A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention

In silico targeting SARS-CoV-2 spike protein and main protease by biochemical compounds

Since there is no general agreement on drug treatment of SARS-CoV-2, the search for a new drug capable of treating COVID-19 is of utmost priority. This study aims to dereplicate the chemical compounds of the methanol extract of Salvia officinalis and Artemisia dracunculus, and assay the inhibitory effect of these compounds as well as the previously dereplicated components of Zingiber officinale against SARS-CoV-2 in an in-silico study. A molecular networking (MN) technique was applied to find the chemical constituents of the extracts. Docking analysis was also used to find the binding affinity of dereplicated components from S. officinalis, A. dracunculus, and Z. officinale to COV-2-SP and M^pro. 57 compounds were dereplicated from the MeOH extracts of S. officinalis and A. dracunculus which include the class of polyphenols, flavonoids, coumarins, phenylpropanoids, anthocyanins, and dihydrochalcones. Molecular docking analysis indicated a high affinity of about 27 compounds from three mentioned plants against studied targets. kaempferol 3-O-rutinoside, neodiosmin, and querciturone with docking score values of -10.575, -10.208, and - 9.904 Kcal/mol and k_i values of 0.016606, 0.030921, and 0.051749, respectively were found to have the highest affinities against COV-2-SP. 2-phenylethyl beta-primeveroside, curcumin PE, and kaempferol 3-O-rutinoside also indicated the highest affinity against M^pro with docking scores of -10.34, -10.126 and - 9.705 and k_i values of 0.024726, 0.035529, and 0.072494, respectively. MN can be successfully used for the dereplication of metabolites from plant extracts. In addition, the in-silico binding energies introduced several inhibitors from Z. officinale, S. officinalis, and A. dracunculus for the treatment of SARS-CoV-2 disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11756-021-00881-z.

Nanoencapsulation of Polyphenols as Drugs and Supplements for Enhancing Therapeutic Profile - A Review

Polyphenolic phytoconstituents have been widely in use worldwide since ages and are categorised as secondary metabolites of plants. The application of polyphenols such as quercetin, resveratrol. curcumin as nutritional supplement has been researched widely. The use of polyphenols, and specifically quercetin for improving the memory and mental endurance have shown significant effects among rats. Even though similar results has not been resonated among human but encouraging preclinical results have encouraged researchers to explore other polyphenols to study the effects as supplements among athletes. The phytopharmacological research has elucidated the use of natural polyphenols to prevent and treat various physiological and metabolic disorders owing to its free radical scavenging properties, anti-inflammatory, anti-cancer and immunomodulatory effects. In spite of the tremendous pharmacological profile, one of the most dominant problem regarding the use of polyphenolic compounds is their low bioavailability. Nanonization is considered as one of the most prominent approaches among many. This article aims to review and discuss the molecular mechanisms of recently developed nanocarrier-based drug delivery systems for polyphenols and its application as drugs and supplements. Nanoformulations of natural polyphenols are bioactive agents, such as quercetin, kaempferol, fisetin, rutin, hesperetin, and naringenin epigalloccatechin-3-gallate, genistein, ellagic acid, gallic acid, chlorogenic acid, ferulic acid, curcuminoids and stilbenes is expected to have better efficacy. These delivery systems are expected to provide higher penetrability of polyphenols at cellular levels and exhibit a controlled release of the drugs. It is widely accepted that natural polyphenols do demonstrate significant therapeutic effect. However, the hindrances in their absorption, specificity and bioavailability can be overcome using nanotechnology.

The modulatory properties of Astragalus membranaceus treatment on endometrial cancer: an integrated pharmacological method

Astragalus membranaceus is a traditional Chinese medicine and has been used for adjuvant clinical therapy for a variety of cancers. However, the mechanism of its action on endometrial carcinoma is unclear. Based on the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) database, and the Traditional Chinese Medicine System Pharmacology Database (TCMSP™), the drug and target compounds were initially screened to construct a common network module. Twenty active compounds in Astragalus membranaceus were successfully identified, which hit by 463 potential targets related to endometrial cancer. Eight of the more highly predictive compounds (such as Jaranol, Bifendate, Isorhamnetin, Calycosin, 7-O-methylisomucronulatol, Formononetin, Kaempferol, Quercetin) were involved in DNA integrity checkpoint, cyclin-dependent protein kinase holoenzyme complex, and histone kinase activity. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway confirmed that Astragalus membranaceus might play a role in the treatment of endometrial cancer through p53 signalling pathway, transcriptional misregulation in cancer, and endometrial cancer signalling pathway. Drug-target-pathway networks were constructed using Cytoscape to provide a visual perspective. In addition, we verified that formononetin inhibited the proliferation of endometrial cancer cells through cell viability tests and clone formation tests. And qPCR and western blot found that formononetin exerts anti-cancer effects by promoting the expression of estrogen receptor beta (ERβ) and p53. Based on a systematic network pharmacology approach, our works successfully predict the active ingredients and potential targets of Astragalus membranaceus for application to endometrial cancer and helps to illustrate mechanism of action on a comprehensive level.

Effect of Yellow Wine Lees Supplementation on Milk Antioxidant Capacity and Hematological Parameters in Lactating Cows under Heat Stress

Simple Summary

The yellow wine lees (YWL), a byproduct of the yellow wine brewing industry which contain high levels of crude protein and anti-oxidative substrates can be a suitable ingredient in dairy rations. Total mixed rations (TMR) containing unfermented/fermented YWL were greater in total phenolic and flavonoid concentrations. Feeding lactating cows under heat stress with TMR containing unfermented or fermented YWL mix can reduce their inflammation response and oxidative stress, as well as improve fatty acid quality and oxidative stability of their milk.

Abstract

Fifteen multiparous lactating Chinese Holstein dairy cows were used in a replicated 3 × 3 Latin Square Design to evaluate the effect of total mixed rations (TMR) containing unfermented and fermented yellow wine lees (YWL) on the oxidative status of heat-stressed lactating cows and the oxidative stability of the milk and milk fatty acids they produced. Cows were fed with three isonitrogenous and isocaloric diets as follows: (1) TMR containing 18% soybean meal, (2) TMR containing 11% unfermented YWL (UM), and (3) TMR containing 11% fermented YWL (FM). The rectal temperature (at 1300 h) and respiratory rate were higher in control cows than in cows fed UM or FM. Both types of YWL were greater in total phenolic and flavonoid contents, reducing power, and radical scavenging abilities than soybean meal. Cows fed UM or FM had higher blood neutrophil, white blood cell, and lymphocyte counts, as well as lower plasma malondialdehyde level, higher plasma superoxide dismutase, glutathione peroxidase, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate levels, and higher total antioxidant capacity in the plasma than those fed control diet. The proportion of milk unsaturated fatty acids was higher and that of saturated fatty acids was lower in UM- and FM-fed animals than in the control animals. Milk from UM- and FM-fed cows had lower malondialdehyde content but higher 2,2-diphenyl-1-picryl-hydrazyl-hydrate content than the control cows. In conclusion, feeding TMR containing UM and FM to cows reduced both the oxidative stress in heat-stressed cows and improved the oxidative capacity of their milk.

Analysis of SYK Gene as a Prognostic Biomarker and Suggested Potential Bioactive Phytochemicals as an Alternative Therapeutic Option for Colorectal Cancer: An In-Silico Pharmaco-Informatics Investigation

BACKGROUND

SYK gene regulates the expression of SYK kinase (Spleen tyrosine kinase), an important non-receptor protein-tyrosine kinase for immunological receptor-mediated signaling, which is also considered a tumor growth metastasis initiator. An onco-informatics analysis was adopted to evaluate the expression and prognostic value of the SYK gene in colorectal cancer (CRC), the third most fatal cancer type; of late, it may be a biomarker as another targeted site for CRC. In addition, identify the potential phytochemicals that may inhibit the overexpression of the SYK kinase protein and minimize the human CRC.

MATERIALS & METHODS

The differential expression of the SYK gene was analyzed using several transcriptomic databases, including Oncomine, UALCAN, GENT2, and GEPIA2. The server cBioPortal was used to analyze the mutations and copy number alterations, whereas GENT2, Gene Expression Profiling Interactive Analysis (GEPIA), Onco-Lnc, and PrognoScan were used to examine the survival rate. The protein-protein interaction network of SYK kinase and its co-expressed genes was conducted via Gene-MANIA. Considering the SYK kinase may be the targeted site, the selected phytochemicals were assessed by molecular docking using PyRx 0.8 packages. Molecular interactions were also observed by following the Ligplot+ version 2.2. YASARA molecular dynamics simulator was applied for the post-validation of the selected phytochemicals.

RESULTS

Our result reveals an increased level of mRNA expression of the SYK gene in colorectal adenocarcinoma (COAD) samples compared to those in normal tissues. A significant methylation level and various genetic alterations recurrence of the SYK gene were analyzed where the fluctuation of the SYK alteration frequency was detected across different CRC studies. As a result, a lower level of SYK expression was related to higher chances of survival. This was evidenced by multiple bioinformatics platforms and web resources, which demonstrated that the SYK gene can be a potential biomarker for CRC. In this study, aromatic phytochemicals, such as kaempferol and glabridin that target the macromolecule (SYK kinase), showed higher stability than the controls, and we have estimated that these bioactive potential phytochemicals might be a useful option for CRC patients after the clinical trial.

