Positive Control Quercetin Research Articles

Novel lignans from Syringa pinnatifolia and protective effect against H2O2-induced oxidative injury through regulating the expression of Nrf2/HO-1 in H9c2 cells

Phytochemical analysis of the peeled stems of Syringa pinnatifolia Hemsl. led to the discovery of 13 undescribed lignans, namely helanols A and B (1 and 2) and alashanenols W–G1 (3–13), as well as four known analogues, of which helanols A and B were lignans with novel skeleton of α-β′ linkage. The structures were unambiguously established by extensive spectroscopic analyses, NMR calculations, ECD calculations, and single crystal X-ray crystallography. Five lignans (1, 2, 5, 11 and 13) exhibited a moderate protective effect against H2O2-induced oxidative injuries in H9c2 cells with the protective rates of 11.3–20.6 % at the concentration of 0.3–20 μM, while the positive control quercetin showed protective rates of 58.7 % at 10 μM. Further mechanism investigation suggested that 1 and 2 exerted the protective effect by regulating the expression of Nrf2/HO-1.

Anti-Inflammatory Effect of Xanthones from Hypericum beanii on Macrophage RAW 264.7 Cells through Reduced NO Production and TNF-α, IL-1β, IL-6, and COX-2 Expression.

Hypericum beanii N. Robson, a perennial upright herb, predominantly inhabits temperate regions. This species has been utilized for the treatment of various inflammation-related diseases. One new xanthone 3,7-dihydroxy-1,6-dimethoxyxanthone (1) and twenty-three known xanthones (2-24) were isolated from the aerial parts of H. beanii. The structure of the new compound was determined based on high-resolution electrospray ionization mass spectroscopy (HR-ESIMS), nuclear magnetic resonance (NMR), Infrared Spectroscopy (IR), ultraviolet spectrophotometry (UV) spectroscopic data. The anti-inflammatory effects of all the isolates were assessed by measuring the inhibitory effect on nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. Compounds 3,4-dihydroxy-2-methoxyxanthone (15), 1,3,5,6-tetrahydroxyxanthone (19), and 1,3,6,7-tetrahydroxyxanthone (22) exhibited significant anti-inflammatory effects at a concentration of 10 μM with higher potency compared to the positive control quercetin. Furthermore, compounds 15, 19, and 22 reduced inducible NO synthase (iNOS), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, and cyclooxygenase 2 (COX-2) mRNA expression in the LPS-stimulated RAW 264.7 macrophages, suggesting that these compounds may mitigate the synthesis of the aforementioned molecules at the transcriptional level, provisionally confirming their anti-inflammatory efficacy.

Mauritone A, a new polyketide from a fungal-bacterial symbiont Aspergillus spelaeus GXIMD 04541/Sphingomonas echinoides GXIMD 04532

A new polyketide, mauritone A (1) with six known polyketides curvulone B (2), curvularin (3), 12-oxocurvularin (4), (10E,15S)-10,11-dehydrocurvularin (5), (11R,15S)-11-hydroxycurvularin (6), and (11S,15S)-11-hydroxycurvularin (7) were isolated from the fungal-bacterial symbiont Aspergillus spelaeus GXIMD 04541/Sphingomonas echinoides GXIMD 04532 derived from Mauritia arabica. Their structures were elucidated by extensive spectral analysis. All compounds (1-7) were evaluated for their anti-inflammatory effects. The inhibitory effects of 4, 5, and 7 on nitric oxide (NO) production were found to be significant, with IC50 values of 5.5 ± 0.26, 2.0 ± 0.31, and 8.3 ± 0.62 μM, respectively, surpassing that of the positive control quercetin (10.6 ± 0.64 μM). Compounds 3 and 6 exhibited moderate inhibition of NO, with IC50 values of 18.6 ± 0.53 and 12.7 ± 0.45 μM, respectively.

Abietane Diterpenes from Medusantha martiusii and Their Anti-Neuroinflammatory Activity.

