Targeting the initiation and termination codons of SARS-CoV-2 spike protein as possible therapy against COVID-19: the role of novel harpagide 5-O-ß-D-glucopyranoside from Clerodendrum volubile P Beauv. (Labiatae).

The global spread of the coronavirus infections disease - 2019 (COVID-19) and the search for new drugs from natural products particularly from plants are receiving much attention recently. In this study, the therapeutic potential of a new iridoid glycoside isolated from the leaves of Clerodendrum volubile against COVID-19 was investigated. Harpagide 5-O-ß-D-glucopyranoside (HG) was isolated, characterised and investigated for its druglikeness, optimized geometry, and pharmacokinetics properties. Its immunomodulatory was determined by chemiluminescence assay using polymorphonuclear neutrophils (PMNs) in addition to T-cell proliferation assay. In silico analysis was used in determining its molecular interaction with severe acute respiratory syndrome coronavirus-2 (SARS-COV-2). HG displayed potent druglikeness properties, with no inhibitory effect on cytochrome P450 (1A2, 2C19, 2C9, 2D6 and 3A4) and a predicted LD50 of 2000 mg/kg. Its 1H-NMR chemical shifts showed a little deviation of 0.01 and 0.11 ppm for H-4 and H-9, respectively. HG significantly suppressed oxidative bursts in PMNs, while concomitantly inhibiting T-cell proliferation. It also displayed a very strong binding affinity with the translation initiation and termination sequence sites of spike (S) protein mRNA of SARS-COV-2, its gene product, and host ACE2 receptor. These results suggest the immunomodulatory properties and anti-SARS-COV-2 potentials of HG which can be explored in the treatment and management of COVID-19.Communicated by Ramaswamy H. Sarma.

Translational suppression of SARS-COV-2 ORF8 protein mRNA as a Viable therapeutic target against COVID-19: Computational studies on potential roles of isolated compounds from Clerodendrum volubile leaves.

The open reading frame 8 (ORF8) protein of SARS-CoV-2 has been implicated in the onset of cytokine storms, which are responsible for the pathophysiology of COVID-19 infection. The present study investigated the potential of isolated compounds from Clerodendrum volubile leaves to stall oxidative bursts in vitro and interact with ORF8 mRNA segments of the SARS-CoV-2 whole genome using computational tools. Five compounds, namely, harpagide, 1-(3-methyl-2-butenoxy)-4-(1-propenyl)benzene, ajugoside, iridoid glycoside and erucic acid, were isolated from C. volubile leaves, and their structures were elucidated using conventional spectroscopy tools. Iridoid glycoside is being reported for the first time and is thus regarded as a new compound. The ORF8 mRNA sequences of the translation initiation sites (TIS) and translation termination sites (TTSs) encoding ORF8 amino acids were retrieved from the full genome of SARS-CoV-2. Molecular docking studies revealed strong molecular interactions of the isolated compounds with the TIS and TTS of ORF8 mRNA. Harpagide showed the strongest binding affinity for TIS, while erucic acid was the strongest for TTS. The immunomodulatory potentials of the isolated compounds were investigated on neutrophil phagocytic respiratory bursts using luminol-amplified chemiluminescence technique. The compounds significantly inhibited oxidative burst, with 1-(3-methyl-2-butenoxy)-4-(1-propenyl)benzene having the best activity. Ajugoside and erucic acid showed significant inhibitory activity on T-cell proliferation. These results indicate the potential of C. volubile compounds as immunomodulators and can be utilized to curb cytokine storms implicated in COVID-19 infection. These potentials are further corroborated by the strong interactions of the compounds with the TIS and TTS of ORF8 mRNA from the SARS-CoV-2 whole genome.

Inhibitory Effects of Myrtucommuacetalone 1 (MCA-1) from Myrtus communis on Inflammatory Response in Mouse Macrophages.

