A multi-faceted comparison of phytochemicals in seven citrus peels and improvement of chemical composition and antioxidant activity by steaming

Soluble Dietary Fiber from Citrus unshiu Peel Promotes Antioxidant Activity in Oxidative Stress Mice and Regulates Intestinal Microecology

Aging is characterized by the progressive degeneration of bodily tissues and decline in physiological functions, a process that may be exacerbated by imbalances in intestinal flora. Soluble dietary fiber (PSDF) from Citrus unshiu peel has demonstrated strong free radical scavenging ability to regulate intestinal flora in vitro. However, further evidence is required to ascertain the effectiveness of PSDF in vivo. In our study, 8-week-old mice were artificially aged through subcutaneous injections of a 200 mg/kg/d D-galactose solution for 42 days, followed by a 28-day dietary intervention with varying doses of PSDF, insoluble dietary fiber (PIDF), and vitamin C. After the intervention, we observed a significant mitigation of D-galactose-induced oxidative stress, as evident by weight normalization and reduced oxidative damage. 16S rRNA gene sequencing revealed that PSDF significantly altered the composition of intestinal flora, increasing Firmicutes and reducing Bacteroidota percentages, while also enriching colonic short-chain fatty acids (SCFAs). Spearman correlation analysis further identified a positive correlation between Firmicutes and isovaleric acid, and negative correlations between Muribaculaceae and acetic acid, and between Lachnospiraceae_NK4A136_group and caproic acid. These findings support the potential of Citrus PSDF to alleviate oxidative stress.

Characterization of soluble dietary fiber from citrus peels (Citrus unshiu), and its antioxidant capacity and beneficial regulating effect on gut microbiota

This study aimed to evaluate the physicochemical, structural and functional properties of soluble dietary fiber extracted from citrus peels (Citrus unshiu) by ultrasound-assisted alkaline extraction. Unpurified soluble dietary fiber (CSDF) was compared with purified soluble dietary fiber (PSDF) in terms of composition, molecular weight, physicochemical properties, antioxidant activity, and intestinal regulatory capacity. Results showed that the molecular weight of soluble dietary fiber was >15 kDa, which showed good shear thinning characteristics and belonged to non-Newtonian fluid. The soluble dietary fiber showed good thermal stability under 200 °C. The contents of total sugar, arabinose and sulfate in PSDF were higher than those in CSDF. At the same concentration, PSDF showed stronger free radical scavenging ability. In fermentation model experiments, PSDF promoted the production of propionic acid and increased the abundance of Bacteroides. These findings suggested that soluble dietary fiber extracted by the ultrasound-assisted alkaline extraction has good antioxidant capacity and promotes intestinal health. It has broad development space in the field of functional food ingredients.

Green synthesis of ZnFe2O4 nanoparticles using plant extracts and their applications: A review

Magnetic nanoparticles, particularly ZnFe₂O₄ are of enormous significance in biomedical and water treatment fields. However, chemical synthesis of ZnFe₂O₄ nanoparticles endures some major limitations, e.g., the use of toxic substances, unsafe procedure, and cost-ineffectiveness. Biological methods are more preferable approaches since they take advantages of biomolecules available in plant extract serving as reducing, capping, and stabilizing agents. Herein, we review plant-mediated synthesis and properties of ZnFe₂O₄ nanoparticles for multiple applications in catalytic and adsorption performance, biomedical, catalyst, and others. Effect of several factors such as Zn²⁺/Fe³⁺/extract ratio, and calcination temperature on morphology, surface chemistry, particle size, magnetism and bandgap energy of obtained ZnFe₂O₄ nanoparticles was discussed. The photocatalytic activity and adsorption for removal of toxic dyes, antibiotics, and pesticides were also evaluated. Main results of antibacterial, antifungal and anticancer activities for biomedical applications were summarized and compared. Several limitations and prospects of green ZnFe₂O₄ as an alternative to traditional luminescent powders have been proposed.

Mechanistic Study of Xanthotoxin-Mediated Inactivation of CYP1A2 and Related Drug-Drug Interaction with Tacrine

Xanthotoxin (XTT) is a biologically active furanocoumarin widely present in foods and plants. The present study is designed to systematically investigate the enzymatic interaction of XTT with CYP1A2, along with pharmacokinetic alteration of tacrine resulting from the co-administration of XTT. The results showed that XTT induced a time-, concentration-, and NADPH-dependent inhibition of CYP1A2, and the inhibition was irreversible. Co-incubation of glutathione (GSH) and catalase/superoxide dismutase was unable to prevent enzyme inactivation. Nevertheless, competitive inhibitor fluvoxamine exhibited a concentration-dependent protective effect against the XTT-induced CYP1A2 inactivation. A GSH trapping experiment provided strong evidence for the production of epoxide or/and γ-ketoenal intermediates resulting from the metabolic activation of XTT. Furthermore, pretreatment of rats with XTT was found to significantly increase the C_max and area under the curve of plasma tacrine relative to those of tacrine administration alone.

