Quinces (Cydonia oblonga, Chaenomeles sp., and Pseudocydonia sinensis) as Medicinal Fruits of the Rosaceae Family: Current State of Knowledge on Properties and Use

In recent years, the evaluation of many plant-derived compounds as potential new drugs or functional foods has become an active research topic. The morphological characteristics of quinces of the genera Cydonia sp., Chaenomeles sp., and Pseuocydonia sp. are largely similar, which is why these fruits are often confused. Although they have been appreciated in Asia for centuries as a valuable component of local ethnomedicine, they are less known in Western countries, and scientific knowledge about their health benefits remains fragmentary. This literature review summarizes studies on the content of chemical compounds responsible for the health-promoting and functional properties of the quince fruit. It focuses on the content of carotenoids, vitamins, minerals, and carboxylic acids, although the main emphasis is on the content and diversity of bioactive polyphenols, which are extremely abundant in these fruits. The quince fruits are rich in antioxidants and compounds with proven anti-inflammatory, anticancer, antiallergic, and immunomodulatory effects. Their phytochemicals effectively regulate glycemia and improve the blood lipid profile, suggesting potential antidiabetic and cardioprotective benefits. Analysis of chemical characteristics showed that the Chaenomeles fruits. are underestimated as functional food ingredients. Studies on the molecular effects of their bioactive compounds and species-specific genomic analyses are sorely lacking in the scientific literature.

Phytochemistry and pharmacology of plants in the genus Chaenomeles

Chaenomeles plants belong to the Rosaceae family and include five species, Chaenomeles speciosa (Sweet) Nakai, Chaenomeles sinensis (Thouin) Koehne, Chaenomeles japonica (Thunb.) Lindl, Chaenomeles cathayensis (Hemsl.) Schneid and Chaenomeles thibetica Yu. Chaenomeles plants are found and cultivated in nearly every country worldwide. China serves as both the origin and distribution hub for the plants in the Chaenomeles genus, and all Chaenomeles species except for C. japonica are indigenous to China. Chaenomeles spp. is a type of edible medicinal plant that has been traditionally used in China to treat various ailments, such as rheumatism, cholera, dysentery, enteritis, beriberi, and scurvy. A variety of chemical constituents have been extracted from this genus, including terpenoids, phenolics, flavonoids, phenylpropanoids and their derivatives, benzoic acid derivatives, biphenyls, oxylipins, and alkaloids. The biological activity of some of these constituents has already been evaluated. Pharmacological investigations have demonstrated that the plants in the genus Chaenomeles exhibit anti-inflammatory, analgesic, antioxidant, antihyperglycemic, antihyperlipidemic, gastrointestinal protective, antitumor, immunomodulatory, antibacterial, antiviral, hepatoprotective, neuroprotective and other pharmacological activities. The objective of this review is to provide a comprehensive and up-to-date summary of the available information on the genus Chaenomeles to serve as a valuable reference for further investigations.

Virtual Screening of Nrf2 Dietary-Derived Agonists and Safety by a New Deep-Learning Model and Verified In Vitro and In Vivo

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an essential regulatory target of antioxidants, but the lack of Nrf2 active site information has hindered discovery of new Nrf2 agonists from food-derived compounds by large-scale virtual screening. Two deep-learning models were separately trained to screen for Nrf2-agonists and safety. The trained models screened potentially active chemicals from approximately 70,000 dietary compounds within 5 min. Of the 169 potential Nrf2 agonists identified via deep-learning screening, 137 had not been reported before. Six compounds selected from the new Nrf2 agonists significantly increased (p < 0.05) the activity of Nrf2 on carbon tetrachloride (CCl₄)-intoxicated HepG2 cells (nicotiflorin (99.44 ± 18.5%), artemetin (97.91 ± 8.22%), daidzin (87.73 ± 3.77%), linonin (74.27 ± 5.73%), sinensetin (72.74 ± 10.41%), and tectoridin (77.78 ± 4.80%)), and their safety were demonstrated by an MTT assay. The safety and Nrf2 agonistic activity of nicotiflorin, artemetin, and daidzin were also reconfirm by a single-dose acute oral toxicity study and CCl₄-intoxicated rat assay.

