Group IIA secreted phospholipase A2 inhibition by elemolic acid as a function of anti-inflammatory activity

Human group IIA secreted phospholipase A2 (GIIA) is a key enzyme in inflammatory reactions, worsening the condition of several chronic inflammatory diseases. The natural inhibitors of GIIA potentially block the production of inflammatory mediators. In the present study, elemolic acid, a triterpenoid from Boswellia serrata inhibited the GIIA enzyme in a concentration-dependent manner with IC50 value of 5.70 ± 0.02 µM. The mode of GIIA inhibition was studied by increasing the concentration of the substrate from 30 to 120 nM, and calcium from 2.5 to 15 mM, the level of inhibition was not changed. The inhibitor-enzyme interaction was examined by fluorimetry and Circular Dichroism (CD) studies; elemolic acid altered intrinsic fluorescence intensity and shifted far UV- CD spectra of GIIA enzyme, suggesting the direct interaction with GIIA. Elemolic acid neutralized the GIIA mediated indirect hemolytic activity from 94.5 to 9.8% and reduced GIIA induced mouse paw edema from 171.75 to 113.68%. Elemolic acid also reduced the hemorrhagic effect of GIIA along with Vipera russelii neurotoxic non-enzymatic peptide -VNTx-II (VR-HC-I). Thus, the elemolic acid has been proven as a potent inhibitor of GIIA enzyme and modulated the GIIA induced inflammatory response by in situ and in vivo methods.

Synthesis and characterization of Zinc oxide nanoparticles utilizing seed source of Ricinus communis and study of its antioxidant, antifungal and anticancer activity

ZnO nanoparticles have been synthesized using solution combustion technique and its antioxidant, antifungal, anticancer activity was studied. Ricinus communis plant seed extract used as fuel in synthesis by the solution combustion technique. Powder X-ray diffraction (PXRD) demonstrates the arrangement of a crystalline hexagonal stage (ICDD card number 89-1397) with space aggregate P63mc (186) and cell parameters a = b = 3.253, c = 5.213 Å. The normal crystallite measure is 20 nm which is ascertained by Debye - Scherer's formula. The Purity of the sample and metal to oxygen bond development was affirmed by utilizing Fourier transformation infrared (FTIR) spectroscopy and the particle size and shape was confirmed by HRTEM. Antifungal action of ZnO NPs was studied against Aspergillus and Penicillium by well dispersion strategy. The antifungal activity shows that ZnO NPs constitute as an effective fungicidal agent against both Aspergillus (4 ± 0.5 mm) and Penicillium (3 mm ± 0.4 mm) at 30 μg/mL fixation. ZnO nanoparticles were subjected to antioxidant activity. The objective of the study was to analyze the anticancer property of ZnO NPs on MDA-MB 231 cancer cells. To check the efficacy of the synthesized drug ZnO NPs MTT assay was performed, that determines % viability and/or cytotoxicity. IC₅₀ of ZnO NPs in case of MDA-MB-231 breast cancer was 7.103 μg/mL. Anticancer outcome demonstrates that ZnO NPs is active against in MDA-MB-231 cells.

Therapeutic potential of Polyalthia cerasoides stem bark extracts against oxidative stress and nociception

BACKGROUND

Polyalthia cerasoides is a medicinal plant known for its ethnopharmacological importance. Despite this, investigation related to its therapeutic benefit is still unexplored.

AIM

To evaluate the stem bark extracts of Polyalthia cerasoides for pharmacological activities relating to inflammation, nociception and oxidative stress using in vivo and in vitro models.

MATERIALS AND METHODS

Pet ether, ethyl acetate and chloroform fractions of the stem bark were evaluated for anti-inflammatory activity by carrageenan-induced hind paw edema in rats. Anti-nociceptive activity in mice was assessed using thermally and chemically induced analgesic models. The free radical quenching potential of the extracts was initially analyzed using the in vitro DPPH photometric assay, Hydroxyl radical scavenging and Lipid Peroxidation assays. Then modulatory effect of the extracts on in vivo antioxidant system was evaluated by carbon tetrachloride induced hepatotoxicity and subsequent measurements of antioxidant enzymes such as Superoxide dismutase, Catalase and Peroxidase from the liver homogenate.

RESULTS

Among the tested fractions, ethyl acetate extract had substantially inhibited the inflammation by 68.5% that was induced by subcutaneous carrageenan injection whereas pet ether and chloroform extract showed only minimal inhibitory effect. Investigation of the anti-nociceptive activity revealed that the ethyl acetate fractions had significantly repressed the algesia in both the analgesic experimental models. In vitro and in vivo individual antioxidant assays demonstrated that the ethyl acetate fraction has strong free radical quenching potential which also restores the endogenous hepatic enzymes.

CONCLUSION

The ethyl acetate fraction enriched with flavinoids and steroids from Polyalthia cerasoides stem bark has potent bioactivity to combat inflammation, ROS and pain. This needs further characterization for potential therapeutic applications.

Pharmacological Potential of Tetrahydrofurano/Pyrano Quinoline and Benzo[b]furoindolyl Derivatives in Acute Inflammation, Pain and Oxidative Stress

OBJECTIVE

Investigation of the pharmacological potential of Tetrahydrofurano/pyrano quinoline and Benzo [b]furoindolyl derivatives in acute inflammation, pain and oxidative stress.

