Sonapatha (Oroxylum indicum) mediates cytotoxicity in cultured HeLa cells by inducing apoptosis and suppressing NF-κB, COX-2, RASSF7 and NRF2.

Oroxylum indicum (Sonapatha) is traditionally used to cure several human ailments. Therefore, the cell killing effect of chloroform, ethanol, and water extracts of Sonapatha was studied in cultured HeLa cells treated with 0-100 µg/mL of these extracts/doxorubicin by MTT assay. Since ethanol extract was most cytotoxic its effect was further investigated by clonogenic, apoptosis, necrosis, and lactate dehydrogenase assays. The mechanism of cytotoxicity of Sonapatha was determined at the molecular level by estimation of caspase 8 and 3 activities and Western blot analysis of NF-κB, COX-2, Nrf2, and RASSF7 which are overexpressed in neoplastic cells. HeLa cells treated with Sonapatha extract exhibited a concentration and time-dependent rise in the cytotoxicity as indicated by the MTT assay. Ethanol extract of Sonapatha (0, 20, 40, and 80 µg/mL) reduced clonogenicity, increased DNA fragmentation, apoptotic and necrotic indices, lactate dehydrogenase release, caspase 8 and 3 activities and inhibited the overexpression of NF-κB, COX-2, Nrf2, and RASSF7 in HeLa cells concentration-dependently.

Evaluation of Selective COX-2 Inhibition and In Silico Study of Kuwanon Derivatives Isolated from Morus alba.

Six kuwanon derivatives (A/B/C/E/H/J) extracted from the roots of Morus alba L. were evaluated to determine their cyclooxygenase (COX)-1 and 2 inhibitory effects. Cyclooxygenase (COX) is known as the target enzyme of nonsteroidal anti-inflammatory drugs (NSAIDs), which are the most widely used therapeutic agents for pain and inflammation. Among six kuwanon derivatives, kuwanon A showed selective COX-2 inhibitory activity, almost equivalent to that of celecoxib, a known COX inhibitor. Kuwanon A showed high COX-2 inhibitory activity (IC50 = 14 µM) and a selectivity index (SI) range of >7.1, comparable to celecoxib (SI > 6.3). To understand the mechanisms underlying this effect, we performed docking simulations, fragment molecular orbital (FMO) calculations, and pair interaction energy decomposition analysis (PIEDA) at the quantum-mechanical level. As a result, kuwanon A had the strongest interaction with Arg120 and Tyr355 at the gate of the COX active site (-7.044 kcal/mol) and with Val89 in the membrane-binding domain (-6.599 kcal/mol). In addition, kuwanon A closely bound to Val89, His90, and Ser119, which are residues at the entrance and exit routes of the COX active site (4.329 Å). FMO calculations and PIEDA well supported the COX-2 selective inhibitory action of kuwanon A. It showed that the simulation and modeling results and experimental evidence were consistent.

A new prenylated benzoquinone from Cyathocalyx pruniferus abrogates LPS-induced inflammatory responses associated with PGE2, COX-2 and cytokines biosynthesis in human plasma.

