Phenolics and Terpenoids Profiling in Diverse Loquat Fruit Varieties and Systematic Assessment of Their Mitigation of Alcohol-Induced Oxidative Stress.

To compare and investigate the phenolic compounds in the peel and flesh of loquat (Eriobotrya japonica) and evaluate their ability to protect against alcohol-induced liver oxidative stress, we employed a combination of ultra-performance liquid chromatography (UPLC) and high-resolution mass spectrometry (HRMS) to qualitatively and quantitatively analyze 22 phenolics and 2 terpenoid compounds in loquat peel and flesh extracts (extraction with 95% ethanol). Among these, six compounds were identified for the first time in loquat, revealing distinct distribution patterns based on variety and tissue. Various chemical models, such as DPPH, FRAP, ORAC, and ABTS, were used to assess free radical scavenging and metal ion reduction capabilities. The results indicate that peel extracts exhibited higher antioxidant capacity compared with flesh extracts. Using a normal mouse liver cell line, AML-12, we explored the protective effects of loquat extracts and individual compounds against ethanol-induced oxidative stress. The findings demonstrate the enhanced cell viability and the induction of antioxidant enzyme activity through the modulation of Nrf2 and Keap1 gene expression. In a C57/BL6 mouse model of alcohol-induced liver damage, loquat extract was found to alleviate liver injury induced by alcohol. The restoration of perturbed serum liver health indicators underscored the efficacy of loquat extract in reclaiming equilibrium. The culmination of these findings significantly bolsters the foundational knowledge necessary to explore the utilization of loquat fruit extract in the creation of health-focused products.

Nobiletin as a chemopreventive natural product against cancer, a comprehensive review.

As a leading cause of death, second only to heart disease, cancer has always been one of the burning topics in medical research. When targeting multiple signal pathways in tumorigenesis chemoprevention, using natural or synthetic anti-cancer drugs is a vital strategy to reduce cancer damage. However, toxic effects, multidrug resistance (MDR) as well as cancer stem cells (CSCs) all prominently limited the clinical application of conventional anticancer drugs. With low side effects, strong biological activity, unique mechanism, and wide range of targets, natural products derived from plants are considered significant sources for new drug development. Nobiletin is one of the most attractive compounds, a unique flavonoid primarily isolated from the peel of citrus fruits. Numerous studies in vitro and in vivo have suggested that nobiletin and its derivatives possess the eminent potential to become effective cancer chemoprevention agents through various cellular and molecular levels. This article aims to comprehensively review the anticancer efficacy and specific mechanisms of nobiletin, enhancing our understanding of its chemoprevention properties and providing the latest research findings. At the end of this review, we also give some discussion and future perspectives regarding the challenges and opportunities in nobiletin efficient exploitation.

Citrus flavonoids and their antioxidant evaluation.

The antioxidant ability is the link and bridge connecting a variety of biological activities. Citrus flavonoids play an essential role in regulating oxidative stress and are an important source of daily intake of antioxidant supplements. Many studies have shown that citrus flavonoids promote health through antioxidation. In this review, the biosynthesis, composition and distribution of citrus flavonoids were concluded. The detection methods of antioxidant capacity of citrus flavonoids were divided into four categories: chemical, cellular, animal and clinical antioxidant capacity evaluation systems. The modeling methods, applicable scenarios, and their relative merits were compared based on these four systems. The antioxidant functions of citrus flavonoids under different evaluation systems were also discussed, especially the regulation of the Nrf2-antioxidases pathway. Some shortcomings in the current research were pointed out, and some suggestions for progress were put forward.

Glycosidically bound volatiles as affected by ripening stages of Satsuma mandarin fruit.