Seven new abietane diterpenoids, comprising medusanthol A-G (1-3, 5, 7-9) and two previously identified analogs (4 and 6), were isolated from the hexane extract of the aerial parts of Medusantha martiusii. The structures of the compounds were elucidated by HRESIMS, 1D/2D NMR spectroscopic data, IR spectroscopy, NMR calculations with DP4+ probability analysis, and ECD calculations. The anti-neuroinflammatory potential of compounds 1-7 was evaluated by determining their ability to inhibit the production of nitric oxide (NO) and the proinflammatory cytokine TNF-α in BV2 microglia stimulated with LPS and IFN-γ. Compounds 1-4 and 7 exhibited decreased NO levels at a concentration of 12.5 µM. Compound 1 demonstrated strong activity with an IC50 of 3.12 µM, and compound 2 had an IC50 of 15.53 µM; both compounds effectively reduced NO levels compared to the positive control quercetin (IC50 11.8 µM). Additionally, both compounds significantly decreased TNF-α levels, indicating their potential as promising anti-neuroinflammatory agents.

The antioxidant and anticancer activity of Quercus coccifera plant leaves extracts

Quercus species are one of the medicinal plants that commonly used in the treatment of different diseases. Quercus coccifera (Q. coccifera) is part of the Quercus species which grow in Jordan and used in traditional folklore medicine. The aim of this study is to confirm the ability of (Q. coccifera) leaves extracts to exert anticancer activity.In this study, an extraction method of the dried-leaves using different polarity solvents was used. Extracts were pre-evaluated for antioxidant and anticancer activities while active extracts were used to measure half maximal effective concentration (EC50) against 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and Half-maximal inhibitory concentration (IC50) against cancer cells.Methanol, boiled and microwaved water extracts had greater than 80 % antioxidant activity, and the strongest activity, of more than 99 %, was boiled water extract. Similarly, the pre-evaluation treatments of cancer cell lines indicated a strong biological activity of more than 70 % from the previously mentioned extracts, and the highest activity, of greater than 90 %, was from boiled water extracts against all cancer cell lines. The highest EC50 against DPPH was obtained by using 0.009 mg/ml boiled water extracts, which was lower than positive control quercetin. In the same manner, lung, breast, and prostate cancer cell lines were highly affected by boiled water extracts with IC50 of 14.1, 7.2, and 25.1 µg/ml, respectively, and a selectivity index (SI) of greater than 4.71.Q. coccifera leaves extracts show promising ability to be a source of a new anticancer therapeutics.

The evaluations of the inhibition of orlistat on Clostridium perfringens sialidase (NanI) activity by in vitro and in silico approaches.

Clostridium perfringens (C. perfringens) is a bacterium that causes serious problems in humans and animals such as food poisoning, gas gangrene and infections. C. perfringens has three sialidases (NanH, NanI, NanJ) and inhibition of NanI constitutes an approach in the treatment of C. perfringens since NanI provides the carbohydrate source necessary for the growth of bacteria. In our study, the inhibition effect of some drugs belonging to different drug groups on NanI activity was investigated. Among these drugs, orlistat (0.21±0.05 μM) was determined to have a lower IC50 value than the positive control quercetin (15.58±1.59 μM). It was determined in vitro by spectrofluorometric method. Additionally, NanI molecular docking studies with orlistatand quercetin were performed using iGemdock, DockThor and SwissDock. Orlistat (-93.93, -8.649 and -10.03 kcal/mol, respectively) was found to have a higher binding affinity than quercetin (-92.68, -7.491 and -8.70 kcal/mol, respectively), and the results were in line with in vitro studies. The results may suggest that orlistat is a molecule with drug potential for C. perfringens because it inhibits the drug target NanI, and that the inhibition efficiency can be increased by studies with orlistat derivatives.

Cistadesertosides B-E, Four New Diastereomeric Lignan Glycosides from the Stems of Cultural Cistanche deserticola in Tarim Desert.

Four previously undescribed diastereomeric lignan glycosides, namely cistadesertosides B-E (1-4) were isolated from the stems of cultural Cistanche deserticola in Tarim desert. The structures of these compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, HR-ESI-MS, 1D and 2D NMR, circular dichroism (CD) data and chemical degradation. The in vitro anti-inflammatory activity of the isolates was also investigated. It showed that compounds 3 and 4 exhibited potential effects with IC50 values of 21.17 μM and 26.97 μM, respectively (positive control quercetin, IC50 , 10.01 μM).

