Investigating the Hepatoprotective Properties of Mulberry Leaf Flavonoids against Oxidative Stress in HepG2 Cells.

Oxidative stress significantly contributes to ageing and disease, with antioxidants holding promise in mitigating its effects. Functional foods rich in flavonoids offer a potential strategy to mitigate oxidative damage by free radicals. We investigated the protective effects of mulberry leaf flavonoids (MLF) against H2O2-induced oxidative damage in HepG2 cells. It assessed the inhibitory effect of MLF (62.5-500 µg/mL) on H2O2-induced oxidative damage by analyzing cellular morphology and oxidative stress markers, including ROS production, mitochondrial membrane potential, antioxidant enzyme levels, MDA, and apoptosis-related proteins. The results demonstrated that MLF prevented spiny cell formation triggered by 750 µM H2O2 and significantly reduced ROS levels, restored mitochondrial membrane potential, decreased lactate dehydrogenase and alanine transaminase leakage, and reduced MDA content induced by H2O2. MLF also modulated antioxidant enzymes and attenuated oxidative damage to HepG2 cell DNA, as confirmed by staining techniques. These findings indicate the potential of MLF as a hepatoprotective agent against oxidative damage in HepG2 cells.

Cellular Antioxidant Properties of Ischnoderma Resinosum Polysaccharide.

A predominant polysaccharide isolated from Ischnoderma resinosum underwent evaluation for its capacity to scavenge free radicals and its potential antioxidant properties at a cellular-oriented level. This proved that Ischnoderma resinosum polysaccharide (IRP) remarkably curtailed AAPH-induced erythrocyte hemolysis through the inhibition of the generation of ROS (p < 0.05). Rather, it caused the restoration of intracellular antioxidant enzyme (SOD, GSH-Px, and CAT) activities at an acceptable pace and the silencing of intracellular MDA formation, as well as the rescaling of LDH leakage. Furthermore, a model of oxidative stress in HepG2 cells was established by adopting 400 µM of hydrogen peroxide, which suggested that IRP manifests promising antioxidant activity. Notably, after the intervention of IRP in the H2O2-induced HepG2 cells, there was a statistical elevation in cell survivability (p < 0.05). IRP diminished the morphological alterations in the nucleus and decreased the secretion of ROS (p < 0.05), with a dose-dependent abrogation of apoptosis (p < 0.05). Consequently, IRP, which was isolated and purified, was able to scavenge free radicals and possessed favorable antioxidant activity that could dampen the occurrence of oxidative stimulation and effectively alleviate the AAPH-induced erythrocyte hemolysis and H2O2-induced oxidative damage in HepG2 cells. This provides a basis and theoretical reference for the development and utilization of IRP as a natural antioxidant, with emphasis on the exploitation of environmentally friendly and cost-effective antioxidants.

Protective Effect of Flavonoids from Mulberry Leaf on AAPH-Induced Oxidative Damage in Sheep Erythrocytes.

To evaluate the antioxidant activity of flavonoids extracted from Chinese herb mulberry leaves (ML), flavonoids from mulberry leaves (FML) were extracted and purified by using ultrasonic-assisted enzymatic extraction and D101 macroporous resin. Using LC-MS/MS-Liquid Chromatography with tandem mass spectrometry analysis, hesperidin, rutoside, hyperoside, cyanidin-3-o-glucoside, myricitrin, cyanidin, and quercetin were identified, and NMR and UV were consistent with the verification of IR flavonoid characteristics. The antioxidant activity of FML has also been evaluated as well as the protective effect on 2,2 0-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress. The results showed that FML exhibited powerful antioxidant activity. Moreover, FML showed dose-dependent protection against AAPH-induced sheep erythrocytes' oxidative hemolysis. In the enzymatic antioxidant system, pretreatment with high FML maintained the balance of SOD, CAT, and GSH-Px; in the non-enzymatic antioxidant system, the content of MDA can be effectively reduced after FML treatment. This study provides a research basis for the development of natural products from mulberry leaves.

Development of a food preservative from sea buckthorn together with chitosan: Application in and characterization of fresh-cut lettuce storage.

