Antioksidacijska aktivnost produkata enzimske hidrolize pšeničnih mekinja

Wheat bran was destarched and deproteinated by α-amylase, protease and amyloglucosidase successively, and further hydrolyzed using Bacillus subtilis xylanases. The yield of enzymatic hydrolysates from wheat bran (EHWB) was 1.84 %. The total phenolics were 0.3712 g of ferulic acid equivalents per gram of EHWB. The antioxidant potency of EHWB was evaluated using different assays, such as iron ion chelation, reducing power, scavenging activity against 2,2’-diphenyl-1-picrylhydrazyl (DPPH) and reactive oxygen species under in vitro conditions. EHWB exhibited an effective ferrous ion chelating activity and strong reducing power. It also showed a high DPPH radical scavenging activity (89.4 %) at 5.0 mg/mL, which was comparable to that of the synthetic antioxidant, butylated hydroxytoluene. EHWB also exerted a marked scavenging effect on ·OH with an EC50 value of 0.46 mg/mL, which was lower than that of mannitol (1.03 mg/mL), a classical hydroxyl radical scavenger, and obvious antioxidant activities toward O2·- and H2O2.Iz pšeničnih su mekinja djelovanjem enzima α-amilaze, proteaze i amiloglukozidaze uklonjeni škrob i proteini, nakon čega je provedena hidroliza pomoću ksilanaze iz bakterije Bacillus subtilis, te ostvaren prinos enzimskih hidrolizata od 1,84 %. Dobiven je udio ukupnih fenola od 0,3712 grama ekvivalenta ferulične kiseline po gramu hidrolizata. Primjenom različitih metoda ispitana je antioksidacijska sposobnost hidrolizata in vitro, tj. sposobnost stvaranja kelata s Fe2+ ionima, redukcije Fe3+ iona, te uklanjanja DPPH radikala i reaktivnih ugljikovih spojeva. Ispitani su hidrolizati imali dobru moć redukcije Fe3+ iona i stvaranja kelata s ionima Fe2+. Pri koncentraciji od 5 mg/L pokazali su vrlo dobru sposobnost uklanjanja DPPH radikala (89,4 %), približnu onoj sintetskog oksidansa (butiliranog hidroksitoluena). Isto tako su odlično uklanjali i hidroksilne radikale (EC50=0,46 mg/mL), puno bolje od manitola (EC50=1,03 mg/mL) koji se uobičajeno koristi za njihovo uklanjanje. Dobiveni enzimski hidrolizati su također imali antioksidacijski učinak protiv superoksidnih radikala i vodikova peroksida

Inhibicija lipidne peroksidacije pomoću enzimskih hidrolizata izoliranih iz pšeničnih mekinja

Wheat bran, an important by-product of the cereal industry, is rich in potentially health-promoting phenolic compounds. The phenolics are mainly esterified to the cell wall polysaccharides. In our previous paper, wheat bran was destarched and deproteinated by α-amylase, protease and amyloglucosidase successively and further hydrolyzed using Bacillus subtilis xylanases, and the enzymatic hydrolysates from wheat bran (EHWB) showed good scavenging activity in vitro. The aim of this study is to further characterize the antioxidant potential of EHWB against various systems, both ex vivo and in vivo, namely, rat liver microsomal lipid peroxidation systems induced by Fe2+/H2O2 and Fe3+-adenosine diphosphate (ADP)/dihydronicotinamide adenine dinucleotide phosphate (NADPH), copper- and 2,2’-azo-bis(2-amidinopropane) dihydrochloride (AAPH)-induced human low-density lipoprotein (LDL) oxidation systems, and alloxan-induced in vivo lipid peroxidation in mice. EHWB inhibited lipid peroxidation in rat liver microsomes induced by Fe2+/H2O2 and Fe3+-ADP/NADPH in a concentration-dependent manner with 90.3 and 87 % inhibition of lipid peroxidation at 50 mg/L, respectively, which were similar to that of butylated hydroxytoluene (BHT) at 20 mg/L. The antioxidant potential of EHWB at a concentration ranging from 10 to 20 mg/L in the nonenzymatic system was more effective than in the enzymatic system. EHWB strongly inhibited in vitro copper- and AAPH-mediated oxidation of LDL in a concentration- and time-dependent manner with 52.41 and 63.03 % inhibition at 20 mg/L, respectively, which were similar to that of ascorbate at 10 mg/L. EHWB significantly decreased the level of thiobarbituric acid reactive substances (TBARS) and increased the activities of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) in serum and liver of alloxan-treated mice compared with the control. These results demonstrated that EHWB might be efficient in the protection of food products and humans against free radical-induced oxidative damage.Pšenične su mekinje važan nusproizvod u proizvodnji žitarica, jer su bogate fenolnim spojevima što pozitivno utječu na zdravlje. Fenoli se uglavnom vežu esterskom vezom na staničnu stijenku polisaharida. U prijašnjem su istraživanju pomoću α-amilaze, proteaze i amiloglukozidaze iz pšeničnih mekinja uklonjeni škrob i proteini, te su enzimskom hidrolizom pomoću ksilanaza iz bakterije Bacillus subtilis dobiveni hidrolizati, koji su učinkovito uklanjali slobodne radikale in vitro. Svrha je ovoga rada bila iscrpnije opisati antioksidativni učinak tih hidrolizata ex vivo i in vivo u različitim sustavima, i to: sustavima lipidne peroksidacije mikrosoma u jetri štakora induciranih pomoću Fe2+/H2O2 i Fe3+-adenozin difosfata (ADP)/dihidronikotinamid adenin dinukleotid fosfata (NADPH), sustavima oksidacije humanoga lipoproteina male gustoće (LDL) induciranih pomoću bakra i 2,2\u27-azo-bis(2-amidinopropan) dihidroklorida (AAPH), te in vivo lipidnoj peroksidaciji u miševa induciranoj pomoću aloksana. Enzimski su hidrolizati iz pšeničnih mekinja u koncentraciji od 50 mg/L inhibirali lipidnu peroksidaciju u mikrosomima jetre štakora induciranu pomoću Fe2+/H2O2 za 90,3 %, a onu induciranu pomoću Fe3+-ADP/NADPH za 87 %. Taj je učinak sličan učinku butiliranog hidroksitoluena (BHT) u koncentraciji od 20 mg/L. Antioksidativni je učinak enzimskih hidrolizata iz pšeničnih mekinja u koncentracijama od 10 do 20 mg/L bio veći u neenzimskim nego u enzimskim sustavima. Hidrolizati su, ovisno o njihovoj koncentraciji (20 mg/L) i vremenu reakcije, znatno inhibirali in vitro oksidaciju LDL, i to onu induciranu bakrom za 52,41 %, a oksidaciju induciranu pomoću AAPH za 63,03 %, što je slično učinku askorbata pri koncentraciji od 10 mg/L. Također su bitno smanjili količinu reaktivnih spojeva tiobarbiturne kiseline i povećali aktivnost glutation-peroksidaze, katalaze i superoksid dismutaze u serumu i jetri miševa tretiranih aloksanom, u usporedbi s kontrolnim uzorkom. Rezultati pokazuju da enzimski hidrolizati iz pšeničnih mekinja mogu biti korisni u zaštiti prehrambenih proizvoda i zdravlja ljudi od oksidacijskih oštećenja uzrokovanih slobodnim radikalima

