XRD analysis of 4 and RA-XXVI acetate (6). The absolute stereochemistry of 4 was established by the total synthesis of 4, and that of 5, by the chemical correlation with 4. Peptides 4 and 5 exhibited cytotoxicity toward human promyelocytic leukemia HL-60 (IC50 =0.062 and 0.066 μm, respectively) and human colonic carcinoma HCT-116 (IC50 =0.028 and 0.051 μm, respectively) cell lines. Analysis of the conformational structures of 4 and 6 in the crystalline state and those of 4 and 5 in solution revealed that the N-methyl group at Tyr-5 functions to make this series of peptides preferentially adopt the active conformation.

Mollugin Has an Anti-Cancer Therapeutic Effect by Inhibiting TNF-α-Induced NF-κB Activation.

The NF-κB signaling pathway plays a pivotal role in regulating the immune response and inflammation. However, it has been shown that NF-κB also has a major role in oncogenesis. Therefore, NF-κB inhibitors have been considered as potential drugs against cancer. Herein, we searched for NF-κB inhibitors from natural sources and identified mollugin from the roots of Rubia cordifolia L. as an inhibitor of NF-κB activation. We found that mollugin significantly inhibited the expression of an NF-κB reporter gene induced by tumor necrosis factor (TNF)-α in a dose-dependent manner. Moreover, mollugin inhibited TNF-α-induced phosphorylation and nuclear translocation of p65, phosphorylation and degradation of inhibitor of κB (IκBα), and IκB kinase (IKK) phosphorylation. Furthermore, we discovered that pretreatment of cells with mollugin prevented the TNF-α-induced expression of NF-κB target genes, such as genes related to proliferation (COX-2, Cyclin D1 and c-Myc), anti-apoptosis (Bcl-2, cIAP-1 and survivin), invasion (MMP-9 and ICAM-1), and angiogenesis (VEGF). We also demonstrated that mollugin potentiated TNF-α-induced apoptosis and inhibited proliferation of HeLa cells. We further demonstrated in vivo that mollugin suppressed the growth of tumor xenografts derived from HeLa cells. Taken together, mollugin may be a valuable candidate for cancer treatment by targeting NF-κB.

Anti-inflammatory action of 2-carbomethoxy-2,3-epoxy-3-prenyl-1,4-naphthoquinone (CMEP-NQ) suppresses both the MyD88-dependent and TRIF-dependent pathways of TLR4 signaling in LPS-stimulated RAW264.7 cells

Ethnopharmacological relevanceThe roots of Rubia cordifolia L. have been widely used as a traditional herbal medicine in Northeast Asia for treating inflammatory diseases. Aim of the studyTo elucidate the anti-inflammatory mechanism of 2-carbomethoxy-2,3-epoxy-3- prenyl-1,4-naphthoquinone (CMEP-NQ), purified from the roots of R. cordifolia L. as the major anti-inflammatory component, in LPS-treated RAW264.7 murine macrophage cells. Materials and methodsAnti-inflammatory activity of CMEP-NQ was investigated in LPS-treated RAW264.7 cells by measuring the levels of NO, PGE2, and cytokines (IL1β, IL-6, TNF-α) in the culture supernatants and the TLR4-mediated intracellular events including association of MyD88 with IRAK1, activation of IRAK1, TAK1, MAPKs, NF-κB/AP-1, and IRF3, and generation of ROS. ResultsPretreatment of RAW264.7 cells with CMEP-NQ reduced LPS-induced production of NO and PGE2 by suppressing iNOS and COX-2 gene expression. CMEP-NQ also reduced the secretion of IL-1β, IL-6, and TNF-α by down-regulating mRNA levels. Under these conditions, TLR4-mediated MyD88-dependent events were inhibited by CMEP-NQ, including the association of MyD88 with IRAK1, phosphorylation of IRAK1, TAK1, and MAPKs (ERK, JNK and p38 MAPK), and activation of NF-κB and AP-1. As TRIF-dependent events of TLR4 signaling, phosphorylation of IRF3 and induction of iNOS protein expression were also inhibited by CMEP-NQ. However, the binding of FITC-conjugated LPS to cell surface TLR4 was not affected by CMEP-NQ. Following LPS stimulation, intracellular ROS production was first detected by DCFH-DA staining at 1h; then it continuously increased until 16h. Although CMEP-NQ failed to exhibit DPPH radical- or ABTS radical-scavenging activity in vitro, LPS-induced ROS production in RAW264.7 cells was more efficiently blocked by CMEP-NQ than by NAC. ConclusionsThese results demonstrate that the suppressive effect of CMEP-NQ on LPS-induced inflammatory responses in RAW264.7 cells was mainly exerted via its inhibition of TLR4-mediated proximal events, such as MyD88-dependent NF-κB/AP-1 activation and ROS production, and TRIF-dependent IRF3 activation.