The purpose of this study was to elucidate the effects of green tea catechins (GTC) on the lipid peroxidation and superoxide dismutase (SOD). GTC showed the high SOD activity, while significantly inhibited the peroxide value of linoleic acid (93%) and lipid petoacidation (84%) from rat liver microsomal fraction induced by Fe^(2+)/ascorbate system. The effects of GTC on the SOD and catalase activities, and lipid peroxidation after oral administration were investigated. GTC (50 mg/kg) significantly increased SOD (62%) and catalase activities (75%), while significantly inhibited the lipid peroxidation (52%) of rat liver microsome in a dose-dependent manner. These results suggest that GTC has the antioxidative effect which is related to the prevention of aging and cancer.

Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl₄ induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl₄ treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl₄. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

Phytic acid, making up 1-5% of the composition of many plant seeds and cereals, is known to form iron-chelates and inhibit lipid peroxidation. Thiobarbituric acid reactive substances (TBARS), as an indication of lipid peroxidation, were measured in beef round, chicken breast, pork loin, and halibut muscle after the meats were stored for 0, 1, 3, 5, and 7 days at various temperatures [frozen (-20℃), refrigerator (4℃), and room temperature (25℃)]. Phytic acid effectively inhibited lipid peroxidation in beef round, chicken breast, halibut, and pork loin muscle (p$lt;0.05). The inhibitory effect of phytic acid was dependent on concentration, storage time, and temperature. At frozen temperature, the inhibitory effect of phytic acid was minimal, whereas at room temperature, the inhibitory effect of phytic acid was maximal, probably due to the variation of the control TBARS values. At the concentration of 10 mM, phytic acid completely inhibited lipid peroxidation in all the muscle foods by maintaining TBARS values close to the level of the controls, regardless of storage time or temperature (p$lt;0.05). The rate of lipid peroxidation was the highest in beef round muscle, although they had a close TBARS value at 0 day. Addition of phytic acid to lipid-containing foods such as meats, fish meal pastes, and canned seafoods may prevent lipid peroxidation, resulting in improvement of the sensory quality of many foods and prolonged shelf-life.

Panax ginseng C.A. Meyer has been extensively used in the traditional oriental medicine as a restorative, tonic and prophylatac agent. This study was devised to develop a chemopreventive agent from panax ginseng to be able to suppress the genotoxicity and oxidative damage by reactive oxygen species, which are involved with cancer or aging. Ginseng petroleum ether extract (GPE) and one of its fraction, P2, showed an antioxidative effect on the lipid peroxidation of ethyl linoleate with Fenton's reagents and free radical scavenging effect to 1,1-diphenyl-2-picryl hydrazil (DPPH) radical generation. They also showed the suppressive effect of H₂O₂ or KO₂ induced DNA damage by single cell gel electrophoresis (SCGE). Results from our study indicate that GPE and P2 are capable of protecting lipid peroxidation, and oxidative DNA damage. Therefore, GPE and P2 may be useful chemopreventive agents which are involved with cancer and aging.

The purpose of this study was to investigate the bioactivity of extracts from the seeds of Gardenia jasminoides Ellis fructus (GJE) found in Namhae, Korea. Extraction was performed using three solvents, 70% methanol, Distilled Water (DW), and Ethyl Acetate (EA). We determined the total phenol and phytic acid contents of the extracts to evaluate their nitrogen oxide scavenging activity, antioxidant activity, reducing power, and lipid peroxidation inhibition ability. The phytic acid content of GJE was found to be 1.157 mg PAE (Phytic Acid Equivalent) /g DW. The yields of the three extraction processes were as follows: DW, 36.61%; 70% methanol, 30.10%; and EA, 20.40%. The physiological activities of the extract solvents increased significantly with increasing concentrations (0.2, 0.4, and 0.6 mg/mL) (p<0.05), but were lower than those of ascorbic acid, BHA, and trolox. Total phenol content was the highest in the 70% methanol extract, followed by DW and EA extracts. Further, nitrogen oxide scavenging activity and antioxidant activity were the highest for the 70% methanol extract followed by DW and EA extracts. Based on these results, the bioactivities of the 70% methanol and DW extracts of GJ seeds were excellent. These extracts can be used as natural antioxidants

방사선에 의해서 유도된 간 손상에 대한 백삼과 발효인삼추출물의 보호효과를 비교 연구하였다. ICR계 생쥐에게 코발트-60 감마선의 5Gy조사 7일 전부터 백삼과 발효인삼추출물(150㎎/㎏/day)을 각각 투여하였 다. 대조군은 생리적 식염수를 투여하고 방사선조사군은 생리적 식염수를 투여하면서 5Gy를 조사하였다. 그리고 각각의 실험군에서 간조직의 H2O2, catalase, MDA를 측정하였다. 그 결과 방사선조사군과 보다 백 삼과 발효인삼추출물 투여군에서 catalase함량이 유의성 있게 증가하여 간의 보호효과가 있었으며 H2O2와 MDA함량도 유의성 있게 감소하였다. 백삼과 발효인삼이 간 조직에 대한 방사선조사로 부터 매우 우수한 방호제라고 할 수가 있다.

