• Advances in Traditional Medicine
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• v.6 no.3
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• pp.167-173
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• 2006

A growing body of evidence supports lipid peroxidation as having a role in the pathogenesis of liver disease. Although the probable cause of damage to human hepatocytes may be multifactorial, free radicals have been implicated in a variety of liver diseases, particularly in the presence of iron overload and toxic substances such as ethanol. Consequently, antioxidants, particularly those of plant origin such as flavonoids, may help to reduce the risk of developing these diseases. Silybum (S.) marianum, a medicinal plant widely used in traditional European medicine for the treatment of liver disorders, was evaluated for antioxidant activity. Thin layer chromatography and High Performance Liquid Chromatography analyses of crude extract of the plant confirmed the presence of a number of flavonoids reported in the literature. The antioxidant activity of these flavonoids was measured through inhibition of lipid peroxidation and 1, 1-diphenyl-2- picrylhydrazyl radical scavenging. The crude plant extract showed marked antioxidant activity in both assays. These results suggest that S. marianum contains flavonoids with antioxidant activity, capable of inhibiting or scavenging free radicals, thus supporting its traditional use as a hepatoprotective agent.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.34-39
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• 1999

To search for less toxic antiherpetic agents, the inhibitory effects of twelve kinds of flavonoids including chrysin, quercetin, quercitrin, rutin, fisetin, gossypin, kaempferol, morin, naringenin, naringin, hesperetin and hesperidin on the plaque formation of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in Vero cells were examined by plaque reduction assay in vitro. Some flavonoids tested in this study showed potent antiherpetic activity, reducing intracellular replication of herpes simplex viruses when Vero cell monolayers were infected and subsequently cultured in medium containing flavonoids. Naringenin showed the most potent antiviral activity against HSV-1 with selectivity index (SI) of 19.1 and hesperetin showed the most potent antiviral activity against HSV-2 with SI of 9.8. These results suggest that some flavonoids may be a potential therapeutic agent for the treatment and prevention of herpes simplex virus infections.

• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.47-54
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• 1995

To investigate and evaluated the scavenging and antioxidative effects of various flavonoids on paraquat induced toxicity, in vivo and vitro tests of eight flavonoids (catechin, epocatechin, flavone, chrysin, apigenin, quercetin, morin and biochanin A) were carried out. The generation of reactive oxygen substances(ROS) in PMS-NADH system $H_2O_2$ induced hemolysis and lipidperoxidation to blood, NADPH dependent lipidperoxidation to liver and lung microsome by paraquat were studied.The results are summerized as follows; 1) In the concentration ranges from 3.3 to 9.8$\mu$M of catechin,epicatechin, quercetin and biochanin A removed the 50% of DPPH radical scavenging effects. 2) In the concentration ranges from 0.60 to 1.86 mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on superoxide anion which gernerated in PMA-NADH system. 3) In the concentration ranges from 0.12 to 0.49mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on H202 which generated in PMA-NADH system. 4) In the concentration ranges from 0.6 x10$^{-5}$ to 6.3 x 10$^{-5}$mM of catechin, epicatechin, flavone, chrysin, quercetin and morin showed the inhibitory and antioxidative activity on $H_2O_2$ induced hemolysis to blood 5) All flavonoids tested exhibited inhibitory and antioxidative effects on paraquat induced liver and tung microsomal lipidperoxidation. Therefore, all flavonoids evaluated showed the useful compounds for scavenger and antioxidant on paraquat induced toxicity.

• Korean Journal of Pharmacognosy
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• v.51 no.2
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• pp.139-145
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• 2020

The leaves of Diospyros kaki Thunb. were used to treat heart disease and hypotension in traditionally East Asia. The purpose of this study is to simultaneously quantitiative analyze the content of flavonoids in leaves of D. kaki. The isolated flavonoids from the leaves of D. kaki, and the structure of the isolated flavonoids were analyzed based on ¹H and ¹³C NMR spectrum compared to literature data. Simultaneous quantitative analysis of the isolated flavonoids was validated using high performance liquid chromatography (HPLC). Results showed that the calibration curves of the flavonoid compounds were confirmed that they have a large linearity with a correlation coefficient (R²) of 0.99. In the intra-day and inter-day analysis, accuracy and precision of five compounds were measured that accuracy was 94.39 to 114.47% and precision was less than 3.00%. Content analysis showed hyperoside (1.30 ± 0.09%), astragalin (0.81 ± 0.06%), trifoline (1.58 ± 0.07%), quercetin (0.13 ± 0.02%) and kaempferol (1.33 ± 0.25%).

