Flavonoids: antioxidants or signalling molecules?

Chemical Profiling and Dose-Dependent Assessment of Fear Reducing and Memory-Enhancing Effects of Solanum virginianum in Rats

The current study was planned to investigate the pharmacological basis of Solanum virginianum extract (SV.CR) pertaining to anxiolytic, antidepressant and memory-enhancing effects in rats. The SV.CR was analyzed in-vitro for phytoconstituents, antioxidant potential and anticholinesterase activity. The rats treated in a dose-dependent manner (25, 50 and 100 mg/kg of SV.CR) were subjected to behavioral tests for anxiety, depression and memory judgment followed by biochemical studies. A notable dose-dependent anxiolytic potential of SV.CR was observed in elevated plus maze and open field tests (P < 0.05). The decreased immobility time of the treated rats in the forced swim test (P < 0.01) unveiled the plant’s potential to reduce depression. Moreover, SV.CR treatment also reversed scopolamine-impaired cognition (P < 0.05) in various deployed memory and learning tasks. Biochemical studies of brain homogenates of SV.CR treated animals demonstrated decreased anticholinesterase activity and lipid peroxidation levels whereas increased levels of superoxide dismutase and glutathione peroxidase (P < 0.05 vs scopolamine group) were noted. The scientific validation of the study supported the use of Solanum virginianum in reducing anxiety, depression and amnesia in experimental models. Phytoconstituents in SV.CR such as oleanolic acid and caffeic acid might have played a significant neuroprotective role via modulation of oxidative stress and neurochemical aspects.

Luteolin as a modulator of skin aging and inflammation

Luteolin belongs to the group of flavonoids and can be found in flowers, herbs, vegetables and spices. It plays an important role in defending plants, for example against UV radiation by partially absorbing UVA and UVB radiation. Thus, luteolin can also decrease adverse photobiological effects in the skin by acting as a first line of defense. Furthermore, anti-oxidative and anti-inflammatory activities of luteolin were described on keratinocytes and fibroblasts as well as on several immune cells (e.g., macrophages, mast cell, neutrophils, dendritic cells and T cells). Luteolin can suppress proinflammatory mediators (e.g., IL-1β, IL-6, IL-8, IL-17, IL-22, TNF-α and COX-2) and regulate various signaling pathway (e.g., the NF-κB, JAK-STAT as well as TLR signaling pathway). In this way, luteolin modulates many inflammatory processes of the skin. The present review summarizes the recent in vitro and in vivo research on luteolin in the field of skin aging and skin cancer, wound healing as well as inflammatory skin diseases, including psoriasis, contact dermatitis and atopic dermatitis. In conclusion, luteolin might be a promising molecule for the development of topic formulations and systemic agents against inflammatory skin diseases.

Herbal Medicine in the Treatment of Epilepsy

Epilepsy is one of the most common disorders of the central nervous system. Although epilepsy is common worldwide, approximately 80% of epileptic patients live in the developing countries or those with low-middle income. Up until the second decade of the 20th century, epilepsy was treated mostly by traditional remedies. Today, antiepileptic drugs are used as a general treatment instead to prevent and control epileptic seizures. However, patient access to these drugs is hindered due to the healthcare systems of their countries and a number of other reasons, such as cultural, socio-demographic, and financial poverty. In addition, approximately 30-40%of epileptic patients suffer from refractory epilepsy, additionally, AEDs have adverse side-effects that can lead to treatment failure or reduce the patient's quality of life. Despite recent advances in the treatment of epilepsy, there is still a need for improving medical treatment with a particular focus on efficacy, safety, and accessibility. Since herbal medicines have been used for many centuries around the world for treating epilepsy, it is, therefore, plausible that a rigorous study on herbal medicine and phytochemical components within plants of various species and origin may lead to the discovery of novel AEDs. Nowadays, many medicinal plants used in different cultures and regions of the world have been identified. Most phytochemical components of these plants have been identified and, in some cases, their targets located. Therefore, it is possible that new, effective, and accessible anticonvulsants drugs can be obtained from a medicinal plant.

Natural Polyphenols as Targeted Modulators in Colon Cancer: Molecular Mechanisms and Applications

Colon cancer commonly develops from long-term chronic inflammation in the intestine and seriously threatens human health. Natural polyphenols have been valued as a crucial regulator of nutrient metabolism and metabolic diseases, owing to their anti-inflammatory and antioxidant functions and the ability to maintain a balance between gut microbes and their hosts. Notably, experimental and clinical evidence has shown that natural polyphenols could act as a targeted modulator to play a key role in the prevention or treatment of colon cancer. Thus, in this review, we summarized recent advances in the possible regulatory mechanism and the potential application of natural polyphenols in colon cancer, which might be regarded as a novel platform for the colon cancer management.

Dietary Luteolin: A Narrative Review Focusing on Its Pharmacokinetic Properties and Effects on Glycolipid Metabolism

Luteolin, a flavone subclass of flavonoids, is commonly found in food plants and has multiple biological activities. Recently, evidence is growing with regard to the potential of luteolin intake to beneficially affect glycolipid metabolism disorders (GLMDs), particularly insulin resistance, diabetes, and obesity. The aim of this contribution is to provide an overview of recent advances in identifying and understanding the pharmacokinetic properties (absorption, metabolism, and bioavailability) of luteolin, its regulatory effects on glycolipid metabolism, and the underlying mechanisms of action of luteolin in the brain, liver, adipose tissues, and other tissues/organs. Collectively, luteolin or its principal metabolites may contribute to counteracting GLMDs, especially for human obesity and diabetes.

Oxidative Stress and Antioxidative Activity in Leaves and Roots of Carrot Plants Induced by Candidatus Phytoplasma Solani

The present study examined the effects of Candidatus Phytoplasma solani infection on antioxidative metabolism in leaves and roots of carrot (Daucus carota L.). Disease symptoms appeared at the end of June in the form of the chlorosis on some of the leaves, which became intensely red one week later, while the previously healthy leaves from the same branch becme chlorotic. A few days later, all leaves from the infected leaf branch were intensely red. Infected plants also had slower growth compared to the healthy ones with fewer leaf branches developed. The roots of infected plants were less developed, seared, or gummy with or without brown-colored root hair. The presence of the pathogen was detected by sequencing the 16S rRNA. National Center for Biotechnology Information (NCBI) BLAST analyses of the obtained sequence revealed 100% identity of tested strain with deposited Ca. Phytoplasma solani strains from various countries and hosts, all belonging to the “stolbur” group (16SrXII-A). Identity of 99.74% was found when the tested Serbian strain (MF503627) was compared with the reference stolbur strain STOL11 (AF248959). The oxidative damage of membranes in carrot cells was accompanied by a decrease in the content of photosynthetic pigments. Furthermore, for the determination of specific scavenging properties of the extracts, in vitro antioxidant assay was performed. In phytoplasma-infected carrot leaves, there was a greater reduction in the level of glutathione content (GSH); however; flavonoids and anthocyanidins seem to be responsible for the accompanied increased antioxidative capacity against hydroxyl radical and hydrogen peroxide.

Flavonoids as an Intervention for Alzheimer's Disease: Progress and Hurdles Towards Defining a Mechanism of Action

Attempts to develop a disease modifying intervention for Alzheimer's disease (AD) through targeting amyloid β (Aβ) have so far been unsuccessful. There is, therefore, a need for novel therapeutics against alternative targets coupled with approaches which may be suitable for early and sustained use likely required for AD prevention. Numerous in vitro and in vivo studies have shown that flavonoids can act within processes and pathways relevant to AD, such as Aβ and tau pathology, increases in BDNF, inflammation, oxidative stress and neurogenesis. However, the therapeutic development of flavonoids has been hindered by an ongoing lack of clear mechanistic data that fully takes into consideration metabolism and bioavailability of flavonoids in vivo. With a focus on studies that incorporate these considerations into their experimental design, this review will evaluate the evidence for developing specific flavonoids as therapeutics for AD. Given the current lack of success of anti-Aβ targeting therapeutics, particular attention will be given to flavonoid-mediated regulation of tau phosphorylation and aggregation, where there is a comparable lack of study. Reflecting on this evidence, the obstacles that prevent therapeutic development of flavonoids will be examined. Finally, the significance of recent advances in flavonoid metabolomics, modifications and influence of the microbiome on the therapeutic capacity of flavonoids in AD are explored. By highlighting the potential of flavonoids to target multiple aspects of AD pathology, as well as considering the hurdles, this review aims to promote the efficient and effective identification of flavonoid-based approaches that have potential as therapeutic interventions for AD.

