Journal of Food Biochemistry

Pestil is a traditional and functional snack produced by removing moisture from fruit pulp using different methods. Although solar drying is common in traditional pestil drying, modern drying methods are preferred in industrial production. As one of these methods, heat pump drying (HPD) is considered to be the most favorable technique owing to its notable efficiency in the drying process and low energy consumption. Additionally, it has the capability to accurately regulate drying conditions, thereby enhancing the overall quality of the dried foods. The aim of this study was to investigate the effects of HPD conditions on drying kinetics and quality profile (total monomeric anthocyanin (TMA) content, total phenolic content (TPC), antioxidant capacity (AC), and carotenoid content) and their in vitro bioaccessibility of the cornelian cherry-capia pepper pestil. Also, it was aimed to produce high-quality pestil having bioactive properties by optimizing HPD conditions. Drying temperature (40–50°C) and cornelian cherry concentration (30–40%) were selected as independent variables for the response surface methodology (RSM). After in vitro digestion, pestil samples have higher bioaccessible β-carotene, α-carotene, lutein, and AC (especially for the DPPH method), whereas the drying process reduced the bioaccessibility of TPC in pestil samples. Using a RSM, we found that the way the responses (TMA, TPC, AC, and carotenoids) were related to the independent variables can be best explained by quadratic (Qc), reduced quadratic (RQc), and reduced cubic (RCc) models. These models had high R² values, which mean they can accurately predict the outcomes. The optimal condition of responses with composite desirability of 0.852 was drying temperature at 46.68°C and 44.94% cornelian cherry concentration.

In the present study, the methanolic extract of Calotropis procera root bark was subjected to solvent-solvent partitioning using n-hexane fraction (HF), dichloromethane fraction (DMF), ethyl acetate fraction (EAF), and methanol fraction (MF). The resultant fractions were tested for antioxidant activity using in vitro radical scavenging assay. Preliminary phytochemical investigation revealed the presence of varying proportions of secondary metabolites in solvent fractions such as glycosides, flavonoids, triterpenoids, sterols, and polyphenolic compounds. The total phenolic content of EAF was 25.7 ± 3.12 mg TAE/g followed by 19.05 ± 3.29 mg TAE/g in DMF. The total flavonoid content was 13.69 ± 1.74 mg QUE/g in DMF and 11.4 ± 1.88 mg QUE/g in EAF. The EAF showed significant radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH, IC50  = 369.87 μg/mL), nitric oxide (IC50  = 317.46 μg/mL), hydrogen peroxide (H2O2 , IC50  = 396.85 μg/mL), and hydroxyl radicals (IC50  = 195.39 μg/mL). DMF was most effective in scavenging superoxide radicals (IC₅₀ = 679.60 μg/mL), while greater metal chelating activity was exhibited by MF (IC₅₀ = 614.73 μg/mL). Moreover, the total antioxidant activity for EAF was found to be 94.14 ± 9.114 mg AAE followed by DMF (68.10 ± 8.78 mg AAE). EAF also significantly reduced the formation of thiobarbituric acid reactive substances in a dose-dependent manner in CuSO₄. The observed antioxidant effect might be attributed to the presence of secondary metabolites. Subsequent GC-MS analysis of EAF confirmed the presence of lupeol, α-amyrin, β-amyrin, and ursolic acid. The current investigation reveals that the high polyphenolic and antioxidant pentacyclic triterpenes in EAF of C. procera root bark methanol extract correlates with its good antioxidant activity and can provide protection against free radicals-induced damage in a variety of chronic health conditions.

Peroxidation during organism growth and development might have catastrophic implications. It is critical to further investigate the antioxidant potential of plant anthocyanins. In this study, anthocyanins from Eleutherococcus brachypus fruits (EBF) were extracted by an ultrasonic-assisted method. The anthocyanins were then tested for stability under various storage conditions. Based on single-factor combination with response surface optimization, the best ethanol concentration for anthocyanin extraction was 75%, the ideal ultrasonic irradiation power was 160 W, the liquid-to-solid ratio was 10.18 mL/g, and the maximum anthocyanin yield was 1.86 mg/g. Anthocyanins are readily degraded by bright light and remain stable under acidic storage conditions (pH 3.0) and at temperatures below 60°C. The inhibition rates of anthocyanins against ABTS and DPPH radicals were 54.59% and 48.70%, respectively, using vitamin C (Vc) as a positive control. The data cited above make it clear that anthocyanins may act as natural antioxidants. In addition, this research provides a sound theoretical foundation for the creation of natural green antioxidants.

