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Identification and quantification of phenolic and flavonoid components in straw and seed husk of some rice varieties (Oryza sativa L.) and their antioxidant properties

Karimi E, Mehrabanjoubani P, Keshavarzian M, Oskoueian E, Jaafar HZ, Abdolzadeh A

J Sci Food Agric, 2014 Aug;94(11):2324-30.
PMID: 24415452 DOI: 10.1002/jsfa.6567

Plant foods are rich sources of bioactive compounds that can act as antioxidants to prevent heart disease, reduce inflammation, reduce the incidence of cancers and diabetes. This study aimed to determine the phenolics and flavonoids profiling in three varieties of rice straw and five varieties of the seed husk of Iranian rice using high-performance liquid chromatography (HPLC). Furthermore, the antioxidant activities of the extracts were evaluated by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and nitric oxide assays.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext Impact of specific functional groups in flavonoids on the modulation of platelet activation

Ravishankar D, Salamah M, Akimbaev A, Williams HF, Albadawi DAI, Vaiyapuri R, et al.

Sci Rep, 2018 Jun 22;8(1):9528.
PMID: 29934595 DOI: 10.1038/s41598-018-27809-z

Flavonoids exert innumerable beneficial effects on cardiovascular health including the reduction of platelet activation, and thereby, thrombosis. Hence, flavonoids are deemed to be a molecular template for the design of novel therapeutic agents for various diseases including thrombotic conditions. However, the structure-activity relationships of flavonoids with platelets is not fully understood. Therefore, this study aims to advance the current knowledge on structure-activity relationships of flavonoids through a systematic analysis of structurally-related flavones. Here, we investigated a panel of 16 synthetic flavones containing hydroxy or methoxy groups at C-7,8 positions on the A-ring, with a phenyl group or its bioisosteres as the B-ring, along with their thio analogues possessing a sulfur molecule at the 4th carbon position of the C-ring. The antiplatelet efficacies of these compounds were analysed using human isolated platelets upon activation with cross-linked collagen-related peptide by optical aggregometry. The results demonstrate that the hydroxyl groups in flavonoids are important for optimum platelet inhibitory activities. In addition, the 4-C=O and B ring phenyl groups are less critical for the antiplatelet activity of these flavonoids. This structure-activity relationship of flavonoids with the modulation of platelet function may guide the design, optimisation and development of flavonoid scaffolds as antiplatelet agents.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext In vitro antioxidant activity of Ficus carica L. latex from 18 different cultivars

Shahinuzzaman M, Yaakob Z, Anuar FH, Akhtar P, Kadir NHA, Hasan AKM, et al.

Sci Rep, 2020 07 02;10(1):10852.
PMID: 32616768 DOI: 10.1038/s41598-020-67765-1

As synthetic antioxidants that are widely used in foods are known to cause detrimental health effects, studies on natural additives as potential antioxidants are becoming increasingly important. In this work, the total phenolic content (TPC) and antioxidant activity of Ficus carica Linn latex from 18 cultivars were investigated. The TPC of latex was calculated using the Folin-Ciocalteu assay. 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) were used for antioxidant activity assessment. The bioactive compounds from F. carica latex were extracted via maceration and ultrasound-assisted extraction (UAE) with 75% ethanol as solvent. Under the same extraction conditions, the latex of cultivar 'White Genoa' showed the highest antioxidant activity of 65.91% ± 1.73% and 61.07% ± 1.65% in DPPH, 98.96% ± 1.06% and 83.04% ± 2.16% in ABTS, and 27.08 ± 0.34 and 24.94 ± 0.84 mg TE/g latex in FRAP assay via maceration and UAE, respectively. The TPC of 'White Genoa' was 315.26 ± 6.14 and 298.52 ± 9.20 µg GAE/mL via the two extraction methods, respectively. The overall results of this work showed that F. carica latex is a potential natural source of antioxidants. This finding is useful for further advancements in the fields of food supplements, food additives and drug synthesis in the future.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext In vitro antioxidant and in vivo hepatoprotective effect on ethanol-mediated liver damage of spray dried Vernonia amygdalina water extract

