Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older humans

Araghi‒Niknam, Mohsen; Chung, Sangbun; Nelson-White, Tresa; Eskelson, Cleamond D.; Watson, Ronald R.

doi:10.1016/0024-3205(96)00396-7

Cited by 114 publications

(73 citation statements)

References 32 publications

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“…The total leukocyte concentration then decreased at each subsequent time point to 21 days. This trend is consistent with previous studies of PEUU-A and PEUU-A with vitamin E. 9,18 However, there were no differences among materials in the rate of decrease in the total leukocyte concentrations with time.…”

Section: Exudate Analysissupporting

confidence: 93%

Biocompatibility of poly(etherurethane urea) containing dehydroepiandrosterone

Collier

Tan

Shive

et al. 1998

J. Biomed. Mater. Res.

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Poly(etherurethane urea) (PEUU) elastomers, with their broad range of mechanical properties and high biocompatibility, are used clinically for medical applications. However, the possibility exists for the ether soft segment of PEUU to degrade in long-term uses. To retard degradation, antioxidants that scavenge reactive oxygen intermediates are added. In this study, we incorporated dehydroepiandrosterone (DHEA), which functions by the alternate mechanism of modulating or down-regulating adherent macrophage activity, to retard the biodegradation of PEUUs. Biocompatibility of PEUU samples containing 1% DHEA, 5% DHEA, and 5% vitamin E (alpha-tocopherol) by weight were studied in vivo and in vitro. The biocompatibility was initially evaluated by examination of the inflammatory cellular exudate. Compared to PEUU without additives and PEUU with 5% vitamin E, the addition of 5% DHEA to PEUU caused a decrease in the total leukocyte exudate concentration at 4 days. The addition of 5% DHEA also caused lower macrophage adhesion and FBGC formation compared to the other materials at 7 days. Despite these short-term effects, the biocompatibility at later time points (14, 21, and 70 days) was similar for all materials. Transmission infrared analysis of the materials revealed that more than 70% of the DHEA had leached out of the samples by 3 days implantation. Furthermore, through attenuated total reflectance Fourier transform analysis and scanning electron microscopy, it was determined that unlike vitamin E, DHEA did not enhance long-term PEUU biostability. The effect of DHEA on inflammatory cell activity appeared to be dose dependent, with improved biocompatibility in vivo for higher loading levels of DHEA, but the overall effect was limited owing to the rapid diffusion of the water-soluble DHEA from the PEUU.

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Section: Exudate Analysissupporting

confidence: 93%

Biocompatibility of poly(etherurethane urea) containing dehydroepiandrosterone

Collier

Tan

Shive

et al. 1998

J. Biomed. Mater. Res.

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“…Modern researches have shown that yam extracts can reduce blood sugar (Hikino et al, 1986;Undie and Akubue, 1986) and blood lipid (Araghiniknam et al, 1996), inhibit microbe activity (Hu et al, 1996(Hu et al, , 1999Oladeji et al 403 Kelmanson et al, 2000) and show antioxidative activity (Farombi et al, 2000). Yams also have pharmaceutical usage as they contain a steroid sapogenin compound called diosgenin, which can be extracted and used as base for drugs such as cortisone and hormonal drugs (Opara, 2003).…”

Section: Introductionmentioning

confidence: 99%

Physicochemical and bioactive properties of selected white yam (Dioscorea rotundata) varieties adapted to riverine areas of Nigeria

Alamu¹,

Maziya-Dixon²,

Okonkwo³

et al. 2014

Afr. J. Food Sci.

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Yam (Dioscorea spp.) is a major food of cultural, economic and nutritional importance in Nigeria and throughout West Africa. In this sub-region, white yam (Dioscorea rotundata) is the most dominant and important species. This study is aimed at characterizing high yielding yam varieties of this species adapted to riverine areas and forest zones of Nigeria for physical and chemical characteristics. Eleven yam varieties collected from local farmers in the South-southern part of Nigeria were evaluated for their physicochemical characteristics, bioactive compounds (vitamin C, phytic acid and tannin), functional and pasting properties. Results indicated that there were significant varietal differences (P<0.05) among the parameters evaluated. The moisture contents of the investigated varieties ranged from 59.5 to 68.8%, ash content ranged from 1.39 to 2.93%, protein content from 1.96 to 4.90%, fat content from 0.356 to 3.39%, total free sugars from 1.05 to 7.02% and total starch from 33.9 to 75.7%. The bioactive content results show that vitamin C content ranged from 5.64 mg/100 g to 6.99 mg/100 g, phytate from 1.12 to 2.37% and tannin from 0.359 to 1.18 mg/g. The pasting properties results show that peak viscosity ranged from 215 to 470 RVU, trough viscosity from 198 to 385 RVU, breakdown viscosity from 8.71 to 84.5 RVU, final viscosity from 278 to 571 RVU, setback viscosity from 66.2 to 204 RVU; peak time ranged from 4.97 to 7.0 min and the pasting temperature from 61.7 to 62.6°C. This study shows that the physical and chemical characteristics of these high yield yam varieties were similar to those reported for most yam varieties in other parts of Nigeria and has a great potential as source of bioactive compounds and protein.

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“…In the previous papers, it was reported that yam extracts were shown to exert significant antioxidative activity and to reduce serum lipid levels in human subjects [15]. Yam from D. rotundata flour has also been reported to protect rats from chemically induced toxicity [16].…”

Section: Discussionmentioning

confidence: 98%

Antioxidative activity of water extracts from the yam ( Dioscorea opposita Thunb.) tuber mucilage tororo

Nagai

Suzuki

Nagashima

2006

Eur. J. Lipid Sci. Technol.

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Antioxidative activity of water extracts from the yam (Dioscorea opposita Thunb.) tuber mucilage tororo A water extract as a viscous solution was obtained from the yam Dioscorea opposita tuber mucilage tororo, and its functional properties were demonstrated. The protein content was about 280 mg/mL extract, and the main protein bands with an MW of ,33 kDa without 2-mercaptoethanol (2-ME) and ,31 kDa with 2-ME were detected by SDS-PAGE. The water extract possessed high antioxidative activity and scavenging activities against superoxide anion and hydroxyl radicals. However, it showed no inhibitory activity against angiotensin I-converting enzyme. The yam tuber contains relatively high contents of vitamins, different micro-and macroelements, enzymes, and dietary fibers. The yam D. opposita tuber will be increasingly regarded as a healthpromoting food.

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Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older humans

Cited by 114 publications

References 32 publications

Biocompatibility of poly(etherurethane urea) containing dehydroepiandrosterone

Biocompatibility of poly(etherurethane urea) containing dehydroepiandrosterone

Physicochemical and bioactive properties of selected white yam (Dioscorea rotundata) varieties adapted to riverine areas of Nigeria

Antioxidative activity of water extracts from the yam ( Dioscorea opposita Thunb.) tuber mucilage tororo

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