Composition and changes in free volatiles have been extensively studied in citrus fruit such as mandarin. However, components of glycosidically bound volatiles and changes during fruit ripening have been rarely investigated. A total of 56 glycosidically-bound volatiles were identified in fruit peel at four ripening stages. The highest concentrations in glycosidically-bound volatiles were observed for methyl salicylate in ripening fruit. Concentration of total bound volatiles increased from color conversion stage at 150days after bloom (DAB), peaked at yellow stage (190DAB), followed by a decrease at orange stage (210DAB). Satsuma mandarin fruit at different ripening stages could be separated in a partial least squares-discriminant analysis (PLS-DA) plot using glycosidically bound volatiles as variables. In total 35 glycosidically bound volatiles were identified with variable importance in projection (VIP) score exceeding 1, which may be potential markers for separating fruit at different ripening stages.

Antioxidant and antidiabetic properties of tartary buckwheat rice flavonoids after in vitro digestion.

Oxidative stress and diabetes have a tendency to alter protein, lipid, and DNA moieties. One of the strategic methods used to reduce diabetes-associated oxidative stress is to inhibit the carbohydrate-digesting enzymes, thereby decreasing gastrointestinal glucose production. Plant-derived natural antioxidant molecules are considered a therapeutic tool in the treatment of oxidative stress and diabetes. The objective of this study was to identify tartary buckwheat rice flavonoids and evaluate the effect of in vitro digestion on their antioxidant and antidiabetic properties. High performance liquid chromatography (HPLC) analysis indicated the presence of rutin as a major component and quercitrin as a minor component of both digested and non-digested flavonoids. Both extracts showed a significant antioxidant capacity, but digested flavonoids showed reduced activity compared to non-digested. There were some decreases of the antioxidant activities (2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazy (DPPH) radical, and ferric reducing antioxidant power (FRAP)) of digested tartary buckwheat rice flavonoids compared with non-digested. Flavonoids from both groups significantly inhibited reactive oxygen species (ROS) production and α-glucosidase activity. Both digested and non-digested flavonoids markedly increased glucose consumption and glycogen content in HepG2 cells. Tartary buckwheat rice flavonoids showed appreciable antioxidant and antidiabetic properties, even after digestion. Tartary buckwheat rice appears to be a promising functional food with potent antioxidant and antidiabetic properties.

The Growth of SGC-7901 Tumor Xenografts Was Suppressed by Chinese Bayberry Anthocyanin Extract through Upregulating KLF6 Gene Expression.

To investigate the antitumor effect of anthocyanins extracted from Chinese bayberry fruit (Myrica rubra Sieb. et Zucc.), a nude mouse tumor xenograft model was established. Treatments with C3G (cyanidin-3-glucoside, an anthocyanin) significantly suppressed the growth of SGC-7901 tumor xenografts in a dose-dependent manner. Immunohistochemical staining showed a significant increase in p21 expression, indicating that the cell cycle of tumor xenografts was inhibited. qPCR screening showed that C3G treatment up-regulated the expression of the KLF6 gene, which is an important tumor suppressor gene inactivated in many human cancers. Western blot showed that C3G treatments markedly increased KLF6 and p21 protein levels, inhibited CDK4 and Cyclin D1 expression, but did not notably change the expression of p53. These results indicated that KLF6 up-regulates p21 in a p53-independent manner and significantly reduces tumor proliferation. This study provides important information for the possible mechanism of C3G-induced antitumor activity against gastric adenocarcinoma in vivo.

[Hypoglycemic and hypolipidemic effects of quercetin and its glycosides].

Quercetin and its glycosides are important flavonols in traditional herbal drugs and plant-derived food, and they have diverse hiological activities such as antioxidant, anticarcinogenic, anti-inflammatory, hypoglycemic and hypolipidemic activities. Numerous studies have demonstrated that quercetin and its glycosides were effective in the prevention and treatment of non-infectious chronic disease such as diabetes, obesity, and hyperlipidemia. They can regulate glucose and lipid metaholism through different mechanisms. They can decrease blood glucose via protecting pancreatic/p cells or/and improving insulin sensitivity. Also, they have lipid-lowering effects, which may be the result of regulation of lipid catabolism or/and anabolism. Their distributions, as well as the hypoglycemic and hypolipidemic effects are reviewed in this paper. In addition, further bioactivities as well as their dose-activity relationship, structure-activity relationship, bioavailability, and future clinical application of quercetin and its glycosides are discussed and proposed.

