Flavonoid-rich Extract Research Articles

Cadmium-Induced Kidney Injury in Mice Is Counteracted by a Flavonoid-Rich Extract of Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, via the Enhancement of Different Defense Mechanisms.

Cadmium (Cd) represents a public health risk due to its non-biodegradability and long biological half-life. The main target of Cd is considered the kidney, where it accumulates. No effective treatment for Cd poisoning is available so that several therapeutic approaches were proposed to prevent damages after Cd exposure. We evaluated the effects of a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), in the kidney of mice exposed to cadmium chloride (CdCl2). Male mice were administered with CdCl2 and treated with Cur, Re, or BJe alone or in combination for 14 days. The kidneys were processed for biochemical, structural and morphometric evaluation. Cd treatment significantly increased urea nitrogen and creatinine levels, along with tp53, Bax, Nos2 and Il1b mRNA, while reduced that of Bcl2, as well as glutathione (GSH) content and glutathione peroxidase (GPx) activity. Moreover, Cd caused damages to glomeruli and tubules, and increased Nrf2, Nqo1 and Hmox1 gene expression. Cur, Re and BJe at 40 mg/kg significantly improved all parameters, while BJe at 20 mg/kg showed a lower protective effect. After treatment with the associations of the three nutraceuticals, all parameters were close to normal, thus suggesting a new potential strategy in the protection of renal functions in subjects exposed to environmental toxicants.

Promising Antiviral Activities of Natural Flavonoids against SARS-CoV-2 Targets: Systematic Review.

The ongoing COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a globally leading public health concern over the past two years. Despite the development and administration of multiple vaccines, the mutation of newer strains and challenges to universal immunity has shifted the focus to the lack of efficacious drugs for therapeutic intervention for the disease. As with SARS-CoV, MERS-CoV, and other non-respiratory viruses, flavonoids present themselves as a promising therapeutic intervention given their success in silico, in vitro, in vivo, and more recently, in clinical studies. This review focuses on data from in vitro studies analyzing the effects of flavonoids on various key SARS-CoV-2 targets and presents an analysis of the structure-activity relationships for the same. From 27 primary papers, over 69 flavonoids were investigated for their activities against various SARS-CoV-2 targets, ranging from the promising 3C-like protease (3CLpro) to the less explored nucleocapsid (N) protein; the most promising were quercetin and myricetin derivatives, baicalein, baicalin, EGCG, and tannic acid. We further review promising in silico studies featuring activities of flavonoids against SARS-CoV-2 and list ongoing clinical studies involving the therapeutic potential of flavonoid-rich extracts in combination with synthetic drugs or other polyphenols and suggest prospects for the future of flavonoids against SARS-CoV-2.

Inhibition of phospholipase A2, platelet aggregation and egg albumin induced rat paw oedema as anti-inflammatory effect of Peltophorun pterocarpus stem-bark

BackgroundMost medicinal plants presently employed in traditional medicine are used without scientific evidence, thereby suggesting a need to explore efficient and reliable investigations of their potential. We, therefore, conducted the present study to ascertain the efficacy of flavonoid-rich extract of Peltophorum pterocarpum sterm-bark in the treatment and management of inflammatory disorders as employed in folk medicine.Materials and methodsFlavonoid-rich extract of Peltophorum pterocarpum sterm-bark and a total of fifty-five (55) Wistar rats were used for this study. Eighteen (18) mice were used for toxicity testing, and the phytochemical analysis was done using the Trease and Evans method, while the acute toxicity was done using Lorke’s method. In vivo anti-inflammatory study was done using the egg albumin-induced paw oedema method, while the in vitro anti-inflammatory studies were performed for the extract using phospholipase A2 inhibition and calcium chloride-induced platelet aggregation assays.ResultsThe phytochemical analysis revealed that the extract of Peltophorum pterocarpum sterm-bark contains tannins, terpenoids, steroids, phenols, alkaloids, flavonoids, glycosides, and saponins ranging from 0.307 ± 0.02 to 1279.567 ± 149.868. The acute toxicity test of the extract showed no toxicity up to 5000 mg/kg body weight. In the systemic oedema of the rat paw, scalar doses of the extract significantly (p < 0.05) suppressed the development of paw oedema induced by egg albumin, particularly with the Indomethacin (1.77 ± 0.41) when compared with the control (5.50 ± 0.26). However, varying doses of the extract significantly (p < 0.05) inhibited phospholipase A2 activity and CaCl2-Induced platelet aggregation in a concentration, dose, and time-dependent manner, in comparison to prednisolone.ConclusionThese results indicate that the extract exhibited anti-inflammatory potential, and the mechanism of this activity has a promising ability to inhibit phospholipase A2 activity and platelet aggregation in rats inflicted with paw oedema.