In our previous laboratory findings, Cyathocalyx pruniferus extracts exhibited platelet-activating factor inhibition, suggesting their anti-inflammatory potential. Hence, this study was designed with the aim to isolate phyto-constituents from C. pruniferus with potent anti-inflammatory activities. Column and volume liquid chromatography were used for isolation of phyto-constituents. The structure elucidation was carried out using spectroscopic analysis (HRESI-MS, 1H and 13C-NMR) and compared with published literature. For cytotoxicity analysis, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide assay was performed on peripheral blood mononuclear cells. Anti-inflammatory activities were evaluated against the levels of inflammatory cytokines (IL-1ß and IL-6), prostaglandin-E2 (PGE2) and cyclooxegenase-2 (COX-2), in lipopolysaccharide (LPS)-induced human plasma using ELISA and radioimmunoassay (RIA). The chromatographic purification of methanol leaves extract afforded 13 (1-13) secondary metabolites. Additionally, cytotoxicity analysis suggested that isolates were non-cytotoxic at 100 µM. In anti-inflammatory evaluation, 2-octaprenyl-1, 4-benzoquinone (5) produced strong (≥ 70%) inhibition of PGE2, COX-2, IL-1ß and IL-6 at 50 µM. Moreover, 2-octaprenyl-1,4-benzoquinone (5) exhibited concentration-dependent inhibition with IC50 values (µM) of 11.21, 6.61, 2.20 and 3.56 as compared to controls; indomethacin for PGE2 (11.84) and dexamethasone in COX-2 (5.19), IL-1ß (1.83) and IL-6 (3.76) analysis, respectively. In conclusion, two new compounds including 2-octaprenyl-1, 4-benzoquinone (5) and 14-methyloctadec-1-ene (6) are reported for the first time from plant species. Additionally, 2-octaprenyl-1, 4-benzoquinone (5) dose-dependently suppressed the production of pro-inflammatory mediators involved in acute and chronic inflammation at non-cytotoxic concentrations.

Bioassay-guided isolation of cyclooxygenase-2 inhibitory and antioxidant phenylpropanoid derivatives from the roots of Dendropanax dentiger.

The root of Dendropanax dentiger (Harms) Merr. is a traditional Chinese medicine that has been used to treat inflammation-related diseases with little scientific validation. In this study, a bioassay-guided phytochemical investigation of D. dentiger led to the isolation of 19 phenylpropanoid derivatives including one new compound (1) and 18 known ones (2-19). Their structures were elucidated by NMR and HRMS as well as comparison with literature data. The ability of cyclooxygenase-2 (COX-2) inhibition and antioxidant of all isolated compounds were measured in vitro. Chlorogenic acid derivatives (14-19) exhibited outstanding COX-2 inhibitory (IC50 = 5.1-93.4 µM) and antioxidant (IC50 = 13.2-31.9 µM) activities. Moreover, the tight structure-activities relationships were proposed. This is the first report on the COX-2 inhibitory activity of phenylpropanoids and D. dentiger.

Stomopneulactone D from long-spined sea urchin Stomopneustes variolaris: Anti-inflammatory macrocylic lactone attenuates cyclooxygenase-2 expression in lipopolysaccharide-activated macrophages.

Cyclooxygenase-2 is one of the prominent enzymes to cause an increased production of prostaglandins during inflammation and immune responses. Cyclooxygenase-2 expression is up-regulated in inflammatory conditions owing to the induction by different inflammatory stimuli including cytokines, and therefore, the expression studies of cyclooxygenase-2 in lipopolysaccharide-induced macrophage cells (RAW 264.7 cell line) could be used for screening of the compounds with anti-inflammatory potential. The present study evaluated the anti-inflammatory properties of four homologous stomopneulactones A-D, classified under the class of macrocyclic lactones isolated from the solvent extract of the long-spined sea urchin Stomopneustes variolaris (familyStomopneustidae) in the lipopolysaccharide-induced macrophages. The structures of these isolated compounds were assigned using detailed spectroscopic techniques. Stomopneulactone D bearing 5-butyl-4-hydroxy-12-oxo-1-oxa-5,9-cyclododecadienyl moiety exhibited relatively greater anti-inflammatory potentials against cyclooxygenase-2 (IC50 ~ 2 mM) and 5-lipoxygenase (IC50 2.6 mM) than those displayed by other macrocyclic lactones. The studied compounds displayed higher selectivity index values (anti-cyclooxygenase-1IC50/anti-cyclooxygenase-2IC50 > 1), which designated the selective anti-inflammatory potentials of the macrocyclic lactones against inducible inflammatory mediators than those exhibited by the anti-inflammatory agent ibuprofen (0.43). The in silico molecular modelling analyses of the stomopneulactones with cyclooxygenase-2/5-lipoxygenase enzymes recorded lowest binding energy (-7.71 and -9.60 kcal mol-1, respectively) and docking score (-8.82 and -11.12 kcal mol-1, respectively) for stomopneulactone D along with its higher electronic parameter (topological polar surface area of 72.83), which further confirmed its greater anti-inflammatory potential than other compounds in the series. Stomopneulactone D also inhibited the generation of inducible nitric oxide synthase, intracellular reactive oxygen species, along with 5-lipoxygenase and cyclooxygenase-2 in the lipopolysaccharide-stimulated macrophage cells. Additionally, the studied macrocyclic lactone decreased the mRNA expression of cyclooxygenase-2 in the inflammatory cells in dose-dependent manner, which demonstrated the therapeutic potential of stomopneulactone D in down-regulating the inflammatory pathogenesis.

