ABTS Free Radical Research Articles

Functional properties of Ganoderma lucidum extract: antimicrobial and antioxidant activities

This research was conducted to investigate the functional properties of Ganoderma lucidum extract. The antimicrobial activity was evaluated on some bacteria causing food spoilage like Staphylococcus aureus and Escherichia coli. Antioxidant activity was investigated by examining the effect of the extract on DPPH and ABTS free radicals, determining the amount of total phenolic compounds and flavonoids. Based on the results, the antimicrobial and antioxidant activities of the extract were increased by increasing the concentration. Staphylococcus aureus showed the highest sensitivity to Ganoderma extract with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 50 and 100 μg/mL, respectively. The total phenols amount was equal to 383.727 milligrams of gallic acid equivalent per gram (mg GAE/g) of the extract and the total flavonoid was equal to 28.047 milligrams of quercetin equivalents per gram (mg QE/g) of extract. The results of antioxidant activity tests showed that the concentration of 400 μg/mL had the highest scavenging activity of 85.9 and 90.12% for DPPH and ABTS free radicals, respectively. Therefore, considering the potential antioxidant activity and the rich amounts of phenolic compounds in Ganoderma extract, it can be used in the pharmaceutical and food industries instead of synthetic antioxidants and other chemical preservatives to delay lipid peroxidation and prevent the growth of food pathogens.

Secondary metabolite profiling, antioxidant capacity, enzyme inhibitory potential and in silico studies of Launaea intybacea (Jacq.) Beauverd: A multifunctional approach to probe into the new nutraceuticals

Regular intake of bioactive components in herbal supplements and functional foods exert significant long-term health promoting effects; however, there is limited knowledge about medicinal potential of many wild plants. Launaea intybacea, growing in Cholistan Desert is being used in folk medicine system without authentication. In the present study dry powdered of L. intybacea was extracted separately with methanol, n-hexane, ethyl acetate and water. The methanolic extract (LI-M) afforded equal phenolic (20.68 ± 0.19 mgGAE/g extract) and flavonoid (20.92 ± 0.17 mgQE/g extract), whereas, hexane (LI-H) and ethyl acetate (LI-E) extracts showed the highest phenolic contents with values as 25.30 ± 0.14 and 25.38 ± 0.48 mg GAE/g extract, respectively, and LI-E showed significant flavonoid content (12.42 ± 0.29 mg GAE/g extract). The LI-M exhibited good inhibitory activity against DPPH and ABTS free radical (30.67 ± 0.07 and 58.28 ± 4.98 mg TE/g extract, respectively), while the LI-E showed free radical inhibitory values as 11.74 ± 0.27 and 44.79 ± 1.56 mg TE/g extract, respectively. LI-H only displayed significant inhibitory value (28.19 ± 1.24 mg TE/g extract) against ABTS radical. The highest CUPRAC activity (86.22 ± 1.35 mg TE/g extract) was also associated with LI-H, while LI-M and LI-E also showed significant activity with the values as 78.77 ± 0.88 and 76.77 ± 1.08 mg TE/g extract, respectively. FRAP activity was nearly equally associated with LI-M, LI-H and LI-E in the range of 47.46 to 40.07 mg TE/g extract, whereas, the phosphomolybdenum and metal chelating activities were observed higher for LI-H (1.29 ± 0.05 mmol TE/g extract and 27.48 ± 0.32 mg EDTAE/g extract, respectively, followed by LI-E. In enzyme inhibition assay, all the extracts were equally active (3.94 to 3.41 mg GALAE/g extract) against AChE, while LI-H showed the highest inhibitory values of 5.13 ± 0.28 mg GALAE/g extract against BChE. Against tyrosinase, the LI-M showed inhibitory value as 46.94 ± 1.53 mg KAE/g extract, while against α-amylase and α-glucosidase, the higher values (0.58 ± 0.02 and 1.80 ± 0.01 mmol ACAE/g extract, respectively) were associated with LI-E. UHPLC-MS analysis disclosed 102 secondary metabolites comprising of various classes. The above results authenticate medicinal use of Launaea intybacea (Jacq.) Beauverd and proposed the use of its extracts in nutraceutical and health promoting formulations.