Antioxidant vs. Prooxidant Properties of the Flavonoid, Kaempferol, in the Presence of Cu(II) Ions: A ROS-Scavenging Activity, Fenton Reaction and DNA Damage Study

Kaempferol is a flavonoid that occurs in tea and in many vegetables and fruits, including broccoli, cabbage, beans, grapes, apples, and strawberries. The efficacy of Kaempferol has been demonstrated in the treatment of breast, esophageal, cervical, ovarian, and liver cancers and leukemia, which very likely arises from its prooxidant properties and the activation of pro-apoptotic pathways. Indeed, this matter has already been the focus of a number of published studies and reviews. The aim of the present study was to elucidate the antioxidant vs. prooxidant properties of flavonoids in the presence of the redox-active metal, copper (II) ion, by means of the Fenton reaction. The specific motivation of this work is that, since an increased level of Cu(II) ions is known to be associated with many disease states such as neurological conditions (Alzheimer’s disease) and cancer, any interaction between these ions and flavonoids might affect the outcome of therapeutic uses of the latter. The structure of the Cu-kaempferol complex in DMSO was investigated by means of low temperature EPR spectroscopy, which confirmed the existence of at least two distinct coordination environments around the copper (II) ion. UV vis-spectra of kaempferol and its Cu(II) complex in DMSO revealed an interaction between the 5-OH (A ring) group and the 4-CO (C ring) group of kaempferol with Cu(II) ions. An ABTS assay confirmed that kaempferol acted as an effective radical scavenger, and that this effect was further enhanced in the form of the Cu(II)-kaempferol complex. Quantitative EPR spin trapping experiments, using DMPO as the spin trap, confirmed suppression of the formation of a mixture of hydroxyl, superoxide, and methyl radicals, in a Fenton reaction system, upon coordination of kaempferol to the redox-active Cu(II) ions, by 80% with respect to the free Cu(II) ions. A viscometric study revealed a better DNA-intercalating ability of the Cu-kaempferol complex than for free kaempferol, essential for conferring anticancer activity of these substances. The results of the viscometric measurements were compared with those from a DNA damage study of Cu-kaempferol complexes in a Fenton reaction system, using gel electrophoresis. At low concentrations of kaempferol (Cu–kaempferol ratios of 1:1 and 1:2), a very weak protective effect on DNA was noted, whereas when kaempferol was present in excess, a significant DNA-protective effect was found. This can be explained if the weakly intercalated kaempferol molecules present at the surface of DNA provide protection against attack by ROS that originate from the Fenton reaction involving intercalated Cu(II)-kaempferol complexes. Following the application of ROS scavengers, L-histidine, DMSO, and SOD, gel electrophoresis confirmed the formation of singlet oxygen, hydroxyl radicals, and superoxide radical anions, respectively. We propose that the prooxidant properties of Cu-kaempferol complexes may provide anticancer activity of these substances. When present in excess, kaempferol displays antioxidant properties under Cu-Fenton conditions. This suggests that kaempferol might prove a suitable candidate for the prevention or treatment of oxidative stress related medical conditions that involve a disturbed metabolism of redox metals such as copper, for example, Menkes disease, and neurological disorders, including Alzheimer’s disease. For the potential use of kaempferol in clinical practice, it will be necessary to optimize the dose size and critical age of the patient so that this flavonoid may be beneficial as a preventive drug against cancer and neurological disorders.

Genetic modification of the flavonoid pathway alters growth and reveals flexible responses to enhanced UVB - Role of foliar condensed tannins

Accumulation of certain phenolics is a well-known response of plants to enhanced UVB radiation (280-315 nm), but few experiments have compared the relative importance of different phenolic groups for UVB resilience. To study how an altered phenolic profile affects the responses and resilience of silver birch (Betula pendula) to enhanced UVB, we used RNA interference (RNAi) targeting dihydroflavonol reductase (DFR), anthocyanidin synthase (ANS), or anthocyanidin reductase (ANR) to change the accumulation of phenolics. The unmodified control line and RNAi-modified plants were grown for 51 days under ambient or +32% enhanced UVB dose in a greenhouse. RNAi greatly affected phenolic profile and plant growth. There were no interactive effects of RNAi and UVB on growth or photosynthesis, which indicates that the RNAi and unmodified control plants were equally resilient. UVB enhancement led to an accumulation of foliar flavonoids and condensed tannins, and an increase in the density of stem glands and glandular trichomes on upper leaf surfaces in both the control and RNAi-modified plants. Our results do not indicate a photoprotective role for condensed tannins. However, decreased growth of high-flavonoid low-tannin DFRi and ANRi plants implies that the balance of flavonoids and condensed tannins might be important for normal plant growth.

Investigation of Selected Flavonoid Derivatives as Potent FLT3 Inhibitors for the Potential Treatment of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive disease with a poor prognosis and a high degree of relapse seen in patients. Overexpression of FMS-like tyrosine kinase 3 (FLT3) is associated with up to 70% of AML patients. Wild-type FLT3 induces proliferation and inhibits apoptosis in AML cells, while uncontrolled proliferation of FLT3 kinase activity is also associated with FLT3 mutations. Therefore, inhibiting FLT3 activity is a promising AML therapy. Flavonoids are a group of phytochemicals that can target protein kinases, suggesting their potential antitumor activities. In this study, several plant-derived flavonoids have been identified with FLT3 inhibitory activity. Among these compounds, compound 40 (5,7,4'-trihydroxy-6-methoxyflavone) exhibited the most potent inhibition against not only FLT3 (IC₅₀ = 0.44 μM) but also FLT3-D835Y and FLT3-ITD mutants (IC₅₀ = 0.23 and 0.39 μM, respectively). The critical interactions between the FLT3 binding site and the compounds were identified by performing a structure-activity relationship analysis. Furthermore, the results of cellular assays revealed that compounds 28, 31, 32, and 40 exhibited significant cytotoxicity against two human AML cell lines (MOLM-13 and MV-4-11), and compounds 31, 32, and 40 resulted in cell apoptosis and G0/G1 cell cycle arrest. Collectively, these flavonoids have the potential to be further optimized as FLT3 inhibitors and provide valuable chemical information for the development of new AML drugs.

Protective Effect of Mitochondria-Targeted Antioxidants against Inflammatory Response to Lipopolysaccharide Challenge: A Review

Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is the most abundant proinflammatory agent. Considerable evidence indicates that LPS challenge inescapably causes oxidative stress and mitochondrial dysfunction, leading to cell and tissue damage. Increased mitochondrial reactive oxygen species (mtROS) generation triggered by LPS is known to play a key role in the progression of the inflammatory response. mtROS at excessive levels impair electron transport chain functioning, reduce the mitochondrial membrane potential, and initiate lipid peroxidation and oxidative damage of mitochondrial proteins and mtDNA. Over the past 20 years, a large number of mitochondria-targeted antioxidants (mito-AOX) of different structures that can accumulate inside mitochondria and scavenge free radicals have been synthesized. Their protective role based on the prevention of oxidative stress and the restoration of mitochondrial function has been demonstrated in a variety of common diseases and pathological states. This paper reviews the current data on the beneficial application of different mito-AOX in animal endotoxemia models, in either in vivo or in vitro experiments. The results presented in our review demonstrate the promising potential of approaches based on mito-AOX in the development of new treatment strategies against Gram-negative infections and LPS per se.