Compound Characterization and Evaluation of Antioxidant Potential of Ethanol Extract Spatholobus littoralis Hassk in Kolaka, Southeast Sulawesi, Indonesia

The bajakah tampala plant (Spahtolobus littoralis Hassk) has been traditionally believed by the public to cure cancer, tumors, heart disease, stroke, and diabetes. However, empirically the public does not yet know the chemical compound content and there have been no studies on biological activity tests, especially the antioxidants of bajakah tampala from Kolaka, Southeast Sulawesi. The aim of this research is a qualitative analysis of the chemical compounds of the ethanol extract of bajakah tampala roots and testing of antioxidant activity. Analysis of the chemical compounds of the ethanol extract of bajakah tampala roots using an FT-IR spectrophotometer and LC-MS/MS. The antioxidant activity of the bajakah tampala root ethanol extract was tested using the DPPH immersion method and the absorption was measured using a UV-Viss spectrophotometer and using the positive control quercetin. The results of the research showed that the ethanol extract of bajakah tampala roots had 8 chemical components that were detected, namely compound 1 apocynoside I, compound 2 quercetin, compound 3 hexosylphingosine, compound 4 3-hydroxy-7-methoxybaicalein, compound 5 momor-cerebroside I, compound 6 ambronal, compound 7 stigmastan-3,6-dione, and compound 8 trilaurin. The ethanol extract of bajakah tampala roots has an antioxidant activity of 21.75 µg/mL which is lower, compared to the antioxidant activity of quercetin of 2.91 µg/mL as a positive control, however the antioxidant activity of the ethanol extract of bajakah tampala roots is still included in the very strong category.

Antioxidant activity test of 70% and 96% ethanol extract of tandui stem bark (Mangifera rufocostata Kosterm.) with DPPH method

Background: The genus Mangifera has been reported to have many activities as a natural antioxidant; one of them is the tandui plant (Mangifera rufucostata Kosterm). The study of 70% and 96% ethanol extracts of tandui leaves has shown potential as an antioxidant with the DPPH method, which is a strong category. The potential as an antioxidant in leaves is also possible in other parts, such as stem bark. Objective: This study is to determine the antioxidant potential of tandui stem bark in 70% and 96% ethanol solvents with the DPPH method. Methods: The tandui stem bark was extracted using the soxhletation method with 70% and 96% ethanol solvents. Potential antioxidant activity was measured using a UV-Vis spectrophotometer and the positive control, quercetin. Results: Antioxidant activity results showed that the IC50 of 70% ethanol extract of tandui stem bark (EE70%KBT) was 9.657 µg/mL, the IC50 of 96% ethanol extract of tandui stem bark (EE96% KBT) was 6.362 µg/mL and the IC50 of positive control quercetin was 3.441 µg/mL. Conclusion: The results showed that tandui stem bark extracted using 70% and 96% ethanol has a strong potential as a natural antioxidant (very strong category) using the DPPH method.

Two new anti-inflammatory trachylobane diterpenoids from Euphorbia atoto

Two new rare trachylobane euphoratones A-B (1-2), together with five known diterpenoids (compounds 3-7), were isolated from the aerial parts of Euphorbia atoto. Their structures were unambiguously elucidated through HRESIMS, 1D and 2D NMR spectral analysis. Compounds 1, 3, 4 and 7 showed weak anti-inflammatory activities (IC50 77.49 ± 6.34, 41.61 ± 14.49, 16.00 ± 1.71 and 33.41 ± 4.52 μM, respectively), compared to the positive control quercetin (IC50 15.23 ± 0.65 μM).