Isolation, classification and transcription profiles of the AP2/ERF transcription factor superfamily in citrus.

The AP2/ERF gene family encodes plant-specific transcription factors. In model plants, AP2/ERF genes have been shown to be expressed in response to developmental and environmental stimuli, and many function downstream of the ethylene, biotic, and abiotic stress signaling pathways. In citrus, ethylene is effective in regulation citrus fruit quality, such as degreening and aroma. However, information about the citrus AP2/ERF family is limited, and would enhance our understanding of fruit responses to environmental stress, fruit development and quality. CitAP2/ERF genes were isolated using the citrus genome database, and their expression patterns analyzed by real-time PCR using various orange organs and samples from a fruit developmental series. 126 sequences with homologies to AP2/ERF proteins were identified from the citrus genome, and, on the basis of their structure and sequence, assigned to the ERF family (102), AP2 family (18), RAV family (4) and Soloist (2). MEME motif analysis predicted the defining AP2/ERF domain and EAR repressor domains. Analysis of transcript accumulation in Citrus sinensis cv. 'Newhall' indicated that CitAP2/ERF genes show organ-specific and temporal expression, and provided a framework for understanding the transcriptional regulatory roles of AP2/ERF gene family members in citrus. Hierarchical cluster analysis and t tests identified regulators that potentially function during orange fruit growth and development.

Cyanidin-3-glucoside-rich extract from Chinese bayberry fruit protects pancreatic ß cells and ameliorates hyperglycemia in streptozotocin-induced diabetic mice.

Chinese bayberry fruit is a rich source of anthocyanins, especially cyanidin-3-glucoside (C3G). The present study investigated the protective effects of C3G-rich bayberry fruit extract (CRBFE) against pancreatic ß cells against oxidative stress-induced injury as well as its hypoglycemic effect in diabetic mice. Bayberry extract from "Biqi" was used for both in vitro and in vivo testing because of its high C3G content and high antioxidant capacity. Pretreatment of ß cells with CRBFE (containing 0.5 µmol/L C3G) prevented cell death, increased cellular viability, and decreased mitochondrial reactive oxygen species production and cell necrosis induced by 800 or 1,200 µmol/L H2O2. CRBFE dose-dependently up-regulated pancreatic duodenal homeobox 1 gene expression, contributing to increased insulin-like growth factor II gene transcript levels and insulin protein in INS-1 cells. In addition, administration of CRBFE (150 µg of C3G/10 g of body weight twice per day) significantly reduced blood glucose in streptozotocin-induced diabetic ICR mice and increased the glucose tolerance in an oral glucose tolerance test (P<.05). Such results indicated that CRBFE might be useful in prevention and control of diabetes mellitus and diabetes-associated complications.

Characterization of cDNAs associated with lignification and their expression profiles in loquat fruit with different lignin accumulation.

The ripening fruit of two loquat (Eriobotrya japonica Lindl.) cultivars with different levels of lignin accumulation provide an intriguing example of lignification in flesh tissue. Increase in firmness as a result of lignification in ripening red-fleshed Luoyangqing (LYQ) fruit was confirmed, whereas white-fleshed Baisha (BS) fruit softened without lignification. Six cDNAs associated with the lignification pathway, i.e. EjPAL1, EjPAL2 (phenylalanine ammonia lyase, PAL, EC 4.3.1.5), Ej4CL (4-coumarate: coenzyme A ligase, 4CL, EC 6.2.1.12), EjCAD1, EjCAD2 (cinnamyl alcohol dehydrogenase, CAD, EC 1.1.1.195) and EjPOD (peroxidase, POD), were cloned from flesh tissue of LYQ fruit. Expression profiles of the six corresponding genes differed greatly in different tissues, and during fruit development and ripening in both LYQ and BS cultivars. Associated activities of PAL, 4CL, CAD, and POD enzymes were also measured. CAD and POD enzyme activities and the expression of EjCAD1 and EjPOD genes were most closely associated temporally with lignification of loquat flesh tissue. Levels of EjCAD1 transcripts were particularly aligned with changes in lignification during ripening as modified either by ethylene treatment or low temperature conditioning. The two PAL genes showed different expression patterns during fruit development, with EjPAL1 strongly expressed in mature fruit and EjPAL2 only expressed in early stages of development. In addition, EjCAD1 expression was stimulated by low temperature and may contribute to low temperature injury in the fruit. Our integrated data on lignin, monolignol precursors, and associated enzymes and genes, provide a consistent model of fruit lignification.

