Antioxidant properties, radical scavenging activity and biomolecule protection capacity of flavonoid naringenin and its glycoside naringin: a comparative study

Citrus Flavonoids Supplementation as an Alternative to Replace Zinc Oxide in Weanling Pigs’ Diets Minimizing the Use of Antibiotics

Since citrus flavonoids have antioxidant and anti-inflammatory properties, it was hypothesized that these compounds would become a suitable alternative to the use of therapeutic doses of zinc oxide at weaning. A total of 252 weaned pigs ([LargeWhite × Landrace] × Pietrain) were distributed according to BW (5.7 kg ± 0.76) into 18 pens (6 pens per diet, 14 pigs/pen). Three experimental diets for the prestarter (0–14 d postweaning) and starter (15–35 d postweaning) period were prepared: (i) a nonmedicated (CON) diet, (ii) a CON diet supplemented with zinc oxide at 2500 mg/kg, amoxicillin at 0.3 mg/kg and apramycin at 0.1 mg/kg (ZnO), and (iii) CON diet with the addition of a commercial citrus flavonoid extract at 0.3 mg/kg and amoxicillin at 0.3 mg/kg (FLAV). Pig BW, ADG, ADFI, and FCR were assessed on d7, d14, and d35, and ADFI and FCR were calculated. Samples of intestinal tissue, cecal content, and serum were collected on day seven (18 piglets). FLAV treatment achieved greater BW and ADG during the starter and for the entire experimental period compared with the CON diet (p < 0.05), whereas ZnO pigs evidenced intermediate results. Jejunum tissue analysis showed that pigs fed the FLAV diet overexpressed genes related to barrier function, digestive enzymes, and nutrient transport compared to those pigs fed the CON diet (p < 0.05). An increase in the abundance of bacterial genera such as Succinivibrio, Turicibacter, and Mitsuokella (p < 0.05) was observed in the FLAV compared with the CON and ZnO piglets. ZnO and FLAV increased the expression of TAS2R39, while ZnO pigs also expressed greater TAS2R16 than CON (p < 0.05) in the intestine. FLAV treatment improved the gut function, possibly explaining a higher performance at the end of the nursery period. Consequently, citrus flavonoids supplementation, together with amoxicillin, is a promising alternative to the use of zinc oxide plus amoxicillin and apramycin in weanling pigs, minimizing the use of antibiotics.

Naringenin protects hepato-renal tissues against antituberculosis drugs induced toxic manifestations by modulating interleukin-6, insulin like growth factor-1, biochemical and ultra-structural integrity

BACKGROUND

The antituberculosis drugs (ATDs), isoniazid, rifampicin, pyrazinamide and ethambutol prompt extreme hepatic and renal damage during treatment of tuberculosis. The present study aimed to investigate protective potential of naringenin against ATDs induced hepato-renal injury.

METHODS

Rats were administered with ATDs (pyrazinamide; 210, ethambutol; 170, isoniazid; 85, rifampicin; 65 mg/kg b.wt) orally for 8 weeks (3 days/week) followed by naringenin at three different doses (10, 20 and 40 mg/kg b.wt) conjointly for 8 weeks (3 days/week alternately to ATDs administration) and silymarin (50 mg/kg b.wt) as positive control.

RESULTS

Exposure to ATDs caused significant increase in interleukin-6 (IL-6), triglycerides, cholesterol, bilirubin whereas depletion in insulin like growth factor-1 (IGF-1), albumin and glucose in serum. Endogenous antioxidant enzymes glutathione reductase (GR), glutathione peroxidase (GPx) and glucose-6-phosphate-dehydrogenase (G-6-PDH) were diminished in liver and kidney tissues with parallel increase in triglycerides, cholesterol, microsomal LPO and aniline hydroxylase (CYP2E1 enzyme). Ultra-structural observations of liver and kidney showed marked deviation in plasma membranes of various cellular and sub-cellular organelles after 8 weeks of exposure to ATDs.

CONCLUSIONS

Conjoint treatment of naringenin counteracted ATDs induced toxic manifestations by regulating IL-6, IGF-1, CYP2E1, biochemical and ultra-structural integrity in a dose dependent manner. Naringenin has excellent potential to protect ATDs induced hepato-renal injury by altering oxidative stress, modulation of antioxidant enzymes, serum cytokines and ultra-structural changes.

Zebrafish: A Model Deciphering the Impact of Flavonoids on Neurodegenerative Disorders

Over the past century, advances in biotechnology, biochemistry, and pharmacognosy have spotlighted flavonoids, polyphenolic secondary metabolites that have the ability to modulate many pathways involved in various biological mechanisms, including those involved in neuronal plasticity, learning, and memory. Moreover, flavonoids are known to impact the biological processes involved in developing neurodegenerative diseases, namely oxidative stress, neuroinflammation, and mitochondrial dysfunction. Thus, several flavonoids could be used as adjuvants to prevent and counteract neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Zebrafish is an interesting model organism that can offer new opportunities to study the beneficial effects of flavonoids on neurodegenerative diseases. Indeed, the high genome homology of 70% to humans, the brain organization largely similar to the human brain as well as the similar neuroanatomical and neurochemical processes, and the high neurogenic activity maintained in the adult brain makes zebrafish a valuable model for the study of human neurodegenerative diseases and deciphering the impact of flavonoids on those disorders.

Natural flavonoids derived from herbal medicines are potential anti-atherogenic agents by inhibiting oxidative stress in endothelial cells

As the common pathological basis of various cardiovascular diseases, the morbidity and mortality of atherosclerosis (AS) have increased in recent years. Unfortunately, there are still many problems in the treatment of AS, and the prevention and treatment of the disease is not ideal. Up to now, the occurrence and development of AS can roughly include endothelial cell dysfunction, vascular smooth muscle cell proliferation, inflammation, foam cell production, and neoangiogenesis. Among them, endothelial dysfunction, as an early event of AS, plays a particularly important role in promoting the development of AS. In addition, oxidative stress occurs throughout the causes of endothelial dysfunction. Some previous studies have shown that flavonoids derived from herbal medicines are typical secondary metabolites. Due to its structural presence of multiple active hydroxyl groups, it is able to exert antioxidant activity in diseases. Therefore, in this review, we will search PubMed, Web of Science, Elesvier, Wliey, Springer for relevant literature, focusing on flavonoids extracted from herbal medicines, and summarizing how they can prevent endothelial dysfunction by inhibiting oxidative stress. Meanwhile, in our study, we found that flavonoid represented by quercetin and naringenin showed superior protective effects both in vivo and in vitro, suggesting the potential of flavonoid compounds in the treatment of AS.

Effect of the main constituents of Pistacia lentiscus leaves against the DPPH radical and xanthine oxidase: experimental and theoretical study

The aim of this work is to study the content of phenolic compounds in P lentiscus leaves and their antioxidant effect. After extracting the phenolic compounds, fractionation by liquid/liquid partition with increasing polarity gives five extracts. Three of them (ButF, AqF and ButA) were found to have good antioxidant activity. Their IC_50s for the inhibition of the free radical formation of DPPH are 1.76 µg/mL, 1.307 µg/ml, and 1.77 µg/mL, respectively. These values are very interesting, considering the effect of the powerful flavonoid quercetin, whose IC₅₀ against DPPH is 1.53 µg/mL. These extracts are also active against xanthine oxidase (XO). The IC_50s measured are 0.14 mg/mL, 0.186 mg/mL and 0.33 mg/mL for ButF, Aq F and ButAq F extract respectively, in comparison with allopurinol (0.44 mg/mL). A phytochemical analysis by LC/ESI-MS-MS was performed to explain the observed activities. The results show 22 peaks representing: flavanols, namely catechin, d-Gallocatechin, and gallocatechin gallate. The only flavone detected in the studied extracts was luteolin glucuronide and was found to be in higher amounts in butanolic extract (2,71mg/mL). The phenolic acids and derivatives were also identified in the extracts. A theoretical study was performed to deduce the specificity of the binding between the major compounds identified in the P. lentiscus extract and the xanthine oxidase enzyme using Schrödinger software. The docking procedure was validated using the extraction of ligands from the binding site. Their re-anchoring to the xanthine oxidase structure using quercetin and allopurinol was considered reference molecules. After docking, post-docking minimization was performed to achieve the best scoring poses with the MM-GBSA approach. The dGBind energy of MM-GBSA representing the binding energy of the receptor and the ligand was calculated based on molecular mechanics. Results reveal that β-Glucogallin compounds such as Digalloylquinic acid, Gallocatechin, and Myricetin-3-O rhamnoside are more active than allopurinol, with stronger Docking score (Gscore) and MM-GBSA dGBind.Communicated by Ramaswamy H. Sarma.