(1) Introduction: Reactive oxygen species (ROS) and nitric oxide (NO) are key signaling molecules that play important roles in the progression of inflammatory disorders. The objective of this study was to explore the use of myrtucommuacetalone-1 (MCA-1), as a novel compound of natural origin and a potential anti-inflammatory agent. (2) Methodology: The anti-inflammatory potential of MCA-1, which was isolated from Myrthus communis Linn, was determined by assaying superoxide, hydrogen peroxide, and nitric oxide production in macrophages. Furthermore, the effects of the compound were analyzed via phosphorylation and translocation of the transcription factor NF kappa B, which is a key regulator of iNOS activation. The effect of MCA-1 on the inducible nitric oxide synthase (iNOS) enzyme was also examined using in silico docking studies. The anticancer potential for MCA-1 was evaluated with an MTT cytotoxic assay. (3) Results: In stimulated macrophages, MCA-1 inhibited superoxide production by 48%, hydrogen peroxide by 53%, and nitric oxide (NO) with an IC50 of <1 µg/mL. MCA-1 also showed a very strong binding pattern within the active site of the inducible nitric oxide synthase enzyme. Furthermore, 25 µg/mL of MCA-1 inhibited inducible nitric oxide synthase expression and abolished transcription factor (NFκB) phosphorylation and translocation to the nucleus. Cytotoxicity analyses of MCA-1 on 3T3 mouse fibroblasts, CC1 liver cell line, J774.2, macrophages and MDBK bovine kidney epithelial cell, yielded IC50 values of 6.53 ± 1.2, 4.6 ± 0.7, 5 ± 0.8, and 4.6 ± 0.7, µg/mL, respectively. (4) Conclusion: Our results suggest that MCA-1, a major phloroglucinol-type compound, shows strong anti-inflammatory activity and has a potential to be a leading therapeutic agent in the future.

Pectolinarigenin from the leaves of Clerodendrum volubile shows potent immunomodulatory activity by inhibiting T - cell proliferation and modulating respiratory oxidative burst in phagocytes.

There have been increasing interest in the use of plant-derived substance as immunomodulators for the treatment and management of inflammatory ailments. Clerodendrum volubile, a leafy vegetable is known for its folkloric applications in the treatments of several inflammatory related ailments, but with little scientific evidence. This study reports the isolation, structure elucidation and in vitro immunomodulatory potentials of pectolinarigenin from C. volubile leaves. The immunomodulatory potentials of the crude methanolic extract and fractions [n-hexane (Hex), dichloromethane (DCM), ethyl acetate (EtOAc) and n - butanol (BuOH)] were investigated on whole blood, neutrophil and macrophage phagocytic respiratory burst using luminol-amplified chemiluminescence technique. DCM fraction showed higher inhibitory activity on respiratory burst, indicating high suppressive immunomodulatory potency. The DCM fraction was further fractionated using a gravity column chromatography loaded with silica gel. The column was eluted with mixtures of Hex and DCM (92.5:7.5) in increasing order of polarity up to Hex: DCM (88:12) to afford 5,7-Dihydroxy-6,4'-dimethoxyflavone (pectolinarigenin). The structure of the compound was established using data obtained from 1H- and 13C NMR spectroscopies and mass spectrometry. The isolated flavone was investigated for its inhibitory activity of neutrophil phagocytes respiratory burst as well as T - Cell proliferation. The compound exhibited significant activities (at p <0.05) indicating high suppressive immunomodulatory potency. The potent suppressive effect of pectolinarigenin on polymorphonuclear neutrophils (PMNs) respiratory oxidative burst and T - cell proliferation suggests an immunomodulatory potential and pathway of the flavonoid.

Interleukin-4 receptor signaling and its binding mechanism: A therapeutic insight from inhibitors tool box.