The purpose was to create a novel composite food preservative for fresh-cut lettuce using flavonoids and chitosan from sea buckthorn leaves (SBL). Sea buckthorn leaves were extracted with ethanol as the extraction solvent and ultrasonic-assisted extraction to obtain flavonoid from sea buckthorn leaf crude (FSL), and then the FSL was secondarily purified with AB-8 resin and polyamide resin to obtain flavonoid from sea buckthorn leaf purified (FSL-1). Different concentrations of FSL-1 and chitosan were made into a composite preservative (FCCP) by magnetic stirring and other methods, containing 1% chitosan preservative (CP) alone, 0.5-2 mg/ml of FSL-1 and 1% chitosan composite preservative (FCCP-1, FCCP-2, FCCP-3, and FCCP-4), and the FSL-1 concentrations were analyzed the effect of FSL-1 concentration on the physicochemical properties of the composite preservatives, including their film-forming ability, antioxidant capacity and ability to prevent bacterial growth, was analyzed. To further investigate the effect of the combined preservatives on fresh-cut lettuce, different FCCPs were applied to the surface was stored at 4°C for 7 days. Then the changes in weight loss, hardness, browning index, total chlorophyll content, SOD and MDA were analyzed. It was used to assess the physicochemical indicators of fresh-cut lettuce throughout storage. According to the results of Fourier transform infrared spectroscopy, FSL-1 and chitosan interacted to form hydrogen bonds, and the contact angle and viscosity of FCCP increased on both horizontal glass and polystyrene plates, indicating the good film-forming properties of the composite preservation solution. With the diameter of the antibacterial zone of Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes being (21.39 ± 0.22), (17.43 ± 0.24), (15.30 ± 0.12), and (14.43 ± 0.24) mm, respectively. It was proved that the antibacterial activity of FCCP became stronger with the increase of FSL-1 concentration and had the best antibacterial effect on S. aureus. The complex preservative showed the best scavenging effect on ferric reducing antioxidant capacity, DPPH radicals (96.64%) and 2,2'-Azinobis- (3-ethylbenzthiazoline-6-sulphonate) (ABTS) radicals (99.42%) when FSL-1 was added at 2 mg/ml. When fresh-cut lettuce was coated with FCCP for the same storage time, various indicators of lettuce such as weight loss, hardness, browning index, SOD activity and MDA content were better than the control group showing good potential in fresh-cut vegetables and fruits preservation. FCCP holds great promise for food safety quality and shelf-life extension as a new natural food preservative. The waste utilization of sea buckthorn leaves can greatly improve his utilization and economic benefits.

Preparation of Solid Lipid Nanoparticles of Cinnamaldehyde and Determination of Sustained Release Capacity.

Natural plant essential oils cannot be applied on a large scale due to their high volatility, easy deactivation, etc. This study provides a new method to prepare a long-lasting, slow-release essential oil product by taking advantage of solid lipid nanoparticles, which will provide a scientific guideline for the future essential oil industry. In this article, solid lipid cinnamaldehyde nanoparticles were prepared using an ultrahigh-pressure homogenization method. SLN-CA with a particle size of 74 ± 5 nm, PDI of 0.153 ± 0.032, and zeta potential of -44.36 ± 2.2 mV was screened using an additional amount of cinnamaldehyde, the ratio of oil phase components, and the homogenization pressure and number of times as factors. Differential thermal analysis and spectroscopy demonstrated that cinnamaldehyde was successfully encapsulated inside the nanoparticles. The change in particle size of nanoparticles under different conditions and times was used as an indicator of stability. The stability of the finished nanoparticles was evaluated. The retention and slow-release ability of cinnamaldehyde were investigated using the concentration of cinnamaldehyde in nanoparticles as an indicator. The results showed that after 15 days, SLN-CA retained 52.36% of the concentration from 15 days prior. The bacterial inhibition test shows that SLN-CA can inhibit bacteria.

Neuroprotection of Gastrodia elata polyphenols against H2O2-induced PC12 cell cytotoxicity by reducing oxidative stress.