Flavonoids Are Intra- and Inter-Kingdom Modulator Signals

Flavonoids are a broad class of secondary metabolites with multifaceted functionalities for plant homeostasis and are involved in facing both biotic and abiotic stresses to sustain plant growth and health. Furthermore, they were discovered as mediators of plant networking with the surrounding environment, showing a surprising ability to perform as signaling compounds for a multitrophic inter-kingdom level of communication that influences the plant host at the phytobiome scale. Flavonoids orchestrate plant-neighboring plant allelopathic interactions, recruit beneficial bacteria and mycorrhizal fungi, counteract pathogen outbreak, influence soil microbiome and affect plant physiology to improve its resilience to fluctuating environmental conditions. This review focuses on the diversified spectrum of flavonoid functions in plants under a variety of stresses in the modulation of plant morphogenesis in response to environmental clues, as well as their role as inter-kingdom signaling molecules with micro- and macroorganisms. Regarding the latter, the review addresses flavonoids as key phytochemicals in the human diet, considering their abundance in fruits and edible plants. Recent evidence highlights their role as nutraceuticals, probiotics and as promising new drugs for the treatment of several pathologies.

Disorders of Hippocampus Facilitated by Hypertension in Purine Metabolism Deficiency is Repressed by Naringin, a Bi-flavonoid in a Rat Model via NOS/cAMP/PKA and DARPP-32, BDNF/TrkB Pathways

Individuals who are hypertensive have a higher tendency of predisposition to other genetic diseases including purine metabolism deficiency. Therefore, the search for nontoxic and effective chemo protective agents to abrogate hypertension-mediated genetic disease is vital. This study therefore investigated the repressive effect of naringin (NAR) against disorder of hippocampus facilitated by hypertension in purine metabolism deficiency. Male albino rats randomly assigned into nine groups (n = 7) were treated for 35 days. Group I: control animals, Group II was treated with 100 mg/kg KBrO₃, Group III was treated with 250 mg/kg caffeine, and Group IV was treated with 100 mg/kg KBrO₃ + 250 mg/kg caffeine. Group V was administered with 100 mg/kg KBrO₃ + 100 mg/kg haloperidol. Group VI was administered with 100 mg/kg KBrO₃ + 50 mg/kg NAR. Group VII was administered with 250 mg/kg caffeine + 50 mg/kg NAR, and Group VIII was administered with 100 mg/kg KBrO₃ + 250 mg/kg caffeine + 50 mg/kg NAR. Finally, group IX was treated with 50 mg/kg NAR. The sub-acute exposure to KBrO₃ and CAF induced hypertension and mediated impairment in the hippocampus cells. This was apparent by the increase in PDE-5¹, arginase, and enzymes of ATP hydrolysis (ATPase and AMPase) with a simultaneous increase in cholinergic (AChE and BuChE) and adenosinergic (ADA) enzymes. The hypertensive-mediated hippocampal impairment was associated to alteration of NO and AC signaling coupled with lower expression of brain-derived neurotrophic factor and its receptor (BDNF-TrkB), down regulation of Bcl11b and DARPP-32 which are neurodevelopmental proteins, and hypoxanthine accumulation. However, these features of CAF-mediated hippocampal damage in KBrO₃-induced hypertensive rats were repressed by post-treatment with NAR via production of neuro-inflammatory mediators, attenuation of biochemical alterations, stabilizing neurotransmitter enzymes, regulating NOS/cAMP/PKA and DARPP-32, BDNF/TrkB signaling, and restoring hippocampal tissues.

Comparative transcriptomic and metabolomic analyses reveal the delaying effect of naringin on postharvest decay in citrus fruit

INTRODUCTION

Naringin exhibits antioxidant capacity and can partially inhibit pathogens in many horticultural products, such as citrus fruit; however, the effects of naringin on the storage quality and mechanisms that regulate senescence in citrus fruit have not been comprehensively analyzed.

METHODS AND RESULTS

In this study, exogenous naringin treatment was found to significantly delay citrus fruit disease, decreasing the H₂O₂ content, increasing the antioxidant capacity and maintaining the quality of the fruit. Metabolomic analysis of citrus peel indicated the vast majority (325) of metabolites belonging to flavonoids. Moreover, the auraptene, butin, naringenin, and luteolin derivative levels within the phenylpropanoid pathway were significantly higher in the naringin-treated fruit than in the control fruit. Transcriptomic analysis also revealed that twelve genes in the phenylpropanoid and flavonoid biosynthesis pathways were significantly upregulated. Further analysis with a co-expression network revealed significant correlation between these differential genes and metabolites. Additionally, MYC and WRKY, screened from the MAPK signaling pathway, may contribute to naringin-induced disease resistance.

CONCLUSION

In conclusion, naringin treatment can efficiently delay decay and maintain the quality of citrus fruit, mainly by promoting metabolites accumulation, and upregulating differentially expressed genes in phenylpropanoid and flavonoid biosynthesis pathway. This study provides a better understanding of the regulatory mechanisms through which naringin delays citrus fruit decay and maintains fruit quality.

Potential usefulness of Mediterranean diet polyphenols against COVID-19-induced inflammation: a review of the current knowledge

The Mediterranean diet is a dietary pattern typical of the populations living in the Mediterranean basin during the 50s-60s of the last century. This diet has demonstrated beneficial effects in the prevention of several pathologies such as cardiovascular diseases, metabolic syndrome, or several cancer types, at least in part, due to its antioxidant compounds. Since the COVID-19 pandemic started, different authors have been studying the effects of certain dietary habits on the presence of COVID-19 and its severity, and the Mediterranean diet is one of them. This review gathers data from studies supporting the potential usefulness of the main phenolic compounds present in the Mediterranean diet, based on their antioxidant and anti-inflammatory effects, as preventive/therapeutic agents against COVID-19. The current evidence supports the potential benefits that hydroxytyrosol, resveratrol, flavonols such as quercetin, flavanols like catechins, and flavanones on the order of naringenin could have on COVID-19. This is due to the increase in the synthesis and translocations of Nrf-2, which increases the activity of antioxidant enzymes and thus reduces ROS production, the scavenging of free radicals, and the suppression of the activity of MMP-9, which is involved in the cytokine storm, and the inhibition of NF-κB.

Fabrication, characterization of carboxymethyl konjac glucomannan/ovalbumin-naringin nanoparticles with improving in vitro bioaccessibility

Naringin is potential functional and therapeutic ingredient, has low bioavailability because of poor aqueous solubility. In this study, an ovalbumin (OVA)-carboxymethyl konjac glucomannan (CKGM) nano-delivery system was developed to enhance the bioavailability of naringin. The effects of proportion (OVA: CKGM), pH and naringin concentration were studied on the formation, encapsulation efficiency (EE) and bioaccessibility of OVA/CKGM-Naringin nanoparticles (OVA/CKGM-Naringin NPs). Its morphology and size were viewed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM). The cross-linkage between OVA and CKGM was verified by Fourier Transform Infrared Spectroscopy (FTIR) and Fluorescence Intensity analysis. The size of OVA/CKGM-Naringin NPs were 463.83 ± 18.50 nm (Polydispersity Index-PDI, 0.42 ± 0.05). It indicated that 2:1 of OVA: CKGM, pH 3 and 7 mg/mL of naringin concentration were optimized processing parameters of OVA/CKGM-Naringin NPs with EE (97.90 ± 2.97 %) and remarkably improved bioaccessibility (85.01 ± 2.52 %). The OVA/CKGM-Naringin NPs was energy efficiently prepared and verified as an ideal carrier of naringin.