Studies on Interlukin-4 (IL-4) disclosed great deal of information about its various physiological and pathological roles. All these roles depend upon its interaction and signaling through either type-I (IL-4Rα/common γ-chain) or type-II (IL-4Rα/IL-13Rα) receptors. Another cytokine, IL-13, shares some of the functions of IL-4, because both cytokines use a common receptor subunit, IL-4Rα. Here in this review, we discuss the structural details of IL-4 and IL-4Rα subunit and the structural similarities between IL-4 and IL-13. We also describe detailed chemistry of type-I and type-II receptor complexes and their signaling pathways. Furthermore, we elaborate the strength of type-II hetero dimer signals in response to IL-4 and IL-13. These cytokines are prime players in pathogenesis of allergic asthma, allergic hypersensitivity, different cancers, and HIV infection. Recent advances in the structural and binding chemistry of these cytokines various types of inhibitors were designed to block the interaction of IL-4 and IL-13 with their receptor, including several IL-4 mutant analogs and IL-4 antagonistic antibodies. Moreover, different targeted immunotoxins, which is a fusion of cytokine protein with a toxin or suicidal gene, are the new class of inhibitors to prevent cancer progression. In addition few small molecular inhibitors such as flavonoids have also been developed which are capable of binding with high affinity to IL-4Rα and, therefore, can be very effective in blocking IL-4-mediated responses.

Anti-TNF-α and anti-arthritic effect of patuletin: A rare flavonoid from Tagetes patula.

Rheumatoid arthritis (RA) poses a serious health problem as a chronic autoimmune joint disease with significant mortality and morbidity. Proinflammatory cytokines TNF-α and IL-1ß, reactive oxygen species (ROS), and activated CD4(+) T-cells play key roles in the progression of arthritis. The aim of the study is to evaluate the in vitro and in vivo immunomodulatory and anti-arthritic effect of flavonoid patuletin, isolated from Tagetes patula. ELISA was applied for quantification of TNF-α and IL-1ß. Intracellular and extracellular ROS production from phagocytes was measured by the chemiluminescence technique. Proliferation of T-cells was observed using a liquid scintillation counter. Cytotoxicity was assessed by a MTT assay. The serological and histological analysis studies were performed using a rodent model of adjuvant-induced arthritis (AIA). Expression of p38 and NF-κB after treatment of compound was observed by western blotting. Patuletin showed potent inhibitory effects on TNF-α in vitro as well as inhibited the production of both cytokines in vivo. It also showed potent suppression of proliferation of T-cells and significantly inhibited the extracellular and intracellular ROS production. Patuletin revealed significant anti-inflammatory and anti-arthritic activities in the rodent model of adjuvant-induced arthritis (AIA). Histologically, it causes mild bone destruction compared to the arthritic control group, thus representing its anti-arthritic potential. Based on these studies, patuletin could be considered as a potential immunosuppressive and anti-arthritic lead candidate.

Orange Peel Extracts: Chemical Characterization, Antioxidant, Antioxidative Burst, and Phytotoxic Activities.

The search for novel drugs and alternative medicine has led to increased research in medicinal plants. Among such plants is the orange fruit. Its peels have been utilized for long as an active ingredient in most traditional medicines. This study aims at investigating the chemical properties of the hexane and dichloromethane (DCM) extracts of orange peel as well as their biological potentials. Blended peels were extracted with n-hexane and n-dichloromethane, respectively. The resulting extracts were subjected to gas chromatography mass spectrometry (GCMS) characterization. The extracts were also assayed for free radical scavenging ability against 1,1 -diphenyl -2 picrylhydrazyl (DPPH), antioxidative burst via measuring luminol -amplified chemiluminescence response in human blood, and phytotoxicity against lemna minor. GCMS analysis revealed a predominance of fatty acid methyl esters in the hexane extract, while the DCM extract had more ketone metabolites. The DCM extract had significant (p < .05) higher free radical scavenging and antioxidative burst activities compared to the hexane. Both extracts revealed a significantly (p < .05) high phytotoxicity activity. Results from this study indicated that solvent type played a vital a role in the extraction of secondary metabolites, which are responsible for the observed biological activities. The higher activities by the DCM extract can be attributed to its constituents as revealed by GCMS analysis. There is great need to explore the phytotoxicity potentials of both extracts as natural herbicides.

Methoxylated Flavones from Salvia Mirzayanii Rech. f. and Esfand with Immunosuppressive Properties.