Development of alantolactone-loaded zein and shellac nanoparticles for controlled release in simulated gastrointestinal digestion

Alantolactone (ALT) is a sesquiterpene lactone compound extracted from Aucklandia and Aucklandia Enolide. The fast metabolism, short solubility range, and low bioavailability of ALT limit its prospects for further development in clinical applications. To enhance the delivery efficacy, stability, and regulated release of ALT in the gastrointestinal system, ALT-loaded zein-shellac composite nanoparticles (NPs) were created. The amount ratio of zein to shellac in the optimum formulation of the NP was 1:1. ALT-loaded NPs had an average size of 289.57 ± 2.08 nm and an encapsulation efficiency (EE) of up to 75.89 ± 0.25%. The controlled release of ALT in the gastrointestinal tract was made possible by ALT-loaded zein-shellac complex NPs. ALT-loaded NPs can scavenge DPPH and ABTS free radicals as high as 40.7% and 55.6%, respectively. In the in vitro antitumor studies, the ALT-loaded NPs showed cytotoxicity to U87-MG cells and reduced the viability of the cells to 16.0%.

Multifunctional cinnamaldehyde-tannic acid nano-emulsion/chitosan composite film for mushroom preservation

Mushrooms are prone to browning, weight loss, softening, lipid oxidation, and microbial growth after harvesting. Therefore, it is particularly necessary to develop a packaging material with UV protection, antibacterial, and antioxidant properties. Herein, we used tannic acid (TA), a green edible natural extract with excellent antioxidant and anti-ultraviolet effects, as an emulsifier to prepare the cinnamaldehyde-tannic acid nano-emulsion (CIN-TA-NEs). The CIN-TA NEs/CS (CSCT) film was successfully prepared by incorporating CIN-TA NEs into chitosan (CS), which effectively improved the utilization rate of CIN and endowed the composite film with multiple functional effects. Due to the introduction of TA, the radius of CIN emulsion was reduced from 356.2 ± 35.89 nm to 147.4 ± 5.61 nm, which enhanced the uniform dispersion of oil phase CIN in aqueous phase CS, improved the compactness of the film, reduced water vapor and oxygen permeability, and increased water resistance of the composite film. The incorporation of CIN-TA NEs endowed CS composite films with 100% UV protection ability, over 99% antibacterial effect, and 90.56% and 94.02% clearance rates for DPPH and ABTS free radicals. In addition, the CSCT composite film had high biosafety, and TA promoted the biodegradation of composite film to a certain extent. The preservation experiment of Agaricus bisporus has proven that CSCT composite film effectively prolongs the preservation time of mushrooms, which is more than 4 days longer than PE film. This work has prepared a composite film with multiple functions, which has great application prospects for extending the shelf life of mushrooms.

Optimization of extraction of lycopene from carrot and determination of its antioxidant activity

Background: Lycopene is a carotenoid which is abundant in mature red plant fruits, especially in tomato, carrot and watermelon. This study investigated lycopene extraction from carrots and its antioxidant properties. Methods and results: Through an orthogonal experiment (L9 (3)3), lycopene extraction was optimized and its antioxidant capacity was assessed by DPPH, ABTS, and hydroxyl radical scavenging assay. The results showed that the maximum yield of lycopene was obtained when the extraction temperature, extraction time and solid-liquid ratio were 40℃, 125 min and 1:2 g/mL, and the influence on the extraction yield of lycopene decreased in the order: solid-liquid ratio > extraction time > extraction temperature. The antioxidant activity test showed that lycopene had strong scavenging ability on DPPH and ABTS free radicals, but poor scavenging ability on hydroxyl radicals. Conclusion: The maximum extraction yield of lycopene is 50.82 ± 0.18 µg/g. Lycopene has good antioxidant capacity. This study provides a theoretical framework and statistical support for the continued development of the lycopene from carrots, which is projected to be exploited as a natural antioxidant or health supplement in the food and cosmetics industries.