Naringenin Alleviates Renal Ischemia Reperfusion Injury by Suppressing ER Stress-Induced Pyroptosis and Apoptosis through Activating Nrf2/HO-1 Signaling Pathway

Endoplasmic reticulum (ER) stress, pyroptosis, and apoptosis are critical molecular events in the occurrence and progress of renal ischemia reperfusion (I/R) injury. Naringenin (4′,5,7-trihydroxyflavanone) is one of the most widely consumed flavonoids with powerful antioxidant and anti-inflammatory activities. However, whether naringenin is able to relieve renal I/R injury and corresponding mechanisms have not been fully clarified. This study was aimed at exploring its role and relevant mechanisms in renal I/R injury. The C57Bl/6 mice were randomly assigned to receive administration with naringenin (50 mg/kg/d) or sterile saline (1.0 mL/d) for 3 d by gavage and suffered from renal I/R surgery. One specific ER stress inhibitor, 4-phenylbutyric acid (4-PBA, 100 mg/kg/d), was intraperitoneally administered to validate the regulation of ER stress on pyroptosis and apoptosis. Cultured HK-2 cells went through the process of hypoxia/reoxygenation (H/R) to perform cellular experiments with the incubation of naringenin (200 μM), 4-PBA (5 mM), or brusatol (400 nM). The animal results verified that naringenin obviously relieved renal I/R injury, while it refined renal function and attenuated tissue structural damage. Furthermore, naringenin treatment inhibited I/R-induced ER stress as well as pyroptosis and apoptosis as indicated by decreased levels of specific biomarkers such as GRP78, CHOP, caspase-12, NLRP3, ASC, caspase-11, caspase-4, caspase-1, IL-1β, GSDMD-N, BAX, and cleaved caspase-3 in animals and HK-2 cells. Besides, the upregulated expression of Nrf2 and HO-1 proteins after naringenin treatment suggested that naringenin activated the Nrf2/HO-1 signaling pathway, which was again authenticated by the usage of brusatol (Bru), one unique inhibitor of the Nrf2 pathway. Importantly, the application of 4-PBA showed that renal I/R-generated pyroptosis and apoptosis were able to be regulated by ER stress in vivo and in vitro. In conclusion, naringenin suppressed ER stress by activating Nrf2/HO-1 signaling pathway and further alleviated pyroptosis and apoptosis to protect renal against I/R injury.

The Preventive Effects of Naringin and Naringenin against Paclitaxel-Induced Nephrotoxicity and Cardiotoxicity in Male Wistar Rats

This study assessed the preventive properties of naringin and naringenin on paclitaxel-induced nephrotoxicity and cardiotoxicity in adult male Wistar rats. Intraperitoneal injection of paclitaxel 2 mg/kg body weight, two days/week on the 2nd and 5th days of each week, with or without oral administration of naringin and/or naringenin 10 mg/kg body weight every other day, was continued for six weeks. Treatment of rats with naringin and/or naringenin significantly reversed elevated serum creatinine, urea, and uric acid levels caused by paclitaxel, reflecting improved kidney function. Similarly, heart dysfunction induced by paclitaxel was alleviated after treatment with naringin and/or naringenin, as evidenced by significant decreases in elevated CK-MB and LDH activities. After drug administration, histopathological findings and lesion scores in the kidneys and heart were markedly decreased by naringin and/or naringenin. Moreover, the treatments reversed renal and cardiac lipid peroxidation and the negative impacts on antioxidant defenses via raising GSH, SOD, and GPx. The preventive effects of naringin and naringenin were associated with suppressing oxidative stress and reestablishing antioxidant defenses. A combination of naringin and naringenin was the most efficacious in rescuing organ function and structure.

Platelet Redox Imbalance in Hypercholesterolemia: A Big Problem for a Small Cell

The imbalance between reactive oxygen species (ROS) synthesis and their scavenging by anti-oxidant defences is the common soil of many disorders, including hypercholesterolemia. Platelets, the smallest blood cells, are deeply involved in the pathophysiology of occlusive arterial thrombi associated with myocardial infarction and stroke. A great deal of evidence shows that both increased intraplatelet ROS synthesis and impaired ROS neutralization are implicated in the thrombotic process. Hypercholesterolemia is recognized as cause of atherosclerosis, cerebro- and cardiovascular disease, and, closely related to this, is the widespread acceptance that it strongly contributes to platelet hyperreactivity via direct oxidized LDL (oxLDL)-platelet membrane interaction via scavenger receptors such as CD36 and signaling pathways including Src family kinases (SFK), mitogen-activated protein kinases (MAPK), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In turn, activated platelets contribute to oxLDL generation, which ends up propagating platelet activation and thrombus formation through a mechanism mediated by oxidative stress. When evaluating the effect of lipid-lowering therapies on thrombogenesis, a large body of evidence shows that the effects of statins and proprotein convertase subtilisin/kexin type 9 inhibitors are not limited to the reduction of LDL-C but also to the down-regulation of platelet reactivity mainly by mechanisms sensitive to intracellular redox balance. In this review, we will focus on the role of oxidative stress-related mechanisms as a cause of platelet hyperreactivity and the pathophysiological link of the pleiotropism of lipid-lowering agents to the beneficial effects on platelet function.

An Improved Method of Theabrownins Extraction and Detection in Six Major Types of Tea (Camellia sinensis)

Tea pigments consisting of theabrownins (TBs), theaflavins (TFs), and thearubigins (TRs) affect the color and taste of tea. TBs include a variety of water-soluble compounds, but do not dissolve in n-butanol and ethyl acetate. Previously, the traditional method of TB extraction only mixed tea with n-butanol, and TBs were retained in the water phase. However, without ethyl acetate extraction, TFs and TRs remained in the water phase and affected the detection of TB content. Although an improved method had been devised by adding an ethyl acetate extraction step between tea production and n-butanol extraction, the proportional equation for calculating TB content (%) was not yet developed. In this study, we compared the absorbance at 380 nm (A380) of TB solutions from six major types of tea (green, yellow, oolong, white, black, and dark teas) extracted by improved and traditional methods from the same tea samples. Significantly lower A380 values were obtained from TB solutions via the improved method compared to the traditional method for six major types of tea, and the highest and lowest slops in TB concentrations from A380 analyses were from dark tea and green tea, respectively. Moreover, newly developed equations for TB content in those six tea types extracted by the improved methods were also established.

Naringin-loaded Arabic gum/pectin hydrogel as a potential wound healing material

Wound healing is a complicated cellular process with overlapping phases. Naringin (NAR); a flavanone glycoside, possesses numerous pharmacological effects such as anti-inflammatory, antioxidant and anti-apoptotic effects. In the current study, Arabic gum (AG)/pectin hydrogel was utilized to encapsulate NAR. Drug-loaded AG/pectin hydrogel exhibited excellent EE% of about 99.88 ± 0.096 and high DL% of about 16.64 ± 0.013. The formulated drug-loaded hydrogel was characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Zetasizer analyzer, besides determination of equilibrium degree of swelling (EDS%). Afterwards, wound healing potential of NAR-loaded AG/pectin hydrogel was evaluated in an in vivo animal model. Results manifested that NAR-loaded AG/pectin hydrogel was able to accelerate wound healing in terms of enhanced angiogenesis, re-epithelialization and collagen deposition. Furthermore, it significantly (P < 0.001) down-regulated the mRNA expression of inflammatory mediators (TNF-α) and apoptosis (BAX). In addition, NAR-loaded AG/pectin hydrogel was found to possess potent antioxidant activity as it enhanced the levels of SOD and GSH, besides decreasing the levels of MPO, MDA and nitrite. These data suggest that NAR-loaded AG/pectin hydrogel could be utilized in wound healing applications.