Small-Molecule SB216763-Loaded Microspheres Repair Peripheral Nerve Injury in Small Gap Tubulization

Peripheral nerve injury has yet to be fully resolved because of its complicated pathological process. SB216763 is a small molecular compound that can enhance the remyelination of peripheral nerves by inhibiting glycogen synthase kinase-3β (GSK3β). GSK-3β inhibitor stimulates myelin gene expression and restores the myelin structure. Herein, we presented the effect of integrating small gap tubulization with SB216763-loaded microspheres by using a chitosan conduit. In vitro, SB216763 could promote neurite growth of dorsal root ganglia. In vivo studies showed that SB216763 increased the number of myelinated axons and the thickness of myelin sheaths. Electrophysiological examination and sciatic functional index results also indirectly indicated the role of SB216763 in repairing peripheral nerve injury. SB216763 promoted the recovery of muscle function. Therefore, combining SB216763-loaded PLGA microspheres with conduit small gap tubulization shows potential for applications in repairing peripheral nerve injury

The Lunar Lander Neutron and Dosimetry (LND) Experiment on Chang'E 4

Chang'E 4 is the first mission to the far side of the Moon and consists of a lander, a rover, and a relay spacecraft. Lander and rover were launched at 18:23 UTC on December 7, 2018 and landed in the von K\'arm\'an crater at 02:26 UTC on January 3, 2019. Here we describe the Lunar Lander Neutron \& Dosimetry experiment (LND) which is part of the Chang'E 4 Lander scientific payload. Its chief scientific goal is to obtain first active dosimetric measurements on the surface of the Moon. LND also provides observations of fast neutrons which are a result of the interaction of high-energy particle radiation with the lunar regolith and of their thermalized counterpart, thermal neutrons, which are a sensitive indicator of subsurface water content.Comment: 38 pages, submitted to Space Science Review

Scavenging Activity of Enzymatic Hydrolysates from Wheat Bran

Wheat bran was destarched and deproteinated by α-amylase, protease and amyloglucosidase successively, and further hydrolyzed using Bacillus subtilis xylanases. The yield of enzymatic hydrolysates from wheat bran (EHWB) was 1.84 %. The total phenolics were 0.3712 g of ferulic acid equivalents per gram of EHWB. The antioxidant potency of EHWB was evaluated using different assays, such as iron ion chelation, reducing power, scavenging activity against 2,2’-diphenyl-1-picrylhydrazyl (DPPH) and reactive oxygen species under in vitro conditions. EHWB exhibited an effective ferrous ion chelating activity and strong reducing power. It also showed a high DPPH radical scavenging activity (89.4 %) at 5.0 mg/mL, which was comparable to that of the synthetic antioxidant, butylated hydroxytoluene. EHWB also exerted a marked scavenging effect on ·OH with an EC50 value of 0.46 mg/mL, which was lower than that of mannitol (1.03 mg/mL), a classical hydroxyl radical scavenger, and obvious antioxidant activities toward O2·- and H2O2