Nephrocurative Effect of Flavonoids-Rich Fraction of Irvingia gabonensis Seed Extract against Acetaminophen-induced Kidney Damage in Mice

This paper investigated the nephrocurative effect of flavonoids-rich fraction of Irvingia gabonensis seed extract in acetaminophen-induced kidney damage in mice. The total flavonoids content of the different fractions of the extracts were reported to be higher in the Ethyl acetate fraction with a value of 47.20mg QE/g followed by Methanol 30.41mg QE/g, Chloroform 20.10mg QE/g, and Petroleum ether with 12.40mg QE/g. Further studies on the flavonoids-rich extract (Ethyl acetate fraction) revealed a significant difference (p < 0.05) between the inhibitory power of the flavonoids-rich fraction of Irvingia gabonensis (IG) seed extract and that of Vit. C. Accordingly, the IC50 of the flavonoids-rich fraction of Irvingia gabonensis seed extract (47.97µg/ml) calculated was observed to be higher than that of Vit. C. standard (25.76µg/ml). Studies on the nephrocurative effect indicate a positive result with significant deference across the group and an ultimate normalization of the kidney biomarkers. The curative effect of the extract is assumed to be dose and time depended on a drastic decrease in kidney biomarkers after four weeks of extract administration. Toxicity study of the extract also revealed the extract to be safe at ≤ 3000mg/kgbw. This study to an extent has proven that Irvingia gabonensis seeds are a promising source of alternative raw material in pharmaceuticals for kidney toxicity treatment. Therefore, the flavonoids rich fraction of Irvingia gabonensis seed extract may have curative effect in the treatment of kidney diseases.

Antihyperlipidemic and Antioxidant Activities of Flavonoid-Rich Extract of Ziziphus lotus (L.) Lam. Fruits

Ziziphus lotus (L.) Lam. (Z. lotus) is a medicinal plant species that is widely distributed throughout the Mediterranean basin. Moroccans traditionally use it to treat many illnesses thanks to its beneficial medicinal properties. The purpose of this study is to assess the anti-hyperlipidemic and antioxidant activities of a flavonoid-rich aqueous extract of Z. lotus fruits (ZLF). The 2-2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and the β-carotene bleaching test were used to determine the antioxidant activity of ZLF. The anti-hyperlipidemic effect of the aqueous extract of ZLF (200 and 400 mg/kg) was evaluated in albino mice exposed to the chronic high-fat diet, based on lipid profile, blood sugar, and changes in growth performance. The results showed that the aqueous extract of ZLF rich in flavonoids (2242.89 ± 25 µg QE (quercitin equivalent)/mg), and has a considerable antioxidant power against DPPH radicals (IC50 = 116 ± 0.02 µg/mL) and β-carotene oxidation. The aqueous extract of ZLF also showed a significant anti-hyperlipidemic effect by improving abnormal changes in lipid profile and blood glucose levels in albino mice exposed to a chronic high-fat diet. Our findings suggest that the anti-hyperlipidemic activities of ZLF aqueous extract are correlated with its flavonoid content and antioxidant activity. Therefore, the aqueous extract of ZLF could be an essential therapeutic candidate for hyperlipidemia patients, thanks to its richness in bioactive molecules.