A comprehensive phytochemical, biological, and toxicological studies of roots and aerial parts of Crotalaria burhia Buch.-Ham: An important medicinal plant

This study was designed to seek the phytochemical analysis, antioxidant, enzyme inhibition, and toxicity potentials of methanol and dichloromethane (DCM) extracts of aerial and root parts of Crotalaria burhia. Total bioactive content, high-performance liquid chromatography-photodiode array detector (HPLC-PDA) polyphenolic quantification, and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) analysis were utilized to evaluate the phytochemical composition. Antioxidant [including 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH)], 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP), cupric reducing antioxidant capacity CUPRAC, phosphomolybdenum, and metal chelation assays] and enzyme inhibition [against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, α-amylase, and tyrosinase] assays were carried out for biological evaluation. The cytotoxicity was tested against MCF-7 and MDA-MB-231 breast cell lines. The root-methanol extract contained the highest levels of phenolics (37.69 mg gallic acid equivalent/g extract) and flavonoids (83.0 mg quercetin equivalent/g extract) contents, and was also the most active for DPPH (50.04 mg Trolox equivalent/g extract) and CUPRAC (139.96 mg Trolox equivalent /g extract) antioxidant assays. Likewise, the aerial-methanol extract exhibited maximum activity for ABTS (94.05 mg Trolox equivalent/g extract) and FRAP (64.23 mg Trolox equivalent/g extract) assays. The aerial-DCM extract was noted to be a convincing cholinesterase (AChE; 4.01 and BChE; 4.28 mg galantamine equivalent/g extract), and α-glucosidase inhibitor (1.92 mmol acarbose equivalent/g extract). All of the extracts exhibited weak to modest toxicity against the tested cell lines. A considerable quantities of gallic acid, catechin, 4-OH benzoic acid, syringic acid, vanillic acid, 3-OH-4-MeO benzaldehyde, epicatechin, p-coumaric acid, rutin, naringenin, and carvacrol were quantified via HPLC-PDA analysis. UHPLC-MS analysis of methanolic extracts from roots and aerial parts revealed the tentative identification of important phytoconstituents such as polyphenols, saponins, flavonoids, and glycoside derivatives. To conclude, this plant could be considered a promising source of origin for bioactive compounds with several therapeutic uses.

Synergistic antioxidant effects of natural compounds on H2O2-induced cytotoxicity of human monocytes

Natural compounds are endowed with a broad spectrum of biological activities, including protection against Toxins. Most of them are known for their antioxidant and radical scavenging activities. However, the synergistic combination of these natural molecules is not well studied. Therefore, the present study aims first to investigate the effect of four potent natural molecules [rosmarinic acid (Ros-A), ellagic acid (Ella-A), curcumin (Cur), and syringic acid (Syr-A)] on H₂O₂ -induced cell cytotoxicity and oxidative stress on the human monocytes (THP-1) and then to evaluate their combined action effect. Optimal combinations of these molecules were predicted using an augmented mixture design approach. In the first, as preliminary antioxidant activities screening, two in vitro assays were adopted to assess the single radicals scavenging activity of these natural compounds, DPPH• and ABTS• + tests. Based on the results obtained, the multitude of optimal formulas proposed by the mixture design study led to choosing four potent compositions (comp) in addition to ellagic acid, proposed as the most efficient when applied alone. The different molecules and mixtures were used to assess their cytoprotective effect on THP-1 cells in the presence and absence of H₂O₂. The most potent Comp-4, as well as the molecules forming this mixture, were exploited in a second experiment, aiming to understand the effect on oxidative stress via antioxidant enzyme activities analysis in the H₂O₂-induced oxidative stress in the THP-1 cell line. Interestingly, the natural molecules used for THP-1 cells treatment exhibited a significant increase in the antioxidant defense and glyoxalase system as well as suppression of ROS generation evaluated as MDA content. These results indicate that the natural compounds tested here, especially the synergistic effect of Cur and Ros-A (Comp-4), could serve as cytoprotective and immunostimulant agents against H₂O₂-induced cytotoxicity THP-1 cells, which makes them interesting for further investigations on the molecular mechanisms in preclinical animal models.

Effects of Naringin on Postharvest Storage Quality of Bean Sprouts

This study investigated the effects of naringin on soybean and mung bean sprouts postharvest quality. It was found that naringin could maintain the appearance and quality of soybean sprouts and mung bean sprouts during a 6-day storage period as well as delay the occurrence of browning in mung bean sprouts and soybean sprouts. The optimal application rate of naringin was 50–100 μg/mL, which could effectively inhibit the activity of polyphenol oxidase (PPO) and peroxidase (POD) in bean sprouts and increase the ascorbic acid content, where this inhibition response to the browning of mung bean sprouts and soybean sprouts was significantly reduced. Naringin treatment increased gallic acid and p-coumaric acid content in mung bean sprouts as well as the daidzin and rutin content in soybean sprouts, which was also reflected in the improvement of antioxidant activity. The binding of naringin with PPO and POD was analyzed with molecular docking, naringin, and PPO had a lower binding energy (−1.09 Kcal/mol). In conclusion, naringin application in postharvest preservation of mung bean sprouts and soybean sprouts can maintain favorable consumer quality.

Soluble Free, Soluble Conjugated, and Insoluble Bound Phenolics in Tomato Seeds and Their Radical Scavenging and Antiproliferative Activities

The soluble free, soluble conjugated, and insoluble bound phenolic compounds in tomato seeds were extracted and analyzed using ultra-high-performance liquid chromatography-high-resolution mass spectrometry. Total phenolic content (TPC) and free radical scavenging activities along with the antiproliferative effects against the human colorectal cancer cell line (HCT-116) were also examined for the soluble free, soluble conjugated, and insoluble bound phenolic fractions. 13, 7, and 10 compounds were tentatively identified in the soluble free, soluble conjugated, and insoluble bound phenolic fractions, respectively, including indole-3-acetic acid derivatives, flavonoids, phenolic acid, and tyramine-derived hydroxycinnamic acid amines. The insoluble bound phenolic fraction was observed to have a greater TPC value and stronger free radical scavenging activities against ABTS^•+, DPPH^•, and peroxyl radicals and a stronger inhibitory effect against HCT-116 cells compared with the soluble free and the soluble conjugated fractions. Soluble free and insoluble bound fractions significantly inhibited the proliferation of the HCT-116 cell line, and no antiproliferative effects were observed with the soluble conjugated fraction under the experimental conditions. The results may provide a foundation for future application of tomato seeds as nutraceuticals in dietary supplements and functional foods.

A Review on the Delivery of Plant-Based Antidiabetic Agents Using Nanocarriers: Current Status and Their Role in Combatting Hyperglycaemia

Diabetes mellitus is a prevalent metabolic syndrome that is associated with high blood glucose levels. The number of diabetic patients is increasing every year and the total number of cases is expected to reach more than 600 million worldwide by 2045. Modern antidiabetic drugs alleviate hyperglycaemia and complications that are caused by high blood glucose levels. However, due to the side effects of these drugs, plant extracts and bioactive compounds with antidiabetic properties have been gaining attention as alternative treatments for diabetes. Natural products are biocompatible, cheaper and expected to cause fewer side effects than the current antidiabetic drugs. In this review, various nanocarrier systems are discussed, such as liposomes, niosomes, polymeric nanoparticles, nanoemulsions, solid lipid nanoparticles and metallic nanoparticles. These systems have been applied to overcome the limitations of the current drugs and simultaneously improve the efficacy of plant-based antidiabetic drugs. The main challenges in the formulation of plant-based nanocarriers are the loading capacity of the plant extracts and the stability of the carriers. A brief review of lipid nanocarriers and the amphipathic properties of phospholipids and liposomes that encapsulate hydrophilic, hydrophobic and amphiphilic drugs is also described. A special emphasis is placed on metallic nanoparticles, with their advantages and associated complications being reported to highlight their effectiveness for treating hyperglycaemia. The present review could be an interesting paper for researchers who are working in the field of using plant extract-loaded nanoparticles as antidiabetic therapies.