In vitro and in vivo assessment of the antioxidant potential of isoxazole derivatives

Previously developed fluorophenyl-isoxazole-carboxamides derivatives were re-synthesized and their scavenging activity against DPPH free radical and inhibitory activity against lipase and α-amylase enzymes were evaluated. The inhibition of the tested enzymes was weak while the most potent activities were observed in the DPPH assay. In particular, compounds 2a and 2c demonstrated high antioxidant potency with IC50 values of 0.45 ± 0.21 and 0.47 ± 0.33 µg/ml, respectively, when compared to Trolox, the positive control compound, which has an IC50 value of 3.10 ± 0.92 µg/ml. Based on the in vitro results, the most potent compound 2a was chosen for in vivo evaluation of antioxidant properties using 20 male mice injected intra-peritoneally and divided into four groups. The in vivo results revealed that total antioxidant capacity (TAC) obtained for mice treated with 2a was two folds greater than that of mice treated with the positive control Quercetin. Although further biological and preclinical investigations need to be performed to assess the therapeutic potential of 2a, the results of this study show promising antioxidant activities both in vitro and in vivo.

Arylnaphthalide lignans from Saussurea medusa and their anti-inflammatory activities

Five new arylnaphthalide lignans ( 1 − 4a/4b ), together with five known analogues ( 5 – 9 ), were isolated from whole plants of Saussurea medusa . Compound 4 was characterized as an aryltetralin lignan with an unusual C-7′-C-9 oxygen bridge group, and a chiral HPLC analysis was carried out to afford one pair of enantiomers ( 4a/4b ). Structures of the new compounds were elucidated by extensive spectroscopic and electronic circular dichroism (ECD) calculations. All compounds were firstly isolated from S. medusa , and compounds 1 – 5 , 7 and 8 had never been obtained from the genus Saussurea previously. Furthermore, this is the first report of arylnaphthalide lignans isolated from S. medusa . anti-inflammatory activities of the compounds were evaluated by determining their inhibitory activities on the production of NO by LPS-stimulated RAW 264.7 cells. Compounds (−)- 4a and 5 exerted the significant inhibition activities with IC 50 values of 13.4 ± 1.5 and 15.7 ± 1.1 μM, respectively, which even exceeded the positive control quercetin (IC 50 = 15.9 ± 1.2 μM). Compounds 2 , (+)- 4b , 6 and 9 exhibited moderate inhibitory activities with IC 50 values ranging from 19.7 ± 1.9 to 47.4 ± 3.1 μM. Further analysis by molecular docking showed that almost all the active compounds could interact with the amino acid residues of iNOS proteins, which also supported their anti-inflammatory activities.

Anti-inflammatory sesquiterpene and triterpene acids from Mesona procumbens Hemsley.

Mesona procumbens Hemsley is a plant conventionally processed to provide popular food materials and herbal medicines in Asia. In this study, six triterpene acids, including five new ones (mesonaic acids D-H, 1–5), and one proximadiol-type sesquiterpene (7) were isolated from the methanolic extract of the air-dried M. procumbens. Chemical structures of 1‒7 were established by spectroscopic methods, especially 2D NMR techniques (1H–1H COSY, HSQC, HMBC, and NOESY) and HRESIMS. Concerning their biological activities, compounds 1, 2, 6, and 7 were examined manifesting high inhibition toward the pro-inflammatory NO production with EC50 values ranging from 12.88 to 21.21 µM, outrunning the positive control quercetin (24.12 µM). The mesoeudesmol B (7) identified from M. procumbens is the very first example, which exhibited high anti-inflammatory activity diminishing the level of the lipopolysaccharide-induced NO in RAW264.7 macrophage cells, thereby suppressing the secretion of pro-inflammatory cytokines TNF-α and IL-6 and the level of two critical downstream inflammatory mediators iNOS and COX-2.

Six new tigliane diterpenoids with anti-inflammatory activity from Euphorbia kansuensis

Six new tigliane diterpenoids, euphkanoids A − F (1–6), along with 12 known diterpenoids (7–18) were isolated from the roots of Euphorbia kansuensis, a traditional Chinese medicinal plant. Their structures were elucidated by spectroscopic analysis, ECD calculation and chemical methods. Compounds 1–3 represent the unusual examples of tigliane diterpenoids with a conjugated olefinic aldehyde moiety. 1–18 and two hydrolyzed analogues (1c and 4a) were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells. The results showed that 1–3 and 6 markedly inhibited NO production with IC50 values in the range of 4.8–11.3 μM, which were more active than the positive control quercetin (IC50 = 12.3 μM).