CONCLUSIONS

Our onco-informatics investigation suggests that the SYK gene can be a potential prognostic biomarker of CRC. On the contrary, SYK kinase would be a major target, and all selected compounds were validated against the protein using in-silico drug design approaches. Here, more in vitro and in vivo analysis is required for targeting SYK protein in CRC.

Silver nanoparticles and Chlorella treatments induced glucosinolates and kaempferol key biosynthetic genes in Eruca sativa

Background

Microalgae and nanoparticles are currently considered promising tools for numerous agricultural and biotechnological applications. The green microalga Chlorella sp. MF1 and its biosynthesized silver nanoparticles (AgNPs) were used in this study as biofortification agents to enhance glucosinolate and kaempferol levels in Eruca sativa. UV–visible spectroscopy, XRD, FTIR and TEM were comprehensively used for characterizing Chlorella-based AgNPs.

Results

The biosynthesized AgNPs were found to be spherical in shape, with size ranging from 1.45 to 5.08 nm. According to FTIR measurements, silver ions were reduced to AgNPs by functional groups such as amide, hydroxyl and carboxylate. Different experimental treatments were conducted, including either soaking seeds of E. sativa or foliar spray with various concentrations of Chlorella suspension (1, 2, 3 and 4 g L−1) and AgNPs (5, 10, 20 and 40 mg L−1). Expression levels of five key genes in the biosynthetic pathway of glucosinolates (MAM1, SUR1, MYB34 and MYB51) and kaempferol (CHS) were assessed using qRT-PCR. The results indicated an upregulation in the gene expression levels in all treatments compared to control, recording the highest level at 40 mg L−1 AgNPs and 4 g L−1Chlorella suspension. In addition, high glucosinolates and kaempferol content was detected in plants whose leaves were sprayed with AgNPs and Chlorella suspension (40 mg L−1 and 4 g L−1) based on HPLC analysis. Sequence analysis of amplified CHS fragments from E. sativa plants treated with AgNPs (40 mg L−1) showed high sequence similarity to A. thaliana CHS gene. However, there were several CHS regions with sequence polymorphism (SNPs and Indels) in foliar sprayed plants.

Conclusions

Results of this study evidenced that the application of AgNPs and Chlorella suspension increased glucosinolates and kaempferol content in E. sativa through upregulation of key genes in their biosynthetic pathway.

Antioxidant Role of Kaempferol in Prevention of Hepatocellular Carcinoma

Reactive oxygen species (ROS) are noxious to cells because their increased level interacts with the body's defense mechanism. These species also cause mutations and uncontrolled cell division, resulting in oxidative stress (OS). Prolonged oxidative stress is responsible for incorrect protein folding in the endoplasmic reticulum (ER), causing a stressful condition, ER stress. These cellular stresses (oxidative stress and ER stress) are well-recognized biological factors that play a prominent role in the progression of hepatocellular carcinoma (HCC). HCC is a critical global health problem and the third leading cause of cancer-related mortality. The application of anti-oxidants from herbal sources significantly reduces oxidative stress. Kaempferol (KP) is a naturally occurring, aglycone dietary flavonoid that is present in various plants (Crocus sativus, Coccinia grandis, Euphorbia pekinensis, varieties of Aloe vera, etc.) It is capable of interacting with pleiotropic proteins of the human body. Efforts are in progress to develop KP as a potential candidate to prevent HCC with no adverse effects. This review emphasizes the molecular mechanism of KP for treating HCC, targeting oxidative stress.

Air-Assisted Alkanol-Based Nanostructured Supramolecular Liquid-Liquid Microextraction for Extraction and Spectrophotometric Determination of Morin in Fruit and Beverage Samples

A new air-assisted liquid–liquid microextraction method based on alkanol nanostructured supramolecular solvents coupled to spectrometric analysis was developed for extraction, preconcentration, and spectrophotometric determination of morin. Al(III)-morin complex was performed at pH 4.5. Four different alkanol-based SUPRAS (supramolecular solvents) were prepared for the separation and preconcentration of Al-morin complex from aqueous solution by using vortex and centrifugation. Effect of analytical variables and tolerance limit of matrix ions were investigated. Under the optimum conditions, detection limit, quantification limit, relative standard deviation, preconcentration factor, and enhancement factor were found as 3.5 µg L⁻¹, 10 µg L⁻¹, 3.1%, 120, and 95, respectively. The accuracy of the method was performed with standard addition. The obtained results demonstrated the applicability of the method for the separation, preconcentration, and determination of morin in fruit and beverage samples. The method also complies with green chemistry principles as it uses green solvents, reduces reagent volumes, and produces low amounts of waste.

LC-HRMS Profiling and Antidiabetic, Antioxidant, and Antibacterial Activities of Acacia catechu (L.f.) Willd

Acacia catechu (L.f.) Willd is a profoundly used traditional medicinal plant in Asia. Previous studies conducted in this plant are more confined to extract level. Even though bioassay-based studies indicated the true therapeutic potential of this plant, compound annotation was not performed extensively. This research is aimed at assessing the bioactivity of different solvent extracts of the plant followed by annotation of its phytoconstituents. Liquid chromatography equipped with high resolution mass spectrometry (LC-HRMS) is deployed for the identification of secondary metabolites in various crude extracts. On activity level, its ethanolic extract showed the highest inhibition towards α-amylase and α-glucosidase with an IC₅₀ of 67.8 ± 1 μg/mL and 10.3 ± 0.1 μg/mL respectively, inspected through the substrate-based method. On the other hand, the plant extract showed an antioxidant activity of 23.76 ± 1.57 μg/mL, measured through radical scavenging activity. Similarly, ethyl acetate and aqueous extracts of A. catechu showed significant inhibition against Staphylococcus aureus with a zone of inhibition (ZoI) of 13 and 14 mm, respectively. With the LC-HRMS-based dereplication strategy, we have identified 28 secondary metabolites belonging to flavonoid and phenolic categories. Identification of these metabolites from A. catechu and its biological implication also support the community-based usage of this plant and its medicinal value.

Protein Adducts and Protein Oxidation as Molecular Mechanisms of Flavonoid Bioactivity

There are tens of thousands of scientific papers about flavonoids and their impacts on human health. However, despite the vast amount of energy that has been put toward studying these compounds, a unified molecular mechanism that explains their bioactivity remains elusive. One contributing factor to the absence of a general mechanistic explanation of their bioactivity is the complexity of flavonoid chemistry in aqueous solutions at neutral pH. Flavonoids have acidic protons, are redox active, and frequently auto-oxidize to produce an array of degradation products including electrophilic quinones. Flavonoids are also known to interact with specificity and high affinity with a variety of proteins, and there is evidence that some of these interactions may be covalent. This review summarizes the mechanisms of flavonoid oxidation in aqueous solutions at neutral pH and proposes the formation of protein-flavonoid adducts or flavonoid-induced protein oxidation as putative mechanisms of flavonoid bioactivity in cells. Nucleophilic residues in proteins may be able to form covalent bonds with flavonoid quinones; alternatively, specific amino acid residues such as cysteine, methionine, or tyrosine in proteins could be oxidized by flavonoids. In either case, these protein-flavonoid interactions would likely occur at specific binding sites and the formation of these types of products could effectively explain how flavonoids modify proteins in cells to induce downstream biochemical and cellular changes.

Exploring the Biological Activity and Mechanism of Xenoestrogens and Phytoestrogens in Cancers: Emerging Methods and Concepts

Xenoestrogens and phytoestrogens are referred to as "foreign estrogens" that are produced outside of the human body and have been shown to exert estrogen-like activity. Xenoestrogens are synthetic industrial chemicals, whereas phytoestrogens are chemicals present in the plant. Considering that these environmental estrogen mimics potentially promote hormone-related cancers, an understanding of how they interact with estrogenic pathways in human cells is crucial to resolve their possible impacts in cancer. Here, we conducted an extensive literature evaluation on the origins of these chemicals, emerging research techniques, updated molecular mechanisms, and ongoing clinical studies of estrogen mimics in human cancers. In this review, we describe new applications of patient-derived xenograft (PDX) models and single-cell RNA sequencing (scRNA-seq) techniques in shaping the current knowledge. At the molecular and cellular levels, we provide comprehensive and up-to-date insights into the mechanism of xenoestrogens and phytoestrogens in modulating the hallmarks of cancer. At the systemic level, we bring the emerging concept of window of susceptibility (WOS) into focus. WOS is the critical timing during the female lifespan that includes the prenatal, pubertal, pregnancy, and menopausal transition periods, during which the mammary glands are more sensitive to environmental exposures. Lastly, we reviewed 18 clinical trials on the application of phytoestrogens in the prevention or treatment of different cancers, conducted from 2002 to the present, and provide evidence-based perspectives on the clinical applications of phytoestrogens in cancers. Further research with carefully thought-through concepts and advanced methods on environmental estrogens will help to improve understanding for the identification of environmental influences, as well as provide novel mechanisms to guide the development of prevention and therapeutic approaches for human cancers.