Peperomia pellucida (L.) Kunth as an angiotensin-converting enzyme inhibitor in two-kidney, one-clip Goldblatt hypertensive rats

BackgroudPeperomia pellucida (L.) Kunth has been used widely to treat headache, kidney disease, fever, and hypertension. Previous in vitro studies discovered that the flavonoid-rich extract of this plant has potential hypotensive effects, specifically angiotensin-converting enzyme (ACE)-inhibitory activity. However, there is insufficient scientific evidence to validate the result in vivo.PurposeThis study investigated the dose dependencies of the effects of the ethyl acetate fraction of the ethanolic extract of this plant on blood pressure and biomarkers associated with the renin–angiotensin–aldosterone systems (RAAS), such as angiotensin II (AII) and the plasma renin concentration (PRC).Study designIn total, 30 two-kidney, one-clip (2K1C) hypertensive model rats were divided into five groups (n = 6 each): model group, captopril 25 mg/kg BW group, and three different ethyl acetate groups (25, 50, and 100 mg/kg BW). Another six rats comprised the sham group.MethodsRenal hypertensive rats (RHRs) were generated using stainless steel modification clips. Drugs were administered via oral gavage for 2 consecutive weeks. Blood pressure was measured weekly prior to treatment. Blood samples were collected before treatment and after the last dose to measure AII and PRC. The left kidney was isolated for histopathological examination.ResultsBlood pressure, AII levels, and PRC were elevated after 6 weeks in RHRs. Treatment with captopril and the ethyl acetate fraction of P. pellucida (L.) Kunth decreased blood pressure, AII levels, and PRC. The ethyl acetate fraction at a dose of 50 mg/kg BW had similar ACE-inhibitory effects as captopril. Histopathological examination disclosed coagulative necrosis in clipped kidneys. Impairment was alleviated in a dose-dependent manner by P. pellucida (L.) Kunth, similarly as observed in the captopril group.ConclusionP. pellucida (L.) Kunth targets the renin–angiotensin–aldosterone system, which might explain its antihypertensive effects.

Effect of perinatal administration of flavonoid-rich extract from Hibiscus sabdariffa to feed-restricted rats, on offspring postnatal growth and reproductive development

Abstract Developmental programming is a process where stimulus or insult acting during critical periods of growth and development might permanently alter tissue anatomy and physiology so as to produce adverse effects in adult life. Most forms of exposure include maternal nutrient deprivation, nutrient excess, exogenous glucocorticoid excess and endogenous glucocorticoid due to maternal stress. Hibiscus sabdariffa (Hs) are highly rich in phenolic compounds with marked physiological activities, the sweetened aqueous extract of Hs, commonly known as “Zobo’ in Nigeria, is consumed by humans including pregnant and lactating mothers. This study aimed at determining effects of perinatal administration of flavonoid-rich extract from Hs to feed-restricted rats, on offspring postnatal growth and reproductive development. Twenty-five pregnant female rats were used. Rats were randomly placed into five groups of five rats per group (one animal per cage): Group I (Normal control); Group II (feed-restricted control); Group III (5 mg/kg extract + 70% feed-restricted diet); Group IV (10 mg/kg extract + 70% feed-restricted diet); Group V (20 mg/kg extract + 70% feed-restricted diet). Dams were allowed to nurse only 8 pups. Pups were weaned to ad libitum feed and water and were observed daily for puberty onset. Weights, lengths and body mass index (BMI) of pups were measured at delivery, weaning and puberty onset. At onset of puberty in each of the rats, blood samples were collected for determination of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol and testosterone. Reproductive organs were excised and weighed for histology. The extract caused significant increase in postnatal weight, length and BMI of offspring at birth, weaning and puberty onset and significantly delayed puberty onset in both sexes. There was significant increase in absolute and relative weights of testes and ovaries with alterations in histology. This study has shown that maternal consumption of flavonoid-rich extract of Hs during pregnancy and lactation may accelerate offspring postnatal growth with delay in onset of puberty.