pH-Zone-refining counter-current chromatography for two new lipo-alkaloids separated from refined alkaline extraction of Kusnezoff monkshood root.

An efficient and refined method for the separation of six aconitine-type alkaloids from the alkaline prepared "Kusnezoff monkshood root" was established. It is the first study that two new lipo-alkaloids were successfully isolated from refined sample by pH-zone-refining counter-current chromatography rather than synthetic method. It was of interest that a great deal of lipo-alkaloids was produced in crude extract from the alkalization of "Kusnezoff monkshood root." A refined sample method was proposed to enrich two types of alkaloids by liquid-liquid extraction, i.e. lipo-alkaloids and monoester-diterpenoid alkaloids. The pH-zone-refining counter-current chromatography was performed with an optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:5:4:5, v/v), where upper organic phase was added to 3 mmol/L triethylamine as a retainer and lower aqueous mobile phase was added to 3 mmol/L hydrochloric acid as an eluter. As a result, six aconitum alkaloids, including two lipo-alkaloids (8-lino-14-benzoylaconine, 8-pal-14-benzoylaconine), three monoester-diterpenoid alkaloids (14-benzoylmesaconine, 14-benzoylaconine, beyzoyldeoxyaconine), and one aconine alkaloid (neoline) were acquired from the plant at the same time. The anti-inflammatory activities of the two new lipo-alkaloids were compared to the six alkaloids in vitro, in cyclo-oxygen-ase-2 inhibition assays. The separation mechanism of six alkaloids by pH-zone-refining counter-current chromatography was illustrated.

Extracts and Steroids from the Edible Mushroom Hypholoma lateritium Exhibit Anti-Inflammatory Properties by Inhibition of COX-2 and Activation of Nrf2.

Hypholoma lateritium is an edible macrofungus with a common distribution in Europe, North America, and the Far East. The aim of this study was to investigate the potential anti-inflammatory effects of H. lateritium extracts and its isolated steroids: fasciculic acid B, fasciculol E, fasciculol C, lanosta-7,9(11)-diene-12ß,21α-epoxy-2α,3ß,24ß,25-tetraol, fasciculol F, and demethylincisterol A2. Organic (hexane, chloroform and 50 % methanol) and water extracts of H. lateritium were subjected to in vitro assays to determine pro-inflammatory protein levels, such as cyclooxygenase-2 (COX-2), cytosolic prostaglandin E2 synthase (cPGES), and antioxidant nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Fungal extracts demonstrated significant activities on pro-inflammatory protein levels with minor differences among the activities of the fractions of different polarities. All the compounds proved to exert notable inhibitory properties on COX-2 and were capable to stimulate the Nrf2 pathway. Fungal extracts and the compounds exerted no cytotoxic activities on RAW 264.7 cells.

Bioactive triterpene glycosides from the fruit of Stauntonia hexaphylla and insights into the molecular mechanism of its inflammatory effects.