Molecular imaging of plant-microbe interactions on the Brachypodium seed surface

Plant growth-promoting rhizobacteria (PGPR) play a crucial role in biological control and pathogenic defense on and within plant tissues, however the mechanisms by which plants associate with PGPR to elicit such beneficial effects need further study. Here, we present time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging of Brachypodium distachyon (Brachypodium) seeds with and without exposure to two model PGPR, i.e., Gram-negative Pseudomonas fluorescens SBW25 (P.) and Gram-positive Arthrobacter chlorophenolicus A6 (A.). Delayed image extraction was used to image PGPR-treated seed sections to reveal morphological changes. ToF-SIMS spectral comparison, principal component analysis (PCA), and two-dimensional (2D) imaging show that the selected PGPR have different effects on the host seed surface, resulting in changes in chemical composition and morphology. Metabolite products and biomarkers, such as flavonoids, phenolic compounds, fatty acids, and indole-3-acetic acid (IAA), were identified on the PGPR-treated seed surfaces. These compounds have different distributions on the Brachypodium seed surface for the two PGPR, indicating that the different bacteria elicit distinct responses from the host. Our results illustrate that ToF-SIMS is an effective tool to study plant-microbe interactions and to provide insightful information with submicrometer lateral resolution of the chemical distributions associated with morphological features, potentially offering a new way to study the mechanisms underlying beneficial roles of PGPR.

Effect of supplementation of Rhodomyrtus tomentosa fruit juice in preventing hypercholesterolemia and atherosclerosis development in rats fed with high fat high cholesterol diet

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Nutraceuticals, mainly based on natural products, have been proven to control the risk factors of CVDs effectively. Rhodomyrtus tomentosa is an underutilized fruit that is rich in phenolic compounds and has antioxidant activities. Scientific investigation was needed to verify the pharmacological properties of R. tomentosa fruit juice in Sprague-Dawley rats fed with high fat high cholesterol (HFHC) as antihypercholesterolemic and antiatherosclerotic agents. The experiments were carried out using male albino rats fed with HFHC diet for 75 days and at the same time orally supplemented with R. tomentosa fruit juice (RTFJ) in doses of 0.5, 1, and 2 g/kg body weight (BW) daily for 75 days. Simvastatin was used as a positive control. At the end of the experiment, the blood was collected, and the serum was assayed for total triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C). The histopathology of coronary and aorta arteries was observed under the light microscope. The results demonstrated that the supplementation of RTFJ significantly prevented the increase of total triglycerides, total cholesterol, low-density lipoprotein, and the decrease of high-density lipoprotein in serum. Supplementation of RTFJ also prevents atherosclerosis development by preventing the thickening of the blood vessel wall, deposition of lipid formation, and foam cells in the tunica intima of the aorta and coronary arteries. These findings suggested that supplementation of R. tomentosa fruit juice prevents hypercholesterolemia and atherosclerosis.

Kaempferol Induces Cell Death and Sensitizes Human Head and Neck Squamous Cell Carcinoma Cell Lines to Cisplatin

Cisplatin is a first-line chemotherapeutic drug commonly used to treat patients with head and neck cancer; nevertheless, cisplatin resistance poses a main challenge for its clinical efficacy. Recent studies have shown that kaempferol, a natural flavonoid found in various plants and foods, has an anticancer effect. The following study evaluated the cytotoxic effects of kaempferol on head and neck tumor cells and their mechanism of action, evaluating the effects on proliferation, the oxygen consumption rate, transmembrane potential, tumor cell migration and induction of apoptosis. Moreover, we determined the effects of a combination of kaempferol and cisplatin on head and neck tumor cells. We found that kaempferol inhibited the oxygen consumption rate and decreased the intracellular ATP content in tumor cells. This novel mechanism may inhibit the migratory capacity and promote antiproliferative effects and apoptosis of tumor cells. Additionally, our in vitro data indicated that kaempferol may sensitize head and neck tumor cells to the effects of cisplatin. These effects provide new evidence for the use of a combination of kaempferol and cisplatin in vivo and their future applications in head and neck cancer therapy.

A Synchronized Increase of Stilbenes and Flavonoids in Metabolically Engineered Vitis vinifera cv. Gamay Red Cell Culture

Stilbenes and flavonoids are two major health-promoting phenylpropanoid groups in grapes. Attempts to promote the accumulation of one group usually resulted in a decrease in the other. This study presents a unique strategy for simultaneously increasing metabolites in both groups in V. vinifera cv. Gamay Red grape cell culture, by overexpression of flavonol synthase (FLS) and increasing Phe availability. Increased Phe availability was achieved by transforming the cell culture with a second gene, the feedback-insensitive E. coli DAHP synthase (AroG*), and feeding them with Phe. A combined metabolomic and transcriptomic analysis reveals that the increase in both phenylpropanoid groups is accompanied by an induction of many of the flavonoid biosynthetic genes and no change in the expression levels of stilbene synthase. Furthermore, FLS overexpression with increased Phe availability resulted in higher anthocyanin levels, mainly those derived from delphinidin, due to the induction of F3'5'H. These insights may contribute to the development of grape berries with increased health benefits.

Valorization of waste cabbage leaves by postharvest photochemical treatments monitored with a non-destructive fluorescence-based sensor

The biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The destructive analysis of samples irradiated by the sun for 6 days at the end of October 2015 in Skierniewice (Poland) showed an increase of leaf flavonols by 82% with respect to controls. The treatment by a broadband UVB fluorescent lamp, with irradiance of 0.38 W m^-2 in the 290-315 nm range (and 0.59 W m^-2 in the UVA region) for 12 h per day at 17 °C along with a white light of about 20 μmol m^-2 s^-1, produced a flavonols increase of 58% with respect to controls. The kinetics of flavonols accumulation in response to the photochemical treatments was monitored with the FLAV non-destructive index. The initial FLAV rate under the sun was proportional to the daily radiation doses with a better correlation for the sun global irradiance (R² = 0.973), followed by the UVA (R² = 0.965) and UVB (R² = 0.899) irradiance. The sunlight turned out to be more efficient than the UVB lamp in increasing the flavonols level of waste leaves, because of a significant role played by UVA and visible solar radiation in the regulation of the flavonoid accumulation in cabbage. The FLAV index increase induced on the adaxial leaf side was accompanied by a lower but still significant FLAV increase on the unirradiated abaxial side, likely due to a systemic signaling by mean of the long-distance movement of macromolecules. Our present investigation provides useful data for the optimization of postharvest photochemical protocols of cabbage waste valorization. It can represent a novel and alternative tool of vegetable waste management for the recovery of beneficial phytochemicals.

Cogent role of flavonoids as key orchestrators of chemoprevention of hepatocellular carcinoma: A review

Chemopreventive approaches with food-derived phytochemicals are progressively rising as a significant aspect of tumor management and control. Herein, we have showcased the major phytoconstituents belonging to the group of flavanoid, as anti-cancer agents used for the treatment and prevention of hepatocellular carcinoma (HCC). Sorafenib is the sole drug used for the treatment of advanced HCC, but its clinical application is limited because of its severe adverse effects and drug resistance. Diet-based chemoprevention seems to be the way forward for this disease of malignant nature. As HCC is derived from a chronic inflammatory milieu, the regular incorporation of bioactive phytochemicals in the diet will confer protection and prevent progression to hepatocarcinogenesis. Many preclinical studies proved that the health benefits of flavonoids confer cytotoxic potential against various types of cancers including hepatocellular carcinoma. As flavonoids with excellent safety profile are abundantly present in common vegetables and fruits, they can be better utilized for chemoprevention and chemosensitization in such chronic condition. This review highlights the plausible role of the eight most promising flavonoids (Curcumin, Kaempferol, Resveratrol, Quercetin, Silibinin, Baicalein, Galangin and Luteolin) as key orchestrators of chemoprevention in hepatocellular carcinoma with preclinical and clinical evidence. An attempt to address the challenges in its clinical translation is also included. This review also provides an insight into the close association of HCC and metabolic disorders which may further decipher the chemopreventive effect of dietary bioactive from a proof of concept to extensive clinical translation. PRACTICAL APPLICATIONS: According to GLOBOCAN 2020 database, it is estimated that 905,677 new cases of liver cancer and approximately 830,180 deaths related to that. The cancer incidence and mortality are almost similar as it is diagnosed at an advanced stage in patients where systemic drug therapy is the sole approach. Due to the emergence of multidrug resistance and drug-related toxicities, most of the patient can not adhere to the therapy regimen. Flavonoids are known to be a potential anticancer agent with an excellent safety profile. These are found to be effective preclinically against hepatocellular carcinoma through modulation of numerous pathways in hepatocarcinogenesis. But, the bioavailability issue, lack of well designed-validated clinical evidence, the possibility of food-drug interaction etc limit its clinical utility. The research inputs mainly to overcome pharmacokinetic issues along with suitable validation of efficacy and toxicity will be a critical point for establishing flavonoids as an effective, safe, affordable therapeutics.