Beneficial Flavonoid in Foods and Anti-obesity Effect

ABSTRACT Obesity is a global health problem. In the past decades, the prevalence rate of obesity has risen sharply in epidemiology. Obesity has become an increasingly severe epidemic burden linked with different kinds of diseases, consisting of cardiovascular disease, diabetes, metabolic associated fatty liver disease, and even in COVID-19. Beneficial flavonoids in foods, as functional ingredients, combat obesity and maintain energy balance through multiple mechanisms. This review provides a brief overview of biological targets, possible mechanisms and the current therapeutic interventions including suppressing appetite, increasing energy consumption, regulating gut microbiota, inhibiting adipogenesis, anti-inflammation. In vitro and in vivo experiments as well as available clinical evidence related to the anti-obesity effects of pure flavonoid and flavonoid-rich extracts are also summarized and depicted. Furthermore, the metabolism and bioavailability of flavonoids are also concluded and discussed. Beneficial flavonoids have become promising candidates for treating and avoiding obesity, but poor bioavailability and short elimination half-life affects the absorption and efficacy. This paper reviews the different types of flavonoids and their potential effect of preventing obesity, which provide the basis for further research.

A Flavonoid-Rich Extract from Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, Shows Protective Effects in a Murine Model of Cadmium-Induced Testicular Injury.

It is known that cadmium damages testis structure and functionality. We examined the effects of nutraceuticals such as a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), on mice testicular dysfunction caused by cadmium chloride (CdCl2). Controversial data on the protective effects of Cur and Re are available, while no evidence on the possible role of BJe exists. Adult male C57 BL/6J mice were administered with CdCl2 and treated with Cur, Re, or BJe alone or in combination for 14 days. Then, testes were removed and processed for molecular, structural, and immunohistochemical analyses. CdCl2 increased the mRNA of IL-1β, TNF-α, p53, and BAX while reduced that of Bcl-2 and induced tubular lesions and apoptosis of germinal cells. Cur, Re, and BJe at 40 mg/kg significantly improved all of these parameters and events, although BJe at 20 mg/kg showed a lower protective effect. The association of Cur, Re, and BJe at both doses of 50/20/20 and 100/20/40 mg/kg brought each parameter close to those of the control. Our results indicate that the nutraceuticals employed in this study and their associations exert a positive action against Cd-induced testicular injury, suggesting a possible protection of testis functionality in subjects exposed to environmental toxicants.

Flavonoids-rich extract from Bidens bipinnata L. protects pancreatic β-cells against oxidative stress-induced apoptosis through intrinsic and extrinsic pathways

Ethnopharmacological relevanceAs a traditional Chinese medicinal, Bidens bipinnata L. has been used to treat many diseases with a long history in China. The anti-diabetic effects of extract from B. bipinnata have been demonstrated in the previous reports. Aim of the studyThe protective effects of flavonoids-rich extract from B. bipinnata (BBTF) on cell damage induced by H2O2 in pancreatic β cell and its potential mechanisms were evaluated. Materials and methodsMTT, ROS production, nuclear staining and flow cytometry assays were adopted to determine the effects of BBTF on cell viability, production of ROS and cell apoptosis in H2O2-treated INS-1 cell. Cell apoptosis-related proteins expressions were detected by Western blot assay. ResultsPre-treatment of BBTF could significantly increase INS-1 cell viability, inhibit the production of intracellular ROS and reduced the characteristic features of cell apoptosis induced by H2O2 in INS-1 cells. The studies of the underlying mechanism showed that BBTF could regulate Bax and Bcl-2 proteins expressions, suppress the phosphorylation of JNK, ERK and p38, as well as down-regulate Fas and FasL proteins expressions induced by H2O2. The expressions of caspase-8, caspase-9 and caspase-3 were therefore decreased. ConclusionThe results indicated that flavonoids-rich extract from B. bipinnata could be a natural agent in diabetic prevention and therapy.

Protective properties of Spondias mombin Linn leaves on redox status, cholinergic dysfunction and electrolyte disturbance in cyanide-intoxicated rats.

Cyanide is an environmental neurotoxin which has been reported to arrest the normal functioning of the brain. This study investigated the protective properties of methanol and flavonoid-rich extracts of the leaves of Spondias mombin on redox status, cholinergic dysfunction and electrolyte disturbance in cyanide-induced neurotoxicity in rats. Male Wistar rats were orally pre-treated with Spondias mombin methanol leaf extract (SMC) (50, 100 and 150 mg/kg), flavonoid-rich extract (SMF) (25, 50 and 75 mg/kg) or quercetin (20 mg/kg), followed by intraperitoneal administration of 2 mg/kg potassium cyanide. Cyanide intoxication caused brain damage in rats as echoed in the deleterious alterations to activities/levels of endogenous antioxidants and biomarkers/enzymes linked with electrolyte imbalance and neurotoxicity. Pre-treatment with SMC and SMF significantly attenuated these KCN-induced imbalances (p < 0.05). The results suggested that the protection conferred by SMC and SMF probably involves attenuation of oxidative stress and regulation of ionic homeostasis. SMF displayed a better apparent ameliorative activity than SMC and 75 mg/kg SMF offered the best protection suggesting that flavonoids probably contributed to the protective effect of Spondias mombin leaf.