Ho WY, Yeap S, Liang WS, Beh BK, Mohamad N, Alitheen NB

Pak J Pharm Sci, 2015 Jan;28(1):15-22.
PMID: 25553678

Vernonia amygdalina is a strong natural antioxidant that possessed various medicinal properties. In this study, the spray-dried water extract of V. amygdalina was evaluated for its in vitro antioxidant capacity and in vivo hepatoprotective effect against alcoholic-mediated liver damage. Total phenolic and flavonoid content of spray-dried V. amygdalina water extract were determined. Liver enzyme profiles, liver antioxidant level and nitric oxide level were evaluated in alcohol-induced liver injured mice or co-supplement with spray-dried V. amydalina. Water extract of spray-dried V. amygalina that contained phenolic content of 24.8±1.5 mg/g gallic acid equivalent and total flavonoid content of 25.7±1.3 mg/g catechin equivalent was able to inhibit 50% of xanthine and tyrosinase oxidation at 170 μg/ml and 2 mg/mL, respectively. On the other hand, extracts at both 10 and 50 mg/kg body weight were able to reduce the levels of Alanine transaminase (ALT), Alkaline phosphatase (ALP), Aspartate transaminase (AST), triglyceride and total bilirubin content inthe alcohol-mediated liver injury in mice. Furthermore, it also helped to increase levels of Superoxide dismutase (SOD), Ferric reducing ability of plasma (FRAP) and reduce the levels of Nitric oxide (NO) and Malondialdehyde (MDA) in the liver of the treated mice. These resultssuggestedthat water extract of spray-dried V. amygdalina exhibited liver protective effect, which could be contributed by its antioxidant properties.

Matched MeSH terms: Flavonoids/pharmacology
In vitro effect of important herbal active constituents on human cytochrome P450 1A2 (CYP1A2) activity

Pan Y, Tiong KH, Abd-Rashid BA, Ismail Z, Ismail R, Mak JW, et al.

Phytomedicine, 2014 Oct 15;21(12):1645-50.
PMID: 25442272 DOI: 10.1016/j.phymed.2014.08.003

This study was designed to investigate eight herbal active constituents (andrographolide, asiaticoside, asiatic acid, madecassic acid, eupatorin, sinensetin, caffeic acid, and rosmarinic acid) on their potential inhibitory effects on human cytochrome P450 1A2 (CYP1A2) activity. A fluorescence-based enzyme assay was performed by co-incubating human cDNA-expressed CYP1A2 with its selective probe substrate, 3-cyano-7-ethoxycoumarin (CEC), in the absence or presence of various concentrations of herbal active constituents. The metabolite (cyano-hydroxycoumarin) formed was subsequently measured in order to obtain IC50 values. The results indicated that only eupatorin and sinensetin moderately inhibited CYP1A2 with IC50 values of 50.8 and 40.2 μM, while the other active compounds did not significantly affect CYP1A2 activity with IC50 values more than 100 μM. Ki values further determined for eupatorin and sinensetin were 46.4 and 35.2 μM, respectively. Our data indicated that most of the investigated herbal constituents have negligible CYP1A2 inhibitory effect. In vivo studies however may be warranted to ascertain the inhibitory effect of eupatorin and sinensetin on CYP1A2 activity in clinical situations.

Matched MeSH terms: Flavonoids/pharmacology*
In vitro inhibitory effects of Moringa oleifera leaf extract and its major components on chemiluminescence and chemotactic activity of phagocytes

Vongsak B, Gritsanapan W, Wongkrajang Y, Jantan I

Nat Prod Commun, 2013 Nov;8(11):1559-61.
PMID: 24427941

The ethanol extract of Moringa oleifera Lam. leaves and its major constituents, crypto-chlorogenic acid, quercetin 3-O-glucoside and kaempferol 3-O-glucoside, were investigated on the respiratory burst of human whole blood and isolated human polymorphonuclear leukocytes (PMNs) using a luminol-based chemiluminescence assay. The chemotactic migration of PMNs was also investigated using the Boyden chamber technique. The ethanol extract demonstrated inhibitory activities on the oxidative burst and the chemotactic migration of PMNs. Quercetin 3-O-glucoside, crypto-chlorogenic acid, and kaempferol 3-O-glucoside, isolated from the extract, expressed relatively strong inhibitory activity on the oxidative burst of PMNs with IC50 values of 4.1, 6.7 and 7.0 microM, respectively, comparable with that of aspirin. They also demonstrated strong inhibition of chemotatic migration of PMNs with IC50 values of 9.5, 15.9 and 18.2 microM, respectively. The results suggest that M. oleifera leaves could modulate the immune response of human phagocytes, linking to its ethnopharmacological use as an anti-inflammatory agent. The immunomodulating activity of the plant was mainly due to its major components.