Improvement of hydrolysis efficiency and interfacial properties of zein using nanoemulsions prepared by a low energy emulsification method

Alcalase hydrolysis can improve the interfacial properties and functional features of proteins. It usually reacts in water. However, zein is difficult to dissolve in water due to its amino acid composition, which greatly limits its application in food industry. To achieve heterogeneous hydrolysis of zein, a new and stable reaction system which called bicontinuous microemulsion was constructed. It consisted of Tween-80, absolute ethanol, n-octanol and distilled water. The average particle size of the nanoemulsion system was 18.23 nm. In this dispersion system, alcalase hydrolysis expanded the protein structure, exposed hydrophobic groups and significantly improved the emulsifying activity, foaming capacity and other interface properties. The scavenging activity of DPPH free radicals and ABTS free radicals were greatly promoted, reached 59.66% and 82.91% respectively. This study provides a new idea for enzymatic hydrolysis reaction medium of zein and is conducive to the application of zein in future.

Physicochemical properties of Kakol (Suaeda aegyptiaca) essential oil nanoemulsion and its effect on the storage quality of rainbow trout (Oncorhynchus mykiss) during cold storage.

The study aims to analyze the chemical composition of Suaeda aegyptiaca essential oil (PSAE) by GC-MS, produce the nanoemulsified essential oil (NSAE) using ultrasound, and compare the antimicrobial and antioxidant activity of the PSAE and NSAE in laboratory medium and rainbow trout fish (Oncorhynchus mykiss). Geranyl-acetone (30.52%) and p-Vinylguaiacol (10.66%), and (e)-β-ionone (7.79%) were the main PSAE chemical compounds. The mean droplet size diameter, polydispersity index, and viscosity of NSAE were 179.67 nm, 0.255, and 0.96 cP, respectively. PSAE and NSAE showed a moderate antiradical potential against DPPH- and ABTS-free radicals (50 < IC50 < 250 μg mL-1). There was no significant difference between antiradical scavenging of PSAE and NSAE (p > .05). E. faecalis and K. pneumonia were the most and lowest sensitive bacteria to PSAE and NSAE, respectively. Examining different treatments on the shelf-life of minced fish showed that Kakol essential oil could improve the shelf-life of fish between 12.5% and 60% (depending on quality index). There was no significant difference between the bioactivity of PSAE and NSAE, which means that the nanoemulsion showed acceptable performance at lower essential oil concentrations.

Phenolic Composition, Antioxidant, and α-Glucosidase Inhibitory Activities of Extracts from Polygonatum sibiricum

As a traditional Chinese medicine and functional food, Polygonatum sibiricum contains many bioactive compounds with multiple biological activities. Presently, we obtained three extracts from Polygonatum sibiricum by different solvents and comparably analyzed their total phenols, flavonoids, and chemical compositions. Meanwhile, the antioxidant activity and the attenuation of palmitic acid (PA)-induced hepatic oxidative stress of these extracts were further investigated. The results showed that the active substances in Polygonatum sibiricum were inclined to dissolve in ethanol (EE), and twenty compounds were identified. EE exhibited the best antioxidant activity to scavenging DPPH and ABTS free radicals, as well as reducing power. Meanwhile, extracts from Polygonatum sibiricum, especially EE, could significantly increase the activity of SOD and HO-1 and ameliorate PA-induced oxidative stress in HepG2 cells through Nrf2-related pathways. Furthermore, EE could significantly inhibit the activity of α-glucosidase and effectively reduce the rapid rise of blood glucose induced by sucrose loading.

Development of a Microbial-Assisted Process for Enhanced Astaxanthin Recovery from Crab Exoskeleton Waste

