Effects of fermented red bean extract on nephropathy in streptozocin-induced diabetic rats.

BACKGROUND: The antioxidant effects of Bacillus subtilis-fermented red bean (natto-red bean) extract (NRBE) in young (6 weeks old) Sprague-Dawley rats and aged (12 months old) mice had been reported previously. OBJECTIVE: To evaluate the antioxidant and anti-inflammatory effects of NRBE in the kidneys of streptozocin-induced diabetic rats. DESIGN: Normal control rats and diabetic rats were orally gavaged with saline and low-dose NRBE (100 mg/kg body weight [BW]), medium-dose NRBE (200 mg/kg BW), and high-dose NRBE (500 mg/kg BW), for 12 weeks and then sacrificed. Concentration of fasting glucose, adiponectin, renal function markers, antioxidative markers, and pro-inflammatory markers were measured. RESULTS: Oral administration of 50% ethanolic extract of NRBE with a dosage of 100 mg/kg BW, 200 mg/kg BW, or 500 mg/kg BW could improve the symptoms of kidney enlargement and renal function. Supplementation of NRBE can effectively inhibit the formation of renal reactive oxygen species and advanced-glycation end-products and increase renal glutathione content and serum adiponectin. A low dose of NRBE (100 mg/kg BW) decreased fasting blood sugar and renal interleukin (IL)-6 expression. Serum C-reactive protein, renal tumor necrosis factor-α, and monocyte chemoattractant protein-1 concentrations were decreased, and renal superoxide dismutase activity was increased in the medium-dose NRBE group. Twenty-four hour creatinine clearance and urinary albumin excretion also improved by medium-dose NRBE supplementation. In NRBE, total phenols and flavonoids were 6.3 mg gallic acid equivalent/g and 12.02 mg rutin equivalent/g, respectively, and kampherol was the major active antioxidant compound. CONCLUSION: This study demonstrated that appropriate amount of NRBE, 200 mg/kg BW in rats, could prevent diabetic nephropathy by improving antioxidant status and inhibiting inflammation in renal tissue.

Locust bean gum galactomannan hydrolyzed by thermostable ß-d-mannanase may reduce the secretion of pro-inflammatory factors and the release of granule constituents.

Locust bean gum (LBG) galactomannan has been claimed to have applications in the biopharmaceutical field. However, the effects of LBG galactomannan on immunomodulatory aspects are not yet clear. The purpose of this study was to over-express thermostable ß-d-mannanase from the thermophilic actinomycete Thermobifida fusca BCRC 19214 using a Pichia pastoris expression system. The maximum intracellular ß-d-mannanase activity obtained from the cell-free extract was approximately 40.0U/mL after 72h of cultivating a P. pastoris transformant (pPICZ-man) induced with methanol. Hydrolysis of native LBG galactomannan with 8U/mL ß-d-mannanase for 24h significantly decreased the weight-average molecular weight of LBG galactomannan from 5,580,010 to 3188. Native and hydrolyzed LBG galactomannan in a range of 0-0.2% did not trigger significant cytotoxicity after 24h of treatment compared with the control. The native LBG galactomannan stimulated RAW 264.7 cells to produce cytokine TNF-α dose-dependently, but there was no significant IL-1ß or nitric oxide production. The native LBG galactomannan also stimulated ß-hexosaminidase secretion in RBL-2H3 cells. After the native LBG galactomannan was hydrolyzed with ß-d-mannanase, all of the immunological properties disappeared. These results suggest the possible immunomodulatory effects of native LBG galactomannan.

The Topoisomerase 1 Inhibitor Austrobailignan-1 Isolated from Koelreuteria henryi Induces a G2/M-Phase Arrest and Cell Death Independently of p53 in Non-Small Cell Lung Cancer Cells.

Koelreuteria henryi Dummer, an endemic plant of Taiwan, has been used as a folk medicine for the treatment of hepatitis, enteritis, cough, pharyngitis, allergy, hypertension, hyperlipidemia, and cancer. Austrobailignan-1, a natural lignan derivative isolated from Koelreuteria henryi Dummer, has anti-oxidative and anti-cancer properties. However, the effects of austrobailignan-1 on human cancer cells have not been studied yet. Here, we showed that austrobailignan-1 inhibited cell growth of human non-small cell lung cancer A549 and H1299 cell lines in both dose- and time-dependent manners, the IC50 value (48 h) of austrobailignan-1 were 41 and 22 nM, respectively. Data from flow cytometric analysis indicated that treatment with austrobailignan-1 for 24 h retarded the cell cycle at the G2/M phase. The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21Waf1/Cip1 and p27Kip1 expression, and decrease of Cdc25C expression. Moreover, treatment with 100 nM austrobailignan-1 for 48 h resulted in a pronounced release of cytochrome c followed by the activation of caspase-2, -3, and -9, and consequently induced apoptosis. These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2. Furthermore, our study also showed that austrobailignan-1 was a topoisomerase 1 inhibitor, as evidenced by a relaxation assay and induction of a DNA damage response signaling pathway, including ATM, and Chk1, Chk2, γH2AX phosphorylated activation. Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.