Coffee Intake Interacted with the Bcl-2 rs1944420, rs7236090, and rs2849382 Haplotype to Influence Breast Cancer Risk in Middle-Aged Women

We hypothesized that the haplotype of Bcl-2 genetic variants increases breast cancer risk and interacts with lifestyles in Korean women. We identified single nucleotide polymorphism (SNPs) of Bcl-2 associated with breast cancer risk after adjusting for covariates in 390 breast cancer patients and 36,726 women without any cancer that participated in the Korean Genomic Epidemiology Study (KoGES). An allelic genetic model showed that three SNPs (rs1944420, rs7236090, and rs2849382) in the Bcl-2 gene were significantly associated with breast cancer (ORs = 1.28, 0.84, and 0.79, respectively). The participants with the minor allele of the haplotype with three SNPs had 1.65-fold higher breast cancer risk than those with the major allele, after adjusting for covariates. Serum C-reactive protein concentration had a positive association with breast cancer risk. A significant interaction was also observed between the minor allele of the Bcl-2 haplotype and coffee intake (P = 0.03). A low coffee intake in women with the minor allele presented a higher breast cancer risk than a low coffee intake in those with the major allele. In conclusion, the risk of breast cancer risk was higher in post-menopausal women with the minor allele of the Bcl-2 haplotype, and consuming more than 1 cup of coffee per day reduced the risk. The results of this study could be applied to reduce the risk of breast cancer.

Bioactive Molecules from the Alpinia Genus: A Comprehensive Review

BACKGROUND

Floral has diversity and unique nature due to the complex structure and component. Alpinia is an important genus of the Zingiberaceae family having complex taxonomical diversity. The presence of many unique bioactive molecules makes this genus, a pharmaceutically important genus. They provide a wide range of medicinal properties, including traditional remedies to modern therapeutic applications.

METHODS

Extracts of Alpinia mostly contain bioactive molecules and secondary metabolites such as polyphenolics, tannins, flavonoids and other therapeutically important compounds. These bioactive molecules are biologically active, treating against inflammation, cancer, arterial hypertension, and other deadly diseases.

RESULTS

These bioactive molecules can act as natural enzyme inhibitors for some of the deadly diseases and can block the pathway for metabolic activities. In addition, these genera have played a major role in multidisciplinary studies of phytochemistry, ethnobotany, and pharmacological aspects in day-to-day life.

CONCLUSION

Therefore, this review highlights the fewer known facts of the genus Alpinia in terms of bioactive molecules and its significant therapeutic applications to help in combating major diseases of humans.

Flavonoids: Nutraceuticals for Rheumatic Diseases via Targeting of Inflammasome Activation

Inflammation, an innate immune response that prevents cellular damage caused by pathogens, consists of two successive mechanisms, namely priming and triggering. While priming is an inflammation-preparation step, triggering is an inflammation-activation step, and the central feature of triggering is the activation of inflammasomes and intracellular inflammatory protein complexes. Flavonoids are natural phenolic compounds predominantly present in plants, fruits, and vegetables and are known to possess strong anti-inflammatory activities. The anti-inflammatory activity of flavonoids has long been demonstrated, with the main focus on the priming mechanisms, while increasing numbers of recent studies have redirected the research focus on the triggering step, and studies have reported that flavonoids inhibit inflammatory responses and diseases by targeting inflammasome activation. Rheumatic diseases are systemic inflammatory and autoimmune diseases that primarily affect joints and connective tissues, and they are associated with numerous deleterious effects. Here, we discuss the emerging literature on the ameliorative role of flavonoids targeting inflammasome activation in inflammatory rheumatic diseases.

Combined effect of Bacillus fortis IAGS 223 and zinc oxide nanoparticles to alleviate cadmium phytotoxicity in Cucumis melo

Cadmium (Cd), prevailing in most of the agricultural lands of the world contaminates food chain, thereby causing several health implications. It has become the main heavy metal contaminant in most of the agricultural lands of Pakistan due to the widespread use of phosphate fertilizers besides application of irrigation water contaminated with industrial and mining effluents. Plant growth promoting bacteria (PGPB) are capable to enhance growth and metal stress tolerance in supplemented plants. Zinc oxide nanoparticles (ZnO-NPs) are capable to alleviate various abiotic stresses when applied to plants. During current research, the efficacy of single and combined application of Bacillus fortis IAGS 223 and ZnO-NPs was evaluated for alleviation of Cd (75 mg kg^-1) induced phytotoxicity in Cucumis melo plants. For this purpose, C. melo plants, subjected to Cd stress were treated with B. fortis IAGS 223 and ZnO-NPs (20 mg kg^-1), either alone or in combination. The growth relevant characteristics including photosynthetic pigments, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and activities of antioxidative enzymes as well as Zn and Cd contents in treated plants were examined. The individual application of ZnO-NPs and B. fortis IAGS 223 slightly enhanced all the above-mentioned growth characteristics in plants under Cd stress. However, the combined application of ZnO-NPs and B. fortis IAGS-223 considerably modulated the activity of antioxidant enzymes besides upgradation of the biochemicals and growth parameters of Cd stressed plants. The decreased amount of stress markers such as H₂O₂, and MDA in addition with reduction of Cd contents was observed in shoots of ZnO-NPs and B. fortis IAGS-223 applied plants. B. fortis IAGS-223 inoculated plants supplemented with ZnO-NPs, exhibited reduced amount of Cd as well as protein bound thiols and non-protein bound thiols under Cd stress. Subsequently, the reduced Cd uptake improved growth of ZnO-NPs and B. fortis IAGS-223 applied plants. Henceforth, field trials may be performed to formulate appropriate combination of ZnO-NPs and B. fortis IAGS-223 to acquire sustainable crop production under Cd stress.

Luteolin delays photoreceptor degeneration in a mouse model of retinitis pigmentosa

Luteolin is neuroprotective for retinal ganglion cells and retinal pigment epithelial cells after oxidative injury, whereby it can inhibit microglial neurotoxicity. Therefore, luteolin holds the potential to be useful for treatment of retinal diseases. The purpose of this study was to investigate whether luteolin exhibits neuroprotective effects on rod cells in rd10 mice, a slow photoreceptor-degenerative model of retinitis pigmentosa. Luteolin (100 mg/kg) intraperitoneally injected daily from postnatal day 14 (P14) to P25 significantly enhanced the visual performance and retinal light responses of rd10 mice at P25. Moreover, it increased the survival of photoreceptors and improved retinal structure. Mechanistically, luteolin treatment attenuated increases in reactive oxygen species, photoreceptor apoptosis, and reactive gliosis; increased mRNA levels of anti-inflammatory cytokines while lowering that of pro-inflammatory and chemoattractant cytokines; and lowered the ratio of phospho-JNK/JNK. Application of the JNK inhibitor SP600125 exerted a similar protective effect to luteolin, suggesting that luteolin delays photoreceptor degeneration and functional deterioration in rd10 mice through regulation of retinal oxidation and inflammation by inhibiting the JNK pathway. Therefore, luteolin may be useful as a supplementary treatment for retinitis pigmentosa. This study was approved by the Qualified Ethics Committee of Jinan University, China (approval No. IACUC-20181217-02) on December 17, 2018.