Astaxanthin is a xanthophyll carotenoid possessing impressive nutraceutical, antioxidant, and bioactive merits. Traditionally, astaxanthin is extracted from crustacean wastes via solvent extraction methods. However, the rigid structure of shells that comprise complex proteins and chitin challenges the extraction process. This investigation addressed an efficient microbial-assisted method to facilitate astaxanthin recovery from crab exoskeleton waste utilizing chitinolytic and proteolytic microorganisms. Herein, we evaluated the effect of pretreatment of the exoskeleton waste with a newly isolated probiotic strain, Bacillus amyloliquefaciens CPFD8, showing remarkable protease and chitinase activity and a proteolytic Saccharomyces cerevisiae 006-001 before solvent extraction, using acetone/hexane, on astaxanthin recovery. Furthermore, the antioxidant and anti-inflammatory activities of the recovered astaxanthin were inspected. Results revealed that both strains boosted the astaxanthin yield from the crab (Callinectes sapidus) exoskeleton compared with solvent extraction using acetone/hexane. Under optimum conditions, astaxanthin yield was 217 and 91 µg/g crab exoskeleton in samples treated with B. amyloliquefaciens CPFD8 and S. cerevisiae 006-001, respectively. Interestingly, pretreatment of crab exoskeleton waste with B. amyloliquefaciens CPFD8 yielded more than 6-fold astaxanthin compared with the solvent extraction method that yielded just 35 µg/g. This increase could be attributed to the proteolytic activity of B. amyloliquefaciens CPFD8 that rendered deproteinized shell chitin accessible to chitinase, facilitating the penetration of solvents and the recovery of astaxanthin. The recovered astaxanthin exhibited excellent antioxidant activity in scavenging DPPH or ABTS free radicals with IC50 values of 50.93 and 17.56 µg/mL, respectively. In addition, the recovered astaxanthin showed a remarkable anti-inflammatory impact on LPS-induced murine macrophage RAW264.7 cells and significantly inhibited the production of nitric oxide, TNF-α, and IL-6 compared with the untreated control. These findings suggest the potential use of the developed microbial-assisted method utilizing chitinolytic and proteolytic B. amyloliquefaciens CPFD8 to maximize the recovery of bioactive astaxanthin from crab (C. sapidus) exoskeleton waste.

Structural characterization of polysaccharides from Medicago sativa L. roots and lipid-lowering activity in oleic acid-induced HepG2 cells

Polysaccharides have multiple pharmacological activities without toxicity or side effects. In the present study, the structure, antioxidant and lipid-lowering activities of alfalfa (Medicago sativa L.) polysaccharides (APS) were reported. Three alfalfa root polysaccharides (RAPS), RAPS-1, RAPS-2, and RAPS-3 were isolated, purified, and characterized. The structural analyses demonstrated that the homogeneous RAPS had molecular weights of 22.60, 26.95, and 38.25 kDa, respectively. Furthermore, RAPS-1 was composed of rhamnose, arabinose, xylose, glucuronic acid, glucose, and galactose with molar ratios of 10.25%, 12.53%, 6.58%, 4.56%, 15.74%, and 36.30%, RAPS-2 comprised rhamnose, arabinose, xylose, glucose, and galactose in the molar ratios of 24.07%, 14.48%, 1.24%, 15.05%, and 39.37%, while RAPS-3 was composed of rhamnose, arabinose, xylose, glucuronic acid, mannose, glucose, and galactose in the molar ratios of 31.61%, 11.78%, 1.93%, 5.49%, 3.18%, 14.56%, and 24.63%. The SEM analysis suggested that with the increase of the molecular weight of polysaccharides, its structure is more compact and the stability is stronger. In vitro, RAPS showed strong scavenging ability against DPPH and ABTS free radicals. In addition, RAPS had potent antioxidant activity and reduced the accumulation of lipids in oleic acid-induced NAFLD in HepG2 cells, with RAPS-1 being the most effective. Furthermore, RAPS-1 decreased MDA production, improved the activities of SOD and the total antioxidant capacity of cells, demonstrating that RAPS could effectively restrict lipid accumulation in HepG2 cells induced by oleic acid by restoring the antioxidant system. Western blot analysis indicated that the RAPS-1 can activate the Nrf2/HO-1 signaling pathway to relieve oxidative stress induced by oleic acid, thus playing a role in the treatment of NAFLD.

Optimization of Extraction Process and Dynamic Changes in Triterpenoids of Lactuca indica from Different Medicinal Parts and Growth Periods.

In this study, the triterpenoids in the leaves of Lactuca indica L.cv. Mengzao (LIM) were extracted via microwave-assisted ethanol extraction, and the optimum extraction conditions for triterpenoids were determined through single-factor experiments and the Box-Behnken method. The effects of three factors (solid-liquid ratio, microwave power and extraction time) on the total triterpenoids content (TTC) were evaluated. The TTC of different parts (roots, stems, leaves and flowers) of LIM in different growth stages was studied, and the scavenging effects of the highest TTC parts on DPPH, ABTS and hydroxyl free radicals were investigated. The results showed that the optimum extraction conditions for microwave-assisted extraction of total triterpenoids from LIM leaves were as follows: solid-liquid ratio of 1:20 g/mL; microwave power of 400 W; and extraction time of 60 min. Under these conditions, the TTC was 29.17 mg/g. Compared with the fresh raw materials, the TTC of the materials increased after freeze drying. The leaves of LIM had the highest TTC, and the flowering stage was the best time. The triterpenoids from the leaves had a strong ability to eliminate DPPH and ABTS free radicals, and the elimination effect of dried leaves was better than that of fresh leaves, while the elimination effect of hydroxyl free radicals was not obvious. The tested method was used to extract total triterpenoids from LIM using a simple process at low cost, which provides a reference for developing intensive processing methods for L. indica.