Baicalein, Baicalin, and Wogonin: Protective Effects against Ischemia-Induced Neurodegeneration in the Brain and Retina

Ischemia is a common pathological condition present in many neurodegenerative diseases, including ischemic stroke, retinal vascular occlusion, diabetic retinopathy, and glaucoma, threatening the sight and lives of millions of people globally. Ischemia can trigger excessive oxidative stress, inflammation, and vascular dysfunction, leading to the disruption of tissue homeostasis and, ultimately, cell death. Current therapies are very limited and have a narrow time window for effective treatment. Thus, there is an urgent need to develop more effective therapeutic options for ischemia-induced neural injuries. With emerging reports on the pharmacological properties of natural flavonoids, these compounds present potent antioxidative, anti-inflammatory, and antiapoptotic agents for the treatment of ischemic insults. Three major active flavonoids, baicalein, baicalin, and wogonin, have been extracted from Scutellaria baicalensis Georgi (S. baicalensis); all of which are reported to have low cytotoxicity. They have been demonstrated to exert promising pharmacological capabilities in preventing cell and tissue damage. This review focuses on the therapeutic potentials of these flavonoids against ischemia-induced neurotoxicity and damage in the brain and retina. The bioactivity and bioavailability of baicalein, baicalin, and wogonin are also discussed. It is with hope that the therapeutic potential of these flavonoids can be utilized and developed as natural treatments for ischemia-induced injuries of the central nervous system (CNS).

Differential Metabolomics and Network Pharmacology Analysis of Silkworm Biotransformation between Mulberry Leaves and Silkworm Droppings

Silkworm droppings are the product of mulberry leaves digested by silkworm intestines, which are an important medicinal resource in traditional Chinese medicine (TCM). The contents of total fat, fat acids, crude protein, amino acids, and secondary metabolites of obtained mulberry leaves and silkworm droppings were analyzed by HPLC, GC-MS, and UHPLC-Q-TOF MS. The target genes and enriched pathways related to significantly changed compositions between mulberry leaves and silkworm droppings were analyzed by network pharmacology. High unsaturated C18 : 3 fatty acids were transformed to low unsaturated C18 : 1 from mulberry leaves to silkworm droppings. Only lysine and 17 mini-peptides had significantly higher content in silkworm droppings than in mulberry leaves. There were 36 common target genes or the different compounds between mulberry leaves and silkworm droppings. The main pathways of mulberry leaf were enriched in antivirus and anticancer properties, while the pathways of silkworm droppings were enriched in hormone regulation and signal transduction.

Kaempferol Alleviates Steatosis and Inflammation During Early Non-Alcoholic Steatohepatitis Associated With Liver X Receptor α-Lysophosphatidylcholine Acyltransferase 3 Signaling Pathway

Background: Kaempferol (KP) has a variety of biological effects such as anti-inflammatory, anti-oxidant, anti-aging and cardiovascular protection. Whether KP has a therapeutic effect on non-alcoholic steatohepatitis (NASH), and the detailed mechanism is currently unclear. This study aims to explore the mechanism of KP in the treatment of NASH through in vivo and in vitro experiments.

Methods: 1) In vivo experiment: In the C57BL/6 NASH mice model induced by high fat diet (HFD), KP was administered by gavage at a dose of 20 mg/kg/day. 2) In vitro experiment: Palmitic acid/Oleic acid (PA/OA, 0.375/0.75 mM) was used to intervene HepG2 and AML12 cells to establish a steatosis cell model. Three concentrations of KP, low (20 μmol/L), medium (40 μmol/L) and high (60 μmol/L) were used in vitro. The mRNA and protein expression of related molecules involved in LXRα-LPCAT3-ERS pathway were detected using RT-qPCR and Western blot.

Results: In the NASH mouse model, KP can significantly reduce the expression of LXRα, LPCAT3 and ERS-related factors PERK, eIF2α, ATF6, ATF4, XBP1, CHOP, IRE1α and GRP78. In the PA/OA-induced cell model, KP could decrease the content of triglyceride and lipid droplets, and also decrease the expression of LXR α, LPCAT3 and ERS related factors PERK, eIF2α, ATF6, ATF4, XBP1, CHOP, IRE1α and GRP78.

Conclusion: KP may decrease the expression level of LXRα and LPCAT3, thus improve ERS and reduce hepatic steatosis and inflammation.

Food frequency questionnaire is a valid assessment tool of quercetin and kaempferol intake in Iranian breast cancer patients according to plasma biomarkers

In epidemiological and clinical studies, the most common nutritional tool to assess dietary flavonol intake is the food frequency questionnaire (FFQ), which needs to contain a detailed list of plant-based foods and be previously validated. Our study aimed to assess the accuracy of dietary flavonol (quercetin, kaempferol, and isorhamnetin) intake from a food frequency questionnaire (FFQ) compared to fasting plasma flavonol concentrations, as biomarkers of exposure, in breast cancer patients. In a consecutive case series, newly diagnosed patients with breast cancer (n = 140) were recruited at Nour-Nejat Hospital, Tabriz, Iran. Flavonol intake was assessed using a validated FFQ. Plasma flavonol concentrations were measured using high-performance liquid chromatography-ultraviolet detection. The accuracy of dietary status was evaluated using a receiver operating characteristic (ROC) and area under the ROC curve (AUC). Dietary status was shown in dichotomous using ROC-cutoff point. The plasma concentrations of quercetin were moderately correlated with dietary intake of quercetin (Spearman's correlation coefficient (r_s) = 0.188, P < .05; r_partial= 0.330, P < .01) and plasma concentrations of isorhamnetin (r_s = 0.337, P < .001). A linear correlation between dietary levels and plasma concentrations of kaempferol was attained (r_partial = 0.240, P < .05). Using a ROC-cutoff of 61.9 nmol/L for plasma quercetin (test reference), we were able to differentiate between lower and higher consumers of quercetin with an AUC_{ROC-based reference} =0.65 (P < .01, sensitivity = 61.8%, and specificity = 60.0%). Using a plasma kaempferol concentration of 60.1 nmol/L (ROC-cutoff), it was possible to detect significant differences between higher and lower intakes of kaempferol (AUC_{ROC-based reference} = 0.64, P < .05). The correlations and diagnostic performance with plasma concentrations could present a significant accuracy rate (validity), which seems acceptable for a nutritional questionnaire (FFQ) to assess intakes intake levels of quercetin and kaempferol. An improvement in the accuracy of the flavonol exposure can provide more precise relationship with health outcomes, which may increase their clinical significance.

A narrative review of clinical studies of herbal treatment of difficult to manage asthma

Asthma can be complex and difficult to manage. Patients often seek alternative treatment options, including Traditional Chinese Medicine (TCM). The paradigms that inform TCM treatments include a philosophy focusing on modifying the whole body status ('bian zheng') to treat the lungs. TCM practitioners use personalized treatment plans based on clusters of clinical patterns (eg. cold-related wheezing, kidney insufficiency/energy-deficiency-related wheezing). TCM includes herbal remedies and non-oral therapies such as cupping, acupuncture, and massage. The efficacy of TCM treatments of asthma is not well described as the majority of studies are published only in Chinese literature. We reviewed all available clinical trials in CNKI, Chaoxin, Wanfang, CQVIP, Springer-link, Science Direct, and Pubmed. Papers in Chinese were translated by dual lingual TCM and Western medicine doctors. Based on the identified studies, TCM is a safe additive treatment to Western medicine that can improve both symptoms and quality of life for patients with asthma.

Thesium chinense Turcz.: An ethnomedical, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Thesium chinense Turcz. has been used to treat mastitis, pulmonitis, tonsillitis, iaryngopharyngitis and upper respiratory tract infections in the indigenous medicine of China for a long history. Presently, several pharmaceutics prepared by this medical herb have been clinically used for the therapy of infectious diseases.

AIM OF THE REVIEW

This review aims to comprehensively summarize the current researches on the ethnomedical, phytochemical and pharmacological aspects of T. chinense, and discuss their possible opportunities for the future research.

MATERIALS AND METHODS

Extensive database searches, including Web of Science, SciFinder, Google Scholar and China Knowledge Resource Integrated, were performed using keywords such as 'Thesium chinense', 'Bai Rui Cao', and their chemical constituents. In addition, local classic herbal literature on ethnopharmacology and relevant textbooks were consulted to provide a comprehensive survey of this ethnomedicine.

RESULTS

Thirty four chemical constituents, including flavonoids, alkaloids, and terpenoids, have been identified from T. chinense. Of which, flavonoids are the predominant and characteristic constituents. The crude extracts, the purified constituents, and commercial available pharmaceutics have displayed diverse in vitro and in vivo pharmacological functions (e.g. anti-inflammation, antimicrobial activity, analgesic effect, hepaprotection), and are particularly useful as a potential therapeutic agent against inflammation-related diseases.

