• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.915-923
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• 2007

Rubber hoses for automobile radiators are apt to be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under thermal and mechanical loadings. The aging behaviors of the skin part of the hoses due to thermo-oxidative and electro-chemical stresses were experimentally analyzed. Through the thermo-oxidative aging test, it was shown that the surface hardness IRHD(International Rubber Hardness Degrees) of the rubber increased with a considerable reduction of failure strain as the aging time and temperature increased. On account of the penetration of coolant liquid into the skin part influenced by the electro-chemical degradation(ECD) test the weight of the rubber hose increased, whereas their failure strain and IRHD hardness decreased. The hardness of the hose in the side of the negative pole was the most deteriorated at the test site of the hose skin just below the coolant surface.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.291-312
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• 2003

Reactive oxygen species are capable of damaging biomolecules such as lipids, proteins, and DNA, which can not only lead to various diseases, but also oxidative damage resulting aging. In our previous study, Cercis chinensis (Leguminosae) showed a potent antioxidant activity. Nineteen compounds were isolated through antioxidant activity-guided fractionation. The C. chinensis extract and some of the constituents exhibited a potent antioxidant activity on the free radicals and lipid peroxidation and a notable protective effect on the t-BuOOH induced oxidative damage. In vivo test of skin damage induced by UVB irradiation, the extract of C. chinensis and a constituent, piceatannol, exhibited a significant protective effect. The life-span of the HEK-N/F cells were extended by 1.21-2.12 fold as a result of the continuous administration of 3 $\mu\textrm{g}$/ml of the C. chinensis extract and the active constituents compared to that of the control. These observations were attributed to the inhibitory effect of the C. chinensis extract and its constituents on the age-dependent shortening of the telomere. Thus, C. chinensis was demonstrated to protect the skin cells against oxidative stress and inhibit thereby the cellular aging, followed by expectation as anti-aging cosmetic ingredient.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.117-138
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• 2003

Reactive oxygen species are capable of damaging biomolecules such as lipids, proteins, and DNA, which can not only lead to various diseases, but also oxidative damage resulting aging. In our previous study, Cercis chinensis (Leguminosae) showed a potent antioxidant activity. Nineteen compounds were isolated through antioxidant activity-guided fractionation. The C. chinensis extract and some of the constituents exhibited a potent antioxidant activity on the free radicals and lipid peroxidation and a notable protective effect on the t-BuOOH induced oxidative damage. In vivo test of skin damage induced by UVB irradiation, the extract of C. chinensis and a constituent, piceatannol, exhibited a significant protective effect. The life-span of the HEK-N/F cells were extended by 1.21-2.12 fold as a result of the continuous administration of 3 $\mu\textrm{g}$/ml of the C. chinensis extract and the active constituents compared to that of the control. These observations were attributed to the inhibitory effect of the C. chinensis extract and its constituents on the age-dependent shortening of the telomere. Thus, C. chinensis was demonstrated to protect the skin cells against oxidative stress and inhibit thereby the cellular aging, followed by expectation as antiaging cosmetic ingredient.

• Proceedings of the Korean Reliability Society Conference
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• 2006.05a
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• pp.27-31
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• 2006

Rubber hoses for automobile radiators are apt to degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under thermal and mechanical loadings. The aging behaviors of the skin part of the hoses due to thermo-oxidative and electro-chemical stresses were experimentally analyzed. Through the thermo-oxidative aging test, it was shown that the surface hardness IRHD(International Rubber Hardness Degrees) of the rubber increased with a considerable reduction of failure strain as the aging time and temperature were large. On account of the penetration of coolant liquid into the skin part the weight of rubber specimens influenced by electro-chemical degradation (ECD) test increased, whereas their failure strain and IRHD hardness decreased. The hardness decreased further as the test site on the hose skin approached to the negative pole.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.368-376
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• 2005

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under thermal and mechanical loadings. In this study, for EPDM(ethylene-propylene diene monomer) rubber conventionally used as a radiator hose material the aging behaviors of the skin part due to thermo-oxidative and electro-chemical stresses were nondestructively evaluated. Through the thermo-oxidative aging test, it was shown that the surface hardness IRHD(International Rubber Hardness Degrees) of the rubber increased with a considerable reduction of failure strain. On account of the penetration of coolant liquid into the skin part the weight of rubber specimens degraded by electro-chemical degradation(ECD) test increased, whereas their. failure strain and IRHD hardness decreased largely. The penetration of coolant liquid seemed to induce some changes in inner structure and micro hardness distribution of the rubbers. Consequently, EPDM rubbers degraded by thermo-oxidative aging and ECD could be characterized nondestructively by micro-hardness and chemical structure analysis methods.

• Journal of Life Science
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• v.9 no.5
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• pp.548-555
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• 1999

Long-term effects of Ganoderma lucidum (GL) on memory and oxidative stress of senescence-accelerated mice (SAM) were investigated. Senescence-resistant (R1) and prone (P8) strains of SAM were fed GL diets, premixed with low (20 mg/kg/day, T1) or high (200 mg/kg/day, T2) levels of GL powder for 9 months starting from young (3 months of age) or for 5 months starting from old (7 months of age). After the final feeding at 12 months of age, all animals were subjected to passive avoidance test for the evaluation of memory function. In addition, the changes in hepatic thiobarbituric acid-reactive substance (TBARS) and glutathione were analyzed. SAMP8 fed GL diets from old age (7 months) exhibited the improvement of memory, although GL rather inhibited the memory function of both SAMR1 and SAMP8 mice fed diets from young (3 months of age). Hepatic TBARS contents were decreased in SAMP8 fed high GL diet for 9 months and in SAMR1 fed low GL diet for 5 months. Hepatic glutathione content was also remarkably increased in SAMR1 following both feeding periods, and less extent in SAMP8 fed diet for 5 months of age. Taken together, it is proposed that GL extracts may play an anti-aging role through antioxidant action, and thereby may improve the senescence-related memory dysfunction.