Carotenoids in white- and red-fleshed loquat fruits.

Fruits of 23 loquat ( Eriobotrya japonica Lindl.) cultivars, of which 11 were white-fleshed and 12 red-fleshed, were analyzed for color, carotenoid content, and vitamin A values. Color differences between two loquat groups were observed in the peel as well as in the flesh. beta-Carotene and lutein were the major carotenoids in the peel, which accounted for about 60% of the total colored carotenoids in both red- and white-fleshed cultivars. beta-Cryptoxanthin and, in some red-fleshed cultivars, beta-carotene were the most abundant carotenoids in the flesh, and in total, they accounted for over half of the colored carotenoids. Neoxanthin, violaxanthin, luteoxanthin, 9- cis-violaxanthin, phytoene, phytofluene, and zeta-carotene were also identified, while zeaxanthin, alpha-carotene, and lycopene were undetectable. Xanthophylls were highly esterified. On average, 1.3- and 10.8-fold higher levels of colored carotenoids were observed in the peel and flesh tissue of red-fleshed cultivars, respectively. The percentage of beta-carotene among colored carotenoids was higher in both the peel and the flesh of red-fleshed cultivars. Correlations between the levels of total colored carotenoids and the color indices were analyzed. The a* and the ratio of a*/ b* were positively correlated with the total content of colored carotenoids, while L*, b*, and H degrees correlated negatively. Vitamin A values, as retinol equivalents (RE), of loquat flesh were 0.49 and 8.77 microg/g DW (8.46 and 136.41 microg/100 g FW) on average for white- and red-fleshed cultivars, respectively. The RE values for the red-fleshed fruits were higher than fruits such as mango, red watermelon, papaya, and orange as reported in the literature, suggesting that loquat is an excellent source of provitamin A.

[Changes in respiratory rate, ethylene production rate and quality of postharvest Chinese bayberry fruits with different maturities].

Harvested fruits of three Chinese bayberry (Myrica rubra Sieb. & Zucc.) varieties, i.e. "Biqi", "Dongkui" and "Zaodamei" which were divided into three maturities (designated as "Immature", "Mature" and "Ripe") according to fruit colour, were investigated for the changes in climacteric pattern and quality at 20 degrees C. Respiration rate and ethylene production rate were underwent 3 h during 48 h storage. Our result showed that both Immature and Mature fruits underwent rises in respiration and ethylene production rate of a climacteric rise, but no such peak was observed in Ripe fruit (Fig.1 and 2). Total soluble solids (TSS) contents increased with maturity and decreased over the 48 h at 20 degrees C (Fig.3); titratable acidity (TA) decreased with the maturity and throughout 48 h storage period (Fig.4). In "Biqi" Chinese bayberry fruit, PAL activities increased in Immature and Mature fruit, but, it decreased in Ripe fruit during the storage period; the change in Cy-3-Glu with fruit ripening was consistent with PAL activities (Table 1); there was significant positive correlation between CIRG (Color Index for Red Grape) values and Cy-3-Glu content (r=0.96**). This study provides important information on the postharvest behaviour of Chinese bayberry fruit, and our result shows that it is climacteric fruit.