Secondary Metabolites with Anti-Inflammatory Activities from an Actinobacteria Herbidospora daliensis

Bioassay-guided fractionation of extracts derived from solid cultures of a Herbidospora daliensis originating from Taiwan led to the isolation of five new compounds, for which we propose the name herbidosporadalins A–E (1–5), one isolated for the first time, herbidosporadalin F (6), together with two known compounds (7 & 8). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR experiments with those of known analogues, and on the basis of HR-EI-MS mass spectrometry, their anti-inflammatory activities were also evaluated. Of these isolates, herbidosporadalin A (1), B (2), F (6) and G (8) showed NO inhibitory activity, with IC50 values of 11.8 ± 0.9, 7.1 ± 2.9, 17.8 ± 1.7, and 13.3 ± 6.5 μM, stronger than the positive control quercetin (IC50 = 36.8 ± 1.3 μM). To the best of our knowledge, this is the first report on 3,4-seco-friedelane metabolites (5, 6 & 8) from the genus Herbidospora.

Ptaeroxylon obliquum leaf extracts, fractions and isolated compounds as potential inhibitors of 15-lipoxygenase and lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophage cells

Ptaeroxylon obliquum is used traditionally to treat inflammatory diseases and related symptoms such as arthritis, rheumatism, fever and headache. The aim of the study was to determine the anti-inflammatory activities of the crude extracts, fractions and isolated compounds from P. obliquum leaves. Nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and soybean 15-lipoxygenase (15-LOX) inhibitory assays were used to evaluate the anti-inflammatory activity. The acetone crude extracts and fractions had weak 15-LOX inhibitory activity and also had some toxicity against the RAW 264.7 macrophage cells. The three isolated compounds, obliquumol, lupeol and β-amyrin mixture, and eranthin had good 15-LOX inhibitory activity with IC50 values ranging from 7.4 to 13.9 µg/mL which was in the same order as the positive control quercetin (2.1 µg/mL). The high percentage inhibition of NO production by the crude extracts, fractions and isolated compounds appeared to be due to the toxicity to the macrophage cells. Eranthin had the most promising activity with 71.1% inhibition and 89.1% cell viability at a 0.5 µg/mL concentration. The 15-LOX inhibitory activity of obliquumol, lupeol and β-amyrin mixture and eranthin may explain the traditional uses of P. obliquum to treat various inflammatory diseases even though the possibility that the anti-inflammatory activity might still be exerted through other inflammatory mechanisms.

In vitro studies on the cytotoxicity, elastase, and tyrosinase inhibitory activities of tomato (Solanum lycopersicum Mill.) extract.

ABSTRACTTomatoes (Solanum lycopersicum Mill.), a common vegetable in Indonesia, contain high levels of lycopene, which is good for the body. This research further investigates the activity of polar and nonpolar fractions of tomatoes as elastase and tyrosinase inhibitory, and cytotoxic agents. The extraction procedure used is maceration, fractionation through liquid-liquid fractionation, purification of phytochemical substances is achieved through the application of thin layer chromatography. Elastase and tyrosinase inhibitory activity was analyzed using spectrophotometry and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxic assay. The result showed that the extract yield was 0.004%. The percentage of polar fraction from the extract was 2.58%, while the nonpolar fraction was 0.69%. The elastase inhibitory activity of polar and nonpolar fractions of tomato extract is 87.21% ± 7.57% and 73.12% ± 7.44%, respectively, The elastase inhibitory activity of polar and nonpolar fractions of tomato extract is 87.21% ± 7.57% and 73.12% ± 7.44%, respectively. The fractions had higher the anti-elastase activity than the positive control quercetin (65.97% ± 3.00%). The tyrosinase inhibitory activity of polar and nonpolar fractions of tomato extract is 23.71% ± 7.91% and 41.16% ± 5.41% (kojic acid as standard is 65.07% ± 0.86%), respectively. The IC50 of the cytotoxic assay to NIH 3T3 mouse embryonic fibroblast cells of the polar and nonpolar fraction of tomato extract is 1820.90 μg/mL and 1643.86 μg/mL, respectively.

