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Chemoprotective Effect (chemoprotective + effect)
Selected AbstractsChemoprotective effect of plant phenolics against anthracycline-induced toxicity on rat cardiomyocytes.PHYTOTHERAPY RESEARCH, Issue 7 2004Part III. Abstract Flavonoids are found universally in plants and act as free radical scavenging and chelating agents with antiin,ammatory, antiischemic, vasodilating and chemoprotective properties. In this study, the antilipoperoxidative and cytoprotective effects of apigenin, baicalein, kaempferol, luteolin and quercetin against doxorubicin-induced oxidative stress were investigated in isolated rat heart cardiac myocytes, mitochondria and microsomes. After preincubation of cardiomyocytes with the test compounds for 1 h the cardiomyocytes were treated with the toxic agent, doxorubicin (100 µM for 8 h). Cardiomyocyte protection was assessed by extracellular LDH and cellular ADP and ATP production. Cytoprotection was concentration dependent for baicalein > luteolin , apigenin > quercetin > kaempferol. All test compounds had signi,cantly better protective effects than dexrazoxan, an agent currently used for adjuvant therapy during anthracycline antibiotic therapy. In microsomes/mitochondria the IC50 values of lipid peroxidation inhibition for quercetin, baicalein, kaempferol, luteolin, and apigenin were 3.1 ± 0.2/8.2 ± 0.6, 3.3 ± 0.3/9.6 ± 0.5, 3.9 ± 0.3/10.1 ± 0.8, 22.9 ± 1.7/18.2 ± 0.7, and 338.8 ± 23.1/73.1 ± 6.4 mM, respectively. The antilipoperoxidative activity of apigenin differed from its cytoprotective effects, but correlated with the free radical scavenging of 2,2-diphenyl-1-picrylhydrazyl radical and half peak oxidation potential (Ep/2). Apigenin was the least effective of the ,avonoids studied in all models except the cardiomyocyte model where its cardiomyocyte cytoprotective effect was comparable to other compounds. Copyright © 2004 John Wiley & Sons, Ltd. [source] Chemoprotective effect of plant phenolics against anthracycline-induced toxicity on rat cardiomyocytes.PHYTOTHERAPY RESEARCH, Issue 2 2004Part I. Silymarin, its flavonolignans Abstract Silymarin, an extract of ,avonolignans from the dried fruits of milk thistle (Silybum marianum L. Gaertneri) and its constituents silibinin, dehydrosilibinin, silychristin and silydianin were tested for protective effects on rat cardiomyocytes exposed to doxorubicin. Silymarin and individual ,avonolignans did not exert cytotoxicity in the range 25,100 µm (incubation 9 h). Dehydrosilibinin was tested only at 25 µm concentration due to its low solubility. All substances increased the cell ATP level. Silymarin and ,avonolignans displayed a dose-dependent cytoprotection against doxorubicin (100 µm, incubation 8 h). The protective effects of silymarin, silibinin, dehydrosilibinin and silychristin were comparable to that of dexrasoxane, while silydianin exerted the best protective effect. The ability of silymarin complex and its components to protect cardiomyocytes against doxorubicin-induced oxidative stress is due mainly to their cell membrane stabilization effect, radical scavenging and iron chelating potency. Copyright © 2004 John Wiley & Sons, Ltd. [source] Lysosomal abnormalities during benzo(a)pyrene-induced experimental lung carcinogenesis , defensive role of capsaicinFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2009P. Anandakumar Abstract The objective of the present study was to investigate whether lysosome is a target in benzo(a)pyrene-induced, oxidative stress-mediated lung cancer in Swiss albino mice and the plausible role of the phytochemical substance capsaicin in mitigating lysosomal damage. Oxidative stress was assessed based on the level of carbonyl content. The activities of lysosomal proteases like cathepsin-D, cathepsin-B, ,- d -glucosidase, ,- d -galactosidase, ,- d -glucuronidase, ,- d - N -acetylglucosaminidase and acid phosphatase were assessed to evaluate lysosomal function. Administration of benzo(a)pyrene (50 mg/kg body weight) to mice induced a increase in the activities of lysosomal enzymes and oxidative stress was evident by the increase in carbonyl content. Treatment with capsaicin (10 mg/kg body weight) decreased carbonyl content and restored the activities of lysosomal enzymes to near normalcy. Transmission electron microscopic study of lysosomes further showed the defensive action of capsaicin against the lysosomal damage caused in benzo(a)pyrene-induced lung cancer. From the present study, it can be concluded that lysosomal damage is an indispensable event in benzo(a)pyrene-induced lung cancer, and capsaicin was able to effectively prevent it, which proves the chemoprotective effect of capsaicin against benzo(a)pyrene-induced experimental lung carcinogenesis. [source] Date seed oil limit oxidative injuries induced by hydrogen peroxide in human skin organ cultureBIOFACTORS, Issue 2-3 2007Ines Dammak Abstract The skin is chronically exposed to pro-oxidant agents, leading to the generation of reactive oxygen species (ROS). To protect the skin against an over-load of oxidant species, we studied the chemoprotective effect of one new natural product: "date seed oil: DSO". This oil may serve as a potential source of natural antioxidants such as phenols and tocopherols. Here, the antioxidative potential of DSO was compared that of to extra virgin olive oil. Adult human skin was maintained in organ culture in the presence of the DSO and extra virgin olive oil before the addition of hydrogen peroxide (H2O2 ), in order to prevent the tissue from its oxidizing effects. Skin specimens were collected for histology and for melanin studies. In the investigated model system, DSO protects skin against oxidative injuries. It has a significant chemoprotective effect, by inhibition of damage caused by H2O2 compared with specimens without such addition endowing with a radical scavenging ability. The various components from DSO were much more potent antioxidant and more free radical scavengers of the H2O2 than those of olive oil. Our study shows that topical DSO treatment of the skin stimulates events in the epidermis leading to repair skin damage possibly due to antioxidant synergisms. [source] | ||||||||||