Measurement of Environmentally Influenced Variations in Anthocyanin Accumulations in Brassica rapa subsp. Chinensis (Bok Choy) Using Hyperspectral Imaging

Dietary supplements of anthocyanin-rich vegetables have been known to increase potential health benefits for humans. The optimization of environmental conditions to increase the level of anthocyanin accumulations in vegetables during the cultivation periods is particularly important in terms of the improvement of agricultural values in the indoor farm using artificial light and climate controlling systems. This study reports on the measurement of variations in anthocyanin accumulations in leaf tissues of four different cultivars in Brassica rapa var. chinensis (bok choy) grown under the different environmental conditions of the indoor farm using hyperspectral imaging. Anthocyanin accumulations estimated by hyperspectral imaging were compared with the measured anthocyanin accumulation obtained by destructive analysis. Between hyperspectral imaging and destructive analysis values, no significant differences in anthocyanin accumulation were observed across four bok choy cultivars grown under the anthocyanin stimulation environmental condition, whereas the estimated anthocyanin accumulations displayed cultivar-dependent significant differences, suggesting that hyperspectral imaging can be employed to measure variations in anthocyanin accumulations of different bok choy cultivars. Increased accumulation of anthocyanin under the stimulation condition for anthocyanin accumulation was observed in "purple magic" and "red stem" by both hyperspectral imaging and destructive analysis. In the different growth stages, no significant differences in anthocyanin accumulation were found in each cultivar by both hyperspectral imaging and destructive analysis. These results suggest that hyperspectral imaging can provide comparable analytic capability with destructive analysis to measure variations in anthocyanin accumulation that occurred under the different light and temperature conditions of the indoor farm. Leaf image analysis measuring the percentage of purple color area in the total leaf area displayed successful classification of anthocyanin accumulation in four bok choy cultivars in comparison to hyperspectral imaging and destructive analysis, but it also showed limitation to reflect the level of color saturation caused by anthocyanin accumulation under different environmental conditions in "red stem," "white stem," and "green stem." Finally, our hyperspectral imaging system was modified to be applied onto the high-throughput plant phenotyping system, and its test to analyze the variation of anthocyanin accumulation in four cultivars showed comparable results with the result of the destructive analysis.

Novel Phospholipid-Based Labrasol Nanomicelles Loaded Flavonoids for Oral Delivery with Enhanced Penetration and Anti-Brain Tumor Efficiency

BACKGROUND

Owing to the rich anticancer properties of flavonoids, there is a need for their incorporation into drug delivery vehicles like nanomicelles for safe delivery of the drug into the brain tumor microenvironment.

OBJECTIVE

This study, therefore, aimed to prepare the phospholipid-based Labrasol/Pluronic F68 modified nano micelles loaded with flavonoids (Nano-flavonoids) for the delivery of the drug to the target brain tumor.

METHODS

Myricetin, quercetin and fisetin were selected as the initial drugs to evaluate the biodistribution and acute toxicity of the drug delivery vehicles in rats with implanted C6 glioma tumors after oral administration, while the uptake, retention, release in human intestinal Caco-2 cells and the effect on the brain endothelial barrier were investigated in Human Brain Microvascular Endothelial Cells (HBMECs).

RESULTS

The results demonstrated that nano-flavonoids loaded with myricetin showed more evenly distributed targeting tissues and enhanced anti-tumor efficiency in vivo without significant cytotoxicity to Caco-2 cells and alteration in the Trans Epithelial Electric Resistance (TEER). There was no pathological evidence of renal, hepatic or other organs dysfunction after the administration of nanoflavonoids, which showed no significant influence on cytotoxicity to Caco-2 cells.

CONCLUSION

In conclusion, Labrasol/F68-NMs loaded with MYR and quercetin could enhance antiglioma effect in vitro and in vivo, which may be better tools for medical therapy, while the pharmacokinetics and pharmacodynamics of nano-flavonoids may ensure optimal therapeutic benefits.

Antioxidant and Biological Activities of Hydroxytyrosol and Homovanillic Alcohol Obtained from Olive Mill Wastewaters of Extra-Virgin Olive Oil Production

Some constituents of the Mediterranean diet, such as extra-virgin olive oil (EVOO) contain substances such as hydroxytyrosol (HT) and its metabolite homovanillic alcohol (HA). HT has aroused much interest due to its antioxidant activity as a radical scavenger, whereas only a few studies have been made on the HA molecule. Both chemical synthesis and extraction techniques have been developed to obtain these molecules, with each method having its advantages and drawbacks. In this study, we report the use of tyrosol from olive mill wastewaters as a starting molecule to synthesize HT and HA, using a sustainable procedure characterized by high efficiency and low cost. The effects of HT and HA were evaluated on two cell lines, THP-1 human leukemic monocytes and L-6 myoblasts from rat skeletal muscle, after treating the cells with a radical generator. Both HT and HA efficiently inhibited ROS production. In particular, HT inhibited the proliferation of the THP-1 leukemic monocytes, while HA protected L-6 myoblasts from cytotoxicity.

Antihyperglycemic activity of crude extract and isolation of phenolic compounds with antioxidant activity from Moringa oleifera Lam. leaves grown in Southern Brazil

The antihyperglicemic activity of crude extract from Moringa oleifera leaves and isolation of phenolic compounds with antioxidant activity using bioguided assay were employed by the first time in leaves cultivated in Brazil. The hydroalcoholic extract (HE) was produced by using ethanol:water (80:20 v/v) and purified by solid-liquid procedure using solvents in ascending order of polarity. The ethyl acetate fraction (Fr-EtOAc) presented high antioxidant potential and it was purified using chromatographic techniques rendering isolated compounds that were identified from the spectral data. The HE extract (500 mg kg^-1) was adimistrated in diabetic rats induced by streptozotocin and chemical markers and lipid peroxidation in liver and kidney were evaluated. The Fr-EtOAc showed high antioxidant potential by FRAP reduction method (1678 µmol Fe²⁺ g^-1), DPPH and ABTS scavenging methods (526.7 and 671.5 µmol TEAC g^-1 respectively) and ORAC assay (3560.6 µmol TEAC g^-1). Therefore, the Fr-EtOAc was purified and yielded three bioactive subfractions (S-12, S-13 abd S-15) that were rechromatoghaphed in HPLC-SemiPrep. After that, two main bioactive glycosylated flavonoids (isoquercitrin and astragalin) and phenolic acid (3-O-caffeoylquinic acid) were obtained. Additionally, the HE extract provided protection against oxidative damage in liver and kidney of diabetic rats ameliorating endogenous antioxidant defenses by increase catalase (CAT), glutathione S-transferase (GST) and non-protein thiol groups (NPSH) levels as well as decreased the lipid peroxidation in these tissues. Our results indicate that three phenolic compounds with high antioxidant activity were isolated and, the chemical composition of HE crude extract, rich in flavonoids glycosylated could be intimately related to antihyperglycemic action. So, it is possible to suggest that these compounds may be used as chemical biomarkers for this plant in Brazil, ensuring quality and supporting the use of aerial parts in tradicional medicine.

The Microbiota-Gut-Brain Axis and Alzheimer's Disease: Neuroinflammation Is to Blame?

For years, it has been reported that Alzheimer’s disease (AD) is the most common cause of dementia. Various external and internal factors may contribute to the early onset of AD. This review highlights a contribution of the disturbances in the microbiota–gut–brain (MGB) axis to the development of AD. Alteration in the gut microbiota composition is determined by increase in the permeability of the gut barrier and immune cell activation, leading to impairment in the blood–brain barrier function that promotes neuroinflammation, neuronal loss, neural injury, and ultimately AD. Numerous studies have shown that the gut microbiota plays a crucial role in brain function and changes in the behavior of individuals and the formation of bacterial amyloids. Lipopolysaccharides and bacterial amyloids synthesized by the gut microbiota can trigger the immune cells residing in the brain and can activate the immune response leading to neuroinflammation. Growing experimental and clinical data indicate the prominent role of gut dysbiosis and microbiota–host interactions in AD. Modulation of the gut microbiota with antibiotics or probiotic supplementation may create new preventive and therapeutic options in AD. Accumulating evidences affirm that research on MGB involvement in AD is necessary for new treatment targets and therapies for AD.

Naringenin Prevents Propofol Induced Neurodegeneration in Neonatal Mice Brain and Long-Term Neurocognitive Impacts on Adults

Background

Natural products have shown neuroprotective effects in neurodegenerative conditions. Naringenin is a natural flavonoid with various pharmacological activities especially antioxidant, anti-inflammatory and neuroprotective properties. We investigated the effects of naringenin on anesthetic propofol-induced impacts on neonatal mouse brain development and consequent long-term neurocognitive impacts during adulthood.