Antibacterial Activity Test of Ganitri (Elaeocarpus ganitrus Roxb.) Leaf Methanol Extract against Bacteria (Propionibacterium acne)

Ganitri plant (Elaeocarpus ganitrus Roxb.) is one type of plant that can be discovered in several countries, such as Indonesia. This plant has a number of benefits as it contains flavonoid, tannins, phenolics, alkaloids, along with triterpenoids. In addition, that plant has significant role to decrease microbial activities including Staphylococcus aureus, Bacillus cereus, Candida albicans and Penicillium sp. These activities consist of three stages as follows inhibiting nucleic acid synthesis, then followed by hampering cell membrane function and finally decreasing bacterial energy metabolism. The mechanism denatures cell proteins leading an imbalance of molecules, ions and cell lysis as well. Extraction process has been completed by maceration method of 3-kg-wet leaves, a 1-kg-dry simplicial, a 500-g macerated simplicial mixed with 5 L methanol solvent and 33.33 % of simplicial, and 95.08 g of yield extract with 19.01%. Its process generated green color extract having bitter taste and thick form, 0.5% of water, 15.9% of ash, and 0.4% of insoluble acid. Identification of these active ingredients that using positive phytochemical resulted flavonoids. TLC (Thin-layer chromatography) test was used with 0.75 of positive control quercetin and 0.81 of flavonoid extract. Antibacterial activity testing was applied by calculating the inhibitory power of Nutrient Agar with negative control using sterile water. Afterwards, implemented a positive control using clindamycin resulted of several concentration as follows of 10 % (10.6), 20% (10.6), 30% (9.25), 40% (10.12), 50% (9.37) and 100% (38.75).

Discovery of glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates with anti-inflammatory activities from Pleione grandiflora

Six new glucosyloxybenzyl 2-hydroxy-2-isobutylsuccinates, pleionesides A-F (1–6), along with two known compounds (7, 8) were obtained from the pseudobulbs of Pleione grandiflora (Rolfe) Rolfe. The structures and absolute configurations of new compounds were established by HRESIMS and NMR data, along with acidic hydrolysis and alkaline hydrolysis experiments. Compounds 1–6 were tested for their anti-inflammatory activities on LPS-induced BV2 microglial cells. Amoung them, 2, 4 and 5 showed moderate activities with IC50 values of 73.4, 32.8 and 57.1 μM, respectively, compared with the positive control quercetin with an IC50 value of 28.3 μM.

Antioxidant and ROS Inhibitory Activities of Heterocyclic 2-Aryl-4(3H)-quinazolinone Derivatives

Background: Antioxidants are small molecules that prevent or delay the process of oxidations caused by highly reactive free radicals. These molecules are known for their ability to protect various cellular architecture and other biomolecules from oxidative stress and free radicals. Thus, antioxidants play a key role in the prevention of oxidative damages caused by highly reactive free radicals. Methods: In the present study, a series of previously synthesized heterocyclic 2-aryl-4(3H)- quinazolinone derivatives 1-25 were screened for antioxidant activity by employing in vitro DPPH and superoxide anion radical scavenging activities. ROS inhibitory activities were also evaluated by serum-opsonized zymosan activated whole blood phagocytes and isolated neutrophils. Cytotoxicity studies were carried out by employing an MTT assay against the 3T3 cell line. Results: Most of the 2-aryl-4(3H)-quinazolinone derivatives showed potent antioxidant activities in superoxide anion radical scavenging assay with IC50 value ranging between 0.57 μM - 48.93 μM, as compared to positive control quercetin dihydrate (IC50 = 94.1 ± 1.1 μM ). Compounds 5, 6, and 14 showed excellent activity in DPPH assay. Compounds 5-8, 12-15, 17, and 20 showed promising activities in the ROS inhibition assay. All compounds were found to be non-cytotoxic against the 3T3 cell line. Structure antioxidant activity has been established. Conclusion: It can be concluded that most of the heterocyclic 2-aryl-4(3H)-quinazolinone derivatives 1-25 are identified as promising antioxidant agents that are capable of fighting against free radicals and oxidative stress. Thus, they can serve as a lead towards treating oxidative stress and related pathologies.