Chromatography of the ethanol extract of the medicinal fruit Stauntonia hexaphylla resulted in the purification of 26 compounds (1-26), including two undescribed triterpene saponins 1 and 2 (hexaphylosides A and B). Their structures were confirmed by spectroscopic data, including IR, HR QTOF MS, 1H, 13C NMR, COSY, HMQC, HMBC, and TOCSY, and HPLC sugar analysis after acid hydrolysis. The anti-inflammatory effects of the high-purity constituents (1-26) on lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells were investigated by screening nitric oxide production. The NO inhibitory activity of compounds 6 and 10 with the IC50 values of 1.33 and 1.10 µM, respectively. The structure-activity relationships (SAR) of the isolated compounds were also analyzed. Furthermore, compounds 6 and 10 inhibited the protein expression inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2 via Western blotting analysis. This showed that compounds 6 and 10 contributed to the anti-inflammatory effects of S. hexaphylla fruit, which could be developed as a natural nutraceutical and functional food ingredient.

Screening and isolation of cyclooxygenase-2 inhibitors from the stem bark of Phellodendron amurense Ruprecht by ultrafiltration with liquid chromatography and tandem mass spectrometry, and complex chromatography.

Nonsteroidal anti-inflammatory drugs appear to reduce the risk of developing cancer. One mechanism through which nonsteroidal anti-inflammatory drugs act to prevent carcinogenesis is inhibition of the activity of the enzyme cyclooxygenase-2. The cyclooxygenase-2 inhibitors are widely used to reduce the risk of developing cancer. Natural products are considered to be a promising source of several novel cyclooxygenase-2 inhibitors. Ultrafiltration with liquid chromatography and mass spectrometry is an efficient method that can be applied to rapidly screen and identify the ligands from the barks of Phellodendron amurense Ruprecht. A continuous online method comprised of pressurized liquid extraction, countercurrent chromatography, and semi-preparative liquid chromatography was developed for the efficient scaled-up production of eight compounds with high purities. The bioactivities of the separated compounds were assessed by an in vitro enzyme inhibition assay. The use of bioactivity screening method combined with preparation method of bioactive compounds and an in vitro enzyme inhibition assay facilitated the efficient screening and isolation of the cyclooxygenase-2 inhibitors from complex samples. This could be used as an efficient method for the large-scale production of functional ingredients.

Screening and isolation of cyclooxygenase-2 inhibitors from Trifolium pratense L. via ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography.

Nonsteroidal anti-inflammatory drugs reportedly reduce the risk of developing cancer. One mechanism by which they reduce carcinogenesis involves the inhibition of the activity of cyclooxygenase-2, an enzyme that is overexpressed in various cancer tissues. Its overexpression increases cell proliferation and inhibits apoptosis. However, selected cyclooxygenase-2 inhibitors can also act through cyclooxygenase-independent mechanisms. In this study, using ultrafiltration, enzyme-immobilized magnetic beads, high-performance liquid chromatography, and electrospray-ionization mass spectrometry, several isoflavonoids in Trifolium pratense L. extracts were screened and identified. Semi-preparative high-performance liquid chromatography and high-speed counter-current chromatography were then applied to separate the active constituents. Using these methods, seven major compounds were identified in Trifolium pratense L. As cyclooxygenase-2 inhibitors: rothindin, ononin, daidzein, trifoside, pseudobaptigenin, formononetin, and biochanin A, which were then isolated with >92% purity. This is the first report of the presence of potent cyclooxygenase-2 inhibitors in Trifolium pratense L. extracts. The results of this study demonstrate that the systematic isolation of bioactive components from Trifolium pratense L., by using ultrafiltration, enzyme-immobilized magnetic beads, semi-preparative high-performance liquid chromatography, and high-speed counter-current chromatography, represents a feasible and efficient technique that could be extended for the identification and isolation of other enzyme inhibitors.

Biphenyl Derivatives from the Aerial Parts of Oenanthe javanica and Their COX-2 Inhibitory Activities.

Four new biphenyl derivatives (1-4), along with six known biphenyl derivatives (5-10) were isolated and elucidated by their detailed analyses of spectroscopic data and references from the aerial parts of Oenanthe javanica for the first time. Compounds (1-10) were assayed for their activities about the inhibition of COX-2 enzyme in vitro for the first time. Compounds 1, 2, 4, and 6 showed inhibitory activities against COX-2 with IC50 values ranging from 22.18±0.29 to 108.54±0.42 µm.