It has been suggested that oxidative stress (OS) has a role in the development of aging and neurodegenerative disorders. Biological molecules are easily damaged by reactive oxygen species, which can ultimately result in necrotic or apoptotic cell death. Foods containing phytochemicals, such as phenolic compounds, may have potential preventive effects against several diseases, including alzheimer's disease (AD), according to epidemiological and in vitro research. Gastrodia elata is a well-known homology of medicine and food plant that has been used for centuries in China and other East Asian countries to treat central nervous system disorders. In this study, we focused on the potential of the extract, Gastrodia elata polyphenols (GPP), for the prevention and treatment of AD. H2O2 induced PC12 cell damage was used to simulate the oxidative stress of AD. The effects of GPP on the injury model were evaluated by cell survival rate, lactate dehydrogenase (LDH), lipid peroxidation (MDA), production of intracellular antioxidant enzymes, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), cellular inflammation level and apoptosis level. The results showed that GPP pretreatment had a protective effect by increasing cell viability, reducing lactate dehydrogenase infiltration, decreasing MDA and increasing intracellular antioxidant enzymes, diminishing reactive oxygen species production and decreasing mitochondrial membrane potential, reducing cell inflammation and decreasing apoptosis. Accordingly, it is suggested that GPP possessed promising neuroprotective benefits which enabled the prevention or therapeutic implementation of AD along with serving as a reference towards the exploitation of functional foods or drugs derived from Gastrodia elata.

Preparation and characterization of geraniol nanoemulsions and its antibacterial activity.

Geraniol nanoemulsions (G-NE) based on Tween 80 and medium chain triglyceride (MCT) as surfactant and co-surfactant, respectively, has been prepared by the spontaneous emulsification method. Its physical and chemical properties such as mean particle size, zeta potential, PDI, pH, viscosity, contact angle, appearance morphology, and stability (storage stability, thermal stability, centrifugal properties, acid-base stability, and freeze-thaw properties) of the droplet were analyzed. The results showed that the mean particle size of G-NE was 90.33 ± 5.23 nm, the PDI was 0.058 ± 0.0007, the zeta potential was -17.95 ± 5.85 mV and the encapsulation efficiency was >90%. The produced G-NE has been demonstrated to be fairly stable in long-term storage at 4°C, pH = 5 and high-speed centrifuges. Moreover, G-NE had a significant inhibition effect on Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes (p < 0.05). The bacterial inhibition rates of G-NE at a concentration of 1 MIC were 48, 99, 71.73, and 99% after 12 h of action against these four foodborne pathogenic bacteria, respectively. Therefore, the results obtained indicated that nanoemulsification enhanced the stability and antibacterial activity of geraniol to some extent, which will promote the utilization of geraniol in food preservation.

The synthesis of strigolactone is affected by endogenous ascorbic acid in transgenic rice for l-galactono-1, 4-lactone dehydrogenase suppressed or overexpressing.

Rice tillering, which determines the panicle number per plant, is an important agronomic trait for grain production. In higher plants, ascorbic acid (Asc) plays a major role in ROS-scavenging activity. l-Galactono-1, 4-lactone dehydrogenase (GalLDH, EC1.3.2.3) is an enzyme that catalyzes the last step of Asc biosynthesis in plants. Previously, we have reported that homozygous L-GalLDH-suppressed transgenic rice plants (GI) display a reduced tiller number and a lower level of foliar carotenoids (Car) compared with wild type. Strigolactones (SL), which play an important role in the suppression of shoot branching, are synthesized in the roots of rice plant using Car as substrates. In this paper, the relationship between Asc, SL, the accumulation of H2O2, changes in antioxidant capacity, enzyme activities, and gene transcriptions related to the synthesis of SL were analyzed in transgenic rice plants for L-GalLDH suppressed (GI-1 and GI-2) and overexpressing (GO-2). The results showed that the altered level of Asc in the L-GalLDH transgenic rice plants leads to a change in redox homeostasis, resulting in a marked accumulation of H2O2 and decreased antioxidant capacity in GI-1 and GI-2, but lower H2O2 content and increased antioxidant capacity in GO-2. Meanwhile, the altered level of Asc also leads to altered enzyme activities and gene transcript abundances related to SL synthesis in L-GalLDH transgenics. These observations support the conclusion that Asc influences tiller number in the L-GalLDH transgenics by affecting H2O2 accumulation and antioxidant capacity, and altering those enzyme activities and gene transcript abundances related to SL synthesis.