Aerial parts of Salvia Mirzayanii was extracted with methanol. Methanol extract was suspended in water and defatted with petroleum ether. The defatted part was then partitioned between ethyl acetate and water. The ethyl acetate partition was chromatographed on a silica gel column to afford several fractions. Lymphocyte proliferation inhibitory assay of the resulted fractions was compared in-vitro and the fraction with more immunosuppressive activity was subjected to more purification to yield three methoxylated flavones: 5,7-dihydroxy,6,4'- dimethoxyflavone(1), 5-hydroxy,6,7,3',4'-tetramethoxyflavone(2) and 5,3'-dihydroxy,6,7,4'- trimethoxyflavone (3). Compounds 2 and 3 potently suppressed the proliferation of human blood lymphocytes with IC50 values of 1.3 ± 0.04 µg/mL and 1.3 ± 0.21 µg/mL in comparison with prednisolone as one of the lymphocyte suppressor drugs (IC50=1.45 ± 0.6 µg/mL). In phagocyte chemiluminescence assay, compounds 1 and 3 in peripheral mononuclear cells (PMNCs) exerted suppressive moderate activity against ROS with IC50 of 55.3 ± 0.4 and 36.2 ± 0.7 µg/mL, respectively, while compound 2 showed weak activity with IC50 values more than 100 µg/mL. In conclusion, compounds 2 and 3 have a similar suppressive effect more than compound 1 on PHA-activated lymphocyte proliferation, which might be because of their C-3' oxidation pattern of ring B. It is indicated that the presence of 3'-OH or 3'-OMe in flavone ring B, caused more anti-proliferation activity than 3'-H. Oxidative burst assay showed more activity for compound 1 which is less methoxylated than others. It also showed more activity for compounds 3 than 2, which differ only in 3'-OH instead of 3'-OMe.

Synthetic indole Mannich bases: Their ability to modulate in vitro cellular immunity.

The synthetic indole Mannich bases 1-13 have been investigated for their ability to modulate immune responses measured in vitro. These activities were based on monitoring their affects on T-lymphocyte proliferation, reactive oxygen species (ROS), IL (interleukin)-2, IL-4, and nitric oxide production. Compound 5 was found to be the most potent immunomodulator in this context. Four of the synthesized compounds, 5, 11, 12, and 13, have significant potent inhibitory effects on T-cell proliferation, IL-4, and nitric oxide production. However, none of the thirteen indole compounds exerted any activity against ROS production.

Characterization of immunomodulatory activities of honey glycoproteins and glycopeptides.

Recent evidence suggests an important role for natural honey in modulating immune response. To identify active components responsible, this study investigated the immunomodulatory properties of glycoproteins and glycopeptides fractionated from Ziziphus honey. Honey proteins/peptides were fractionated by size exclusion chromatography into five peaks with molecular masses in the range of 2-450 kDa. The fractionated proteins exhibited potent, concentration-dependent inhibition of reactive oxygen species production in zymosan-activated human neutrophils (IC50 = 6-14 ng/mL) and murine macrophages (IC50 = 2-9 ng/mL). Honey proteins significantly suppressed the nitric oxide production by LPS-activated murine macrophages (IC50 = 96-450 ng/mL). Moreover, honey proteins inhibited the phagocytosis latex bead macrophages. The production of pro-inflammatory cytokines IL-1ß and TNF-α by human monocytic cell line in the presence of honey proteins was analyzed. Honey proteins did not affect the production of IL-1ß; however, TNF-α production was significantly suppressed. These findings indicated that honey glycoproteins and glycopeptides significantly interfere with molecules of the innate immune system.

Chemical constituents of Marrubium vulgare as potential inhibitors of nitric oxide and respiratory burst.

Phytochemical investigation of the whole plant of Marrubium vulgare L., led to the isolation of three new secondary metabolites, 11-oxomarrubiin (1), vulgarcoside A (2) and 3-hydroxyapigenin-4'-O-(6"-O-p-coumaroyl)-beta-D-glucopyranoside (3), along with four known constituents 4-7 from the polar fractions of the methanolic extract. The structures of all compounds were deduced on the basis of NMR data and HRESI-MS measurements. The new constituents 1-3 exhibited moderate to low level of inhibition on nitric oxide (NO.) production. The compound 2 also showed a moderate inhibition on pro-inflammatory cytokine TNF-alpha. The new constituents 1-3 showed no inhibitory effect on Reactive Oxygen Species (ROS) production.