Materials and Methods

Female C57Bl/6 and male CD-1 mice and postnatal day 7 (P7) pups were exposed to propofol (2.5 mg/kg) and propofol with naringenin (50 mg/kg). Mice pups were allowed to grow until week 10 (adulthood), and memory and learning were assessed.

Results

Propofol caused neurodegeneration by inducing apoptosis in the neonatal mouse brains while naringenin administration prevented neuronal cell loss by preventing neuronal apoptosis in neonatal mouse brains. Propofol caused degenerative alterations in metabolic factors pH, PO₂, glucose and lactate, which were subsequently restored by naringenin treatment. Propofol-exposed mice, when developed into adults, showed long-term neuronal deficits, impaired neurocognitive functions, and memory and learning restrictions.

Conclusion

Administration of naringenin to propofol-exposed mice resulted in significant neuroprotective effects by restoring long-term neurocognitive functions. The molecular mechanism behind the effects of naringenin was mediated by suppressing apoptosis and preventing cellular inflammation. These findings suggest that propofol administration requires careful consideration and that naringenin may prevent neurodegeneration and neurocognitive functions.

An exploratory analysis on the toxicity & safety profile of Polyherbal combination of curcumin, quercetin and rutin

Background

Curcumin, quercetin and rutin are flavonoids having strong antioxidant potential, individually used in treatment of numerous ailments. The safety assessment of each of them is already established but no toxicological assessment has been done that would guarantee the safe use of these three flavonoids when used as a polyherbal combination (PHC). The aim of this study to evaluate the possible toxicological effect of polyherbal combination of these three flavonoids in female Swiss albino mice.

Methods

In acute toxicity study, the oral dose of poly herbal combination was administered to four groups stepwise in single dose and general behaviour, adverse effects and mortality were determined up to 14 days and compared to normal group. In sub-acute study, the tested poly herbal combination was administered orally for 28 days to the four experimental groups and their body weight was measured each alternate day from the first day of dosing. On 29th day the final body weight was recorded and euthanized by using thiopentone sodium, blood was collected and later haematological, lipid profile, biochemical parameter was evaluated and compared to normal group.

Result

In acute toxicity study, no abnormal general behaviour, adverse effects were reported. No significant changes were reported in body weight, haematological, lipid profile, biochemical parameter in sub-acute toxicity study. No mortality was reported in both the study. Histopathological examination revealed no alterations in clinical signs or organ weight at any dose.

Conclusion

The result concludes that the oral administration of Polyherbal combination did not produce any significant toxic effect in swiss albino mice. Hence, the Polyherbal combination can be utilized safely for therapeutic use.

Beneficial effects of olive oil and Mediterranean diet on cancer physio-pathology and incidence

Virgin olive oil is a characteristic component and the main source of fat of the Mediterranean diet. It is a mix of high-value health compounds, including monounsaturated fatty acids (mainly oleic acid), simple phenols (such as hydroxytyrosol and tyrosol), secoiridoids (such as oleuropein, oleocanthal), flavonoids, and terpenoids (such as squalene). Olive oil consumption has been shown to improve different aspects of human health and has been associated with a lower risk of cancer. However, the underlying cellular mechanisms involved in such effects are still poorly defined, but seem to be related to a promotion of apoptosis, modulation of epigenetic patterns, blockade of cell cycle, and angiogenesis regulation. The aim of this review is to update the current associations of cancer risk with the Mediterranean diet, olive oil consumption and its main components. In addition, the identification of key olive oil components involved in anticarcinogenic mechanisms and pathways according to experimental models is also addressed.

Engagement of phytoestrogens in breast cancer suppression: Structural classification and mechanistic approach

Cancer is the world's devastating disease, and breast cancer is the most common reason for the death of women worldwide. Many synthetic drugs and medications are provided with their beneficial actions, but all of these have side effects and resistance problems. Natural remedies are coming forward to overcome the disadvantages of synthetic drugs. Among the natural categories, phytoestrogens having a structural similarity of mammalian oestradiol proves its benefit with various mechanisms not only in the treatment of breast cancer but even to prevent the occurrence of postmenopausal symptoms. Phytoestrogens are plant-derived compounds that were utilized in ancient medications and traditional knowledge for its sex hormone properties. Phytoestrogens exert pleiotropic effects on cellular signalling and show effects on estrogen-dependent diseases. However, because of activation/inhibition of steroid hormonal receptor ER-α or ER-β, these compounds induce or inhibit steroid hormonal (estrogen) action and, therefore, have the potential to disrupt hormone (estrogen) signalling pathway. In this review, we have discussed and summarize the effect of certain phytoestrogens and their possible mechanisms that can substantiate advantageous benefits for the treatment of post-menopausal symptoms as well as for breast cancer.

Important Flavonoids and Their Role as a Therapeutic Agent

Flavonoids are phytochemical compounds present in many plants, fruits, vegetables, and leaves, with potential applications in medicinal chemistry. Flavonoids possess a number of medicinal benefits, including anticancer, antioxidant, anti-inflammatory, and antiviral properties. They also have neuroprotective and cardio-protective effects. These biological activities depend upon the type of flavonoid, its (possible) mode of action, and its bioavailability. These cost-effective medicinal components have significant biological activities, and their effectiveness has been proved for a variety of diseases. The most recent work is focused on their isolation, synthesis of their analogs, and their effects on human health using a variety of techniques and animal models. Thousands of flavonoids have been successfully isolated, and this number increases steadily. We have therefore made an effort to summarize the isolated flavonoids with useful activities in order to gain a better understanding of their effects on human health.

Are Flavonoids Effective Antioxidants in Plants? Twenty Years of Our Investigation

Whether flavonoids play significant antioxidant roles in plants challenged by photooxidative stress of different origin has been largely debated over the last few decades. A critical review of the pertinent literature and our experimentation as well, based on a free-of-scale approach, support an important antioxidant function served by flavonoids in plants exposed to a wide range of environmental stressors, the significance of which increases with the severity of stress. On the other side, some questions need conclusive answers when the putative antioxidant functions of plant flavonoids are examined at the level of both the whole-cell and cellular organelles. This partly depends upon a conclusive, robust, and unbiased definition of "a plant antioxidant", which is still missing, and the need of considering the subcellular re-organization that occurs in plant cells in response to severe stress conditions. This likely makes our deterministic-based approach unsuitable to unveil the relevance of flavonoids as antioxidants in extremely complex biological systems, such as a plant cell exposed to an ever-changing stressful environment. This still poses open questions about how to measure the occurred antioxidant action of flavonoids. Our reasoning also evidences the need of contemporarily evaluating the changes in key primary and secondary components of the antioxidant defense network imposed by stress events of increasing severity to properly estimate the relevance of the antioxidant functions of flavonoids in an in planta situation. In turn, this calls for an in-depth analysis of the sub-cellular distribution of primary and secondary antioxidants to solve this still intricate matter.

Natural compounds as inhibitors of SARS-CoV-2 endocytosis: A promising approach against COVID-19

BACKGROUND AND AIM

The recent COVID-19 pandemic caused by SARS-CoV-2 affected more than six million people and caused thousands of deaths. The lack of effective drugs or vaccines against SARS-CoV-2 further worsened the situation. This review is focused on the identification of molecules that may inhibit viral entry into host cells by endocytosis.

METHODS

We performed the literature search for these natural compounds in the articles indexed in PubMed.

RESULTS

Natural products against viral infections have been gaining importance in recent years. Specific natural compounds like phytosterols, polyphenols, flavonoids, citrus, galangal, curcuma and hydroxytyrosol are being analyzed to understand whether they could inhibit SARS-CoV-2.