CONCLUSIONS

T. chinense is an important ethnomedical medicine and possesses a satisfying effect for treating inflammation, microbial infection, and upper respiratory diseases. It has received plenty of researches on its phytochemical and pharmacological aspects since 1970s. These findings definitely establish the link between chemical composition and pharmacological application, and support the ethnomedical use of T. chinense in the indigenous medicine of China. However, chemical composition of this plant and the molecular mechanisms of purified constituents have not been comprehensively investigated, and thus the trace constituents and the therapeutic targets of bioactive constituents deserve a further exploration. Collectively, the researchers should pay more attention to a better understanding and application of this ethnomedical plant.

Extensive Metabolite Profiling in the Unexploited Organs of Black Tiger for Their Potential Valorization in the Pharmaceutical Industry

Black tiger (Kadsura coccinea (Lem.)) has been reported to hold enormous pharmaceutical potential. The fruit and rhizome of black tiger are highly exploited in the pharmaceutical and other industries. However, the most important organs from the plant such as the leaf and stem are considered biowastes mainly because a comprehensive metabolite profile has not been reported in these organs. Knowledge of the metabolic landscape of the unexploited black tiger organs could help identify and isolate important compounds with pharmaceutical and nutritional values for a better valorization of the species. In this study, we used a widely targeted metabolomics approach to profile the metabolomes of the K. coccinea leaf (KL) and stem (KS) and compared them with the root (KR). We identified 642, 650 and 619 diverse metabolites in KL, KS and KR, respectively. A total of 555 metabolites were mutually detected among the three organs, indicating that the leaf and stem organs may also hold potential for medicinal, nutritional and industrial applications. Most of the differentially accumulated metabolites between organs were enriched in flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, arginine and proline metabolism, arginine biosynthesis, tyrosine metabolism and 2-oxocarboxylic acid metabolism pathways. In addition, several important organ-specific metabolites were detected in K. coccinea. In conclusion, we provide extensive metabolic information to stimulate black tiger leaf and stem valorization in human healthcare and food.

Phytochemical and Ethnopharmacological Perspectives of Ehretia laevis

Ehretia laevis Roxb. (Boraginaceae) has been extensively used as a traditional remedy for the treatment of a diverse range of ailments related to the respiratory system, the gastrointestinal tract, the reproductive system, and against several infections. This review critically assesses and documents, for the first time, the fragmented information on E. laevis, including its botanical description, folklore uses, bioactive phyto metabolites and pharmacological activities. The goal is to explore this plant therapeutically. Ethnomedicinal surveys reveal that E. laevis has been used by tribal communities in Asian countries for the treatment of various disorders. Quantitative and qualitative phytochemical investigations of E. laevis showed the presence of important phytoconstituents such as pentacyclic triterpenoids, phenolic acids, flavonoids, fatty acids, steroids, alkaloids, aliphatic alcohols, hydrocarbons, amino acids, carbohydrates, vitamins and minerals. Fresh plant parts, crude extracts, fractions and isolated compounds have been reported to exhibit broad spectrum of therapeutic activities viz., antioxidant, antiarthritic, antidiabetic, anti-inflammatory, antiulcer, antidiarrheal, antidysenteric, wound healing and anti-infective activities. E. laevis is shown to be an excellent potential source of drugs for the mitigation of jaundice, asthma, dysentery, ulcers, diarrhea, ringworm, eczema, diabetes, fissure, syphilis, cuts and wounds, inflammation, liver problems, venereal and infectious disorders. Although few investigations authenticated its traditional uses but employed uncharacterized crude extracts of the plant, the major concerns raised are reproducibility of therapeutic efficacy and safety of plant material. The outcomes of limited pharmacological screening and reported bioactive compounds of E. laevis suggest that there is an urgent need for in-depth pharmacological investigations of the plant.

Extraction and quantification of some valuable flavonoids from pinecone of Pinus brutia via Soxhlet and Supercritical CO2 extraction: a comparison study

In this study, the extraction of oil from pinecone of Pinus brutia was evaluated by supercritical CO₂ (Sc-CO₂) and Soxhlet extraction methods. The quercetin, rutin and kaempferol (QRK) contents of oil were analyzed one by one via HPLC. The rutin compound investigated in this study has the potential to be a drug against the COVID 19 virus. SEM and BET analysis were performed to observe the structural change and increase in surface area after Sc-CO₂ extraction. The operating conditions were investigated in the range of 35–65 °C temperatures, 140–220 bar of pressures, 0.30–1.00 mm of mean particle sizes, 3–7 l/min of CO₂ flow rates, 0–8% w/w co-solvent and 30–150 min extraction periods. When the results obtained by the Sc-CO₂ method were compared with the results of Soxhlet extraction method, the maximum recovery of total QRK was found 4.18% in co-solvent-free studies and 30.94% in co-solvent-added Sc-CO₂ studies. Sc-CO₂ extraction results of Q, R, and K were found as 14.75 ± 1.08 µg/g, 14.23 ± 1.27 µg/g, and 15.70 ± 1.13 µg/g pinecone, respectively. Soxhlet extraction results of Q, R, and K were found as 36.43 ± 2.26 μg/g, 57.19 ± 3.81 μg/g, and 50.80 ± 2.79 μg/g pinecone, respectively. The maximum amount of QRK was found as 44.68 ± 2.89 μg/g pinecone by Sc-CO₂ method via adding 8% ethanol by mass and as 144.42 ± 5.39 μg/g pinecone by Soxhlet method. According to the reference Soxhlet method efficiency, the Sc-CO₂ extraction recovery was found as 30.94%.

The polyphenol/saponin-rich Rhus tripartita extract has an apoptotic effect on THP-1 cells through the PI3K/AKT/mTOR signaling pathway

Background

Hyperactivation of mechanistic target of rapamycin (mTOR) signaling pathway is involved in the regulation of cellular growth, proliferation, and more in general, is a common phenomenon in most types of cancers. Thus, natural substances targeting this pathway can be of great therapeutic potential in supporting the treatment of tumor patients. Rhus tripartita (Ucria) Grande is a plant growing in desertic areas which is traditionally used for the treatment of several diseases in Tunisia. In the present work, the biochemical profile of the main compounds present in the plant leaf extract was determined and the anti-leukemic potential of the plant extracts against acute monocytic leukaemia (AML) THP-1 cells was investigated.

Methods

After HPLC identification of some phenolic compounds present in the plant extract and the quantification of saponin content, the cytotoxic effect of Rhus tripartita extracts on THP-1 cell culture was evaluated using the colorimetric MTT assay for cell viability. THP-1 cells were incubated with medium containing the relative IC₅₀ concentrations of total plant extract, saponin extract and some standard compounds (rutin (R); kaempferol (K); mixture of catechin, epicatechin, and epicatechin-gallate (CEEG); ellagic acid (EA). Finally, qRT-PCR and western blotting analysis were used to evaluate the effect of some flavonoids present in a crude extract of polyphenols and the total extract of saponins on cell survival and apoptosis.

Results

Analysis of expression level of some gene (PIK3CA, PTEN, AKT1, mTOR, EIF4E, RPS6KB1, and TSC1) involved in the mTOR pathway and the phosphorylation of S6 and AKT proteins allowed to observe that a total Rhus tripartita extract and some of the compounds found in the extract controls THP-1 cell proliferation and apoptosis via regulation of the PI3K-Akt-mTOR signaling pathway.

Conclusion

Rhus tripartita-induced inhibition of cell cycle and induction of apoptosis may involve the mTOR pathway. Therefore, Rhus tripartita extract may be a useful candidate as a natural anti-cancer drug to support the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03328-9.

Enhanced cytotoxicity and antioxidant capacity of kaempferol complexed with α-lactalbumin

As a dietary polyphenol, kaempferol exhibits numerous biological activities such as antioxidant and anticancer properties. However, its application is limited because of its poor solubility and low permeability. This work aims to investigate the interaction of kaempferol with α-lactalbumin. Multiple-spectroscopic techniques were used to prove the interaction between kaempferol and α-lactalbumin. UV-vis absorption spectra suggested that the conformation of α-lactalbumin could be changed via binding with kaempferol. The fluorescence quenching test showed that kaempferol significantly quenched the intrinsic fluorescence of α-lactalbumin. Circular dichroism spectroscopy showed that the percent helicity of α-lactalbumin secondary structure increased when combined with kaempferol. In addition, the α-lactalbumin-kaempferol complex showed stronger inhibition ability on the growth of HeLa cells compared with kaempferol alone. The complex also showed higher antioxidant capacity than kaempferol alone. Molecular docking provided three predicted binding sites of α-lactalbumin for kaempferol, as well as five predicted binding poses of kaempferol. The weak intermolecular interactions were the main forces to stabilize the α-lactalbumin-kaempferol complex. Besides, the binding stability between α-lactalbumin and kaempferol was explored by molecular dynamics simulation. In conclusion, this work provides a basis for the potential application of α-lactalbumin as a delivery carrier for kaempferol owing to its nontoxic and biocompatible properties.