Salama AA, Tadros SH, El Gedaily RA. Novel Neuroprotective Potential of Bunchosia armeniaca (Cav.) DC against Lipopolysaccharide Induced Alzheimer’s Disease in Mice

Bunchosia armeniaca (Cav.) DC (Malpighiaceae) is one of the well-known traditionally used remedies worldwide. This study aims to explore the leaves’ metabolome via Quadrupole-Time-of-Flight-Liquid-Chromatography-Mass Spectrometry and to investigate the neuroprotective effect of leaves using lipopolysaccharide (LPS) induced Alzheimer’s disease model. Mice were administered LPS (0.25 mg/kg/day; intraperitoneal) as well as methanolic extract (BME), dichloromethane (BDMF), and butanol (BBF) fractions (each 200 mg/kg/day; oral) for one week. BME and BBF improved behavioral activity on the Y maze test, decreased brain content of inflammatory markers such as nuclear factor kappa B and interleukin 1 beta, and prevented the elevation of cytochrome P450 2E1, and glial fibrillary acidic protein compared to the LPS-administered group. Histopathological examination of several brain parts confirmed the neuroprotective effect of the tested extracts. In addition, BBF exhibited higher activity in all tested in vitro antioxidant and acetylcholinesterase inhibition assays. Metabolic profiling offered tentative identification of 88 metabolites, including mainly flavonoids, phenolic acids, and coumarins. Several detected metabolites, such as quercetin, apigenin, baicalin, vitexin, and resveratrol, had previously known neuroprotective effects. The current study highlighted the possible novel potential of B. armeniaca in preventing memory impairment, possibly through its antioxidant effect and inhibition of acetylcholinesterase, inflammatory and oxidative stress mediators.

Measurement of Naringin from Citrus Fruits by High-Performance Liquid Chromatography - a Review

Naringin is a flavonoid found primarily in citrus species with especially high concentrations being present in grapefruit (Citrus paradisi), bitter orange (Citrus aurantium), and pomelo (Citrus grandis). Because of its many positive effects on human health, naringin has been the focus of increasing attention in recent years. Recently, conventional extraction methods have been commonly replaced with unconventional methods, such as ultrasound-assisted extraction (UAE) and other, more eco-friendly extraction methods requiring little-to-no environmentally harmful solvents or significantly less energy. Naringin analysis is most commonly done via high-performance liquid chromatography (HPLC), and ultrahigh-performance liquid chromatography (UHPLC) coupled with a mass spectrometer (MS) or a photodiode array (DAD) detector. The aim of this review is to provide an overview of recent trends developments in the extraction, sample preparation, and liquid chromatographic analysis of the compound originating from citrus fruits or their products.

Physicochemical and Biochemical Evaluation of Amorphous Solid Dispersion of Naringenin Prepared Using Hot-Melt Extrusion

Naringenin (NRG) is a plant-derived flavonoid. Due to its antioxidant, anti-inflammatory, and analgesic activities it is beneficial to human health and is often used as a functional food ingredient; however, it has poor water solubility and low in vivo bioavailability. Therefore, the efficacy of NRG can be improved by enhancing its water solubility to increase gastrointestinal absorption. Conventional methods for the formulation of NRG are very complex and use toxic organic solvents, making them impractical for the production of functional foods. The objective of this study was to develop a safe and effective NRG-based functional food material. Previously, we established a technology to prepare amorphous solid dispersions (SDs) from functional food ingredients with poor water solubility and used hot-melt extrusion technology that is comparatively simple and does not involve the use of organic solvents. In this study, we prepared NRG SD and evaluated them both physicochemically and biochemically. NRG SD had superior water solubility and gastrointestinal absorption relative to native NRG and showed higher analgesic efficacy in rats than crystalline NRG. NRG SD was administered to mice in a mixed diet for 28 days, and organ weights and hematological/clinical biochemical parameters were assessed. NRG SD did not demonstrate severe adverse effects. The results suggest that NRG SD is a safe and highly efficacious formulation that can be used as a functional food material in the future.

The Cross-Talk between Polyphenols and the Target Enzymes Related to Oxidative Stress-Induced Thyroid Cancer

The most serious hallmark step of carcinogenesis is oxidative stress, which induces cell DNA damage. Although in normal conditions ROS are important second messengers, in pathological conditions such as cancer, due to imbalanced redox enzyme expression, oxidative stress can occur. Recent studies with firmly established evidence suggest an interdependence between oxidative stress and thyroid cancer based on thyroid hormone synthesis. Indeed, a reduced antioxidant defense system might play a part in several steps of progression in thyroid cancer. Based on studies that have been conducted previously, future drug designs for targeting enzymatic ROS sources, as a single agent or in combination, have to be tested. Polyphenols represent the potential for modulating biological events in thyroid cancer, including antioxidative activity. Targeting enzymatic ROS sources, without affecting the physiological redox state, might be an important purpose. As regards the underlying chemopreventive mechanisms of natural compounds that have been discussed in other cancer models, the confirmation of the influence of polyphenols on thyroid cancer is inconclusive and rarely available. Therefore, there is a need for further scientific investigations into the features of the antioxidative effects of polyphenols on thyroid cancer. The current review illustrates the association between some polyphenols and the key enzymes that take place in oxidation reactions in developing thyroid cancer cells. This review gives the main points of the enzymatic ROS sources act and redox signaling in normal physiological or pathological contexts and supplies a survey of the currently available modulators of TPO, LOX, NOX, DUOX, Nrf2, and LPO derived from polyphenols.

Erythrocyte Storage Lesion Improvements Mediated by Naringin Screened from Vegetable/Fruit Juice Using Cell Extract and HPLC-MS

In blood banking, storage at 4°C for weeks is known to cause damages to erythrocytes, called storage lesions that may later cause transfusion-related adverse events. In previous experiments, we found that vegetable/fruit juices can effectively reduce the storage lesion. Currently, we attempt to analyze the potential bioactive components and test whether the compounds can improve the storage lesions of erythrocytes. Equal portions in wet weight of 20 fresh vegetables and fruits were blended with phosphate buffered solution (PBS), and clear solutions were produced as additive to the packed erythrocytes from consented blood donors at 1 : 10 ratio (ml : gram). The blood samples were stored for 35 days at 4°C, and the supernatants were performed high liquid chromatography-mass spectrometry (HPLC-MS) analysis at 0 days, 14 days, and 35 days. The blood bags supplemented with identified bioactive components were stored in a refrigerator for 35 days, and the morphology, complete blood count (CBC), phosphatidylserine (PS) extroversion, hemolysis, and reactive oxygen species (ROS) levels were measured at the end of storage. Five potential bioactive components from vegetable/fruit juices contributed to the improvements of storage lesion. One of the compounds was unequivocally identified as naringin, and two were tentatively assigned as vitexin 6″-O-malonyl 2″-O-xyloside and luteolin 7-(6″-malonyl neohesperidoside). Naringin alleviated the storage lesion of red blood cells (RBCs) by reducing ROS levels and living cell extraction with HPLC-MS is a simple, reliable, and effective method for screening potential bioactive components.

Influence of Rutin, Sinapic Acid, and Naringenin on Binding of Tyrosine Kinase Inhibitor Erlotinib to Bovine Serum Albumin Using Analytical Techniques Along with Computational Approach

Flavonoid-containing food supplements are widely used as antioxidants, and the continuous use of these supplements with other drugs can lead to clinically significant interactions between these and other drugs. The medications in systemic circulation are mainly transported by serum albumin, a major transport protein. This study evaluated the interactions of rutin (RUT), naringenin (NAR), and sinapic acid (SIN) with the most abundant transport protein, bovine serum albumin (BSA), and the anticancer drug, the tyrosine kinase inhibitor Erlotinib (ETB), using various analytical methods. Interaction between multiple types of ligands with the transport proteins and competition between themselves can lead to the bound ETB’s displacement from the BSA-binding site, leading to elevated ETB concentrations in the systemic circulation. These elevated drug fractions can lead to adverse events and lower tolerance, and increased resistance to the therapeutic regimen of ETB. The experimental and computational methods, including molecular-docking studies, were used to understand the molecular interactions. The results suggested that the complexes formed were utterly different in the binary and the ternary system. Furthermore, comparing the ternary systems amongst themselves, the spectra differed from each other. They thus inferred that complexes formed between BSA-ETB in the presence of each RUT, NAR, and SIN separately were also different, with the highest value of the reduction in the binding energy in RUT, followed by SIN and then NAR. Thus, we conclude that a competitive binding between the ETB and these flavonoids might influence the ETB pharmacokinetics in cancer patients by increasing ETB tolerance or resistance.