A Flavonoid-Rich Extract of Mandarin Juice Counteracts 6-OHDA-Induced Oxidative Stress in SH-SY5Y Cells and Modulates Parkinson-Related Genes.

Parkinson’s disease (PD) is a degenerative disorder of the nervous system due to unceasing impairment of dopaminergic neurons situated in the substantia nigra. At present, anti-PD drugs acting on dopamine receptors are mainly symptomatic and have only very limited neuroprotective effects, whereas drugs slowing down neurodegeneration of dopaminergic neurons and deterioration of clinical symptoms are not yet available. Given that, the development of more valuable pharmacological strategies is highly demanded. Comprehensive research on innovative neuroprotective drugs has proven that anti-inflammatory and antioxidant molecules from food sources may prevent and/or counteract neurodegenerative diseases, such as PD. The present study was aimed at the evaluation the protective effect of mandarin juice extract (MJe) against 6-hydroxydopamine (6-OHDA)-induced SH-SY5Y human neuroblastoma cell death. Treatment of differentiated SH-SY5Y cells with 6-OHDA brought cell death, and specifically, apoptosis, which was significantly inhibited by the preincubation with MJe through caspase 3 blockage and the modulation of p53, Bax, and Bcl-2 genes. In addition, it showed antioxidant properties in abiotic models as well as in vitro, where it reduced both reactive oxygen and nitrogen species induced by 6-OHDA, along with restored mitochondrial membrane potential, and prevented the oxidative DNA damage evoked by 6-OHDA. Furthermore, MJe restored the impaired balance of SNCA, LRRK2, PINK1, parkin, and DJ-1 gene levels, PD-related factors, caused by 6-OHDA oxidative stress. Overall, these results indicate that MJe exerts neuroprotective effects against 6-OHDA-induced cell death in SH-SY5Y cells by mechanisms involving both the specific interaction with intracellular pathways and its antioxidant capability. Our study suggests a novel possible strategy to prevent and/or ameliorate neurodegenerative diseases, such as PD.

Flavonoid-rich extract of Buchholzia coriacea Engl. seeds reverses Plasmodium berghei-modified haematological and biochemical status in mice

BackgroundMalaria still remains a serious global public health challenge and the growing resistance of Plasmodium species to the existing antimalarial drugs is aggravating the burden. Considering the growing knowledge of the contribution of dyslipidemia, oxidative stress, and hepatic and kidney damages, in addition to the well-known anaemia and hypoglycemia in pathogenesis of malaria complication, a good antimalarial candidate should not only kill malaria parasite but also normalize the associated haematological and biochemical modifications. Buchholzia coriacea (Capparaceae) is a medicinal plant traditionally used in treating malaria whose antimalarial activity has been investigated. Aimto evaluate the ameliorative effects of flavonoid-rich extract of B. coriacea seeds (FEBCS) on modifications in haematological and biochemical status induced by malaria in mice. Materials and methodsFEBCS was prepared and its effects on malaria parasitemia, haematological (packed cell volume, total erythrocyte and leucocyte counts and haemoglobin concentration) and biochemical (liver, lipid peroxidation and antioxidant and lipid profile) status of P. berghei Anka-65-infected mice were evaluated using established protocols. In addition, the phytochemicals in FEBCS as well as its acute toxicity status were investigated. A total of sixty inbred Swiss albino mice (7 weeks, body weight of 26 ± 5 g) were used for this study (30 were used for acute toxicity study while the rest for antimalarial study) and were maintained on commercial rodent diet and water ad libitum in our animal laboratory. ResultsUpon treatment with combisunate (140 mg/kg/ b.w.) and FEBCS (200, 400 and 600 mg/kg/d body) for four consecutive days (4-day suppressive assay), there were significant reductions in parasitemia levels compared with baseline. When the parasitemia levels of mice post-treatment and pre-treatment were compared, it was observed that FEBCS exhibited a dose-dependent chemosuppression which were however, lower compared to that by combisunate. Compared to the malaria control, it was observed that FEBCS improved the status indicators of haematology and biochemistry to near normal levels. There was no significant morphological and behavioural sign of toxicity, indicating that FEBCS was tolerable up to 5000 mg/kg b.w. ConclusionThese findings suggest that FEBCS possesses antimalarial activity, and normalized haematological and biochemical alterations triggered by malaria. This finding necessitates the isolation and characterization of the active principles in FEBCS which could serve as lead compounds for the development of novel antimalarial agents.