CONCLUSIONS

We reviewed natural compounds with potential antiviral activity against SARS-CoV-2 that could be used as a treatment for COVID-19.

Association between flavonoid intake and risk of hypertension in two cohorts of Australian women: a longitudinal study

PURPOSE

Epidemiological evidence suggests higher dietary flavonoid intake is associated with lower risk of several chronic diseases. This study aimed to investigate the association between intake of flavonoids and their subclasses, and incidence of hypertension among Australian women in two age cohorts.

METHODS

This population-based study included 6599 middle-aged (52.5 ± 1.5 years) and 6099 reproductive-aged (27.5 ± 1.5 years) women from the Australian Longitudinal Study on Women's Health. Food frequency questionnaires were used to quantify intake of flavonoids by cross-referencing with the Phenol-Explorer food composition database. Generalised Estimating Equation analyses investigated associations with incident hypertension, adjusting for demographic and dietary variables and hypertension risk factors.

RESULTS

There were 1645 cases (24.9%) of hypertension during 15 years follow-up in the middle-aged cohort and 336 cases (5.5%) during 12 years follow-up in the reproductive-aged cohort. Higher intakes of flavones [adjusted relative risk (ARR) for quintile 5 vs. 1: 0.82, 95% CI 0.70-0.97], isoflavones (0.86, 0.75-0.99) and flavanones (0.83, 0.69-1.00) were associated with a lower risk of hypertension in the middle-aged cohort. In the reproductive-aged cohort, higher intakes of flavanols (0.70, 0.49-0.99) were associated with a lower risk of hypertension. Key foods that provided these flavonoids were oranges, orange juice, apples, red wine and soy milk.

CONCLUSION

Higher intakes of total flavonoids and subclasses were associated with a lower risk of hypertension in Australian women. These findings can be used in nutrition messaging and policies for improved cardiovascular health of women.

Combination of Balsamin and Flavonoids Induce Apoptotic Effects in Liver and Breast Cancer Cells

Flavonoids such as naringenin, quercetin, and naringin are known to exhibit anticancer properties. In this study, we examined the effects of these flavonoids on cell viability and apoptotic pathways of cancer cells, either singly or in combination with the type 1 ribosome inactivating protein, Balsamin. Treatment with flavonoids (naringenin, quercetin, and naringin) plus Balsamin for 48 h reduced HepG2 and MCF-7 cell viability, increased the activation of caspase-3 and -8, and induced apoptosis through up-regulation of pro-apoptotic genes and down-regulation of anti-apoptotic genes. Out of the three flavonoids tested, the Balsamin-Naringenin and Balsamin-Quercetin combinations appeared to be most effective compared to the Balsamin-Naringin combination. Balsamin combined with flavonoids also activated endoplasmic reticulum (ER)-stress–mediated apoptosis in breast cancer (MCF-7) cells, which was not activated by Balsamin treatment alone. These experimental results showed that Balsamin combined with flavonoids can reduce HepG2 and MCF-7 cells viability and induce apoptosis, which could be considered as a promising therapeutic approach to sensitize cells to Balsamin treatment, thereby improving its efficacy in breast or liver cancer therapy.

Short-term exposure to the simple polyphenolic compound gallic acid induces neuronal hyperactivity in zebrafish larvae

A growing body of evidence suggests that the biological effects of polyphenols are not restricted to antioxidant activity, but they exert a wide range of modulatory effects on metabolic pathways, cellular signaling and gene expression. In this study, we tested the minimum safe concentration of gallic acid (GA) in 72 hpf zebrafish larvae in order to evaluate the effects on the central nervous system and the behavioral response. We showed that a short exposure (30 min) induces the depletion of the two main excitatory and inhibitory neurotransmitters, Glu and GABA, respectively, in the larval nervous system. The acute impairment of GABAergic-glutamatergic balance was paralleled by an increase of the fosab neuronal activity marker in specific brain areas, such as the forebrain, olfactory bulbs, pallial area, ventral midbrain, tegmentum, and the medulla oblongata ventral area. The neuronal excitation was mirrored by the increased cumulative motor response. The inhibition of the olfactory epithelium with brief cadmium exposition suggests a direct involvement of olfaction in the larvae response to GA. Our results demonstrate that a brief exposure to GA induces motoneuronal hyperexcitability in zebrafish. The behavioral response was probably elicited through the activation of an odorous, or chemical, stimulus. The specificity of the activated neuronal territories suggests the involvement of additional signaling pathways. Although the underlying molecular mechanisms remain to be elucidated, our data support the hypothesis that GA acts as an excitatory molecule, capable of inducing a specific nerve response. These results offer a new vision on potential effects of GA.

Euglena tuba extract provides protection against lipopolysaccharide-induced inflammatory response and oxidative stress in mice

Lipopolysaccharide (LPS), an endotoxin, is known to induce inflammatory response and oxidative stress in rodents. We evaluated the protective role of Euglena tuba extract (ETME) against LPS induced inflammatory response and oxidative stress in male Balb/c mice. Male Balb/c mice were divided into 4 groups. Group 1 (control) were intraperitoneally administered 0.5 mL PBS. Group 2, 3 and 4 were treated with a single dose of LPS (i.p. 40 mg/kg body weight). Prior 1 h, Group 3 and 4 received orally 100 mg/kg body weight and 200 mg/kg body weight ETME respectively. Biomarkers of oxidative stress including TBARS, SOD, Catalase, Liver marker enzyme (SGPT and SGOT), Nitric Oxide, and inflammatory cytokines including IL-6 and TNF-α, were estimated in serum. Oxidative stress and inflammatory markers were significantly increased in the LPS treated group, whereas ETME treated group at different concentrations protected mice from pro inflammatory cytokines and oxidative stress. Our results indicate that 70% methanolic extract of Euglena tuba can efficiently counteract free radical generation and increased level of inflammatory cytokine in an LPS induced mice model.

Therapeutic benefits of rutin and its nanoformulations

BACKGROUND

Rutin as a natural flavonoid compound has revealed an extensive range of therapeutic potentials.

PURPOSE

The current paper is focused on the numerous studies on rutin nanoformulations regarding its broad spectrum of therapeutic potentials.

STUDY AND METHODS

A review was conducted in electronic databases (PubMed) to identify relevant published literature in English. No restrictions on publication date were imposed.

RESULTS

The literature search provided 7,078 results for rutin. Among them, 25 papers were related to the potential biological activities of rutin nanoformulations. Polymeric nanoparticles were the most studied nanoformulations for rutin (14 titles) and lipid nanoparticles (5 titles) were in second place. The reviewed literature showed that rutin has been used as an antimicrobial, antifungal, and anti-allergic agent. Improving the bioavailability of rutin using novel drug-delivery methods will help the investigators to use its useful effects in the treatment of various chronic human diseases.

CONCLUSION

It can be concluded that the preparation of rutin nanomaterials for the various therapeutic objects confirmed the enhanced aqueous solubility as well as enhanced efficacy compared to conventional delivery of rutin. However, more investigations should be conducted to confirm the improved bioavailability of the rutin nanoformulations.

Mechanism of antidiabetic effects of Plicosepalus Acaciae flower in streptozotocin-induced type 2 diabetic rats, as complementary and alternative therapy

Background

Diabetes and its related complications remain to be a major clinical problem. We aim to investigate the antidiabetic mechanistic actions of Plicosepalus Acaciae (PA) flowers in streptozotocin (STZ)-induced diabetic rats.

Methods

After diabetes induction, rats were divided randomly into five groups, including: 1) normal control group, 2) diabetic control group, 3) diabetic group treated with 150 mg/kg of ethanolic extract of PA flowers, 4) diabetic group treated with 300 mg/kg of ethanolic extract of PA flowers, and 5) diabetic group treated with 150 mg/kg of metformin. After 15 days of treatment; fasting blood glucose, glycated hemoglobin (HBA1c%), insulin, C-peptide, superoxide dismutase (SOD), catalase, reduced glutathione (GSH), malondialdehyde (MDA), triglyceride (TGs), total cholesterol (Tc), low density lipoprotein cholesterol (LDL-c), very LDL (VLDL), high DLc (HDL-c), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were assessed. Histopathology of pancreas was also assessed.