• Natural Product Sciences
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• v.2 no.1
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• pp.1-8
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• 1996

Flavonoids are widely distributed polyphenol compounds in plant kingdom and known to possess varieties of biological/pharmacological activities in vitro and in vivo. A search for antiinflammatory/immunoregulatory flavonoids as potential therapeutic agents has been continued, since serious side effects of currently used nonsteroidal and steroidal antiinflammatory drugs limit their long term uses for the inflammatory disorders. In this reserch, various flavonids were isolated and tested for their in vivo antiinflammatory activity and in vitro inhibitory activity of lymphocyte proliferation. Using a mouse ear edema assay, it was found that certain flavones/flavonols possess mild antiinflammatory activity and a C-2,3-double bond might be essential. Isoflavones were less active. These flavonoids inhibited in vitro lymphocyte proliferation, relatively specific for T-cell proliferation $(IC_{50}=1-10\;{\mu}M)$ and the inhibition was reversible. We have also tested several biflavonoid derivatives, since we recently found that biflavones were phospholipase $A_2$ inhibitors. It was demonstrated that biflavones such as ochnaflavone and ginkgetin inhibited lymphocyte proliferation induced by both concanavaline A and lipopolysaccharide. The inhibition was irreversible in contrast to that of flavones/flavonols. And antiinflammatory activity of biflavonoids are discussed.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.320-327
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• 1999

The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

• Journal of fish pathology
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• v.28 no.1
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• pp.17-26
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• 2015

The purpose of this study is to explore the possibility of essential oils and flavonoids improving the performance of antibiotics, proving a higher efficacy in the presence of natural substances against Edwardsiella tarda and Streptococcus iniae. Increased efficacy was observed in several cases: both essential oils and flavonoids increased antibacterial efficacy of oxytetracycline and flumequine against E. tarda by 2-fold; essential oils and flavonoids increased antibacterial efficacy of nalidixic acid against E. tarda by 4-fold; flavonoids increased antibacterial efficacy of josamycin against S. iniae by 4-fold. The results obtained in this study suggest that essential oils and flavonoids might be especially useful in increasing the antimicrobial activity of nalidixic acid and josamycin against E. tarda and S. iniae in fish. Natural compounds examined in this study could also be useful to help decrease the overuse of antibiotics in fish.

• Journal of Menopausal Medicine
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• v.24 no.3
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• pp.169-175
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• 2018

Objectives: The rate of metabolic syndrome (MetS) in women diagnosed as they age is one of the main concerns of health cares. Recently new strategies used to prevent progressions of MetS toward the diagnosis of diabetes have focused on plant flavonoids. This study was aimed to investigate the beneficial effects of flavonoids fraction of Mespilus germanica leaves (MGL) on MetS in ovariectomized (OVX) rats. Methods: Twenty-four adult female Wistar rats, weighing 200 to 250 g, were divided into 3 groups: Sham surgery, OVX + Salin, or OVX + Flavonoid. Three weeks after ovariectomy, animals displayed MetS criteria received flavonoid injection (10 mg/kg, intraperitoneally) for 21 days. Then the body weight, body mass index, waist circumference, visceral fat, fasting blood glucose, serum insulin, lipid profiles and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) were measured. Results: Treatment with flavonoids fraction of MGL significantly decreased serum level of insulin (P = 0.011), glucose (P = 0.024), $TNF-{\alpha}$ (P = 0.010), also MetS Z score (P = 0.020) and homeostasis model assessment of insulin resistance (P = 0.007). Lipid profiles and visceral fat showed insignificant reduction. Conclusions: Flavonoids of MGL attenuates some of the MetS components possibly via reduction in $TNF-{\alpha}$ inflammatory cytokine.

• Natural Product Sciences
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• v.28 no.1
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• pp.27-32
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• 2022

This study evaluated the general nutritional ingredients such as crude fats, crude ashes, crude proteins, total polyphenols, and total flavonoids in 18 kinds of edible tree sprouts. The tree sprouts of Philadelphus schrenckii, Lycium chinense, and Morus alba had the highest crude fat, crude ash, and crude protein content, respectively. The tree sprouts of Cedrela sinensis (CSS) with high ABTS⁺ radical scavenging activities had a high content of total polyphenols (175.65 mg/g ext.) and total flavonoids (75.18 mg/g ext.). The simultaneous determination of flavonoids such as rutin, isoquercitrin, quercitrin, afzelin, and quercetin in CSS was conducted using high-performance liquid chromatography with a wavelength of 270 nm. Among the flavonoids, the content of quercitrin in CSS was the highest at 59.28 mg/g ext. This study also aids the quality control of many edible tree sprouts by analyzing the general components, total polyphenols, and total flavonoids.

• Natural Product Sciences
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• v.4 no.1
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• pp.38-41
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• 1998

From the dried leaves of Isodon eriocalyx (Labiatae) six flavonoids were isolated and two of them were elucidated to be novel ones named 5,7,8,4'-tetrahydroxy-6-methoxyflavone (1), and $isothymusin-8-O-{\beta}-D-glucoside$ (2).