Intra-peritoneal application of catechins and EGCG as in vivo inhibitors of ozone-induced oxidative stress

Simos, Yannis V.; Karkabounas, Spyridon; Verginadis, Ioannis I.; Charalampidis, Pavlos S.; Filiou, D.; Charalabopoulos, Konstantinos; Zioris, Ioannis V.; Kalfakakou, Vasiliki; Evangellou, A.

doi:10.1016/j.phymed.2010.10.011

Cited by 12 publications

(13 citation statements)

References 30 publications

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“…A number of studies have shown the beneficial effects of ozone as an antioxidant agent in several pathologies and IR injury of several organs . The ability of ozone therapy to block the disruptive effects of IR injury on the cochlea in the present study is similar to its protective effect reported in other studies, which administered ozone under different experimental protocols and in other organ systems . Ozone preconditioning decreased IR injury in the kidney by increasing the activity of SOD and GSH‐Px enzymes and preventing the induction of ROS .…”

Section: Discussionsupporting

confidence: 85%

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Ozone Prevents Cochlear Damage From Ischemia–Reperfusion Injury in Guinea Pigs

Önal¹,

Elsürer

Selimoglu³

et al. 2017

Artificial Organs

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The cochlea is an end organ, which is metabolically dependent on a nutrient and oxygen supply to maintain its normal physiological function. Cochlear ischemia and reperfusion (IR) injury is considered one of the most important causes of human idiopathic sudden sensorineural hearing loss. The aim of the present study was to study the efficacy of ozone therapy against cochlear damage caused by IR injury and to investigate the potential clinical use of this treatment for sudden deafness. Twenty-eight guinea pigs were randomized into four groups. The sham group (S) (n = 7) was administered physiological saline intraperitoneally (i.p.) for 7 days. The ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 days. In the IR + O group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 days before IR injury. On the eighth day, the IR + O group was subjected to cochlear ischemia for 15 min by occluding the bilateral vertebral artery and vein with a nontraumatic clamp and then reperfusion for 2 h. The IR group was subjected to cochlear IR injury. After the IR procedure, the guinea pigs were sacrificed on the same day. In a general histological evaluation, cochlear and spiral ganglionic tissues were examined with a light microscope, and apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The apoptotic index (AI) was then calculated. Blood samples were sent for analyses of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase, malondialdehyde (MDA), the total oxidant score (TOS), and total antioxidant capacity (TAC). Data were evaluated statistically using the Kruskal-Wallis test. The AI was highest in the IR group. The AI of the IR + O group was lower than that of the IR group. The biochemical antioxidant parameters SOD and GSH-Px and the TAC values were highest in the O group and lowest in the IR group. The MDA level and TOS were highest in the IR group and lowest in the O group. Controlled ozone administration stimulated endogenous antioxidant defense systems, thereby helping the body to combat IR injury. Although this study revealed a statistically significant decrease in cochlear IR damage following ozone therapy, further studies will be necessary to explain the protective mechanisms of ozone therapy in cochlear IR injury.

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Section: Discussionsupporting

confidence: 85%

“…Ozone maintains cellular antioxidant systems, including glutathione, SOD, and enzymatic reactions, and repetitive doses prepare the body to confront pathophysiological conditions, mediated by oxidative stress . In the present study, we investigated whether ozone could protect the cochlea against IR.…”

Section: Discussionmentioning

confidence: 98%

Ozone Prevents Cochlear Damage From Ischemia–Reperfusion Injury in Guinea Pigs

Önal¹,

Elsürer

Selimoglu³

et al. 2017

Artificial Organs

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“…The antioxidant action of catechin epimers was observed not only in in vitro studies but also in ex vivo and in vivo studies [12,[26][27][28]. Since pH range of different human body fluids and tissues varies widely, from pH [12]; SC 50 concentration of catechins required to give a 50 % decrease in the signal intensity of DPPH Á radical; c [24], IC 50 concentration of catechins required to give a 50 % decrease in the lipid peroxidation assay; d [14]; e [25] 1.0-2.0 in the stomach, pH 5.7-6.5 in the duodenum, pH 5.5-7.0 in the colon, pH 5.9-6.8 in jejunum, pH 6.8 in esophagus, through pH 7.3-7.7 in ileum, pH 7.4 in blood and other body fluids to the pH 7.6-8.6 in pancreas [15,16], the effect of pH on the antioxidant properties of catechin epimers may be of biological relevance.…”

Section: Resultsmentioning

confidence: 99%

The influence of stereochemistry on the antioxidant properties of catechin epimers

Muzolf-Panek

Gliszczyńska‐Świgło

Szymusiak

et al. 2012

Eur Food Res Technol

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The influence of stereochemistry on the radical scavenging activity of catechins was investigated by studying the effect of pH on the antioxidant properties of catechin epimers. The difference in the pH-dependent Trolox equivalent antioxidant capacity (TEAC) profiles was observed only in case of gallocatechin gallate (GCG) and epigallocatechin gallate (EGCG), indicating the influence of steric structure on the TEAC antioxidant activity of these galloyl moiety-containing catechins. Based on comparison of the pH-dependent TEAC values to theoretically calculated parameters, including homolytic OH bond dissociation energy and ionization potential (IP) as well as theoretically predicted structures of the most stable monoanions of GCG and EGCG, it was concluded that due to steric hindrance in GCG molecule, the IP value of GCG monoanion increases reflecting lower radical scavenging capacity of GCG in comparison with EGCG. It results in the difference in the pH-dependent TEAC profiles of these two catechin epimers at pH above 3.5. This effect does not occur for other pairs of catechin epimers of this study.

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“…Besides from presenting potent antioxidant properties in vitro, these compounds have also the ability to modulate the activity of the antioxidant defense enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase. [15][16][17][18][19] Flavonoids could be used alone or in combination with synthetic drugs or antibiotics to produce a new generation of phytopharmaceuticals, 20 which could have prominent applications in human diseases accompanied by free radical injury. Based on this concept, intra-peritoneal (i.p.)…”

Section: Introductionmentioning

confidence: 99%