New inhibitors of ROS generation and T-cell proliferation from Myrtus communis.

Phytochemical investigation on Myrtus communis Linn. afforded myrtucommuacetalone (1) with an unprecedented carbon skeleton and a new phloroglucinol-type compound, myrtucommulone M (2), along with four known constituents 3-6. Their structures were established by extensive analyses of NMR and mass spectral data as well as by single-crystal X-ray diffraction studies. These constituents were evaluated for their ability to modulate the immune response, based on their effects on various components of immune system. Compounds 1 and 5 exhibited significant inhibitory effect against nitric oxide (NO(•)) production. Compound 1 also exhibited significant antiproliferative activity (IC50 < 0.5 µg/mL) against T-cell proliferation. Myricetin (3) exerted a significant inhibition (IC50 = 1.6 µg/mL) on zymosan-stimulated whole blood phagocytes ROS production. Compounds 1 and 3 were active against PMA-stimulated ROS generation.

Identification of novel Interleukin-2 inhibitors through computational approaches.

Interleukin-2 (IL-2), is a 15.5-kDa cytokine that is now emerging as a target in drug discovery for novel therapeutic approaches in several autoimmune disorders. In an attempt to identify new inhibitors for the IL-2/IL-2R interaction, virtual screening (VS) was performed. Four different docking programs (GOLD, FlexX, Glide, and LigandFit) in combination with several scoring functions were used to identify novel IL-2/IL-2R interaction inhibitors.VSof a database of 6,000compounds resulted in the identification of three novel and moderately active hits with IC50 values ranging from 6.6 to 44.3 µM. Furthermore, the effect of these three compounds on the expression of IL-2Rα was assessed. The three active hits showed dose-dependent inhibitory effects on the expression of IL-2Rα with an IC50 range of 5.8 to 140µM. The cytotoxicity of these active hits was assessed using three normal cell-lines: bovine kidney cell-line (MDBK), mouse fibroblast cell-line (3T3), and rat hepatocytes cell-line (CC-1).Thecompoundswere found to have negligible cytotoxicity compared to their IC50 as IL-2/IL-2R interaction inhibitors. These results demonstrate that our VS protocol can identify novel inhibitors for IL-2/IL-2R interaction that effectively suppress IL-2 production, as well as the expression of IL-2Rα. Optimization of these molecules could lead to improved and effective anti-inflammatory therapeutics.

Identification of anti-inflammatory and other biological activities of 3-carboxamide, 3-carbohydrazide and ester derivatives of gatifloxacin.

BACKGROUND: Seventeen 1,4-dihydroquinoline-3-carboxamide and 1,4-dihydroquinoline-3-carbohydrazide derivatives of gatifloxacin have been prepared with a facile one step synthesis aiming to improve antibacterial, antifungal and immunological activities. The methodology allows the introduction of a variety of substituents such as amines, alcohol, phenol, amides and alkyl halides into the core structure of gatifloxacin. RESULTS: The analog N-(3-aminophenyl)-1-cyclopropyl-6-fluoro-8-methoxy-7-(3-methylpiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxamide has been identified as a potentially excellent anti-inflammatory agent, which exhibited highly potent effects on the oxidative burst activity of whole blood phagocytes (IC50 <12.5 µg mL-1), neutrophils (IC50 <0.1 µg mL-1) and macrophages phagocytes (IC50 <3.1 µg mL-1) as well as potent T-cell proliferation inhibitory effect (IC50 3.7 µg mL-1) while having comparable antibacterial activity to gatifloxacin. Another analog, 1-cyclopropyl-6-fluoro-8-methoxy-7-(3-methylpiperazin-1-yl)-4-oxo-N-phenyl-1,4-dihydroquinoline-3-carbohydrazide has tremendous T-cell proliferation inhibitory effect IC50 <3.1 µg mL-1 as compared to prednisolone, whereas, 3,5-dihydroxyphenyl1-cyclopropyl-6-fluoro-8-methoxy-7-(3-methylpiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate and 2-hydroxyphenyl-1-cyclopropyl-6-fluoro-8-methoxy-7-(3-methylpiperazin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate envision good inhibitory activity on T-cells proliferation (IC50 6.8 & 8.8 µg mL-1 respectively). CONCLUSIONS: The structural modification at carboxylic group has resulted in improved anti-inflammatory activities with comparable antibacterial activity to gatifloxacin. We believe that C3 structural modifications of gatifloxacin are definitely important in bringing major immunomodulatory changes in these compounds.