Assessment of inhibitory properties of flavonoid-rich fig (Ficus carica L.) peel extracts against tyrosinase, α-glucosidase, urease and cholinesterases enzymes, and relationship with antioxidant activity

IntroductionKey-enzyme inhibition is a recent approach for the treatment of some health disorders, including diabetes, skin hyperpigmentation, Alzheimer's disease, and some microbial infections. Looking for potential natural multi-target inhibitors, flavonoid-rich extracts from the peel of Ficus carica fruits were simultaneously tested against five enzymes and various methods were used to evaluate their antioxidant activity. MethodsExtracts from peels from F. carica cultivars (Bakor Noir, Bouankik, Azenjer, and Tazegaght) were prepared using methanol acidified by 5% citric acid. Inhibitory activities of extracts at 10 mg/mL were measured in vitro against α-glucosidase, tyrosinase, urease, acetylcholinesterase, and butyrylcholinesterase. Also, the antioxidant activity was evaluated using free radical scavenging, iron and copper chelating, and reducing assays. ResultsExtracts were efficient in inhibiting tyrosinase and α-glucosidase (IC50 values from 0.09 to 0.45, and 1.18 to 3.38 mg/mL, respectively). However, a weak inhibition was observed against urease and cholinesterases. Among the antioxidant activities studied, extracts were more efficient for copper chelation and radical scavenging (IC50 values from 0.05 to 0.13, and 0.30 to 1.33 mg/mL, respectively). Phytochemical analysis revealed the extraction of large quantities of flavonoids (up to 50.4 mg/g of peels), mainly flavonols (up to 81% of total flavonoids). Given the specific extract composition, including two fractions (flavonoids and citric acid), a strong synergy was observed for enzyme inhibition and metal chelation. ConclusionFlavonoid-rich extracts from F. carica could be considered as multifunctional bioactive ingredients to be used in anti-hyperglycemic and skin-whitening pharmaceutical formulations.

Trichilia catigua and Turnera diffusa extracts: In vitro inhibition of tyrosinase, antiglycation activity and effects on enzymes and pathways engaged in the neuroinflammatory process

Ethnopharmacological relevanceFlavonoids interact with multiple targets in Central Nervous System resulting in a broad neuroprotection mediated by complementary processes and synergic interactions. Therefore, flavonoid-based therapies may input positive outcomes in the prevention and early management of neurodegenerative diseases. In Brazilian folk medicine Trichilia catigua is used for its neuroactive properties, such as neurostimulant, antioxidant and anti-neuroinflammatory, while Turnera diffusa is traditionally used as a tonic in neurasthenia. Both species are known to be rich in flavonoids. Aim of the studyTo study aqueous extracts of T. catigua and T. diffusa in terms of their antioxidant and antiglycation effects, inhibition of tyrosinase activity, and interaction with enzymes and pathways engaged in neuroinflammation. Moreover, whenever possible, to establish a relationship between the studied activities and the traditional usage of the species. Materials and methodsThe phenolic profiles of the aqueous extracts were validated by HPLC-DAD. The effect of the extracts over mushroom tyrosinase and 5-lipoxygenase activities, as well as their capacity to impair bovine serum albumin glycation, were assessed by in vitro assays. The anti-neuroinflammatory potential of the same extracts was evaluated by their capacity to mitigate the pro-inflammatory stimulus induced in BV-2 microglia cells by interferon-gamma. ResultsT. catigua extract, a rich mixture of phenolic acids, catechins and flavonolignans, excels by its ability to decrease lipid peroxidation (EC50 = 227.18 ± 9.04 μg/mL), and to work as anti-glycation agent, and inhibitor of both tyrosinase and 5-lipoxigenase (IC50 = 358.84 ± 19.05 and 56.25 ± 14.53 μg/mL, respectively). However, only T. diffusa extract, mainly composed by luteolin derivatives, is able to lower NO production by BV-2 microglia cells stimulated with interferon-gamma, despite its lower activities in the other assays. ConclusionsOverall, this work highlights the value of medicinal plant extracts as sources of bioactive flavonoid-rich extracts with neuroactive effects. Furthermore, these results support their application as alternative strategies to develop functional foods and therapeutics to fight chronic neurodegenerative disorders.

Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea (Ampelopsis grossedentata)

Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea (Ampelopsis grossedentata)

Flavonoids from Rosa davurica Pall. fruits prevent high-fat diet-induced obesity and liver injury via modulation of the gut microbiota in mice.

Rosa davurica Pall. (RDP) fruits are popularly consumed as beverages and healthy food in China because of their various beneficial activities. In particular, flavonoids are one of the major active ingredients of RDP fruits with predominant pharmacological effects. However, the anti-obesity activities of flavonoids from RDP fruits and their regulation effect on the gut microbiota have not been determined. In the present study, the flavonoid-rich extracts (RDPF) were isolated from RDP fruits and their anti-obesity effects were investigated using a high-fat diet (HFD)-induced obese mouse model. The results showed that RDPF intervention significantly inhibited the body weight, liver weight, kidney weight and epididymal adipose tissue weight of HFD-fed mice without affecting the calorie intake. Plasma lipid levels were also significantly lowered by RDPF treatment. Histological examination showed that RDPF supplementation partially recovered HFD-induced hepatic steatosis in the liver. RDPF also prevented oxidative injury of the liver, as evidenced by the altered superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) levels. The expression levels of CCAAT/enhancer binding protein α (C/EBPα), sterol regulatory element binding protein-1C (SREBP-1C), fatty acid synthase (FAS), acyl-coenzyme A oxidase 1 (ACOX1), peroxisome proliferator-activated receptor (PPARα) and CAT mRNA in the livers of mice were also regulated by RDPF administration. 16S rRNA gene sequence data further indicated that RDPF addition increased the microbial diversity and reshaped the community composition. Intriguingly, RDPF intervention did not exhibit inhibitory tendency toward the ratio of Firmicutes to Bacteroidetes, but markedly decreased the relative abundance of Erysipelotrichaceae. This study provided novel insights into the application of RDPF in the food industry.

Effect of administration of flavonoid-rich extract from Hibiscus sabdariffa to lactating rats on plasma glucocorticoid, leptin, and postnatal growth of offspring

Introduction: Flavonoids are a group of natural substances with variable phenolic structures well-known for their beneficial effects on health. Flavonoids are now considered an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal, and cosmetic applications because of their anti-oxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Aim: This study was aimed at investigating the effect of administration of flavonoids from Hibiscus sabdariffa (HS) to lactating rats on plasma glucocorticoids, leptin, and postnatal weights of the offspring. Materials and Methods: Forty pregnant female Sprague − Dawley rats weighing 150 g–200 g were used for this study. Flavonoids were extracted from HS following standard procedures. On the day of delivery, the rats were divided basically into four groups of 10 dams per group. Group A received tap water; Group B received low dose of flavonoid (5 mg/kg body weight daily); Group C received medium dose of flavonoid (10 mg/kg body weight daily); and Group D received high dose of flavonoid (20 mg/kg body weight daily). Flavonoid administration commenced on day 1 of lactation and ended at weaning. Dams from each group had their blood withdrawn from the orbital sinus on days 1, 7, and 21 for assay of plasma glucocorticoids and leptin. Food intake of the dams and body weight of the offspring was measured. Results: There was a progressive dose-dependent decrease (P < 0.05) in maternal plasma glucocorticoids and leptin with the most decrease seen in the high dose group and PND 21. Low dose flavonoid caused a progressive decrease in maternal food consumption when compared with the control group (P < 0.05). Low dose extract caused a progressive decrease in the body weight of the offspring, whereas the high dose caused a progressive increase in the body weight of the offspring (P < 0.05). Conclusion: Flavonoids from HS caused a progressive decrease in glucocorticoids and leptin with a resultant progressive increase in maternal food intake and body weights of the offspring.

