Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

Objective:To investigate thein vitroantioxidant potential of Carica papaya(C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation.Methods:Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract(at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage.Results:Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities usingin vitro models in a concentration dependent manner(P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid(P<0.05). The IC50values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid(the reference antioxidant) possessed higher activity than the extract.Conclusions:The findings show that C. papayaleaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy.Thus, the leaves can be exploited for pharmaceutical and nutritional purposes.

人的 U937 房间生存能力和激活的 cadmiummediated 改变上的芙蓉 sabdariffa extractivities

【正】Objective:To investigate the effect of the anthocyanin-rich extract of Hibiscus sabdariffa (H.sabdariffa) calyx on the viability of cadmium-treated 1937 cells and cadmium—mediated activation of 0937-derived macrophages.Methods:The macrophage cell line U937 was treated with cadmium(0.1μmol/L) and later incubated with the anthocyanin-rich extract and cell viability was assessed via trypan blue staining.In the other experiment,the U937 cells were transformed to the macrophage form by treatment with phorbol 12.myristate 13.and acetate and incubated with cadmium(10μmol/L).The anthocyanin-rich extract was added to the cells later and subsequently,the supernatant of each cell culure was analysed lor the production of tumour necrosis factor-alpha(TNF-α).interleukin 1(IL-1).interleukin 6(IL-6).nitric oxide, and catalase activity as indices for the activation of macrophages.Results:It revealed that the anthocynanin-rich extract significantly(P 【 0.05) increased the viability of the cells which was suppressed by cadmium when compared to quercelin dihydrate.The extract also reduced the cadmium—mediated production of the markers of macrophage—activation when compared to quercelin dihydrate.In both experiments,the activity of the extract was concentrationdependent (P 【 0.05).Conclusion:The findings show that H.sabdariffa possesses significant immunoprotective effect.These corroborate the immense reported antioxidant and medicinal potential of the calyces of the plant which could be exploited for pharmacological and neutraceutical advantages.

Quality of Some Nigerian Coals as Blending Stock in Metallurgical Coke Production

Two Nigerian coals, Lafia-Obi and Chikila were blended in the mass ratio of 70:30 with imported American and Polish coking coals. Proximate analysis, free swelling index, Ruhr dilatometer and Gieseler plastometer were used in assessing the coking qualities of both the single coals and the blends. The results show that the blends are lower in moisture and ash contents;higher in volatile matter and fixed carbon than the single Nigerian coals. The rheological parameters revealed superiority in thermo-plastic properties of the blends over the unblended local coals. Lafia-Obi/Foreign coals blends possess lower ash and better rheological properties compared to Chikila/Foreign coal composites which have high ash and poor rheological properties. These together suggest that amongst the two Nigerian coals, Lafia-Obi is superior for blending with the foreign ones in metallurgical coke production.

Some bioactive potentials of two biflavanols isolated from Garcinia kola on cadmium-induced alterations of raw U937 cells and U937-derived macrophages

Objective:To investigate the abilities of two flavonoids - Garcinia hiflavanol-1(GB-1) and Garcinia biflavanol-2(GB-2) from Garcinia kola(G.kola) in reducing cadmium-induced effects on raw U937 cells and 11937-derived macrophages.Methods:Macrophage U937 cells were incubated with cadmium followed by treatment with the flavonoids and cell viability assessed via trypan blue staining.In the other experiment,the U937 cells were transformed to the macrophage form and treated with cadmium in order to activate them.The cells were later incubated with the flavonoids and finally the supernatant of each cell culture was analysed for the secretion of nitric oxide,catalyse activity,and the release of tumour necrosis factor-alpha,interleukin-1 and interleukin-2 as indices of macrophage activation.Quercetin(a flavonol) was used as the reference flavonoid in all experiments.Results:It revealed that the flavonoids significantly increased the viability of the cells and also reduced the cadmium-induced activation of the macrophage cells in a concentration-dependent manner.The flavanols GB-1 and GB-2 possessed higher activities than quercetin in all cases(P【0.05).Garcinia biflavanol-2 possessed a higher bioactivity than GB-1 significantly(P【0.05).Conclusions:In addition to corroborating the several reported importance of G.kola as a potential neutraceutical and pharmacological condiment,the study also clearly indicates the role hydroxylation especially at the 3’- position of polyphenols could play in enhancing bioactivities of flavonoids.

Synthesis,Crystal Structure and Conformational Analysis of (E)-5-Methoxy-2-((4-methoxyphenylimino)methyl)phenol

The title compound,（E）-5-methoxy-2-（（4-methoxyphenylimino）methyl）phenol（C15H15NO3）,crystallizes in monoclinic,space group P21/c with a=9.4361（6）,b=10.6212（5）,c=12.9338（9）,β=93.064（5）o,V=1294.41（14）3,Z=4,Dc=1.320 g/cm3,F（000）=544,Rint=0.116,T=296 K,μ=0.09 mm-1,the final R=0.051 and wR=0.148 for 1836 observed reflections with I2σ（I）.An extensive two-dimensional network of C–H…O hydrogen bonds and π-ring interactions are responsible for the crystal stabilization.Intermolecular hydrogen bonds and C–H…π interactions produce R22（14）,R44（30） and R44（31） rings.In addition to the molecular geometry from X-ray experiment,the molecular geometry of the title compound in the ground state has been calculated using the semi-empirical（AM1 and PM3） and density functional theory method（DFT）（B3LYP） with 6-31G（d） basis set.To determine the conformational flexibility,molecular energy profile of the title compound was obtained by semi-empirical（PM3 and AM1） and DFT/B3LYP calculations with respect to the selected degree of torsional freedom,which varied from –180° to ＋180° in a step of 10°.

(E)-1-[4-(2-hydroxy-5-methoxybenzylideneamino)-phenyl]ethanone and (E)-1-[4-(2-hydroxy-4-methoxybenzylideneamino) phenyl]ethanone:X-ray and DFT-calculated structures

The isomeric structures of（E）-1-[4-（2-hydroxy-5-methoxybenzylideneamino）-phenyl] ethanone（I） and（E）-1-[4-（2-hydroxy-4-methoxybenzylideneamino） phenyl]ethanone（Ⅱ） ,both C16H15NO3,have been determined using X-ray diffraction techniques and characterized by IR,and their molecular structures have also been optimized at the B3LYP/6-31G（d,p） level using density functional theory（DFT） . The energetic behaviors of the title compounds in solvent media have been examined using B3LYP method with the 6-31G（d,p） basis set by applying the polarizable continuum model（PCM） . The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition,DFT calculations of the title compounds＇ molecular electrostatic potentials（MEP） were performed at the B3LYP/6-31G（d,p） level of theory. X-ray study shows that the title compounds both have strong intramolecular O-H…N hydrogen bonds. The molecules of Ⅰ are linked into a one-dimensional framework structure by C-H…π interactions,while in Ⅱ,intermolecular π···π interactions result in the formation of infinite chains running along the [010].