Immunomodulatory properties of S- and N-alkylated 5-(1H-indol-2-yl)-1,3,4-oxadiazole-2(3H)-thione.

A series of S- and N-alkylated indolyloxadiazoles 2-7 were prepared. All compounds were tested for their immunomodulatory activity against T-cell proliferation, oxidative burst and cytokine analysis. Compounds 1, 2a, 2b, 2c and 2k demonstrated highly significant (P ≤ 0.005) inhibition on PHA activated T-cell proliferation with IC(50) less than 3 µg/mL concentration, while 3b exert a moderate inhibitory effect with IC(50) 8.6 µg/mL. Among all compounds of the series, only 2h was found to suppress phagocytes ROS production (IC(50) 2.4 µg/mL) in luminol-based chemiluminescence (CL) assay. Compounds 2a-k have stimulatory effect on proinflammatory cytokine predominantly IL-1ß but no effect on IL-4 and NO production indicating that these compounds might have selective inhibitory effect on T-cell proliferation. Cytotoxic effect on T-cell proliferation was tested on NIH-3T3 mouse fibroblast normal cell line. All compounds were found to be free from toxic effects up to 100 µM concentration.

New immunosuppressive cyclomyrsinol diterpenes from Euphorbia kopetdaghi Prokh.

Aceton: chloroform (1:2) extracts of the aerial parts of Euphorbia kopetdaghi Prokh. (Euphorbiaceae) were investigated for its diterpenoids and afforded three new five-membered ring, pentacyclic myrisinane polyester comprised of 3,5,10-O-triacetyl-8-O-isobutanoyl-14-O-benzoylcyclomyrsinol (1), 3,5,10,14-O-tetraacetyl-8-O-(2'-methyl butanoyl)-cyclomyrsinol (2) and 3,5,10,14-O-tetracetyl-8-O-isobutanoylcyclomyrsinol (3). The structures were elucidated based on (13)C- and (1)H-NMR as well as 2D-NMR, IR and different MS spectra and the immunomodulation activity for compound 1 was evaluated through lymphocyte proliferation assay, IL-2 assay, oxidative burst of phagocytic leukocytes and through their cytotoxicity on two cell lines. Compound 1 showed significant suppressive activity against phytohemagglutinin-activated T-cell proliferation with an IC(50) of 1.83 µg mL(-1), IL-2 suppressive activity with an IC(50) of 19.0 µg mL(-1) and oxidative burst suppressive activity with an IC(50) of 1.6 µg mL(-1) and ignorable cytotoxic effect on the CC-1 rat hepatocyte and 3T3-L1 mouse fibroblast cell-lines.

Synthesis of new bergenin derivatives as potent inhibitors of inflammatory mediators NO and TNF-α.

Bergenin is an isocoumarin natural product which aides in fat loss, healthy weight maintenance, enhancing the lipolytic effects of norepinephrine, inhibiting the formation of interleukin 1α and cyclooxygenases-2. Here we describe the anti-inflammatory activity of new bergenin derivatives 1-15 in the respiratory burst assay. Bergenin was isolated from the crude extract of Mallotus philippenensis after repeated column chromatography and was then subjected to chemical derivatization. The structures of all compounds were elucidated by NMR and mass spectroscopic techniques. Compound 2 was also studied using single crystal X-ray diffraction. Compounds 4, (54.5±2.2%) 5 (47.5±0.5%) 5, and 15 (86.8±1.9%) showed significant (P≤0.005) NO inhibitory activities whereas 6, 7, 11, 12 and 13 displayed moderate inhibitory activities that ranges between 16% and 31%. Furthermore compounds 4 and 15, were discovered as significant (P≤0.005) TNF-α inhibitors with 98% and 96% inhibition, respectively, while compounds 3, 5, 7, 8, 11, and 12 showed low level of TNF-α inhibition (0.4-28%). Compounds 8, 13 and 15 exhibited moderate anti-inflammatory IC(50) activities with 212, 222, and 253 µM, respectively, compared to the standard anti-inflammatory drug indomethacin as well as the parent bergenin compound. No cytotoxic effects could be detected when the compounds were tested on 3T3 cells up to concentrations of 100 µM.