Antidiabetic activity of a Flavonoid-Rich extract from flowers of Wisteria sinensis in type 2 diabetic mice via activation of the IRS-1/PI3K/Akt/GLUT4 pathway

• WS-FRE ameliorated a series of diabetes-related indices. • WS-FRE promoted GLUT4 translocation and expression by activating PI3K/Akt pathway. • WS-FRE ameliorated pathological changes of insulin-sensitive tissues. • WS-FRE regulated glucose metabolism through IRS-1/PI3K/Akt/GLUT4 pathway. The present study aimed to investigate anti-diabetic activities of a flavonoid-rich extract from Wisteria sinensis (WS-FRE). In vitro , WS-FRE significantly promote the translocation of GLUT4 (Glucose transporter 4) to the plasma membrane. Mechanisms analysis revealed that WS-FRE enhanced glucose uptake via activation of Akt and GLUT4. In vivo , 4-week treatment of WS-FRE alleviated the typical symptoms including hyperglycemia, glucose intolerance, hyperinsulinemia and dyslipidemia. Histopathological examinations revealed that WS-FRE relieved hepatic steatosis, adipocyte hypertrophy and pancreatic islet lesion to a certain extent in diabetic mice. Western blot analysis indicated that WS-FRE resulted in the suppression of IRS-1 serine phosphorylation and an elevation of PI3K p85, Akt phosphorylation and GLUT4 expression in insulin target tissues, which contributes to improving insulin sensitivity in peripheral tissues and thereby ameliorating glucose metabolism in diabetic mice. Diverse anti-diabetic effects of WS-FRE may be attributed to regulation of GLUT4, IRS-1 serine phosphorylation, PI3K phosphorylation and Akt phosphorylation.

Antidiabetic effect of a flavonoid-rich extract from Sophora alopecuroides L. in HFD- and STZ- induced diabetic mice through PKC/GLUT4 pathway and regulating PPARα and PPARγ expression

Headings ethnopharmacological relevanceSophora alopecuroides L. is a traditional ethnopharmacological plant, which is widely used in traditional Chinese medicine and Mongolian and Uighur medicine to ameliorate “thirst disease”. Aim of the studyThis study aimed to investigate the antidiabetic activities and mechanisms of a flavonoid-rich extract from Sophora alopecuroides L. (SA-FRE) both in vivo and vitro. Materials and methodsThe main six chemical constituents of SA-FRE were elucidated based on an off-line semi-preparative liquid chromatography nuclear magnetic resonance (LC-NMR) protocol. Myc-GLUT4-mOrange-L6 cell models and mouse model with diabetes induced by high-fat diet combined with STZ injection were respectively adopted to investigate the antidiabetic effects of SA-FRE both in vitro and vivo. ResultsIn vivo, 4-week treatment of SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance in diabetic mice. Mechanically, SA-FRE regulated PPARα and PPARγ expression in white adipose tissue (WAT) and liver, thereby ameliorating dyslipidemia. Moreover, SA-FRE increased the phosphorylation of PKC and further stimulated the GLUT4 expression in WAT and skeletal muscle, thus increasing the glucose utilization in vivo. In vitro, 50 μg/mL SA-FRE increased GLUT4 translocation to about 1.91-fold and glucose uptake to 1.82-fold in L6-myotubes. SA-FRE treatment increased the GLUT4 expression at both gene and protein levels. Furthermore, only Gö6983, a PKC inhibitor, reversed the SA-FRE-induced GLUT4 translocation and expression at the gene and protein levels. ConclusionsGenerally, SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance partly through activating PKC/GLUT4 pathway and regulating PPARα and PPARγ expression.