Regulation of wheat bran feruloyl oligosaccharides in the intestinal antioxidative capacity of rats associated with the p38/JNK-Nrf2 signaling pathway and gut microbiota

BACKGROUND

Feruloyl oligosaccharides (FOs), the ferulic acid ester of oligosaccharides, may possess the physiological functions of both ferulic acid and oligosaccharides, including antioxidative activity and gut microbiota modulation capacity. The present study aimed to investigate whether FOs could regulate the intestinal antioxidative capacity of rats by modulating the MAPKs/Nrf2 signaling pathway and gut microbiota. Thirty Wistar rats were randomly divided into five groups. Rats received a standard diet and were gavaged once daily with 0.85% normal saline, 100 mg kg^-1 body weight vitamin C or FOs solution at doses of 20, 40 and 80 mg kg^-1 body weight for 21 days.

RESULTS

FOs strengthened the antioxidative capacity of the jejunum, as indicated by increased in contents of catalase, superoxide dismutase and glutathione peroxidase, as well as glutathione. Moreover, FOs administration upregulated the mRNA expression level of antioxidant-related genes (glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit and heme oxygenase-1) in the jejunum. Increases in phosphorylation levels of Nrf2, p38 and JNK were also observed. Administration with 40 mg kg^-1 FOs altered the structure and composition of the cecal microbiota, which was indicated by the increased the relative abundances of Actinobacteria, Proteobacteria and Acidobacteriota, and the decreased the relative abundances of Firmicutes, Lachnospiraceae_NK4A136_group and Blautia. Furthermore, Spearman correlation analysis revealed that the altered cecal microbiota closely correlated with jejunal antioxidative capacity of rats.

CONCLUSION

FOs could be used as an antioxidant for gut heath improvement through modulating the p38/JNK-Nrf2 signaling pathway and gut microbiota. © 2022 Society of Chemical Industry.

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

GC-MS analysis of cuticular waxes and evaluation of antioxidant and antimicrobial activity of Chaenomeles cathayensis and Ch. × californica fruits

Fruit extracts of the Chaenomeles species are a rich source of compounds having health-promoting properties, while their distribution between the species and cultivars varies significantly depending on both genotype and environmental threats. This study aimed at discovering antioxidant and antimicrobial potential of the secondary metabolites of fruit and waxes of fruit cuticular of introduced Ch. cathayensis and Ch. × californica plants. The sum of detected polyphenols in the isopropanolic fruit extracts varied slightly between the species, while significant excesses in indices were seen for both species peel extracts as compared to pulp extracts. Antimicrobial assays carried out by disc diffusion method showed notable activity of the fruit peel and pulp extracts of both species against all tested Gram-negative and Gram-positive bacterial strains, and two Candida strains as well. Pseudomonas aeruginosa strain was the most resistant to the action of both fruit extracts, especially peel extracts of Ch. cathayensis fruits. As identified by gas chromatography-mass spectrometry (GC-MS) assays, chloroformic extracts from the fruits of cuticular waxes of Ch. cathayensis and Ch. × californica contained six prevailing fractions: aldehydes, alkanes, alcohols, esters, fatty acids and various terpenoids. The predominant compounds were tetrapentacontane (21.8% of total amount) and heptacosanal (23.1% of total), respectively in the cuticular waxes of Ch. cathayensis and Ch. × californica. Cinnamaldehyde, cis-9-hexadecenal, hexadecanoic acid, oleic acid, olean-12-ene-3,28-diol (3. beta), lupeol, diisooctyl phthalate, 9-octadecenoic acid, 1,2,3-propanetriyl ester, 1,3,12-nonadecatriene-5,14-diol and some other identified compounds are well-known for their bioactivity, indicating the feasibility of studying the antimicrobial potential of plant fruits.

Chemical Characterization and Hepatoprotective Effects of a Standardized Triterpenoid-Enriched Guava Leaf Extract