In silico and in vitro immunomodulatory studies on compounds of Lindelofia stylosa.

Lindolefia stylosa (Kar. and Kir.) is an important medicinal plant in Central and West Asia. Compounds 1 (ethyl lithospermate), 2 (methyl lithospermate), 3 (lithospermate B), 4 (rosmarinic acid), 5 (methyl rosmarinate), 6 (ethyl rosmarinate), 7 (3-O-feruloyl-6'-O-coumaroyl sucrose), 8 (3-O-feruloyl-6'-O-caffeoyl sucrose), 9 (3,6'-O-diferuloyl sucrose), 10 (3,6'-O-diferuloyl-1-kestose), 11 (3-O-feruloyl-6'-O-coumaroyl-1-kestose), 12 (3,6'-O-diferuloyl nystose), 13 (3-O-Feruloyl-6'-O-coumaroyl nystose), 14 (p-coumaric acid), 15 (ferulic acid), 16 (naphthalene glycoside (8-O-ß-D-glucopyranoside)), and 17 (4'-hydroxy-5-methoxy-6,7-methylenedioxyisoflavone), isolated from this plant, were evaluated for their ability to modulate the immune response. Studies included monitoring the effect on reactive oxygen species (ROS) production, T-lymphocyte proliferation, and inhibition of four cytokines (IL-2, TNFα, IL-1ß, and IL-4). These cytokines play a major role in immune response modulation. Molecular docking studies on selected compounds were also conducted, which predict a potent activity of compounds 5 and 6 and moderate activity of compounds 1 and 2 as inhibitors of IL-2. Correlation between the predicted binding scores and the experimental results was found to be valid. Compound 5 was identified as the most potent IL-2 inhibitor in the series.

Effect of natural honey on human platelets and blood coagulation proteins.

Present study was conducted to determine the effects of honey on blood hemostasis, in-vitro effect of honey was observed on platelet aggregation and blood coagulation employing, activated partial prothrombin time (aPTT), prothrombin time (PT), thrombin time (TT) and fibrinogen levels in blood. Honey samples showed moderate inhibition of platelet aggregation with IC(50) 5-7.5%. The coagulation assays showed that at higher concentrations (>15%) honey samples increased whole blood clotting time. When assayed in platelet poor plasma (PPP), honey samples significantly (P>0.005) prolonged aPTT, PT, and TT. The honey samples (at 3.75% and 7.5% concentrations) cause mean increment of aPTT = 19±10% and 62±10%; PT 6±5% and 40±5%; TT 35±15% and 112±30% respectively. Moreover, PPP isolated from whole blood pre-incubated with honey samples (9.0% for 10 minutes) showed mean prolongation of aPTT, PT and TT of 45±21%, 26±9% and 105±24% respectively. Interestingly, incubation of honey at 6.25% and 11.75% concentrations in PPP considerably (P≥0.005) reduced fibrinogen levels i.e. 13±4% and 86±30% respectively. The present study outlines the inhibitory effect of natural honey on platelet aggregation and blood coagulation. These observations provide first line data for modulatory role(s) of honey on process of hemostasis.

New myrsinane-type diterpenoids from Euphorbia aellenii Rech. f. with their immunomodulatory activity.

Two new 14-desoxo-10, 18-dihydromyrinsol diterpenoids (1 and 2) were isolated and characterized from the cytotoxic chloroform fraction of Euphorbia aellenii Rech. f. (Euphorbiaceae). The structures of the new compounds were elucidated by spectroscopic methods and their immunomodulatory properties were evaluated by T-cell proliferation and phagocyte chemiluminescence assays.