Health Benefits of Postbiotics Produced by E. coli Nissle 1917 in Functional Yogurt Enriched with Cape Gooseberry (Physalis peruviana L.)

Changes in the activities of antimicrobial, antitumor, and antioxidant properties of postbiotics (YCG) are related to changes in the composition of phenolic compounds. Antimicrobial activity was found to be highest in postbiotic (YCG-7) against P. aeruginosa, S. aureus, and E. faecalis with an MIC of 3.1 µg/mL. YCG-7 revealed the most cytotoxicity against LS-174T and PC-3 cell lines with an IC50 of 5.78 and 6.56 µg/mL, respectively. YCG-7 was far more effective for scavenging free radicals in the NO• and DPPH assays with a scavenging activity of 70.73% and 85.6%, respectively. YCG-7’s total phenolic acid content is up to eightfold higher compared with control. Escherichia coli Nissle 1917 retained high viable counts during refrigerated storage, particularly in YCG (>108 cells g−1) revealing a potential prebiotic activity of Cape gooseberry juice. EcN affected the phenolic profile of the YCG. Pyrogallol, p-coumaric acid, ellagic acid, 4-hydroxybenzoic acid, salicylic acid, gallic acid, vanillic acid, o-coumaric acid, caffeic acid, catechol, syringic acid, and rutin were the predominant phenolic compounds in YCG-7 or YCG-15. Chlorogenic, rosmarinic, cinnamic acid, naringin, and kaempferol were degraded by EcN in YCG-7 and YCG-15. The YCG had significantly higher sensory scores for appearance, smoothness, sourness, mouthfeel, and overall acceptance. These results provide the basis to target the functional benefits of YCG for further human health applications.

Ameliorative role of naringenin against lead-induced genetic damage and oxidative stress in cultured human lymphocytes

Lead (Pb) is a ubiquitous toxic heavy metal that is known to induce damage to major macromolecules (lipids, proteins, and nucleic acids) by enhancing the level of reactive oxygen species (ROS). Naringenin, a predominant flavonoid primarily found in citrus fruits has attained increasing attention due to its various pharmacological properties. Thus, the present investigation aimed to explore the ameliorative role of naringenin against Pb-induced toxicity in human peripheral blood lymphocytes (PBLs) under in vitro conditions. For this purpose, PBLs were exposed to Pb (350 µg/ml) alone as well in combination with naringenin (10 and 30 µg/ml). Sister chromatid exchange (SCE) and alkaline comet assay were used as genotoxic indices to evaluate the genotoxic and antigenotoxic activity of Pb and naringenin, respectively. Lipid peroxidation (LPO), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) assays were used as oxidative damage markers. The results revealed that Pb induced a significant (p < 0.05) increase in genetic and oxidative damage as compared with the untreated sample whereas the treatment of cells along with naringenin (10 and 30 µg/ml) and Pb (350 µg/ml) caused a significant reduction in genetic damage and elevation in SOD, GPx, and CAT activities and GSH level, accompanied by a significant reduction in LPO level as compared with Pb alone treated sample. So, the present investigation revealed that naringenin might be used as a protective agent against Pb-induced toxicity due to its antigenotoxic and antioxidative properties.

Potential dual inhibitors of PCSK-9 and HMG-R from natural sources in cardiovascular risk management

Atherosclerotic cardiovascular disease (ASCVD) stands amongst the leading causes of mortality worldwide and has attracted the attention of world's leading pharmaceutical companies in order to tackle such mortalities. The low-density lipoprotein-cholesterol (LDL-C) is considered the most prominent biomarker for the assessment of ASCVD risk. Distinct inhibitors of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-R), the chief hepatic cholesterogenic enzyme, are being used since last seven decades to manage hypercholesterolemia. On the other hand, discovery and the association of proprotein convertase subtilisin/kexin type-9 (PCSK-9) with increased ASCVD risk have established PCSK-9 as a novel therapeutic target in cardiovascular medicine. PCSK-9 is well reckoned to facilitate the LDL-receptor (LDL-R) degradation and compromised LDL-C clearance leading to the arterial atherosclerotic plaque formation. The currently available HMG-R inhibitors (statins) and PCSK-9 inhibitors (siRNA, anti-sense oligonucleotides, and monoclonal antibodies) have shown great promises in achieving LDL-C lowering goals, however, their life long prescriptions have raised significant concerns. These deficits associated with the synthetic HMG-R and PCSK-9 inhibitors called for the discovery of alternative therapeutic candidates with potential dual HMG-R and PCSK-9 inhibitory activities from natural origins. Therefore, this report firstly describes the mechanistic insights into the cholesterol homeostasis through HMG-R, PCSK-9, and LDL-R functionality and then compiles the pharmacological effects of natural secondary metabolites with special emphasis on their dual HMG-R and PCSK-9 inhibitory action. In conclusion, various natural products exhibit atheroprotective effects via targeting HMG-R and PCSK-9 activities and lipoprotein metabolism, however, further clinical assessments are still warranted prior their approval for ASCVD risk management in hypercholesterolemic patients.

Nanomedicine of Plant Origin for the Treatment of Metabolic Disorders

Metabolic disorders are major clinical challenges of health that are progressing globally. A concurrence of metabolic disorders such as obesity, insulin resistance, atherogenic dyslipidemia, and systematic hypertension leads to metabolic syndrome. Over the past years, the metabolic syndrome leads to a five- and two-fold rise in diabetes mellitus type II and cardiovascular diseases. Natural products specifically plant extracts have insulin-sensitizing, anti-inflammatory, and antioxidant properties and are also considered as an alternative option due to few adverse effects. Nanotechnology is one of the promising strategies, which improves the effectiveness of treatment and limits side effects. This review mainly focuses on plant extract-based nanosystems in the management of the metabolic syndrome. Numerous nano-drug delivery systems, i.e., liposomes, hydrogel nanocomposites, nanoemulsions, micelles, solid lipid, and core–shell nanoparticles, have been designed using plant extracts. It has been found that most of the nano-formulations successfully reduced oxidative stress, insulin resistance, chronic inflammation, and lipid profile in in vitro and in vivo studies as plant extracts interfere with the pathways of metabolic syndrome. Thus, these novel plant-based nanosystems could act as a promising candidate for clinical applications.

Neuraminidase Inhibitor of Garcinia atroviridis L. Fruits and Leaves Using Partial Purification and Molecular Characterization

Neuraminidase (NA) is an enzyme that prevents virions from aggregating within the host cell and promotes cell-to-cell spread by cleaving glycosidic linkages to sialic acid. The best-known neuraminidase is the viral neuraminidase, which present in the influenza virus. Thus, the development of anti-influenza drugs that inhibit NA has emerged as an important and intriguing approach in the treatment of influenza. Garcinia atroviridis L. (GA) dried fruits (GAF) are used commercially as seasoning and in beverages. The main objective of this study was to identify a new potential neuraminidase inhibitor from GA. A bioassay-guided fractionation method was applied to obtain the bioactive compounds leading to the identification of garcinia acid and naringenin. In an enzyme inhibition study, garcinia acid demonstrated the highest activity when compared to naringenin. Garcinia acid had the highest activity, with an IC₅₀ of 17.34–17.53 µg/mL or 91.22–92.21 µM against Clostridium perfringens-NA, and 56.71–57.85 µg/mL or 298.32–304.31 µM against H1N1-NA. Based on molecular docking results, garcinia acid interacted with the triad arginine residues (Arg118, Arg292, and Arg371) of the viral neuraminidase, implying that this compound has the potential to act as a NA enzyme inhibitor.