Results

The results showed that PA flower ethanolic extract significantly reduced blood glucose, HBA1c%, MDA, TGs, Tc, VLDL, LDL-c, TNF-α, and IL-6 levels in a dose-dependent manner. All these parameters were already increased by diabetic induction in the untreated diabetic group. Treatment of diabetic rats with PA flower increased insulin, HDL-c, GSH, catalase, and SOD levels. Histological examination showed that the PA flower caused reconstruction, repair, and recovery of damaged pancreas when compared with the untreated group.

Conclusions

PA flower has a potential role in the management of diabetes as complementary and alternative therapy, due to its antioxidant, anti-inflammatory, hypolipidemic, hypoglycemic and insulin secretagogue effects.

Optimum Extraction Condition of Clitorea ternatea Flower on Antioxidant Activities, Total Phenolic, Total Flavonoid and Total Anthocyanin Contents

Clitoria ternatea is a herbaceous plant with many health benefits. Extraction is crucial to obtain its bioactive components which contribute to its antioxidant properties. Therefore, this study was conducted to find an optimum extraction condition of C. ternatea flower on total phenolic content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity) as well as to determine its total flavonoid content (TFC) and anthocyanin content based on the optimum extraction condition generated by Response Surface Methodology (RSM)-Design Expert 7.1.5. TPC, TFC and total anthocyanin of C. ternatea were conducted by Folin Ciocalteu (FC), calorimetric assay and pH differential method, respectively. The ranges of selected independent variables were ethanol concentration (30°C–90% v/v), time (60–120 min) and temperature (30°C–70°C). The optimum extraction condition was obtained at 39.62% v/v ethanol concentration, 90 min and 44.24°C. However, these values were slightly adjusted according to the convenience of equipment to operate in which ethanol concentration was adjusted to 37% v/v, time remain at 90 min and temperature at 45°C. The predicted values of TPC and DPPH radical scavenging activity were 41.60 mg GAE/g dry samples and 68.12% inhibition and were experimentally verified to be 41.17 ± 0.5 mg GAE/g dry samples and 63.53 ± 0.95% inhibition of TPC and DPPH radical scavenging activity respectively. This result has showed RSM can optimise TPC and radical scavenging activity of C. ternatea. Upon the optimum condition, the TFC determined was 187.05 ± 3.18 mg quercetin/g dried sample which was higher than TPC and the total anthocyanin content was 28.60 ± 0.04 mg/L. Hence, the extractable phenolic, flavonoid and anthocyanin compounds indicated that C. ternatea is a good source of natural antioxidant.

Propolis as a novel antibacterial agent

Propolis (bee glue) is a bee glue, sticky resinous material released from various plant sources such as bud exudates, flowers, and leaves modified by bee secretions and wax propolis is composed of resins, waxes, polyphenols, polysaccharides, volatile materials, and secondary metabolites that are responsible for various bioactivity such as antibacterial, anti-angiogenic, antiulcer, anti-inflammatory, antioxidant, and anti-viral activities. The physico-chemical characteristics and the natural properties of various kinds of propolis have been studied for the past decade. Novel active anti-microbial compounds have been identified in propolis. Those compounds positively modulated the antimicrobial resistance of multidrug resistant bacteria. Published research has indicated that propolis and its derivatives has many natural antimicrobial compounds with a broad spectrum against different types of bacteria and that it enhanced the efficacy of conventional antibiotics. Besides, the combination of propolis with other compounds such as honey has been studied whereby, such combinations have a synergistic effect against bacterial strains such as Escherichia coli and Staphylococcus aureus. The activity of propolis is very much dependent on seasonal and regional factors, and Middle Eastern propolis have shown best antibacterial efficacy. Propolis and its main flavonoids ingredients should not be overlooked and should be evaluated in clinical trials to better elucidate their potential application in various fields of medicine. Clinical antibacterial potential and its use in new drugs of biotechnological products should be conducted. This review aims at highlighting some of the recent scientific findings associated with the antibacterial properties of propolis and its components.

Roles of the Polyphenol-Gut Microbiota Interaction in Alleviating Colitis and Preventing Colitis-Associated Colorectal Cancer

Accumulating evidence indicates that the gut microbiota can promote or inhibit colonic inflammation and carcinogenesis. Promotion of beneficial gut bacteria is considered a promising strategy to alleviate colonic diseases including colitis and colorectal cancer. Interestingly, dietary polyphenols, which have been shown to attenuate colitis and inhibit colorectal cancer in animal models and some human studies, appear to reach relatively high concentrations in the large intestine and to interact with the gut microbial community. This review summarizes the modulatory effects of polyphenols on the gut microbiota in humans and animals under healthy and diseased conditions including colitis and colitis-associated colorectal cancer (CAC). Existing human and animal studies indicate that polyphenols and polyphenol-rich whole foods are capable of elevating butyrate producers and probiotics that alleviate colitis and inhibit CAC, such as Lactobacillus and Bifidobacterium. Studies in colitis and CAC models indicate that polyphenols decrease opportunistic pathogenic or proinflammatory microbes and counteract disease-induced dysbiosis. Consistently, polyphenols also change microbial functions, including increasing butyrate formation. Moreover, polyphenol metabolites produced by the gut microbiota appear to have anticancer and anti-inflammatory activities, protect gut barrier integrity, and mitigate inflammatory conditions in cells and animal models. Based on these results, we conclude that polyphenol-mediated alteration of microbial composition and functions, together with polyphenol metabolites produced by the gut microbiota, likely contribute to the protective effects of polyphenols on colitis and CAC. Future research is needed to validate the causal role of the polyphenol-gut microbiota interaction in polyphenols' anti-colitis and anti-CAC effects, and to further elucidate mechanisms underlying such interaction.

Review of Phytochemical Compounds as Antiviral Agents Against Arboviruses from the Genera Flavivirus and Alphavirus

Arboviruses are a diverse group of viruses that are among the major causes of emerging infectious diseases. Arboviruses from the genera flavivirus and alphavirus are the most important human arboviruses from a public health perspective. During recent decades, these viruses have been responsible for millions of infections and deaths around the world. Over the past few years, several investigations have been carried out to identify antiviral agents to treat these arbovirus infections. The use of synthetic antiviral compounds is often unsatisfactory since they may raise the risk of viral mutation; they are costly and possess either side effects or toxicity. One attractive strategy is the use of plants as promising sources of novel antiviral compounds that present significant inhibitory effects on these viruses. In this review, we describe advances in the exploitation of compounds and extracts from natural sources that target the vital proteins and enzymes involved in arbovirus replication.

Integrated Metabolomics and Transcriptomics Analyses Reveal the Molecular Mechanisms Underlying the Accumulation of Anthocyanins and Other Flavonoids in Cowpea Pod (Vigna unguiculata L.)

As an important vegetable crop of the legume family, cowpea (Vigna unguiculata L.) is grown widely for its tender pod with good taste and nutrition. The purple cowpea pods attract more attention mainly for the eye-catching color and health-promoting ingredients. Initially, large quantities of two major anthocyanins (delphinidin 3-O-glucoside and cyanidin 3-O-glucoside) and nine kinds of flavonoids (most are quercetin-based flavonol glycosides) were separated and identified from purple cowpea pod by ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry. To study them systematically, two representative cowpea cultivars with a drastic difference in anthocyanin accumulation were further analyzed by the integration of metabolomics and transcriptomics. A total of 56 differentially accumulated metabolites and 4142 differentially expressed genes were identified, respectively. On the basis of the comprehensive analysis of multiomic data, it was shown that VuMYB90-1, VuMYB90-2, VuMYB90-3, VuCPC, VuMYB4, and endogenous bHLH and WD40 proteins coordinately control anthocyanin and flavonoid accumulation via transcriptional regulation of structural genes in purple cowpea pod.