Screening for anti-proliferative and anti-inflammatory components from Rhamnus davurica Pall. using bio-affinity ultrafiltration with multiple drug targets.

Rhamnus davurica Pall. (R. davurica) has been used as a traditional medicine for many years in China and abroad and shown a wide spectrum of biological activities. Previously, we reported the phytochemical fingerprinting profile of R. davurica, its distinct anti-proliferative activities against HT-29 and SGC-7901 cell lines, and the topoisomerase I (Top I) ligands based on bio-affinity ultrafiltration and HPLC-MS (UF-HPLC-MS). Nevertheless, among the 32 peaks detected in the fingerprinting profile, the common bioactive constituents responsible for the anti-inflammatory and anti-proliferative activities in the extracts remain elusive. To further explore the specific responsible components for their diversified activities and their potential action targets/mechanisms, the method based on bio-affinity UF-HPLC-MS using therapeutic targets like Top I and cyclooxygenase 2 (COX-2) was established to rapidly screen and identify the ligands binding to these known target enzymes. As a result, 12 components were revealed as potential Top I ligands along with 11 components as potential COX-2 ligands, where several components were revealed to possess both activities. Further validations of these bioactive components have also been conducted and confirmed their highlighted activities. This integrated method of UF-HPLC-MS exhibits high efficiency in rapidly screening for multi-target bioactive components responsible for multiple pharmacological effects from the complex natural products and could be very useful to explain the complex action mechanisms of herb medicines in a complex multi-component and multi-target mode at the molecular level. Graphical abstract Schematic diagram of UF-HPLC-MS assay to screen for Top I and COX-2 ligands. The principle of the assay usually involves the following steps: incubation, ultrafiltration, and identification.

Isolation and Structure Elucidation of Cembranoids from a Dongsha Atoll Soft Coral Sarcophyton stellatum.

Six new polyoxygenated cembrane-based diterpenoids, stellatumolides A⁻C (1⁻3), stellatumonins A and B (4 and 5), and stellatumonone (6), were isolated together with ten known related compounds (7⁻16) from the ethyl acetate (EtOAc) extract of soft coral Sarcophyton stellatum. The structures of the new compounds were established by extensive spectroscopic analyses, including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and data comparison with related structures. Compounds 8 and 14 were isolated from a natural source for the first time. The isolated metabolites were shown to be not cytotoxic against a limited panel of cancer cells. Compound 9 showed anti-inflammatory activity by reducing the expression of proinflammatory cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) proteins in lipopolysaccharide (LPS)-stimulated mouse leukaemic monocyte macrophage (RAW 264.7) cells.

Sesquiterpene Lactones with COX-2 Inhibition Activity from Artemisia lavandulaefolia.

Two new sesquiterpene lactones, artelavanolides A (1) and B (2), and four known sesquiterpene lactones (3 - 6) were isolated from the leaves of Artemisia lavandulaefolia. Their structures were elucidated based on the analysis of spectroscopic data (1D, 2D-NMR and HR-ESI-MS). The absolute configuration of 1 was determined by the analysis of single-crystal X-ray diffraction data. Artelavanolide A (1) is a rare sesquiterpene lactone possessing an unusual skeleton with the linkage of Me(14)-C(1) that is probably formed through a rearrangement of the guaiane-type sesquiterpenoids. Artelavanolide B (2) is a new highly unsaturated guaianolide. Compounds 1 - 6 were tested for activities on the inhibition of COX-2 enzyme in vitro. All of compounds exhibited inhibitory activity against COX-2 with IC50 values ranging from 43.29 to 287.07 µm compared with the positive control, celecoxib (IC50 = 18.10 µm). Among them, 3 showed the best COX-2 inhibitory activity with an IC50 value of 43.29 µm.

In Vitro and In Vivo Anti-Osteoarthritis Effects of 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-Glucoside from Polygonum Multiflorum.