Nutraceutical/pharmaceutical agents capable of maintaining redox and inflammation homeostasis are considered as candidates for the prevention and/or treatment of liver diseases. Psidium guajava (commonly known as guava) leaf is a commercially available functional food that has been reported to possess hepatoprotective property. However, the hepatoprotective constituents in guava leaf are not known. In the current study, a standardized triterpenoid-enriched extract of guava leaves (TGL) was developed. A new ursolic acid derivative, namely 2α,3β,6β,23,30-pentahydroxyurs-11,13(18)-dien-28,20β-olide (1), and 23 known triterpenoids were isolated and identified from TGL. The hepatoprotective effects of TGL were evaluated through a model using acetaminophen (APAP)-exposed C57BL/6 male mice. Pretreatment of TGL (75 and 150 mg/kg) restored the mice hepatic architecture, improved the serum ALT and AST levels, and reduced the hepatic ROS and MDA contents. Further molecular mechanistic study revealed that TGL modulated Nrf2 and MAPK signaling pathways to alleviate APAP-induced oxidative and inflammatory stress in liver. In addition, the new compound 1 from TGL showed protective effects against APAP-induced cytotoxicity via activation of the Nrf2 pathway in HepG2 cells. Overall, this is the first report on the hepatoprotective effects of a standardized triterpenoid-enriched extract of guava leaves, which supports its potential nutraceutical application in liver disease management.

Phytochemical Screening and Protective Effects of Prunus persica Seeds Extract on Carbon Tetrachloride-Induced Hepatic Injury in Rats

BACKGROUND AND PURPOSE

Carbon tetrachloride (CCl4) is a dynamic environmental toxin released from chemical factories and its concentration in atmosphere is accelerating at an alarming proportion. Potential presence of CCl4 in human body causes liver injury via free radical stimulated inflammatory responses.

OBJECTIVES

In this study, protective effects of hydromethanolic seeds extract of Prunus persica (PPHM) were evaluated for free radical scavenging potential in CCl4 mediated acute liver toxicity in murine model.

EXPERIMENTAL APPROACH

Followed by acute oral toxicity analysis, liver cells of Sprague-dawley (SD) rats were treated with CCl4 and subsequently chemoprophylactic effect of extract (400 mg/Kg dose) was evaluated using in vivo studies including silymarin as positive control. Biochemical parameters, staining (hematoxylin and eosin (H & E) and masson's trichome) and quantitative gene expression analysis via real-time PCR was used to evaluate hepatic damage control.

RESULTS

The results illustrated that PPHM extract exhibit strong antioxidant activity comparable to positive control, gallic acid. Research study results also demonstrated that extract treatment at 400 mg/Kg concentration is highly effective in protecting liver damage due to CCl4 exposure. Mechanistic investigations indicated the therapeutic action of PPHM was correlated with the increase in Nrf2, NQO-1 and decrease in collagen III mRNA genes expression as compared to CCl4 treated group.

CONCLUSIONS AND IMPLICATIONS

Accordingly, our research study indicated that PPHM alleviated CCl4-mediated oxidative stress through Nrf2/NQO-1 pathway, thereby protecting liver damage against environmental toxins. Our findings provide supportive evidence to suggest PPHM as a novel nontoxic hepatoprotective agent.

Biopharmaceutical and pharmacokinetic activities of oxymatrine determined by a sensitive UHPLC-MS/MS method

BACKGROUND

Oxymatrine is one of the most promising alkaloids from Sophora flavescens for its excellent pharmacological effects.

OBJECTIVE

The aim of this research is to assess the biopharmaceutical and pharmacokinetic activities of oxymatrine, and clarify its mechanisms of absorption and metabolism.

METHODS

The biological characteristics of oxymatrine were systematically investigated by UHPLC-MS/MS. The mechanisms of absorption and metabolism of oxymatrine were further clarified through incubation in rat liver microsomes and transport across Caco-2 monolayer cell absorption model.

RESULTS

It was found that the absolute oral bioavailability of oxymatrine was 26.43% and the pharmacokinetic parameters Cmax, Tmax, and t1/2 were 605.5 ng/mL, 0.75 h, and 4.181 h after oral administration, indicating that oxymatrine can be absorbed quickly. The tissue distribution tests showed that oxymatrine distributed throughout all the organs, with the small intestine accumulating the highest level followed by kidney, stomach and spleen. The Papp in Caco-2 cell line absorption model was over 1 × 10-5 and PDR 1.064, t1/2 of oxymatrine in rat liver microsome in vitro was 1.042 h, indicating that oxymatrine can be absorbed easily through passive diffusion and CYP450 enzymes could be involved in its metabolism. The plasma protein binding rate of oxymatrine was 2.78 ± 0.85%.

CONCLUSION

Oxymatrine can be absorbed into blood easily through passive diffusion, mainly distributed in the intestine, stomach, liver and spleen in vivo, and CYP450 enzymes in liver could be involved in its metabolism.