Optimization of the Biosynthesis of B-Ring Ortho-Hydroxy Lated Flavonoids Using the 4-Hydroxyphenylacetate 3-Hydroxylase Complex (HpaBC) of Escherichia coli

Flavonoids are important plant metabolites that exhibit a wide range of physiological and pharmaceutical functions. Because of their wide biological activities, such as anti-inflammatory, antioxidant, antiaging and anticancer, they have been widely used in foods, nutraceutical and pharmaceuticals industries. Here, the hydroxylase complex HpaBC was selected for the efficient in vivo production of ortho-hydroxylated flavonoids. Several HpaBC expression vectors were constructed, and the corresponding products were successfully detected by feeding naringenin to vector-carrying strains. However, when HpaC was linked with an S-Tag on the C terminus, the enzyme activity was significantly affected. The optimal culture conditions were determined, including a substrate concentration of 80 mg·L⁻¹, an induction temperature of 28 °C, an M9 medium, and a substrate delay time of 6 h after IPTG induction. Finally, the efficiency of eriodictyol conversion from P2&3-carrying strains fed naringin was up to 57.67 ± 3.36%. The same strategy was used to produce catechin and caffeic acid, and the highest conversion efficiencies were 35.2 ± 3.14 and 32.93 ± 2.01%, respectively. In this paper, the catalytic activity of HpaBC on dihydrokaempferol and kaempferol was demonstrated for the first time. This study demonstrates a feasible method for efficiently synthesizing in vivo B-ring dihydroxylated flavonoids, such as catechins, flavanols, dihydroflavonols and flavonols, in a bacterial expression system.

Flavonoids from the Genus Euphorbia: Isolation, Structure, Pharmacological Activities and Structure-Activity Relationships

Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure-activity relationship of Euphorbia flavonoids for the period covering 2000-2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure-activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.

Interactions between Phosphatidylcholine and Kaempferol or Myristicin: Langmuir Monolayers and Microelectrophoretic Studies

Flavonoid compounds are known for their antibacterial, anti-inflammatory, and anticancer properties. Therefore, they can influence membrane properties that interest us, modifying both their structure and functions. We used kaempferol (K) and myricetin (M) as representatives of this group. We investigated the influence of the abovementioned compounds on model cell membranes' properties (i.e., Langmuir monolayers and liposomes). The basic research methods used in these studies were the Langmuir method with Brewster angle microscopy and microelectrophoresis. The π-A isotherms were registered for the pure components and mixtures of these compounds with phosphatidylcholine (PC) in appropriate volume ratios. Using mathematical equations, we established that kaempferol, myricetin, and the lipids formed complexes at 1:1 ratios. We derived the parameters characterizing the formed complexes, i.e., the surfaces occupied by the complexes and the stability constants of the formed complexes. Using the microelectrophoretic method, we determined the dependence of the lipid membranes' surface charge density as a function of the pH (in the range of 2 to 10) of the electrolyte solution. The presented results indicate that the PC membrane's modification with kaempferol or myricetin affected changes in the surface charge density and isoelectric point values.

Biologically Active Compounds in Stizolophus balsamita Inflorescences: Isolation, Phytochemical Characterization and Effects on the Skin Biophysical Parameters

Three germacranolides, as well as five flavonoids, natural steroid and simple phenolic compounds, were isolated from the inflorescence of Stizolophus balsamita growing in Iran. The paper presents active compounds found for the first time in the inflorescence of this species. The flavonoids, simple phenolic compounds and natural steroids have been isolated for the first time in the genus Stizolophus. The MTT assay was employed to study in vitro cytotoxic effects of the taxifolin against human fibroblasts. We also evaluate the possible biological properties/cosmetic effects of Stizolophus balsamita extract and taxifolin on the human skin. Sixty healthy Caucasian adult females with no dermatological diseases were investigated. We evaluate the effects of S. balsamita extract and taxifolin on skin hydration and transepidermal water loss (TEWL). It was revealed that S. balsamita extract might decrease TEWL level and fixed the barrier function of the epidermis. The presence of bioactive phytochemical constituents in S. balsamita inflorescences makes them a valuable and safe source for creating new cosmetics and medicines.

Green extraction techniques from fruit and vegetable waste to obtain bioactive compounds-A review

Food wastes imply significant greenhouse gas emissions, that increase the challenge of climate change and impact food security. According to FAO (2019), one of the main food wastes come from fruit and vegetables, representing 0.5 billion tons per year, of the 1.3 billion tons of total waste. The wastes obtained from fruit and vegetables have plenty of valuable components, known as bioactive compounds, with many properties that impact positively in human health. Some bioactive compounds hold antioxidant, anti-inflammatory, and anti-cancer properties and they have the capacity of modulating metabolic processes. Currently, the use of fruit and vegetable waste is studied to obtain bioactive compounds, through non-conventional techniques, also known as green extraction techniques. These extraction techniques report higher yields, reduce the use of solvents, employ less extraction time, and improve the efficiency of the process for obtaining bioactive compounds. Once extracted, these compounds can be used in the cosmetic, pharmaceutical, or food industry, the last one being focused on improving food quality.

The Use of Traditional Chinese Medicine in Relieving EGFR-TKI-Associated Diarrhea Based on Network Pharmacology and Data Mining

In this study, the role of traditional Chinese medicine (TCM) in relieving epidermal growth factor receptor-tyrosine kinase inhibitor- (EGFR-TKI-) associated diarrhea was discussed by network pharmacology and data mining. Prediction of drug targets by introducing the EGFR-TKI molecular structures into the SwissTargetPrediction platform and diarrhea-related targets in the DrugBank, GeneCards, DisGeNET, and OMIM databases were obtained. Compounds in the drug-disease target intersection were screened by absorption, distribution, metabolism, and excretion parameters and Lipinski's rule in Traditional Chinese Medicine Systems Pharmacology. TCM-containing compounds were selected, and information on the property, taste, and meridian tropism of these TCMs was summarized and analyzed. A target-compound-TCM network diagram was constructed, and core targets, compounds, and TCMs were selected. The core targets and components were docked by AutoDock Vina (Version 1.1.2) to explore the target combinations of related compounds and evaluate the docking activity of related targets and compounds. Twenty-three potential therapeutic TCM targets for the treatment of EGFR-TKI-related diarrhea were obtained. There were 339 compounds acting on potential therapeutic targets, involving a total of 402 TCMs. The results of molecular docking showed good binding between the core targets and compounds, and the binding between the core targets and compounds was similar to that of the core target and the recommended drug loperamide. TCMs have multitarget characteristics and are present in a variety of compounds used for relieving EGFR-TKI-associated diarrhea. Antitumor activity and the efficacy of alleviating diarrhea are the pharmacological basis of combining TCMs with EGFR-TKI in the treatment of non-small-cell lung cancer. The core targets, compounds, and TCMs can provide data to support experimental and clinical studies on the relief of EGFR-TKI-associated diarrhea in the future.

Reversed phase versus hydrophilic interaction liquid chromatography as first dimension of comprehensive two-dimensional liquid chromatography systems for the elucidation of the polyphenolic content of food and natural products

Comprehensive two-dimensional liquid chromatography is a well-established method for the unraveling of very complex real-world samples. With regard to food and natural products such a technique turned out to be a very promising approach due to its high resolving power and improved identification capability, especially in combination with mass spectrometry. In this context, polyphenols comprise a particular complex class of bioactive compounds, due to their nature and content in commonly consumed foodstuffs, making their analysis challenging. The present contribution shows an overview of the two commonly employed approaches used for polyphenol analysis, viz. RP-LC × RP-LC and HILIC × RP-LC. Furthermore, the latest implementations as well as limitations and future perspectives are critically reported.

LC-DAD-ESI-MS/MS analysis and cytotoxic and antiproliferative effects of chlorogenic acid derivative rich extract from Nerium oleander L. pink flowers

Nerium oleander L. is a widely used medicinal plant for pharmaceutical purposes. In this work, an extract of the pink flowers of this plant (FE) was characterized in terms of phenolic composition by LC-DAD-ESI-MS/MS and bioactivity, namely, antioxidant and antiproliferative effects. A total of 20 compounds from different classes, including derivatives of phenolic acids and flavonoid glycosylated derivatives, were identified in FE. Chlorogenic acid was the dominant phenolic compound in the extract (62.28 ± 1.74 μg mg^-1 of dry extract). The antioxidant activity was assessed by ORAC assay, and FE showed an ability to reduce peroxyl radicals (ORAC value of 791.26 μmol TEAC per g DE). Additionally, the FE inhibited the proliferation of a colorectal cancer cell line (HT29 cells, EC₅₀ = 11.72 ± 0.02 μg mL^-1) and showed no cytotoxicity to confluent Caco-2 cells, a model of human intestinal epithelium. These results provide new information about the phenolic composition of Nerium oleander pink flowers and the bioactivity of the extracts.

