Effect of Soybean Hypocotyl Extract on Lipid Peroxidation in GK Rats.

Vascular complications, as a consequence of atherosclerosis, are main causes of morbidity and mortality in patients with diabetes mellitus. There is increasing evidence that lipid peroxidation and oxidative modification of low density lipoprotein (LDL) is important in atherogenesis. In this study we investigated the effect of soybean hypocotyl extract (SHE), rich in isoflavones and saponins, on lipid peroxide (LPO) levels in liver, plasma and lipoproteins in GK diabetic rats, and its efficacy on the reduction of susceptibility of LDL and high density lipoprotein (HDL) to oxidation. The oxidative modification of LDL and HDL was determined with the lag time of copper ion-induced oxidation curve identified by the conjugated dienes. In SHE group which were fed diet containing 40 g/kg of SHE for 16 weeks, LPO levels in liver, plasma and HDL fraction were significantly decreased compared with the control group. The lag phage of LDL oxidation curve was prolonged noticeably by a mean of 27 min in SHE group as compared to the control group, indicating a reduced susceptibility to oxidation. The results suggest that intake of soybean hypocotyl extract might be useful for the prevention and treatment of diabetes mellitus and diabetes-associated diseases.

Early diagnosis of cancer by detecting the chemiluminescence of hematoporphyrins in peripheral blood lymphocytes.

Early detection and optimal treatment are the most effective means to improve cancer mortality. Mass screening for cancer has yielded a marked reduction of cancer mortality in the United States. Simple and effective methods are expected for screening of malignancy. Hematoporphyrin derivatives (HPDs) are known to accumulate in cancer cells; thus, HPD has been used for local diagnosis and photodynamic therapy of cancer. The lymphocytes of cancer patients also demonstrate the active uptake of HPD and this phenomenon has been applied for the diagnosis of cancer. In the present study, we have developed a novel method for measurement of the chemiluminescence of HPD in peripheral blood lymphocytes. HPD is composed of hematoporphyrin and its oligomers. Seven cancer patients and seven controls were recruited for this study. The primary cancers included two prostate cancers (one without metastasis and the other with lung metastasis), a renal cancer, a lung adenocarcinoma with systemic metastasis, two gallbladder cancers with lung metastasis, and a colon cancer with liver metastasis. HPD in lymphocytes was measured using a highly sensitive chemiluminescence analyzer with laser light irradiation to detect photoemission by (1)O(2) from HPD. The intensity of chemiluminescence exhibited a linear correlation with the concentrations of HPD. In addition, the level of HPD in lymphocytes was significantly higher in cancer patients than that in healthy volunteers (p < 0.05). These results suggest that detection of the chemiluminescence of HPD in lymphocytes could be a sensitive and simple method for cancer diagnosis and screening.

Banana prevents plasma oxidative stress in healthy individuals.

There is increasing evidence that lipid peroxidation and oxidative modification of low density lipoprotein (LDL) is important in atherogenesis. The present study was designed to study the effects of a single banana meal on plasma lipids and lipoprotein profile, plasma oxidative stress and susceptibility of LDL to oxidation in 20 healthy volunteers. Lipid and lipid peroxide (LPO) levels were measured before the meal (baseline, fasting) and 2 h after it (post-dose). The susceptibility to copper-induced oxidation of baseline and post-dose LDL was measured as conjugated diene (CD) formation. Results showed that the LPO contents in plasma, very low density lipoprotein (VLDL), LDL and high density lipoprotein (HDL) decreased significantly in the 2 h post-dose phase. Prolongation of lag phase and decrease of CD formation during LDL oxidation indicated that post-dose LDL was less susceptible to oxidative modification than the homologous fasting LDL. In conclusion, the consumption of banana reduces the plasma oxidative stress and enhances the resistance to oxidative modification of LDL.

Anti-atherosclerotic effect of soybean isofalvones and soyasaponins in diabetic rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the influence of soybean phytochemical extract containing isoflavones and soyasaponins (SPE) on blood glucose, blood lipids, plasma lipid peroxide and platelet aggregation activity in diabetic rats.</p><p><b>METHODS</b>Diabetic rats were fed with fodder containing 20 g/kg of SPE for 20 weeks. Their plasma very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) were separated by sequential ultracentrifugation.</p><p><b>RESULTS</b>Twenty weeks after experiment, level of blood glucose, atherosclerotic index and plasma level of lipid peroxide were (11.9 +/- 0.9) mmol/L, 0.40 +/- 0.14 and (15.7 +/- 0.5) mmol/L, respectively in diabetic rats fed with SPE, significantly lower than those in control rats not fed with it, (14.2 +/- 2.0) mmol/L, 0.58 +/- 0.22 and (20.7 +/- 3.0) mmol/L, respectively. Accordingly, platelet aggregation rates induced by ADP and collagen in the two groups were (54.1 +/- 8.8)% vs (66.6 +/- 12.4)% and (58.0 +/- 7.9)% vs (69.6 +/- 9.4)%, respectively. Changes in all these indices were significantly different between the two groups.</p><p><b>CONCLUSION</b>SPE could significantly decrease blood glucose, improve atherosclerotic index, and inhibit lipid peroxidation and platelet aggregation in diabetic rats, which might be useful in prevention and control of diabetes mellitus and diabetes-associated atherosclerosis.</p>