Comparative Molecular Mechanisms of Biosynthesis of Naringenin and Related Chalcones in Actinobacteria and Plants: Relevance for the Obtention of Potent Bioactive Metabolites

Naringenin and its glycosylated derivative naringin are flavonoids that are synthesized by the phenylpropanoid pathway in plants. We found that naringenin is also formed by the actinobacterium Streptomyces clavuligerus, a well-known microorganism used to industrially produce clavulanic acid. The production of naringenin in S. clavuligerus involves a chalcone synthase that uses p-coumaric as a starter unit and a P₄₅₀ monoxygenase, encoded by two adjacent genes (ncs-ncyP). The p-coumaric acid starter unit is formed by a tyrosine ammonia lyase encoded by an unlinked, tal, gene. Deletion and complementation studies demonstrate that these three genes are required for biosynthesis of naringenin in S. clavuligerus. Other actinobacteria chalcone synthases use caffeic acid, ferulic acid, sinapic acid or benzoic acid as starter units in the formation of different antibiotics and antitumor agents. The biosynthesis of naringenin is restricted to a few Streptomycess species and the encoding gene cluster is present also in some Saccharotrix and Kitasatospora species. Phylogenetic comparison of S. clavuligerus naringenin chalcone synthase with homologous proteins of other actinobacteria reveal that this protein is closely related to chalcone synthases that use malonyl-CoA as a starter unit for the formation of red-brown pigment. The function of the core enzymes in the pathway, such as the chalcone synthase and the tyrosine ammonia lyase, is conserved in plants and actinobacteria. However, S. clavuligerus use a P₄₅₀ monooxygenase proposed to complete the cyclization step of the naringenin chalcone, whereas this reaction in plants is performed by a chalcone isomerase. Comparison of the plant and S. clavuligerus chalcone synthases indicates that they have not been transmitted between these organisms by a recent horizontal gene transfer phenomenon. We provide a comprehensive view of the molecular genetics and biochemistry of chalcone synthases and their impact on the development of antibacterial and antitumor compounds. These advances allow new bioactive compounds to be obtained using combinatorial strategies. In addition, processes of heterologous expression and bioconversion for the production of naringenin and naringenin-derived compounds in yeasts are described.

Flavonoid mediated selective cross-talk between plants and beneficial soil microbiome

Plants generate a wide variety of organic components during their different growth phases. The majority of those compounds have been classified as primary and secondary metabolites. Secondary metabolites are essential in plants' adaptation to new changing environments and in managing several biotic and abiotic stress. It also invests some of its photosynthesized carbon as secondary metabolites to establish a mutual relationship with soil microorganisms in that specific niche. As soil harbors both pathogenic and beneficial microorganisms, it is essential to identify some specific metabolites that can discriminate beneficial and pathogenic ones. Thus, a detailed understanding of metabolite's architectures that interact with beneficial microorganisms could open a new horizon of ecology and agricultural research. Flavonoids are used as classic examples of secondary metabolites in this study to demonstrate recent developments in understanding and realizing how these valuable metabolites can be controlled at different levels. Most of the research was focused on plant flavonoids, which shield the host plant against competitors or predators, as well as having other ecological implications. Thus, in the present review, our goal is to cover a wide range of functional and signalling activities of secondary metabolites especially, flavonoids mediated selective cross-talk between plant and its beneficial soil microbiome. Here, we have summarized recent advances in understanding the interactions between plant species and their rhizosphere microbiomes through root exudates (flavonoids), with a focus on how these exudates facilitate rhizospheric associations.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-022-09806-3.

Lipid Nanoparticles Containing Mixtures of Antioxidants to Improve Skin Care and Cancer Prevention

Oxidative stress, triggered by UV radiation, is one of the major causes of free radical-associated disorders, such as skin cancer. The application of natural compounds (NCs) with antioxidant effects can attenuate free radicals’ accumulation and, therefore, provide a strategy for skin care and cancer prevention. In this work, three natural compounds, naringenin, nordihydroguaiaretic acid (NDGA), and kaempferol, were encapsulated into nanostructured lipid carriers (NLCs) aiming for the development of a formulation for cutaneous application with antioxidant properties. For the experiments, different formulation parameters were evaluated to optimize the NLCs that showed a diameter around 200 nm, which is an adequate particle size for incorporation in cosmetics. Transmission electron microscopy (TEM) analysis confirmed the NLCs’ typical spherical morphology. Encapsulation efficiency (EE) and loading capacity (LC) values revealed an effective production process, with EEs over 90% and LCs near the maximum value. The developed NLCs revealed a prolonged in vitro release of the natural compounds. The NLCs were stable under storage conditions, maintaining their psychochemical characteristics for 30 days. Additionally, they did not show any physical instability in accelerated stability studies, which also suggests long-term stability. Finally, the NCs antioxidant activity was evaluated. Interestingly, the NDGA and kaempferol mixture provided an antioxidant synergic effect. The NLC formulations’ cytotoxicity was tested in vitro in immortalized human keratinocytes (HaCaT). In addition, putative antioxidant effects of the developed NLC formulations against tert-butyl hydroperoxide (t-BHP)-induced oxidative stress were studied, and the NDGA-loaded NLC was revealed to be the one with the most protective effect. Therefore, we concluded that the naringenin, NDGA, and kaempferol incorporation into NLCs constitutes a promising strategy to increase their bioavailability and delivery to the skin.

Naringenin: A Promising Therapeutic Agent against Organ Fibrosis

Fibrosis is the final common pathology of most chronic diseases as seen in the heart, liver, lung, kidney, and skin and contributes to nearly half of death in the developed countries. Fibrosis, or scarring, is mainly characterized by the transdifferentiation of fibroblasts into myofibroblasts and the excessive accumulation of extracellular matrix (ECM) secreted by myofibroblasts. Despite immense efforts made in the field of organ fibrosis over the past decades and considerable understanding of the occurrence and development of fibrosis gained, there is still lack of an effective treatment for fibrotic diseases. Therefore, identifying a new therapeutic strategy against organ fibrosis is an unmet clinical need. Naringenin, a flavonoid that occurs naturally in citrus fruits, has been found to confer a wide range of pharmacological effects including antioxidant, anti-inflammatory, and anticancer benefits and thus potentially exerting preventive and curative effects on numerous diseases. In addition, emerging evidence has revealed that naringenin can prevent the pathogenesis of fibrosis in vivo and in vitro via the regulation of various pathways that involved signaling molecules such as transforming growth factor-β1/small mother against decapentaplegic protein 3 (TGF-β1/Smad3), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), sirtuin1 (SIRT1), nuclear factor-kappa B (NF-κB), or reactive oxygen species (ROS). Targeting these profibrotic pathways by naringenin could potentially become a novel therapeutic approach for the management of fibrotic disorders. In this review, we present a comprehensive summary of the antifibrotic roles of naringenin in vivo and in vitro and their underlying mechanisms of action. As a food derived compound, naringenin may serve as a promising drug candidate for the treatment of fibrotic disorders.

Phytopharmacological Evaluation of Different Solvent Extract/Fractions From Sphaeranthus indicus L. Flowers: From Traditional Therapies to Bioactive Compounds

Sphaeranthus indicus L. is a medicinal herb having widespread traditional uses for treating common ailments. The present research work aims to explore the in-depth phytochemical composition and in vitro reactivity of six different polarity solvents (methanol, n-hexane, benzene, chloroform, ethyl acetate, and n-butanol) extracts/fractions of S. indicus flowers. The phytochemical composition was accomplished by determining total bioactive contents, HPLC-PDA polyphenolic quantification, and UHPLC-MS secondary metabolomics. The reactivity of the phenolic compounds was tested through the following biochemical assays: antioxidant (DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum, and metal chelation) and enzyme inhibition (AChE, BChE, α-glucosidase, α-amylase, urease, and tyrosinase) assays were performed. The methanol extract showed the highest values for phenolic (94.07 mg GAE/g extract) and flavonoid (78.7 mg QE/g extract) contents and was also the most active for α-glucosidase inhibition as well as radical scavenging and reducing power potential. HPLC-PDA analysis quantified rutin, naringenin, chlorogenic acid, 3-hydroxybenzoic acid, gallic acid, and epicatechin in a significant amount. UHPLC-MS analysis of methanol and ethyl acetate extracts revealed the presence of well-known phytocompounds; most of these were phenolic, flavonoid, and glycoside derivatives. The ethyl acetate fraction exhibited the highest inhibition against tyrosinase and urease, while the n-hexane fraction was most active for α-amylase. Moreover, principal component analysis highlighted the positive correlation between bioactive compounds and the tested extracts. Overall, S. indicus flower extracts were found to contain important phytochemicals, hence could be further explored to discover novel bioactive compounds that could be a valid starting point for future pharmaceutical and nutraceuticals applications.