METHODS

Tetrahydrofurano/ pyrano quinoline and Benzo[b]furoindolyl were evaluated for anti-inflammatory activity by carrageenan-induced hind paw edema in rats. Analgesic activity in mice was assessed by both peripheral and central analgesic models. The free radical scavenging activity of the synthetic compound was analyzed by the in vivo antioxidant assays, by measuring the antioxidant enzymes such as Superoxide dismutase (SOD), Catalase and Peroxidase from the liver homogenate and the in vitro antioxidant activity was evaluated by DPPH photometric assay, Hydroxyl radical scavenging and Lipid Peroxidation assay.

RESULTS

The compounds had substantially inhibited the inflammation induced by subcutaneous carrageenan injection. The same compounds had demonstrated remarkable central and peripheral analgesic activity with potent free radical scavenging activity as evident from both in vitro and in vivo antioxidant assays.

CONCLUSION

Tetrahydrofurano/pyrano quinoline and Benzo[b]furoindolyl derivatives exhibit varied pharmacological activities that include anti-inflammatory, analgesic and antioxidant activity.

Thrombin like activity of Asclepias curassavica L. latex: action of cysteine proteases

AIM OF THE STUDY

To validate the scientific basis of plant latex to stop bleeding on fresh cuts. Cysteine protease(s) from Asclepias curassavica (Asclepiadaceae) plant latex was assessed for pro-coagulant and thrombin like activities.

MATERIALS AND METHODS

A waxy material from the latex of Asclepias curassavica latex was removed by freezing and thawing. The resulted latex enzyme fraction was assayed for proteolytic activity using denatured casein as substrate. Its coagulant activity and thrombin like activity were determined using citrated plasma and pure fibrinogen, respectively. Inhibition studies were performed using specific protease inhibitors to know the type of protease.

RESULTS

The latex enzyme fraction exhibited strong proteolytic activity when compared to trypsin and exerted pro-coagulant action by reducing plasma clotting time from 195 to 58 s whereas trypsin reduced clotting time marginally from 195 to 155 s. The pro-coagulant activity of this enzyme fraction was exerted by selectively hydrolyzing A alpha and B beta subunits of fibrinogen to form fibrin clot when pure fibrinogen was used as substrate as assessed by fibrinogen-agarose plate method and fibrinogen polymerization assay. Trypsin failed to induce any fibrin clot under similar conditions. The electrophoretic pattern of latex enzyme fraction-induced fibrin clot was very much similar to that of thrombin-induced fibrin clot and mimic thrombin like action. The proteolytic activity including thrombin like activity of Asclepias curassavica latex enzyme fraction was completely inhibited by iodoaceticacid (IAA).

CONCLUSION

Cysteine proteases from Asclepias curassavica latex exhibited strong pro-coagulant action and were found to be specific in its action (Thrombin like). This could be the basis for the use of plant latex in pharmacological applications that justify their use as folk medicine.

Anti-inflammatory activity of oleanolic acid by inhibition of secretory phospholipase A2

Oleanolic acid, a triterpenoid known for its anti-inflammatory properties, is commonly present in several medicinal plants. The present study evaluated the effect of oleanolic acid on sPLA (2), a key enzyme in inflammatory reactions. Oleanolic acid inhibited sPLA (2) activities of human synovial fluid (HSF), human pleural fluid (HPF) and VIPERA RUSSELLI (VRV-PL-V) and NAJA NAJA (NN-PL-I) snake venoms in a concentration-dependent manner. The IC (50) values of sPLA (2) from these sources ranged from 3.08 to 7.78 muM. Increasing calcium (Ca (2+)) concentrations from 2.5 to 15 mM and substrate concentration up to 180 nM did not affect the level of inhibition. Oleanolic acid enhanced the relative intrinsic fluorescence intensity of sPLA (2) (VRV-PL-V). In the presence of oleanolic acid, an apparent shift in the far UV-CD spectrum of sPLA (2) was observed. These studies indicate direct interaction with the enzyme and formation of an sPLA (2)-oleanolic acid complex. The complex formed resulted in irreversible inhibition of sPLA (2). Oleanolic acid inhibited indirect hemolytic activity and mouse paw edema induced by sPLA (2). Inhibition of IN VITRO and IN VIVO sPLA (2) activity by oleanolic acid explains the observed anti-inflammatory properties of several oleanolic acid-containing medicinal plants.

Synthesis and evaluation of tricyclic dipyrido diazepinone derivatives as inhibitors of secretory phospholipase A2 with anti-inflammatory activity

A series of tricyclic dipyrido diazepinone derivatives 6(a-f) bearing different substituents at the tenth position of diazepinone ring were designed and are characterized by 1H NMR, FTIR and X-Ray crystallography studies. The synthesised derivatives are tested in-vitro phospholipase A2 (PLA2) enzyme inhibitory activity and in-vivo anti-inflammatory activity against purified group I and group II PLA2 enzymes from the snake venom and human pleural fluid. Compounds bearing aromatic ring with different substituents at different positions shown varied specificity. The 6f derivative with strong electron withdrawing nitro (-NO2) and trifluoromethyl (-CF3) groups at ortho and para positions respectively shown greater inhibitory activity. Inhibitory effect of the compound appeared to be direct interaction with active site and likely competes with substrates as supported by substrate dependent and calcium independent assays. The IC50 value of potent PLA2 inhibitor 6f was 22.1 microM and showed similar potency in the neutralization of in vivo PLA2 induced mouse paw edema and hemolytic activity.