Preparation of oxypeucedanin-loaded PLGA-chitosan nanoparticles: Cytotoxicity, apoptosis induction, and anti-angiogenic effects

There are some serious side effects associated with cancer chemotherapy. The medical properties of oxypeucedanin, among a wide range of natural products, are being tested for minimizing off-target effects. The aim of this study was to prepare and characterize oxypeucedanin (OPD)-loaded poly(lactic-co-glycolic acid (PLGA) nanoparticles (NPs) surface-modified with chitosan (CS) (OPD-PLGA–CS–NP). The cytotoxic, apoptotic, and anti-angiogenesis properties of OPC-NP were then investigated in vitro. OPD-PLGA–CS–NPs showed cytotoxic effects against diverse cancer cell lines, while these effects were less pronounced in HFF normal cells. OPD-PLGA–CS–NPs were also shown to possess apoptotic properties as shown by flowcytometry, fulrecent microscopy and real-time PCR. The antioxidant effects of OPD-PLGA–CS–NPs also demonstrated through scavenging of DPPH and ABTS free radicals. Additionally, OPD-PLGA–CS–NPs were shown to have antiangiogenic properties by using CAM assays. It would be worthwhile to conduct further in vivo studies on animal-bearing tumor models to further demonstrate the properties and anticancer properties of the OPD-PLGA–CS–NPs.

Enzymatic Conversion of Red Tilapia (Oreochromis niloticus) By-Products in Functional and Bioactive Products

ABSTRACT The bioconversion of red tilapia by-products in protein hydrolysates using neutrase and papain demonstrated a high degree of hydrolysis and yield. Tilapia protein hydrolysates (TPH) contained high content in minerals, essential amino acids, and low-molecular-weight peptides. TPH showed water solubility and emulsifying capacity at neutral and alkaline conditions but low foam stability. TPH are also able to scavenge DPPH and ABTS free radicals and high efficiency for bacterial growth. Therefore, TPH represent an interesting source of functional and bioactive products to be added in food formulations, a high-performance bacterial culture media, and a sustainable way to reduce tilapia-processing wastes.

Preparation, characterization, identification, and antioxidant properties of fermented acaí (Euterpe oleracea).

Fermentation technology was used to prepare the acaí (Euterpe oleracea) fermentation liquid. The optimal fermentation parameters included a strain ratio of Lactobacillus paracasei: Leuconostoc mesenteroides: Lactobacillus plantarum=0.5:1:1.5, a fermentation time of 6 days, and a nitrogen source supplemental level of 2.5%. In optimal conditions, the ORAC value of the fermentation liquid reached the highest value of 273.28 ± 6.55 μmol/L Trolox, which was 55.85% higher than the raw liquid. In addition, the FRAP value of the acaí, as well as its scavenging ability of DPPH, hydroxyl, and ABTS free radicals, increased after fermentation. Furthermore, after fermentation treatment, the microstructure, basic physicochemical composition, amino acid composition, γ-aminobutyric acid, a variety of volatile components, and so on have changed. Therefore, fermentation treatment can significantly improve the nutritional value and flavor of the acaí. This provides a theoretical basis for the comprehensive utilization of acaí.

Antioxidant, antimicrobial, and α-glucosidase inhibitory activities of saponin extracts from walnut (Juglans regia L.) leaves

Objective: To investigate the relationship between triterpenoid saponin content and antioxidant, antimicrobial, and α-glucosidase inhibitory activities of 70% ethanolic, butanolic, aqueous, supernate and precipitate extracts of Juglans regia leaves. Methods: Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method. Antioxidant activity was evaluated against DPPH and ABTS free radicals. We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts. Pearson's correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities. Results: The butanolic extract was most effective against DPPH with an IC50 of 6.63 μg/mL, while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50 of 42.27 μg/mL. Pearson's correlation analysis indicated a strong negative correlation (r = -0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined. In addition, the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts. All the extracts had fair antibacterial activity against Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae except for the aqueous extract. Conclusions: Juglans regia extracts show potent antioxidant, antimicrobial, and α-glucosidase inhibitory activities. There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities. However, additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.

