Optimization of Ultrasound-Assisted Extraction on Antioxidative Activity of Malus toringoides Using Response Surface Methodology

Malus toringoides (Rehd.) Hughes Ameliorates Nonalcoholic Fatty Liver Disease with Diabetes via Downregulation of SREBP-1c and the NF-κB Pathway In Vivo and In Vitro

Diabetic patients are more prone to developing nonalcoholic fatty liver disease (NAFLD) compared with healthy people. As a plant homologous to both medicine and food, Malus toringoides (Rehd.) Hughes has been used as an intervention for both NAFLD and diabetes. However, the effect and mechanism of M. toringoides on NAFLD on type 2 diabetes mellitus (T2DM) is unclear. The current investigation was designed to evaluate the ameliorative effects and mechanism of M. toringoides ethanol extract (CBTM-E375) on T2DM, and to identify the compounds in these extracts. The effects of CBTM-E375 on T2DM were verified using a high-fat diet-/streptozotocin-induced diabetic rat and free fatty acid (0.5 mM)-induced human hepatocellular carcinoma cell (HepG2) models. The components of CBTM-E375 were identified by high performance liquid chromatography-mass spectrometry/mass spectrometry. Our results demonstrate that CBTM-E375 ameliorated lipid accumulation (total cholesterol, triglyceride), oxidative stress (superoxide dismutase, catalase, malondialdehyde, glutathione peroxidase), and inflammation (tumor necrosis factor-α [TNF-α], interleukin [IL]-1β, IL-6, C-reactive protein [CRP]) in vivo and in vitro, these effects were associated with a CBTM-E375-mediated downregulation of SREBP-1c (sterol regulatory element binding protein 1c) and the NF-κB (nuclear factor κB) signaling pathway. A total of 20 chemical compounds were identified in CBTM-E375, including phlorizin, isoquercitrin, chlorogenic acid, quercetin, naringenin, and trigonelline, which have been reported to have positive effects on diabetes or on NAFLD.

Chemical characterization of the antioxidant and α-glucosidase inhibitory active fraction of Malus transitoria leaves

Chinese Tibetan tea made from the tender leaves of Malus transitoria is a widely consumed health drink, but there are few reports on its chemical composition and biological activity. In this study, we found that a 50% ethanol extract of M. transitoria had good antioxidant and α-glucosidase inhibitory activities in vitro. Guided by in vitro bioassays, chromatographic separation and purification were conducted, and the most active fraction in M. transitoria was determined. UPLC-Orbitrap-MS/MS was used to further quickly and comprehensively characterize the chemical composition. Library searches, MS/MS fragmentation patterns of two isolated reference compounds, and bibliography were used to annotate 81 compounds, of which 2 were new compounds, and 79 were identified from M. transitoria for the first time. This study provides a scientific basis for the development of antioxidant and anti-diabetic functional foods from M. transitoria.

Optimized extraction of polyphenols from leaves of Rosemary (Rosmarinus officinalis L.) grown in Lam Dong province, Vietnam, and evaluation of their antioxidant capacity

In the present study, the optimized solvent extraction conditions with regards to the total polyphenol content (TPC) and antioxidant capacity of rosemary leaf extract (RLE) were determined. The one-factor-at-a-time method was used to independently investigate the effect of several extraction parameters, including ethanol concentration (0–100% v/v), extraction temperature (50–80°C), extraction period (15–60 min), material–solvent ratio (1:5–1:10 g/mL), and extraction cycles (1, 2, and 3 times) on polyphenol content. Response surface methodology (RSM), in combination with a central composite design, was used to perform optimization. The following optimal conditions that gave maximal TPC were determined and experimentally verified: ethanol concentration of 65% (v/v), extraction temperature of 65°C, material–solvent ratio of 1:7.5 g/mL, extraction time of 15 min, and 2 cycles of extraction. These parameters corresponded with the TPC yield of 87.42 ± 0.25 mg gallic acid equivalent/g dried feed material (mg GAE/g DW). The optimal conditions gave a high extraction yield (337 ± 6 mg dried extract/g dried feed material) with 197.28 ± 3.11 mg GAE/g dried extract. The estimated models were strongly significant (p < 0.05) for TPC values with significant regression coefficients (R 2) of 0.9979. The obtained RLE was supposed to be the top grade of natural antioxidant with the IC50 (DPPH assays) value of 9.4 ± 0.1 μg/mL, which is higher than that of the vitamin C by just three times (IC50 = 3.2 ± 0.1 μg/mL). Current results justify RLE as a potential agent in food preservation applications.

Extraction Process of Polyphenols from Soybean (Glycine max L.) Sprouts: Optimization and Evaluation of Antioxidant Activity

This research aimed to optimize the total polyphenol content (TPC) extracted from soybean sprout powder under different experimental parameters, including ethanol concentration (60–100% v/v), extraction temperature (40–80 °C), extraction time (15–150 min), material:solvent ratio (1:4–1:10 g/mL), the number extraction cycles (1, 2 and 3 times), the age of sprout (0–7 days), and the used part of the sprout (cotyledon, hypocotyl, or radicle). The obtained results were used in response surface methodology, in combination with a central composite design, to model the total polyphenol content (TPC) with respect to three variables, including ethanol concentration, extraction temperature, and material:solvent ratio. The experimental conditions for optimal recovery of TPC consisted of ethanol concentration of 88% (v/v), extraction temperature of 59 °C, material:solvent ratio of 1:6.5 g/mL, extraction time of 60 min, and 2 cycles of maceration. In addition, for maximal TPC, the sprout should undergo the germination of 5 days and the radicle fraction should be used. Based on the suggested optimum conditions, the obtained and verified TPC was 19.801 mg genistein (GE)/g dry weight (d.w.). The obtained dried extract also exhibited low antioxidant activity.