• Toxicological Research
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• v.34 no.4
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• pp.333-341
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• 2018

Ferulate is a phenolic compound abundant in wheat germ and bran and has been investigated for its beneficial activities. The aim of the present study is to evaluate the efficacy of ferulate against the oxidative stress-induced imbalance of protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs), and serine/threonine protein phosphatase 2A (PP2A), in connection with our previous finding that oxidative stress-induced imbalance of PTKs and PTPs is linked with proinflammatory nuclear factor-kappa B $(NF-{\kappa}B)$ activation. To test the effects of ferulate on this process, we utilized two oxidative stress-induced inflammatory models. First, YPEN-1 cells were pretreated with ferulate for 1 hr prior to the administration of 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). Second, 20-month-old Sprague-Dawley rats were fed ferulate for 10 days. After ferulate treatment, the activities of PTKs, PTPs, and PP2A were measured because these proteins either directly or indirectly promote $NF-{\kappa}B$ activation. Our results revealed that in YPEN-1 cells, ferulate effectively suppressed AAPH-induced increases in reactive oxygen species (ROS) and $NF-{\kappa}B$ activity, as well as AAPH-induced PTK activation. Furthermore, ferulate also inhibited AAPH-induced PTP and PP2A inactivation. In the aged kidney model, ferulate suppressed aging-induced activation of PTKs and ameliorated aging-induced inactivation of PTPs and PP2A. Thus, herein we demonstrated that ferulate could modulate PTK/PTP balance against oxidative stress-induced inactivation of PTPs and PP2A, which is closely linked with $NF-{\kappa}B$ activation. Based on these results, the ability of ferulate to modulate oxidative stress-related inflammatory processes is established, which suggests that this compound could act as a novel therapeutic agent.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1311-1315
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• 2009

The objective of this study was to investigate the effects of sesaminol glucosides (SG) on age-related cognitive deficits in senescence-accelerated mice P8 (SAMP8). Male SAMP8 (9 month-old) were randomly divided into 3 groups and received diets containing 0, 0.25, or 0.5% SG for 12 weeks. Step-through latency of the SAMP8 control group was higher than that of the senescence-accelerated resistant mice (SAMR) group, whereas it was lowered in the SG-supplemented group on the passive-avoidance test. In the Morris water maze, the escape latency of the SAMP8 control group was increased and recovered in the 0.5% SG-supplemented group. The SG supplementation significantly decreased thiobarbituric acid reactive substance (TBARS) levels in brains of the SAMP8. On the other hand, catalase, superoxide dismutase, and glutathione peroxidase activities in brains of the SG supplemented group decreased compared with the SAMP8 control group. These results suggest that SG could attenuate cognitive deficits caused by aging through its antioxidant capacity.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.352-356
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• 2007

The present study was investigated the anti-oxidative effects of aloe vera ingestion on brain and kidney in aged rats by monitoring several oxidative-related parameters. Male specific pathogen-free Fischer 344 rats were randomly divided into four groups of five rat each: Group A was fed test chow without aloe supplementation; Group B was fed a diet containing a 1% freeze-dried aloe filet; Group C was fed a diet containing a 1% charcoal-processed, freeze-dried aloe filet; and Group D was fed a diet containing a charcoal-processed, freeze-dried, whole leaf aloe in drinking water. Analyses of tissues were done at 4 months and 16 months of age. Results showed that a long-term intake of aloe, regardless of the preparation used, enhanced antioxidant defenses against lipid peroxidation, as indicated by reduced phosphatidylcholine hydroperoxide levels in both brain and kidney. The additional benefit of aloe intake on the anti-oxidative action was evidenced by enhanced superoxide dismutase and catalase activity in all aloe-ingested groups. Another beneficial effect of aloe shown in this study, although not an anti-oxidative parameter, was its cholesterol-lowering effect as detected in brain and kidney with significant decreases at age16 months of aloe-fed rats. Based on these findings, we conclude that a long-term dietary aloe supplementation modulated the anti-oxidative defense systems and cholesterol level.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.1 s.60
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• pp.33-40
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• 2007

Astradalus membranaceus root extract (ARE) contains saponins, flavonoids, and their glycosides. Two flavonoids, calycosin and formononetin, were predominant constituents with the different amount by diverse extraction conditions. ARE showed the anti-oxidative activities, inhibited tyrosinase activity, and increased type I procollagen expression in proportion to calycosin and formononetin contents. The clinical study also showed that skin wrinkles were significantly reduced in the test group treated with a cream formulation containging 0.1% ARE compared with a group treated with a cream formulation without 0.1% ARE (p < 0.05). These results suggest that ARE may have potential as an anti-aging ingredient in cosmetics.