Kaempferol and Its Glycoside Derivatives as Modulators of Etoposide Activity in HL-60 Cells

Kaempferol is a polyphenol found in a variety of plants. Kaempferol exerts antitumor properties by affecting proliferation and apoptosis of cancer cells. We investigated whether kaempferol and its glycoside derivatives-kaempferol 3-O-[(6-O-E-caffeoyl)-β-D-glucopyranosyl-(1→2)]-β-D-galactopyranoside-7-O-β-D-glucuropyranoside (P2), kaempferol 3-O-[(6-O-E-p-coumaroyl)-β-D-glucopyranosyl-(1→2)]-β-D-galactopyranoside-7-O-β-D-glucuropyranoside (P5) and kaempferol 3-O-[(6-O-E-feruloyl)-β-D-glucopyranosyl-(1→2)]-β-D-galactopyranoside-7-O-β-D-glucuropyranoside (P7), isolated from aerial parts of Lens culinaris Medik.-affect the antitumor activity of etoposide in human promyelocytic leukemia (HL-60) cells. We analyzed the effect of kaempferol and its derivatives on cytotoxicity, DNA damage, apoptosis, cell cycle progression and free radicals induced by etoposide. We demonstrated that kaempferol increases the sensitivity of HL-60 cells to etoposide but does not affect apoptosis induced by this drug. Kaempferol also reduces the level of free radicals generated by etoposide. Unlike kaempferol, some of its derivatives reduce the apoptosis of HL-60 cells (P2 and P7) and increase the level of free radicals (P2 and P5) induced by etoposide. Our results indicate that kaempferol and its glycoside derivatives can modulate the activity of etoposide in HL-60 cells and affect its antitumor efficacy in this way. Kaempferol derivatives may have the opposite effect on the action of etoposide in HL-60 cells compared to kaempferol.

Dietary polyphenols suppress chronic inflammation by modulation of multiple inflammation-associated cell signaling pathways

The high failure rate of the reductionist approach to discover effective and safe drugs to treat chronic inflammatory diseases has led scientists to seek alternative ways. Recently, targeting cell signaling pathways has been utilized as an innovative approach to discover drug leads from natural products. Cell signaling mechanisms have been identified playing key role in diverse diseases by inducing proliferation, cell survival and apoptosis. Phytochemicals are known to be able to modulate the cellular and molecular networks which are associated to chronic diseases including cancer-associated inflammation. In this review, the roles of dietary polyphenols (apigenin, kaempferol, quercetin, curcumin, genistein, isoliquiritigenin, resveratrol and gallic acid) in modulating multiple inflammation-associated cell signaling networks are deliberated. Scientific databases on suppressive effects of the polyphenols on chronic inflammation via modulation of the pathways especially in the recent five years are gathered and critically analyzed. The polyphenols are able to modulate several inflammation-associated cell signaling pathways, namely nuclear factor-kappa β, mitogen activated protein kinases, Wnt/β-catenin and phosphatidylinositol 3-kinase and protein kinase B via selective actions on various components of the networks. The suppressive effects of the polyphenols on the multiple cell signaling pathways reveal their potential use in prevention and treatment of chronic inflammatory disorders. Understanding the mechanistic effects involved in modulation of the signaling pathways by the polyphenols is necessary for lead identification and development of future functional foods for prevention and treatment of chronic inflammatory diseases.

Rhodiola rosea L. Attenuates Cigarette Smoke and Lipopolysaccharide-Induced COPD in Rats via Inflammation Inhibition and Antioxidant and Antifibrosis Pathways

The root cause behind the development of chronic obstructive pulmonary disease (COPD) is cigarette smoke that induces the inflammation of the lung tissue and alveolar destruction. Long-term cigarette smoking can lead to deterioration in lung parenchymal function and cause structural changes in the lung, further resulting in pulmonary fibrosis. Rhodiola rosea L., a traditional medicinal perennial herb, is well known for its numerous pharmacological benefits, including anti-inflammation, antioxidant, antifatigue, antidepressive, and antifibrotic properties. Here, we evaluated the pharmacological effects and mechanisms of the Rhodiola rosea L. (RRL) macroporous resin extract on COPD caused by lipopolysaccharide (LPS) and cigarette smoke (CS) in rats. The RRL significantly improved the pathological structure of the lung tissue. Additionally, RRL decreased the infiltration of inflammatory cells and, subsequently, oxidative stress. Furthermore, the RNAseq assay indicated that RRL attenuated the CS and LPS-induced COPD via anti-inflammatory, antifibrotic, and antiapoptotic activities. Western blot analysis substantiated that the RRL resulted in upregulated levels of Nrf2 and HO-1 as well as downregulated levels of IκBα, NF-κB p65, α-SMA, and TGF-β1. Interestingly, the RRL could protect rats from CS and LPS-induced COPD by inhibiting the ERK1/2 and Smad3 signaling pathways and apoptosis. Thus, the RRL could attenuate CS and LPS-induced COPD through inflammation inhibition and antioxidant and antifibrosis pathways.

Ethnobotanical Research and Compilation of the Medicinal Uses in Spain and the Active Principles of Chiliadenus glutinosus (L.) Fourr. for the Scientific Validation of Its Therapeutic Properties

The species Chiliadenus glutinosus (L.) Fourr. has a large number of therapeutic uses reported in the traditional Spanish medicine. The growing interest in preserving the ethnopharmacological knowledge related to the botanical diversity existing in Spain and the interest in achieving scientific validation of the therapeutic properties of medicinal species has led to the development of this study. To do it, all the known medicinal uses of Ch. glutinosus in Spain were compiled, then an exhaustive bibliographic research on its chemical composition was carried out, and finally, an in silico validation of the bioactive phytochemicals present in a higher proportion in the essential oil of Ch. glutinosus: camphor, borneol, lucinone, glutinone, quercetin, kutdtriol, and kaempferol; in an attempt to justify the reported traditional uses of the species. It was found that much of the traditional medicinal uses of Ch. glutinosus, along with the biological activity of its phytochemicals, are supported by scientific evidence. The results place this species in a prominent position to initiate possible lines of research to develop new, more effective drugs and improve therapies to treat conditions and diseases that affect the different organic systems of the human being.

Chemical Composition of Tomato Seed Flours, and Their Radical Scavenging, Anti-Inflammatory and Gut Microbiota Modulating Properties

In the current study, the chemical composition and total phenolic content of tomato seed flours, along with potential health beneficial properties, including free radical scavenging capacities, anti-inflammatory capacities, and gut microbiota profile modulation, were examined using two different batches. Eight compounds were identified in the tomato seed flour, including malic acid, 2-hydroxyadipic acid, salicylic acid, naringin, N-acetyl-tryptophan, quercetin-di-O-hexoside, kaempferol-di-O-hexoside, and azelaic acid. The total phenolic contents of tomato seed flour were 1.97-2.00 mg gallic acid equivalents/g. Oxygen radical absorbing capacities (ORAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacities (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical scavenging capacities (ABTS) were 86.32-88.57, 3.57-3.81, and 3.39-3.58 µmoles Trolox equivalents/g, respectively, on a per flour dry weight basis. The mRNA expression of the pro-inflammatory markers, interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), were dose-dependently suppressed by tomato seed flour extracts. The extracts altered five of the eight bacterial phyla and genera evaluated. The results may provide some scientific support for the use of tomato seed flour as value-added food ingredients.

Therapeutic effect of kaempferol on atopic dermatitis by attenuation of T cell activity via interaction with multidrug resistance-associated protein 1

BACKGROUND AND PURPOSE

Kaempferol is a natural flavonoid widely investigated in various fields due to its antioxidant, anti-cancer, and anti-inflammatory activities, but few studies have shown its inhibitory effect on T cell activation. This study examined the therapeutic potential of kaempferol in atopic dermatitis by modulating T cell activation.

EXPERIMENTAL APPROACH

Effects of kaempferol on T cell activation and the underlying mechanisms were investigated in Jurkat cells and mouse CD4⁺ T cells. A model of atopic dermatitis in mice was used to determine its therapeutic potential on T cell-mediated conditions in vivo. Western blots, RT-PCR, pulldown assays and ELISA were used, along with histological analysis of skin.

KEY RESULTS

Pretreatment with kaempferol reduced CD69 expression and production of inflammatory cytokines including IL-2 from activated Jurkat cells and murine CD4⁺ T cells without cytotoxicity. Pulldown assays revealed that kaempferol physically binds to MRP-1 in T cells, inhibiting the action of MRP-1. In activated T cells, kaempferol suppressed JNK phosphorylation and the TAK1-IKKα mediated NF-κB pathway. Oral administration of kaempferol to mice showed improved manifestation of atopic dermatitis, a T cell-mediated condition. Western blot results showed that, as in the in vitro studies, decreased phosphorylation of JNK was associated with down-regulated MRP-1 activity in vivo, in the kaempferol-treated mice in the atopic dermatitis model.

CONCLUSION AND IMPLICATIONS

Kaempferol regulates T cell activation by inhibiting MRP-1 activity in activated T cells, thus showing protective effects against T cell mediated disease in vivo.