Osthole promotes the suppressive effects of cisplatin on NRF2 expression to prevent drug-resistant cervical cancer progression

Cervical cancer is one of the most commonly diagnosed lethal malignancies among gynecological malignant tumors worldwide. Chemo-resistance is one of the key causal factors in cervical cancer death. Osthole (OST), a natural compound, exhibits various pharmacological activities, including anti-tumor effects. However, its involvement in the chemoresistance of human cervical cancer has not been reported. In the study, we aimed to clarify the role of OST in regulating the chemoresistance of human cervical cancer. The results indicated that cisplatin (CDDP) combined with OST markedly reduced the cell proliferation and induced cervical cancer cells undergoing apoptosis when compared to CDDP alone treatment. In CDDP-resistant cervical cancer cells, OST significantly decreased nuclear factor, erythroid 2 like 2 (NRF2), heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1) and glutamate-cysteine ligase catalytic subunit (GCLC) expression levels from mRNA or protein levels. Additionally, through combination with CDDP, OST dose- and time-dependently reduced NRF2 expression in CDDP-resistant cervical cancer cells. Moreover, we found that CDDP co-treated with OST significantly blocked phosphatidylinositol-3 kinase (PI3K)/AKT signaling pathway. Importantly, CDDP combined with LY294002, inhibitor of phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (AKT) signaling, markedly decreased the expression of NRF2, HO-1, NQO1 and GCLC in drug-resistant cervical cancer cells. The in vivo study also suggested that OST in combination obviously reduced tumor growth in comparison to the CDDP alone group. Taken together, these findings indicated that OST could be used as a potential sensitizer to reverse chemoresistance of cisplatin-resistant cervical cancer to cisplatin through repressing NRF2 expression partly associated with PI3K/AKT blockage.

Digoxin sensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine via inhibiting Nrf2 signaling pathway

Chemoresistance is a major therapeutic obstacle in the treatment of human pancreatic ductal adenocarcinoma (PDAC). As an oxidative stress responsive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) regulates the expression of cytoprotective genes. Nrf2 not only plays a critical role in chemoprevention, but also contributes to chemoresistance. In this study, we found that digoxin markedly reversed drug resistance of gemcitabine by inhibiting Nrf2 signaling in SW1990/Gem and Panc-1/Gem cells. Further research revealed that digoxin regulated Nrf2 at transcriptional level. In in vivo study, we found that digoxin and gemcitabine in combination inhibited tumor growth more substantially when compared with gemcitabine treatment alone in SW1990/Gem-shControl cells-derived xenografts. In the meantime, SW1990/Gem-shNrf2 cells-derived xenografts responded to gemcitabine and combination treatment similarly, suggesting that digoxin sensitized gemcitabine-resistant human pancreatic cancer to gemcitabine, which was Nrf2 dependent. These results demonstrated that digoxin might be used as a promising adjuvant sensitizer to reverse chemoresistance of gemcitabine-resistant pancreatic cancer to gemcitabine via inhibiting Nrf2 signaling.

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Digoxin could reverse drug resistance of gemcitabine in gemcitabine-resistant pancreatic cancer cells.

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Digoxin significantly inhibited Nrf2 signaling in gemcitabine-resistant pancreatic cancer cells.

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Digoxin-mediated reversing drug resistance of gemcitabine in gemcitabine-resistant pancreatic cancer cells was Nrf2 dependent.

Protective effects of Coptis chinensis inflorescence extract and linarin against carbon tetrachloride-induced damage in HepG2 cells through the MAPK/Keap1-Nrf2 pathway

Coptis chinensis inflorescence is traditionally used as tea and has been popular in the local market. C. chinensis inflorescence extract (CE) exhibits protective effects against carbon tetrachloride (CCl4)-induced damage, but the underlying mechanism remains unclear. The main chemicals of CE were detected, purified, and identified in this study. CE and linarin could reverse changes in cell viability, decrease alanine aminotransferase and aspartate transaminase levels, and reduce reactive oxygen species (ROS) generation induced by CCl4 in HepG2 cells. CE and linarin could also phosphorylate mitogen-activated protein kinases (MAPKs) and up-regulate Kelth-like ECH-associated protein (Keap1). The pathways of MAPKs and Keap1 lead to the separation of Keap1 and nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Free Nrf2 transferred to the nucleus and enhanced the expression of phase II detoxification enzymes. This study provides a scientific basis for the use of C. chinensis inflorescence, which exhibits a hepatoprotective function, as a supplement in the food industry.