Polygonum multiflorum Thunb. is a traditional herbal medicine that is rich in polyphenols. The major compound, 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glucoside (THSG) has many pharmacological activities, such as antioxidative and free radical-scavenging properties, and the abilities to reduce hyperlipidemia, prevent lipid peroxidation, and protect the cardiovascular system. In this study, the anti-osteoarthritis (OA) effects of THSG were explored using in vitro and in vivo models. THSG inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production and inducible NO synthase (iNOS) and cyclooxygenase-2 expressions by lipopolysaccharide-stimulated RAW 264.7 cells. On the other hand, THSG inhibited PGE2 production and iNOS and matrix metalloproteinase-13 expressions by interleukin-1ß-stimulated primary rat chondrocytes. Through a mono-iodoacetate-induced rat OA model assay, THSG reduced paw edema and improved the weight-bearing distribution. Therefore, THSG has anti-inflammatory activity and could be applied as a lead compound for the development as an OA drug.

Assessing the effect of Mentha longifolia essential oils on COX-2 expression in animal model of sepsis induced by caecal ligation and puncture.

CONTEXT: Mentha longifolia L. (Lamiaceae), a traditional Iranian plant, possesses antimicrobial and antioxidant activities. OBJECTIVE: We investigated the potential protective effects of M. longifolia essential oils (E.Os) on caecal ligation and puncture (CLP) induced liver injury. MATERIALS AND METHODS: Wistar Albino rats (n = 50) were grouped as follows: (1) a laparotomy group (LAP); (2) a CLP group (CLP); (3) the treatment groups received orally the E.Os (50 and 100 mg/kg b.w) and indomethacin (2 mg/kg b.w) for 2 weeks. The oxidative stress parameters, liver enzymes and prostaglandin E2 (PGE2) level were measured in liver and plasma tissues. The liver was also harvested for the real time PCR of cyclooxygenase (COX-2) expression following histopathological examinations. RESULTS: The results indicated that the CLP operation significantly increased lipid peroxidation (LP) [1.79-fold], myeloperoxidase (MPO) [2.76-fold], PGE2 [1.56-fold] besides plasma aspartate aminotransferase (AST) [2.4-fold] and alanine aminotransferase (ALT) activities [2.22-fold], while, markedly reduced glutathione (GSH) [0.63-fold] and ferric reducing ability of plasma (FRAP) levels [0.63-fold]. Even COX2 expression significantly increased in the CLP group as compared to the LAP group. Treatments of rats with the E.Os could return all the hepatic and plasma biomarkers to the normal levels. These results were further confirmed by pathological examination on liver indicating that E.Os could successfully improve the CLP-induced liver injuries. DISCUSSION AND CONCLUSIONS: Our findings suggest that E.Os is able to protect liver injuries against sepsis via modulating the oxidative stress parameters concomitant with the suppression of inflammatory reactions such as PGE2 and COX-2.

Molecular insights into the differences in anti-inflammatory activities of green tea catechins on IL-1ß signaling in rheumatoid arthritis synovial fibroblasts.

In this study, we found that catechins found in green tea (EGCG, EGC, and EC) differentially interfere with the IL-1ß signaling pathway which regulates the expression of pro-inflammatory mediators (IL-6 and IL-8) and Cox-2 in primary human rheumatoid arthritis synovial fibroblasts (RASFs). EGCG and EGC inhibited IL-6, IL-8, and MMP-2 production and selectively inhibited Cox-2 expression. EC did not exhibit any inhibitory effects. When we looked at the expression of key signaling proteins in the IL-1ß signaling pathway, we found all the tested catechins could inhibit TAK-1 activity. Therefore, the consumption of green tea offers an overall anti-inflammatory effect. Molecular docking analysis confirms that EGCG, EGC, and EC all occupy the active site of the TAK1 kinase domain. However, EGCG occupies the majority of the TAK1 active site. In addition to TAK1 inhibition, EGCG can also inhibit P38 and nuclear NF-κB expression whereas EC and EGC were not effective inhibitors. Our findings suggest one of the main health benefits associated with the consumption of green tea are due to the activity of EGCG and EGC which are both present at higher amounts. Although EGCG is the most effective catechin at inhibiting downstream inflammatory signaling, its effectiveness could be hindered by the presence of EC. Therefore, varying EC content in green tea may reduce the anti-inflammatory effects of other potential catechins in green tea.