Background. Prostate cancer (PCa) is a major threat to men’s health worldwide, and there is an urgent need to find a supportive strategy to improve traditional PD-1/PD-L1 targeted immunotherapy. Our previous research identified astragaloside IV and polypeptide extract from scorpion venom (PESV) as the main active components of the astragalus-scorpion drug pair for treating PCa. In this study, we wanted to continue exploring the modulatory effect of astragaloside IV-PESV on the immune microenvironment of tumors further to investigate the antitumor efficacy mechanism of astragaloside IV-PESV. Methods. First, molecular docking was performed to verify whether astragaloside IV and PESV could bind to STAT3 and PD-L1. Next, we performed mouse tumorigenesis experiments to explore the role of astragaloside IV-PESV. Additionally, we further validated the effects of astragaloside IV-PESV on the STAT3/PD-L1 pathway and immunity by in vitro cellular experiments. Furthermore, we overexpressed STAT3 and validated the effects of overexpression of STAT3 on cellular function, T cell activation, and immune escape in vitro and in vivo. Results. Molecular docking revealed astragaloside IV and PESV bound to STAT3 and PD-L1. Astragaloside IV-PESV led to notable tumor tissue volume and weight repression and inhibited tumor immunity and STAT3/PD-L1 pathway-related protein expressions. In vitro, astragaloside IV-PESV suppressed PD-L1 expression by inhibiting STAT3 signaling to modulate immunity. In contrast, overexpression of STAT3 restored PCa cell proliferation, migration, and invasion inhibition by astragaloside IV-PESV. In addition, overexpression of STAT3 restored the promoting effect of astragaloside IV-PESV on T cell activation. Finally, in vivo experiments further illuminated that overexpression of STAT3 restored the immune escape effect of astragaloside IV-PESV on the tumor. Conclusion. Astragaloside IV-PESV improved T cell immune escape by inhibiting PD-L1 expression in PCa through the STAT3 pathway.

Fucoxanthin, a natural carotenoid, contains special ene bonds and 5, 6-mono-epoxide compounds in its molecule, which has physiological activities such as anticancer, antioxidant, anti-inflammatory, antiobesity, and antidiabetic. However, the anticancer actions and underlying mechanisms of fucoxanthin on oral cancer remain to be assessed. In this study, we used tongue carcinoma (CAL-27) cells to examine the effects and underlying mechanisms of fucoxanthin derived from Hizikia fusiforme on CAL-27 proliferation. MTT assays were used to estimate fucoxanthin’s effect on the proliferative capacity of CAL-27 cells. Flow cytometry was used to examine how fucoxanthin affects apoptosis initiation and alters cell cycle progression in CAL-27 cells. Spectrophotometry was used to assess the impact of fucoxanthin on adenosine triphosphate (ATP) generation, glucose uptake, lactate production, and the enzymatic activities of pyruvate kinase and hexokinase in CAL-27 cells. Western blotting was used to investigate fucoxanthin’s impact on the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway and glycolysis-related protein expression levels in CAL-27 cells. Fucoxanthin significantly inhibited CAL-27 cell viability time- and dose-dependently . Administration of fucoxanthin induced CAL-27 cell apoptosis and cell cycle arrest at the G1 phase . Furthermore, fucoxanthin significantly decreased glucose uptake, lactate production, and ATP production in CAL-27 cells and significantly inhibited glycolysis-related enzyme activities and protein expression levels . Fucoxanthin also substantially decreased the expression levels of phosphorylated ribosomal protein S6, phosphorylated AKT, and phosphorylated mTOR . In conclusion, fucoxanthin inhibited CAL-27 cell proliferation, and this mechanism may be associated with the AKT/mTOR-mediated glycolysis pathway.

The utilization of natural preservatives presents a promising avenue for mitigating the spoilage of fresh-cut fruits and vegetables induced by microorganisms, enzymatic browning, and water loss. We have developed an innovative method for preserving fresh-cut green peppers using the combined effects of ε-polylysine (ε-PL) and p-Coumaric acid (p-CA). Through concentration screening experiments, we determined that the optimal concentrations of ε-PL and p-CA were 25 mg/L and 10 mg/L, respectively (ε-p-CA). Treatment with ε-p-CA significantly improved the quality of fresh-cut green peppers. It effectively reduced hardness and weight loss, preserving the texture and appearance of the peppers. Furthermore, ε-p-CA treatment delayed the increase in respiratory rate, electrolyte leakage, and ethylene production, thereby maintaining the structural integrity. Meanwhile, ε-p-CA treatment effectively inhibited the malondialdehyde (MDA) content increase and maintained DPPH radical scavenging activity. The microbial analysis demonstrated the ε-p-CA-treated peppers also showed lower total bacterial, mold, and yeast counts, which prolonged the freshness of fresh-cut peppers. In addition, ε-p-CA treatment improved the retention of phenolics and vitamin C without significantly affecting the color and soluble sugar content of green peppers. Overall, the ε-p-CA treatment showed promise as a natural preservative for extending the shelf life of fresh-cut green peppers.