Evaluation of Pomelo Seed Extracts as Natural Antioxidant, Antibacterial, Herbicidal Agents, and Their Functional Components

Pomelo seeds (PS) are important by-product of pomelo fruits (Citrus grandis Osbeck). The value-added utilization of PS remains highly challenged. This study aimed to investigate the utilization potential of PS as natural antioxidant, antibacterial, herbicidal agents, and their functional components. The ethanolic extract (EE) of PS and its four fractions as PEE (petroleum ether extract), AcOEtE (ethyl acetate extract), BTE (butanol extract), and WE (water extract), were prepared and biologically evaluated. BTE exhibited the best antioxidant activity among all these extracts, in both ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) and FRAP (ferric reducing antioxidant power) assays. AcOEtE was superior to other extracts in herbicidal assay against both Festuca elata Keng (IC₅₀ of 0.48 mg mL^-1 ) and Amaranthus retroflexus L. (IC₅₀ of 0.94 mg mL^-1 ). Meanwhile, both AcOEtE and BTE demonstrated inhibitory effects against Bacillus subtilis, Escherichia coli, and Xanthomonas citri subsp. citri, with MIC ranging 2.5-5.0 mg mL^-1 . Furthermore, the primary chemical components involving naringin, deacetylnomilin, limonin, nomilin, and obacunone, were quantified in all these extracts. PCA (principal component analysis) suggested that naringin might highly contribute to the antioxidant activity of PS, and the herbicidal activity should be ascribed to limonoids. This study successfully identified AcOEtE and BTE as naturally occurring antioxidant, antibacterial, and herbicidal agents, showing application potential in food and cosmetics industries, and organic farming agriculture.

Effects of Naringenin on Experimentally Induced Rheumatoid Arthritis in Wistar Rats

Naringenin is one of the most important and abundant known flavonoids found in grapefruit and other citrus fruits. This experimental study aimed to assess the clinical effects and immune responses of naringenin in the animal model of rheumatoid arthritis (RA) according to various reports on its anti-inflammatory effects and modulation of the immune system. To this end, 40 Wistar rats in the weight range of 160-180g were randomly assigned to four groups (n=10) including healthy, control, naringenin, and methotrexate orally treated groups. To induce RA disease, a compound of 200 μl of Freund's adjuvant and collagen type II was injected subcutaneously into the rear footpads of rats. The severity of RA clinical signs was assessed based on a standard scoring method. The treatment lasted for three weeks (days7-28 after induction). The obtained data pointed out that the levels of C-reactive protein (CRP), myeloperoxidase, nitric oxide, IL-17, and IFN-γ cytokines significantly increased in the RA rats, while the level of their serum antioxidants significantly reduced, compared to the healthy rats. The inflammation of the paws and the level of CRP decreased similarly in both methotrexate and naringenin-treated groups. In the naringenin-treated group, a further decrease was detected in serum myeloperoxidase, nitric oxide, and the total antioxidant capacity occurred, as compared to the methotrexate-treated rats. Nonetheless, IL-17 and IFN-γ cytokines levels were further decreased in the methotrexate-treated group. Accordingly, it can be concluded that naringenin can be effectively used for the reduction of inflammatory effects and control of RA disease.

The Zebrafish Embryo as a Model to Test Protective Effects of Food Antioxidant Compounds

The antioxidant activity of food compounds is one of the properties generating the most interest, due to its health benefits and correlation with the prevention of chronic disease. This activity is usually measured using in vitro assays, which cannot predict in vivo effects or mechanisms of action. The objective of this study was to evaluate the in vivo protective effects of six phenolic compounds (naringenin, apigenin, rutin, oleuropein, chlorogenic acid, and curcumin) and three carotenoids (lycopene B, β-carotene, and astaxanthin) naturally present in foods using a zebrafish embryo model. The zebrafish embryo was pretreated with each of the nine antioxidant compounds and then exposed to tert-butyl hydroperoxide (tBOOH), a known inducer of oxidative stress in zebrafish. Significant differences were determined by comparing the concentration-response of the tBOOH induced lethality and dysmorphogenesis against the pretreated embryos with the antioxidant compounds. A protective effect of each compound, except β-carotene, against oxidative-stress-induced lethality was found. Furthermore, apigenin, rutin, and curcumin also showed protective effects against dysmorphogenesis. On the other hand, β-carotene exhibited increased lethality and dysmorphogenesis compared to the tBOOH treatment alone.

Anticancer potential of Naringenin, Biosynthesis, Molecular target, and structural perspectives

Numerous novel medicinal agents isolated from plant sources were used as indigenous remedies for the management and treatment of various types of cancer diseases. Naringenin is a naturally occurring flavanone glycoside and aglycone (genin) moiety of naringin, predominantly found in citrus and grapefruits, has emerged as a potential therapeutic agent for the management of a variety of diseases. A huge number of scientific papers have been published on naringenin describing its detailed studies and its therapeutic application in different diseases. The current study highlights, a comprehensive study on naringenin concerning its biosynthesis, molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), and structure-activity relationships (SARs), and patents granted have been highlighted. Naringenin and its derivatives has remarkable anti-cancer activity due to their inhibitory potential against diverse targets namely ABCG2/P-gp/BCRP, 5a-reductase, 17-bhydroxysteroid dehydrogenase, aromatase, proteasome, HDAC/Situin-1, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, topoisomerase-II, cathepsin-K, Wnt, NF-kB, B-Raf and mTOR, etc. With the huge knowledge of molecular targets, structural intuition, and SARs, the current study may be beneficial to design more potent, safe, effective, and economic anti-cancer naringenin. This is concluded that naringenin is a promising natural product for the management and therapy of cancer. Further evolution for pharmacological importance, clinical research, and trials are required to manifest its therapeutic action on metabolic syndrome in the human community.

The role of quercetin in plants

Flavonoids are a special category of hydroxylated phenolic compounds having an aromatic ring structure. Quercetin is aspecial subclass of flavonoid. It is a bioactive natural compound built upon the flavon structure nC6(ring A)-C3(ring C)-C6(ring B). Quercetin facilitates several plant physiological processes, such as seed germination, pollen growth, antioxidant machinery, and photosynthesis, as well as induces proper plant growth and development. Quercetin is a powerful antioxidant, so it potently provides plant tolerance against several biotic and abiotic stresses. This review highlights quercetin's role in increasing several physiological and biochemical processes under stress and non-stress environments. Additionally, this review briefly assesses quercetin's role in mitigating biotic and abiotic stresses (e.g., salt, heavy metal, and UV stress). The biosynthesis of flavonoids, their signaling pathways, and quercetin's role in plant signaling are also discussed.

The Role of Selected Natural Biomolecules in Sperm Production and Functionality

Emerging evidence from in vivo as well as in vitro studies indicates that natural biomolecules may play important roles in the prevention or management of a wide array of chronic diseases. Furthermore, the use of natural compounds in the treatment of male sub- or infertility has been proposed as a potential alternative to conventional therapeutic options. As such, we aimed to evaluate the effects of selected natural biomolecules on the sperm production, structural integrity, and functional activity. At the same time, we reviewed their possible beneficial or adverse effects on male reproductive health. Using relevant keywords, a literature search was performed to collect currently available information regarding molecular mechanisms by which selected natural biomolecules exhibit their biological effects in the context of male reproductive dysfunction. Evidence gathered from clinical trials, in vitro experiments and in vivo studies suggest that the selected natural compounds affect key targets related to sperm mitochondrial metabolism and motion behavior, oxidative stress, inflammation, DNA integrity and cell death. The majority of reports emphasize on ameliorative, stimulating and protective effects of natural biomolecules on the sperm function. Nevertheless, possible adverse and toxic behavior of natural compounds has been indicated as well, pointing out to a possible dose-dependent impact of natural biomolecules on the sperm survival and functionality. As such, further research leading to a deeper understanding of the beneficial or adverse roles of natural compounds is necessary before these can be employed for the management of male reproductive dysfunction.