Phytochemical Investigations of Three Rhodocodon (Hyacinthaceae Sensu APG II) Species.

The genus Rhodocodon (Hyacinthaceae sensu APG II) is endemic to Madagascar, and its phytochemistry has not been described previously. The phytochemistry of three species in this genus has been investigated, and eight compounds, including three bufadienolides (compounds 1, 4, and 5), a norlignan (2), and four homoisoflavonoids (compounds 3 and 6-8), have been isolated and identified. Compounds 1-3 and 6-8 have not been described previously. The COX-2 inhibitory activity of compound 6 and compound 7 acetate (compound 7A) was investigated on isolated colorectal cancer cells. Compounds 6 and 7A inhibited COX-2 by 10% and 8%, respectively, at a concentration of 12.5 µM compared to 12% for 1 mM aspirin (the positive control).

Anti-inflammatory Activity of Natural Geranylated Flavonoids: Cyclooxygenase and Lipoxygenase Inhibitory Properties and Proteomic Analysis.

Geranyl flavones have been studied as compounds that potentially can be developed as anti-inflammatory agents. A series of natural geranylated flavanones was isolated from Paulownia tomentosa fruits, and these compounds were studied for their anti-inflammatory activity and possible mechanism of action. Two new compounds were characterized [paulownione C (17) and tomentodiplacone O (20)], and all of the isolated derivatives were assayed for their ability to inhibit cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX). The compounds tested showed variable degrees of activity, with several of them showing activity comparable to or greater than the standards used in COX-1, COX-2, and 5-LOX assays. However, only the compound tomentodiplacone O (20) showed more selectivity against COX-2 versus COX-1 when compared with ibuprofen. The ability of the test compounds to interact with the above-mentioned enzymes was supported by docking studies, which revealed the possible incorporation of selected test substances into the active sites of these enzymes. Furthermore, one of the COX/LOX dual inhibitors, diplacone (14) (a major geranylated flavanone of P. tomentosa), was studied in vitro to obtain a proteomic overview of its effect on inflammation in LPS-treated THP-1 macrophages, supporting its previously observed anti-inflammatory activity and revealing the mechanism of its anti-inflammatory effect.

Investigations on Antioxidant, Antiproliferative and COX-2 Inhibitory Potential of Alkaloids from Anthocephalus cadamba (Roxb.) Miq. Leaves.

In the present study, an ayurvedic medicinal plant, Anthocephalus cadamba (Roxb.) Miq. commonly known as 'Kadamb' was explored for its potential against oxidative stress and cancer. The fractions namely AC-4 and ACALK (alkaloid rich fraction) were isolated from A. cadamba leaves by employing two different isolation methods and evaluated for their in vitro antioxidant and antiproliferative activity. The structure of the isolated AC-4 was characterized tentatively as dihydrocadambine by using various spectroscopic techniques such as ESI-QTOF-MS, 1 H- and 13 C-NMR, DEPT, COSY, HMQC, and HMBC. Results of various antioxidant assays viz. 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS cation radical, superoxide anion radical scavenging, and plasmid nicking assay demonstrated that both the fractions viz. AC-4 and ACALK possess ability to scavenge DPPH, ABTS radicals and effectively protected plasmid pBR322 DNA from damage caused by hydroxyl radicals. Further, when both fractions were evaluated for their potential to suppress growth of HeLa and COLO 205 cells, only ACALK fraction showed antiproliferative effects. ACALK exhibited GI50 of 205.98 and 99.54 µg/ml in HeLa and COLO 205 cell lines, respectively. Results of Hoechst staining in cervical carcinoma (HeLa) cells confirmed that ACALK induced cell death in HeLa cells via apoptotic mode. Both the fractions also inhibited COX-2 enzyme activity.