Phytochemical Screening and In vitro Antioxidant, Antibacterial, and Antihemolytic Activities of Putoria calabrica Leaf Extracts

Background:: Putoria calabrica is a common Mediterranean plant used topically in folk medicine for medical purposes. The aim of this study is to evaluate the in vitro antioxidant, antibacterial, and antihemolytic properties of Putoria calabrica leaf extracts.Methods:Total phenol content (TPC), total flavonoid content (TFC), and condensed tannins content (CTC) were determined spectrophotometrically. The antioxidant activity was tested using TAC, DPPH, ABTS, and FRAP assays. Agar diffusion method was used to determine the antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Anti-hemolytic activity was evaluated by the measurement of erythrocytes turbidity and extracellular hemoglobin concentration using AAPH method.Results:Methanol was the optimal solvent to extract the bioactive components with the highest extraction yield (30.11 ± 0.42%), TPC (142.11 ± 4.04 mg GAE/g dry extract) and TFC (29.16 ± 0.99 mg QrE/g dry extract). In terms of antioxidant activity, methanol extract was the most effective against ABTS free radical (IC50 = 5.02 ± 0.13 mg/ml) and FRAP (A0.5 = 2.91 ± 0.09 mg/ml). While, acetone extract showed the highest TAC (214.05 ± 8.74 mg GAE/g dry extract) and DPPH scavenging activity (IC50 = 1.94 ± 0.02 mg/ml). The strongest antimicrobial effect at a concentration of 10.24 mg/well was observed with acetone extract against P. aeruginosa (22.52 ± 0.60 mm) and C. albicans (17.33 ± 0.41 mm). While, methanol extract was the most active against S. aureus (17.31 ± 0.98 mm). Aqueous extract showed a good capacity to protect erythrocytes from oxidative damage by preventing their hemolysis and the oxidation of hemoglobin induced by AAPH.Conclusion:P. calabrica leaves could have a great importance as a source of therapeutic bioactive compounds.

Bioactivity of Walnut: Investigating the Triterpenoid Saponin Extracts of Juglans regia Kernels for Antioxidant, Anti-diabetic, and Antimicrobial Properties

The increasing demand for plant-based medicines makes plant research attractive to find natural alternatives that can replace synthetic products or at least reduce their use. Saponins are a group of natural phytochemical compounds in most herbs, vegetables, and legumes. There are two different types of saponin compounds, which can be classified based on the nature of the aglycone bound to the oligosaccharide fragments, whether it is a steroid or triterpenoid. This paper is devoted to saponins with triterpenoid aglycone and aims to study the relationship between their content and several biological activities in different Juglans regia kernel extracts, including antioxidant, antimicrobial and antibacterial activities. Antioxidant activity was assessed against two free radicals: DPPH and ABTS. Oleanolic acid was used as a standard to quantify triterpenoid saponins, measured by the vanillin method, whereas Acarbose and Tetracycline were used as positive controls to evaluate the α-glucosidase inhibitory and antimicrobial activities, respectively, of walnut kernel extracts. Findings show that hydroalcoholic extract (EtOH 70%) has a considerable content of phenolic compounds, with 59.51 ± 0.26 mg GAE/g in total polyphenol contents, while the content of total flavonoids and condensed tannins were 3.14 ± 0.27 mg QE/g and 85.65 ± 0.37 mg CE/g of crude extract, respectively. In terms of antioxidant activity, the butanolic extract proved to be the most effective against DPPH with IC50 = 7.74 ± 1.49 µg/mL, while the precipitated extract showed the highest scavenging activity against the ABTS free radical with IC50 = 33.14 ± 2.96 µg/mL. In addition, butanolic and hydroalcoholic extracts of Juglans regia kernels showed an α-glucosidase inhibitory activity even more efficiently than synthetic drugs such as Acarbose, with IC50 values of 11.66 µg/mL and 16.17 µg/mL, respectively, versus 18.01 µg/mL in Acarbose. The evaluation of the antimicrobial activity against Bacillus subtilis, Escherichia coli and Klebsiella pneumonia strains revealed that some extracts could inhibit these bacteria. This study successfully assessed the bioactivities of the extracts, suggesting that the extracts of medicinal plants can demonstrate stronger bioactivity than pure synthetic compounds.