Foods with Potential Prooxidant and Antioxidant Effects Involved in Parkinson's Disease

Oxidative stress plays a fundamental role in the pathogenesis of Parkinson's disease (PD). Oxidative stress appears to be responsible for the gradual dysfunction that manifests via numerous cellular pathways throughout PD progression. This review will describe the prooxidant effect of excessive consumption of processed food. Processed meat can affect health due to its high sodium content, advanced lipid oxidation end-products, cholesterol, and free fatty acids. During cooking, lipids can react with proteins to form advanced end-products of lipid oxidation. Excessive consumption of different types of carbohydrates is a risk factor for PD. The antioxidant effects of some foods in the regular diet provide an inconclusive interpretation of the environment's mechanisms with the modulation of oxidation stress-induced PD. Some antioxidant molecules are known whose primary mechanism is the neuroprotective effect. The melatonin mechanism consists of neutralizing reactive oxygen species (ROS) and inducing antioxidant enzyme's expression and activity. N-acetylcysteine protects against the development of PD by restoring levels of brain glutathione. The balanced administration of vitamin B3, ascorbic acid, vitamin D and the intake of caffeine every day seem beneficial for brain health in PD. Excessive chocolate intake could have adverse effects in PD patients. The findings reported to date do not provide clear benefits for a possible efficient therapeutic intervention by consuming the nutrients that are consumed regularly.

A versatile model for investigating the protective effects of Ceratonia siliqua pod extract against 1,4-dioxane toxicity

In this study, the toxic effects of 1,4-dioxane, a common contaminant, and the protective property of Ceratonia siliqua L. pod extract (Cspe) against this toxicity are aimed to be demonstrated with a versatile model. For this purpose, Allium toxicity test was used and six different experimental groups were formed. While the control group was germinated in tap water, the application groups were germinated in mediums containing 750 mg/L Cspe, 1500 mg/L Cspe, 100 mg/L 1,4-dioxane, 750 mg/L Cspe+100 mg/L 1,4-dioxane, and 1500 mg/L Cspe+100 mg/L 1,4-dioxane. Each group was germinated in related solution for 72 h and alterations in physiological, biochemical, genetic, and anatomical parameters were investigated. Germination percentage, relative injury rate, root length, and weight gain parameters were examined as physiological parameters, and no significant difference was observed in the control group and only-Cspe-treated groups. In groups treated with 100 mg/L 1,4-dioxane, germination percentage, root length, and weight gain were significantly decreased, and the relative injury rate reached the highest value as 0.48. It was determined that all physiological parameters improved in the groups where Cspe and 1,4-dioxane treated together, and the relative injury rate decreased to 0.22 in the group treated with 1500 mg/L Cspe+1,4-dioxane. Genotoxic effects were tested by the micronucleus and chromosomal abnormality frequency, and statistically insignificant micronucleus formation was found in control group and Cspe-treated groups. Micronucleus frequency were found to be 58.00 ± 12.12 and 31.00 ± 07.38 in 1,4-dioxane and 1500 mg/L Cspe+1,4-dioxane-treated groups, respectively. This result showed that the application of 1500 mg/L Cspe had a 46.5% reduction in the frequency of 1,4-dioxane-induced micronucleus and had a protective effect on genomic integrity. It has been found that 1,4-dioxane application induces lipid peroxidation and increases malondialdehyde level 4.5 times compared with control group. Oxidative stress, which was proved by increased malondialdehyde levels in 1,4-dioxane-treated group caused induction of superoxide dismutase and catalase enzymes, and it was determined that enzyme activities increased by 1.99 and 4.9 times, respectively, compared with the control group. Cspe treatment with 1,4-dioxane caused a significant decrease in malondialdehyde level, superoxide dismutase, and catalase enzyme activities, indicating that oxidative stress formation in the cells was repressed. Abnormalities such as cell deformation, cell wall thickening, and flattened cell nuclei were seen in 1,4-dioxane-treated group in the cross sections of root tips, and the frequency of these abnormalities decreased with Cspe application. As a result, it was determined that 1,4-dioxane caused a versatile toxicity in the test material Allium cepa, whereas Cspe application had a dose-dependent protective feature against toxicity in all tested parameters.

Assessment of the Quality and Evaluation of the Antioxidant Potential of a Novel Sri Lankan Ayurvedic Polyherbal Formulation

BACKGROUND

In Sri Lanka, a Polyherbal Ayurvedic Formulation (PHAF), which consists of powders of seven medicinal plants, is being trialed for use as an anti-inflammatory drug. In general, anti-inflammatory drugs have good antioxidant properties. Therefore, in the present study, an attempt was made to assess the quality and evaluate the antioxidant potential of PHAF.

METHODS

Physicochemical parameters such as ash content, extractable matter, phytochemical screening for secondary metabolites, levels of heavy metals, and microbes were determined according to standard protocols. Antioxidant activity was evaluated using five in vitro assays: total polyphenolic content (TPC), total flavonoid content (TFC), ORAC (oxygen radical absorbance capacity), DPPH (1,1-diphenyl-2-picryl-hydrazyl), and ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt.

RESULTS

PHAF contained 5.6 ± 0.2% of moisture, 6.5 ± 0.1% of total ash, 1.4 ± 0.1% of water soluble ash, 0.9 ± 0.0% of acid insoluble ash, 7.7 ± 0.2% of hot water extractable matter, 3.9 ± 0.1% of cold water extractable matter, 10.5 ± 4.1% of hot-ethanol extractable matter, and 8.4 ± 0.2% of cold-ethanol extractable matter. Phytochemical screening revealed the presence of phenolic compounds, tannins, flavonoids, coumarins, and saponins in both aqueous and ethanolic extracts of the drug. TPC, TFC, ORAC, DPPH, and ABTS of aqueous and ethanol extracts of PHAF were 103.65 ± 4.94 and 327.07 ± 9.65 mg gallic acid equivalents/g extract, 76.6 ± 5.83 and 224.6 ± 8.42 mg quercetin equivalents/g of extract, 481.11 ± 17.30 and 1481.44 ± 30.20 mg trolox equivalents/g of extract, 79.50 ± 4.42 and 227.17 ± 6.16 mg trolox equivalents/g of extract, and 198.20 ± 4.55 and 577.08 ± 5.48 mg trolox equivalents/g of extract, respectively.

CONCLUSION

Ethanolic extract of PHAF is better than aqueous extract in terms of antioxidant properties.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

Flavonoids and Mitochondria: Activation of Cytoprotective Pathways?

A large number of diverse mechanisms that lead to cytoprotection have been described to date. Perhaps, not surprisingly, the role of mitochondria in these phenomena is notable. In addition to being metabolic centers, due to their role in cell catabolism, ATP synthesis, and biosynthesis these organelles are triggers and/or end-effectors of a large number of signaling pathways. Their role in the regulation of the intrinsic apoptotic pathway, calcium homeostasis, and reactive oxygen species signaling is well documented. In this review, we aim to characterize the prospects of influencing cytoprotective mitochondrial signaling routes by natural substances of plant origin, namely, flavonoids (e.g., flavanones, flavones, flavonols, flavan-3-ols, anthocyanidins, and isoflavones). Flavonoids are a family of widely distributed plant secondary metabolites known for their beneficial effects on human health and are widely applied in traditional medicine. Their pharmacological characteristics include antioxidative, anticarcinogenic, anti-inflammatory, antibacterial, and antidiabetic properties. Here, we focus on presenting mitochondria-mediated cytoprotection against various insults. Thus, the role of flavonoids as antioxidants and modulators of antioxidant cellular response, apoptosis, mitochondrial biogenesis, autophagy, and fission and fusion is reported. Finally, an emerging field of flavonoid-mediated changes in the activity of mitochondrial ion channels and their role in cytoprotection is outlined.