Schisandra chinensis have been traditionally used in Asia for the treatment of dyspnea, cough, mouth dryness, spontaneous diaphoresis, nocturnal diaphoresis, nocturnal emission, dysentery, insomnia and amnesia. The purpose of this study is to evaluate the protective effects of Schisandra chinensis on oxidative DNA damage and lipid peroxidation induced by ROS in non cellular and cellular system. DPPH radical, hydroxyl radical and hydrogen peroxide scavenging assay were used to measure the antioxidant activities. Phi X-174RF I plasmid DNA cleavage assay and intracellular DNA migration assay were used to evaluate the protective effect on oxidative DNA damage. MTT assay and lipid peroxidation assay were used for evaluating the protective effect on oxidative cell damage. It was found to scavenge DPPH radical, hydrogen peroxide and hydroxyl radical and it inhibited oxidative DNA damage, lipid peroxidation and cell death induced by hydroxyl radical. These data indicate that Schisandra chinensis possesses a spectrum of antioxidant and DNA-protective properties

This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation

일당귀의 n-hexane분획이 횐쥐에서 에탄올투여로 생성된oxygen free radical대사와 지질과산화작용에 미치는 영향을검토하기 위하여 실험동물을 정상군, 일당귀 n-hexane 분획70 mg/kg투여군, 알코올투여군(35 ethanol 10 mL/kg, b.w./day), 알코올(35 ethanol 10 mL/kg, b.w./day) 및 일당귀 n-hexane 분획 70 mg/kg 병합투여군과 알코올(35 ethanol 10mL/kg,

In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.

매실 에탄올추출물이 알코올투여로 유발된 횐쥐의 간손상에 미치는 영향을 알아보기 위하여 실험동물을 정상군, 매실 에탄올추출물 200 mg/kg 투여군, 알코올투여군(35% ethanol 10 mL/kg, b.w./day), 알코올 및 매실 에탄올추출물 200 mg/kg 병합투여군과 알코올 및 매실 에탄올추출물 400 mg/kg 병합투여군의 5군으로 나누어 6주간 사육하였고, 체중증가율 및 식이효율, 혈청중 ALT와 AST활성, 간손상 억제 효과를

본 연구는 혀의 분얼최성기의 관수스트레스 시 탁도(청수, 반탁수, 탁수) 및 관수시간에 따라 반응하는 단백질, 지방산 조성 및 지질과산화(malodialdehyde)를 정량하여 관수에 따른 생육장해 및 그 작용기작을 구명하여, 관수에 따른 생화학적 대사의 기초자료를 제공하고자 실시되었다. 관수스트레스에 의해 가용성단백질은 약 20%가 감소하였다. 특히 탁도가 높고 관수시간이 경과할수록 급격히 감소하였으며, 관수 36시간부터 감소량이 크게 나타났다. 단백질 전기영 동패턴은 관수스트레스에 따라 생성이나 소멸한 펩타이드는 없었으나 약 53Kd부위의 폴리펩타이드는 관수초기부터 함량이 증가하였고, 약 28Kd는 48시간, 54시간에서만 함량이 증가하였다. 관수스트레스에 의한 지질의 과산화정도는 약 150%가 증가하였고, 탁도처리에서 청수와 반탁수간의 차이는 작은 경향이었지만, 관수 60시간에서 약 160-180%가 증가하였다. 그러나 탁수에서는 관수초기부터 malondialdehyde함량이 높았고, 36시간이후부터는 약 190-200%로 급격히 증가하였다. Catalase는 탁도가 높고 처리시간이 경과할수록 활성은 급격히 증가하였다. 관수 48시간을 기준으로 catalase 활성변화가 크게 나타났다. 지방산조성의 변화는 포화지방산의 조성비율은 증가하고 불포화지방산은 감소하였다. 특히 불포화지방산 중 monounsaturated은 증가하였고 polyunsaturated의 상대적인 조성비율은 감소하였다. Double bond index는 탁도가 높을수록 관수기간이 경과할수록 감소폭은 커서 불포화정도가 떨어짐을 나타냈다.

The effects of Citrus flavonoids, hesperetin, hesderidin, naringenin, and naringin, on nonenzymatic lipid peroxidation were studied in three different in vitro experimental models. Hesperetin showed the most antioxidant effect in this experimental condition by measuring the malondialdehyde production using the thiobarbiturate and thiocyanate methods, the lipid peroxidation of microsomal membranes, and DPPH () method. The antioxidative activity of the flavonoid aglycone forms, hesperetin, Citrus aglycone flavonoid, suggest the most antioxidant effect in this experimental condition, and this effect indicate more potent in the aglycones than their corresponding glycosides.

The feeding effects of Herba hottuynia extracts on the lipids profiles and the content of TAB-reactive substances were evaluated in rats fed a high cholesterol diet. Hot water or ethanol extracts of the dried leave were evaporated and lyophilized . The experimental animals wer edevided to four groups and fed the following diets for 4 weeks : BAsal (cholesterol-free diet), CHOL(cholesterol-enriched diet),CW (cholesterol plus water extract) and CE(cholesterol plus ethanol extract). Dietary cholesterol increased significantly the activities of serum GOT and GPT, but the extracts feeding (0.5% of diet) did not influence the activities induced by dietary cholesterol. Although dietary cholesterol increased significantly the concentrationof serum andliver cholesterol, it tended to decrease the concentation of serum triglycerides. CHolesterol feeding had a lowering effect on the lipid peroxidation value of serum, but not inliver.Furthermore, the extracts feeding, especially water extract, decreased markedly the liver peroxidation value. The results suggest that Houttyunia cordata extracts have an in vivo antioxidant effect, judged from the TBA value in the liver rats fed a high cholesterol diet.

Rice plants cv. Koshihikari, were subjected to the biologically effective ultraviolet-B (UV-B_BE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) kJ m^-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dry weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV-B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemical protectant against increased UV-B radiation in rice plants.