The Effects of Quercetin on the Apoptosis of Human Breast Cancer Cell Lines MCF-7 and MDA-MB-231: A Systematic Review

This systematic review was performed with a focus on the effects of quercetin (QT) on the human breast cancer cell lines MCF-7 and MDA-MB-231. PubMed, Scopus, Science Direct, and Google Scholar databases were searched up to May 2020 using relevant keywords. All articles written in English evaluating the effects of QT on the human breast cancer cell lines MCF-7 and/or MDA-MB-231 were eligible for the review. Totally, 31 articles were included in this review. Out of them, 23 studies investigated the effects of QT on MCF-7 cells and indicated that QT induces apoptosis in the cells. Of 15 studies that examined the effects of QT on MDA-MB-231 cells, 14 reports showed successful apoptosis. It is concluded that QT might be beneficial in the eliminating of breast cancer cells. However, further clinical trials are warranted to further verify these outcomes.

The important herbal pair for the treatment of COVID-19 and its possible mechanisms

BACKGROUND

Coronavirus Disease 2019 (COVID-19) is an unprecedented disaster for people around the world. Many studies have shown that traditional Chinese medicine (TCM) are effective in treating COVID-19. However, it is difficult to find the most effective combination herbal pair among numerous herbs, as well as identifying its potential mechanisms. Herbal pair is the main form of a combination of TCM herbs, which is widely used for the treatment of diseases. It can also help us to better understand the compatibility of TCM prescriptions, thus improving the curative effects. The purpose of this article is to explore the compatibility of TCM prescriptions and identify the most important herbal pair for the treatment of COVID-19, and then analyze the active components and potential mechanisms of this herbal pair.

METHODS

We first systematically sorted the TCM prescriptions recommended by the leading experts for treating COVID-19, and the specific herbs contained in these prescriptions across different stages of the disease. Next, the association rule approach was employed to examine the distribution and compatibility among these TCM prescriptions, and then identify the most important herbal pair. On this basis, we further investigated the active ingredients and potential targets in the selected herbal pair by a network pharmacology approach, and analyzed the potential mechanisms against COVID-19. Finally, the main active compounds in the herbal pair were selected for molecular docking with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) 3CLpro and angiotensin converting enzyme II (ACE2) for further verification.

RESULT

We obtained 32 association rules for the herbal combinations in the selection of TCM treatment for COVID-19. The results showed that the combination of Amygdalus Communis Vas (ACV) and Ephedra sinica Stapf (ESS) had the highest confidence degree and lift value, as well as high support degree, which can be used in almost all the stages of COVID-19, so ACV and ESS (AE) were selected as the most important herbal pair. There were 26 active ingredients and 44 potential targets, which might be related to the herbal pair of AE against COVID-19. The main active ingredients of AE against COVID-19 were quercetin, kaempferol, luteolin, while the potential targets were Interleukin 6 (IL-6), Mitogen-activated Protein Kinase 1 (MAPK)1, MAPK8, Interleukin-1β (IL-1β), and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) p65 subunit (RELA). The protein-protein interaction (PPI) cluster demonstrated that IL-6 was the seed in the cluster, which plays an important role in connecting other nodes in the PPI network. The potential pathways mainly involved tumor necrosis factor (TNF), Toll-like receptor (TLR), hypoxia-inducible factor-1 (HIF-1), and nucleotide-binding oligomerization domain (NOD)-like receptor (NLRs). The molecular docking results showed that the main active ingredients of AE have good affinity with SARS-COV-2 3CLpro and ACE2, which are consistent with the above analysis.

CONCLUSIONS

There were 32 association rules in the TCM prescriptions recommended by experts for COVID-19. The combination of ACV and EAS was the most important herbal pair for the treatment of COVID-19. AE might have therapeutic effects against COVID-19 by affecting the inflammatory and immune responses, cell apoptosis, hypoxia damage and other pathological processes through multiple components, targets and pathways.

Kaempferol exhibits a synergistic effect with doxorubicin to inhibit proliferation, migration, and invasion of liver cancer

Kaempferol (KF), a flavonoid compound isolated from herbal medicines, has been reported to play a significant role in inhibiting certain types of cancer. Although recent studies reported that KF exerted inhibitive activity on liver cancer, they failed to elucidate the signaling pathways and synergistic effects in combination with chemotherapeutic drugs currently in use in the clinical setting. In the present study, the signaling pathways and synergistic effects of KF in liver cancer cells were investigated. Nine liver cancer cell lines were used to assess the inhibitive activity and synergistic effects of KF. Cellular behavioral experiments, such as viability, colony formation, cell cycle arrest, apoptotic, wound healing, and Transwell assays were used to assess the effects of KF on the proliferation, apoptosis, migration, and invasion of liver cancer cells. Western blotting was performed to validate the key signaling pathway elements underlying those cellular behaviors. KF exhibited inhibitory effects on nine liver cancer cell lines in time- and dose-dependent manners and was mostly nontoxic to the normal hepatocyte cells. The combination of KF and doxorubicin revealed a stronger inhibitive effect on the viability of liver cancer cells. Combination therapy also revealed higher suppressive effects on colony formation, cell cycle progression, survival, DNA damage response, and mitochondrial function. By western blotting assay, mitochondrial and caspase signaling pathways were determined to be involved in proliferation inhibition. In wound healing and Transwell invasion assays, combination therapy also exhibited more robust inhibitory activity in blocking the migration and invasion of liver cancer cells. PI3K/mTOR/MMP protein pathways were also revealed to be related to cell migration inhibition. KF alone exhibited an inhibitory effect on proliferation, migration, and invasion of liver cancer cells, and its synergistic effects revealed stronger inhibitory activities. The present data indicated that KF is a promising candidate as a complementary medicine to conventional chemotherapeutic drugs.

Profiling beneficial phytochemicals in a potato somatic hybrid for tuber peels processing: phenolic acids and anthocyanins composition

The purpose of this study was to characterize the peels of a CN1 somatic hybrid obtained from two dihaploid potato lines (Cardinal H14 and Nicola H1) in terms of the health-promoting phenolic compounds (phenolic acids and anthocyanins). The CN1 hybrid is defined by a pink tuber skin color making it different from the light-yellow-skinned "Spunta," which is the most commonly grown potato cultivar in Tunisia. Oven-dried peel samples derived from CN1 hybrid and cv. Spunta were ground, and phenolic compounds were extracted with water or methanol for quantification. Lyophilized peels were used for the phenolic acid and anthocyanin analyses. Higher total quantities of phenolic compounds were recovered in methanol extracts compared with water extracts. A slightly higher concentration of phenolic acids (100 mg/100 g DW) was obtained in the lyophilized peels extract of CN1 hybrid than in the cv. Spunta corresponding sample (83 mg/100 g DW). The profiles of the chlorogenic acid isomers were almost identical in both of CN1 hybrid and cv. Spunta. Caffeic acid (CA) and three caffeoylquinic acids (CQAs): 3-CQA, 4-CQA, and 5-CQA, were identified from both genotypes, 5-CQA being the dominant form in both potatoes. Since the CN1 hybrid has a pink skin color, its anthocyanin profile was also determined. The anthocyanin quantity in the CN1 peels was 5.07 mg/100 g DW, involving six different anthocyanins that were identified within the extract, namely, Pelargonidin-3-rutinoside-5-glucoside, peonidin-3-rutinoside-5-glucoside, coumaroyl ester of pelargonidin-3-rutinoside-5-glucoside, coumaroyl ester of peonidin-3-rutinoside-5-glucoside, feruloyl ester of pelargonidin-3-rutinoside-5-glucoside, and feruloyl ester of peonidin-3-rutinoside-5-glucoside. These results suggest that the peel waste of CN1 somatic hybrid can be considered as a promising source of high-value compounds for food industry.

Kaempferol attenuates diabetic nephropathy in streptozotocin-induced diabetic rats by a hypoglycaemic effect and concomitant activation of the Nrf-2/Ho-1/antioxidants axis

This study examined the protective effect of Kaempferol against streptozotocin-induced diabetic nephropathy (DN) in rats and studies the underlying mechanisms. Rats were divided into 4 groups as control, control + Kaempferol, STZ, and STZ + Kaempferol. All treatments were conducted for 8 weeks daily after the induction of diabetes. Kaempferol prevented STZ-induced weight and food loss and attenuated renal damage and the alterations in all biochemical related parameters. Concomitantly, Kaempferol reduced renal levels of TNF-α and IL-6, cleaved caspase-3, p38, and Bax, suppressing JNK phosphorylation and NF-κB p65 transactivation, and upregulation of Bcl-2. In both control and STZ-diabetic rats, Kaempferol reduced fasting glucose levels, increased fasting insulin levels and HOMA-β, reduced the levels of ROS and MDA, stimulated SOD and GSH levels, and increased the expression of Nrf2 and HO-1. In conclusion, Kaempferol prevents STZ-induced diabetic nephropathy, mainly, by antioxidant potential, mediated by the upregulation of the Nrf-2/HO-1 axis.