Citrus limon phytocompounds decorated nanoparticles control poultry pathogens

Antibiotic resistance poses a significant threat to the global health, food security, and environment. In poultry and livestock, antibiotics are beneficial since they improve poultry performance and are economically effective. Therefore, it is crucial to search for alternatives that can be environmentally safe and successful in treating these infections. In this study, we employed molecular docking to evaluate lemon peel phytochemical's protein binding capability against various poultry pathogens. The nanoparticles (LP AgNPs) obtained from the lemon peel were characterized and tested for their antibacterial activity against more poultry pathogens. LP AgNPs were characterized by using UV-Visible absorption spectra, which revealed an absorption peak at a wavelength of 420-440 nm. The FT-IR analysis demonstrated that flavonoids and phenolic acids acted as capping, reducing, and stabilizing agents during the biosynthesis of AgNPs. EDAX showed a strong peak was observed at 3 keV which revealed the absorption of metallic silver nanoparticles. The mean diameter was from 2 to 20 nm through HRTEM. Zeta potential of the LP AgNps at - 17.2 mV showed the high stability of the green synthesized AgNps. Maximum inhibitory concentrations of LP AgNps against the isolated poultry pathogens were 50 μg/ml concentration. The toxicity tests were performed in the Vigna radiata seedlings and Artemia nauplii, which showed less toxic effects and eco-friendly nature of the LP AgNps. LP AgNps have the potential to treat antibiotic resistant poultry pathogens, thereby paving the way for the development of value-added novel products incorporated with nanoparticles for treating various infection caused by antibiotic-resistant poultry pathogens.

Effect of Storage and Drying Treatments on Antioxidant Activity and Phenolic Composition of Lemon and Clementine Peel Extracts

Obtaining polyphenols from horticultural waste is an emerging trend that enables the valorization of resources and the recovery of value-added compounds. However, a pivotal point in the exploitation of these natural extracts is the assessment of their chemical stability. Hence, this study evaluates the effect of temperature storage (20 and -20 °C) and drying methods on the phenolic composition and antioxidant activity of clementine and lemon peel extracts, applying HPLC-DAD-MS, spectrophotometric methods, and chemometric tools. Vacuum-drying treatment at 60 °C proved to be rather suitable for retaining the highest antioxidant activity and the hesperidin, ferulic, and coumaric contents in clementine peel extracts. Lemon extracts showed an increase in phenolic acids after oven-drying at 40 °C, while hesperidin and rutin were sustained better at 60 °C. Hydroethanolic extracts stored for 90 days preserved antioxidant activity and showed an increase in the total phenolic and flavonoid contents in lemon peels, unlike in clementine peels. Additionally, more than 50% of the initial concentration was maintained up to 51 days, highlighting a half-life time of 71 days for hesperidin in lemon peels. Temperature was not significant in the preservation of the polyphenols evaluated, except for in rutin and gallic acid, thus, the extracts could be kept at 20 °C.

Phytochemicals Derived from Agricultural Residues and Their Valuable Properties and Applications

Billions of tons of agro-industrial residues are produced worldwide. This is associated with the risk of pollution as well as management and economic problems. Simultaneously, non-edible portions of many crops are rich in bioactive compounds with valuable properties. For this reason, developing various methods for utilizing agro-industrial residues as a source of high-value by-products is very important. The main objective of the paper is a review of the newest studies on biologically active compounds included in non-edible parts of crops with the highest amount of waste generated annually in the world. The review also provides the newest data on the chemical and biological properties, as well as the potential application of phytochemicals from such waste. The review shows that, in 2020, there were above 6 billion tonnes of residues only from the most popular crops. The greatest amount is generated during sugar, oil, and flour production. All described residues contain valuable phytochemicals that exhibit antioxidant, antimicrobial and very often anti-cancer activity. Many studies show interesting applications, mainly in pharmaceuticals and food production, but also in agriculture and wastewater remediation, as well as metal and steel industries.

Xanthotoxin (8-methoxypsoralen): A review of its chemistry, pharmacology, pharmacokinetics, and toxicity

Xanthotoxin (XAT) is a natural furanocoumarins, a bioactive psoralen isolated from the fruit of the Rutaceae plant Pepper, which has received increasing attention in recent years due to its wide source and low cost. By collecting and compiling literature on XAT, the results show that XAT exhibits significant activity in the treatment of various diseases, including neuroprotection, skin repair, osteoprotection, organ protection, anticancer, antiinflammatory, antioxidative stress and antibacterial. In this paper, we review the pharmacological activity and potential molecular mechanisms of XAT for the treatment of related diseases. The data suggest that XAT can mechanistically induce ROS production and promote apoptosis through mitochondrial or endoplasmic reticulum pathways, regulate NF-κB, MAPK, JAK/STAT, Nrf2/HO-1, MAPK, AKT/mTOR, and ERK1/2 signaling pathways to exert pharmacological effects. In addition, the pharmacokinetics properties and toxicity of XAT are discussed in this paper, further elucidating the relationship between structure and efficacy. It is worth noting that data from clinical studies of XAT are still scarce, limiting the use of XAT in the clinic, and in the future, more in-depth studies are needed to determine the clinical efficacy of XAT.

Compositional Analysis of Four Kinds of Citrus Fruits with an NMR-Based Method for Understanding Nutritional Value and Rational Utilization: From Pericarp to Juice

Citrus is one of the most important economic crops and is widely distributed across the monsoon region. Citrus fruits are deeply loved by consumers because of their special color, fragrance and high nutritional value. However, their health benefits have not been fully understood, especially the pericarps of citrus fruits which have barely been utilized due to their unknown chemical composition. In the present study, the pericarp and juices of four typical varieties of citrus fruits (lemon, dekopon, sweet orange and pomelo) were analyzed by NMR spectroscopy combined with pattern recognition. A total of 62 components from the citrus juices and 87 components from the citrus pericarps were identified and quantified, respectively. The different varieties of the citrus fruits could be distinguished from the others, and the chemical markers in each citrus juice and pericarp were identified by a combination of univariate and multivariate statistical analyses. The nutritional analysis of citrus juices offers favorable diet recommendations for human consumption and data guidance for their potential medical use, and the nutritional analysis of citrus pericarps provides a data reference for the subsequent comprehensive utilization of citrus fruits. Our results not only provide an important reference for the potential nutritional and medical values of citrus fruits but also provide a feasible platform for the traceability analysis, adulteration identification and chemical composition analysis of other fruits.