Preparation, characterization and antioxidant activity of polysaccharides copper from Qingzhuan dark tea

Tea polysaccharides was one of the active ingredients of Qingzhuan dark tea, which had antioxidant, anti-tumor, and immune-enhancing effects. The complexation of metal ions of tea polysaccharides was one of the current research hotspots. It can combine the advantages of tea polysaccharides and their complexed trace metal elements, and had great potential development. In this study, the trace element-copper required by the human body was used for complexation with Qingzhuan dark tea polysaccharides, and the structure was characterized by various chemical methods. The copper complexes of Qingzhuan dark tea polysaccharides were characterized by UV spectroscopy, FT-IR, thermogravimetric analysis, X-ray diffraction (XRD), SEM, AFM and X-ray photoelectron spectroscopy (XPS). The tests results show that it was successfully complexed with tea polysaccharides. Meanwhile, the Qingzhuan dark tea polysaccharides copper complex compound (termed TPS-Cu) showed higher scavenging activity of hydroxyl radical and ABTS free radical than the tea polysaccharides (termed TPS). Therefore, TPS-Cu can be used as a potentially effective and stable copper supplement and preventive agent.

Synthesis and Antioxidant Activity of (E) ω-Formylcamphene-Based Thiazole Hydrazone Derivatives

(E) ω-formylcamphene was synthesized from α-pinene, the main component of turpentine, and then reacted with thiosemicarbazide to obtain (E) ω-formylcamphene thiosemicarbazide 3, which was reacted with 14 α-bromoacetophenone compounds to obtain 14 (E) ω-formylcamphene thiazole hydrazone compounds 5a–5n; the yields were all above 80%. The structures of the target compounds were characterized by IR, 1H-NMR, 13C-NMR, and HR-MS analyses. Then, 500, 250, 125, 62.5, and 31.25 mg/L drug solutions were prepared. Free radical scavenging experiments of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2-bis (3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt (ABTS) were carried out with Trolox and L-ascorbic acid as the control samples. The scavenging rates of 14 compounds for DPPH and ABTS free radicals were obtained; the IC50 values of scavenging free radicals were fitted using SPSS software. The results show that 14 (E) ω-formylcamphene-based thiazole hydrazone compounds exhibited good scavenging effects on the two free radicals, especially when the concentration of the drug solution was 125 and 62.5 mg/L; most compounds exceeded the scavenging efficiency of Trolox and L-ascorbic acid.

Lactobacillus casei enhances the apoptosis inducing effect of geniposide on U87 human glioma cells in vitro

The goal of this work was to clarify the mechanism of action of Lactobacillus casei on genipin in triggering glioma apoptosis. DPPH and ABTS free radicals could be successfully eliminated by geniposide, LC-NBRC101979 (Lactobacillus casei), and geniposide + LC-NBRC101979. Geniposide and LC-NBRC101979 had effects that were stronger when combined than when taken alone. Geniposide, LC-NBRC101979, and Geniposide + LC-NBRC101979 did not have any detrimental effects on healthy epithelial cells HBE, but they greatly decreased the growth of U87 glioma cells, according to cell studies. Additionally, the combination of geniposide and LC-NBRC101979 had a stronger inhibitory impact than either drug alone. Results from qPCR revealed that in U87 cells, geniposide, LC-NBRC101979, and eniposide + LC-NBRC101979 could up-regulate caspase-3, COX-2, p53, c-myc, p21 mRNA expression and down-regulate Bcl-2, NF-κB expression. According to the results of the study on the effects of oxidative stress on cells, geniposide, LC-NBRC101979, and geniposide combined with LC-NBRC101979 can decrease the levels of MDA, LDH, and NO in normally damaged epithelial cells caused by oxidative stress and increase the levels of CAT, SOD, GSH-Px, and T-AOC. According to HPLC data, LC-NBRC101979 was able to convert the majority of geniposide into geniposide. It is clear that LC-NBRC101979 may enhance geniposide's inhibitory impact on glioma.