Matched MeSH terms: Flavonoids/pharmacology
Fulltext In vitro investigation of cytotoxic and antioxidative activities of Ardisia crispa against breast cancer cell lines, MCF-7 and MDA-MB-231

Nordin ML, Abdul Kadir A, Zakaria ZA, Abdullah R, Abdullah MNH

BMC Complement Altern Med, 2018 Mar 12;18(1):87.
PMID: 29530022 DOI: 10.1186/s12906-018-2153-5

BACKGROUND: Ardisia crispa Thunb. D.C is used mostly in some parts of the Asian region by traditional practitioners to treat certain diseases associated with oxidative stress and inflammation including cancer and rheumatism. In Malaysia, it is popularly known as 'Mata Ayam' and local traditional practitioners believed that the root of the plant is therapeutically beneficial.
METHODS: The cytotoxic effect of hydromethanolic extract of A. crispa and its solvents partitions (ethyl acetate and aqueous extracts) against breast cancer cells were evaluated by using MTT assay. The cells were treated with concentration of extracts ranging from 15.63 μg/mL- 1000 μg/mL for 72 h. The quantification of phenolic and flavonoid contents of the extracts were carried out to determine the relationship between of phytochemical compounds responsible for cytotoxic and antioxidative activities. The antioxidant capacity was measured by DPPH and ABTS free radical scavenging assay and expressed as milligram (mg) Trolox equivalent antioxidant capacity per 1 g (g) of tested extract.
RESULTS: The hydromethanolic and ethyl acetate extracts showed moderate cytotoxic effect against MCF-7 with IC50 values of 57.35 ± 19.33 μg/mL, and 54.98 ± 14.10 μg/mL, respectively but aqueous extract was inactive against MCF-7. For MDA-MB-231, hydromethanolic, ethyl acetate and aqueous extracts exhibited weak cytotoxic effects against MDA-MB-231 with IC50 values more than 100 μg/mL. The plant revealed high total phenolic content, total flavonoid and antioxidant capacity.
CONCLUSION: The response of different type of breast cancer cell lines towards A. crispa extract and its partitions varied. Accordingly, hydromethanolic and ethyl acetate extracts appear to be more cytotoxic to oestrogen receptor (ER) positive breast cancer than oestrogen receptor (ER) negative breast cancer. However, aqueous extract appears to have poor activity to both types of breast cancer. Besides that, hydromethanolic and ethyl acetate extracts exhibit higher TPC, TFC and antioxidant capacity compared to aqueous extract. Synergistic effect of anticancer and antioxidant bioactives compounds of A. crispa plausibly contributed to the cytotoxic effects of the extract.

Matched MeSH terms: Flavonoids/pharmacology
In vitro modulation of naturally occurring flavonoids on cytochrome P450 2A6 (CYP2A6) activity

Tiong KH, Yiap BC, Tan EL, Ismail R, Ong CE

Xenobiotica, 2010 Jul;40(7):458-66.
PMID: 20402563 DOI: 10.3109/00498251003786749

1. The effect of flavonoids on coumarin 7-hydroxylation, an activity marker of an important human liver cytochrome P450 isoform, cytochrome P450 2A6 (CYP2A6), was investigated in this study. 2. Coumarin 7-hydroxylase activity was measured fluorometrically in reaction mixtures containing cDNA-expressed CYP2A6, nicotinamide adenine dinucleotide phosphate generating system and 10 uM coumarin, at various concentrations of flavonoids. 3. Among the 23 compounds tested, most of the active members were from flavonol group of hydroxylated flavonoids, with myricetin being the most potent inhibitor followed by quercetin, galangin, and kaempferol. 4. Further exploration of the inhibition mechanism of these compounds revealed that myricetin, galangin, and kaempferol exhibited mixed-type of inhibition pattern while quercetin was observed to exhibit competitive mode of inhibition. 5. Structure-function analyses revealed that degree of inhibition was closely related to the number and location of hydroxyl groups, glycosylation of the free hydroxyl groups, degree of saturation of the flavane nucleus as well as the presence of the alkoxylated function.

Matched MeSH terms: Flavonoids/pharmacology
In vitro modulatory effects of Andrographis paniculata, Centella asiatica and Orthosiphon stamineus on cytochrome P450 2C19 (CYP2C19)

Pan Y, Abd-Rashid BA, Ismail Z, Ismail R, Mak JW, Pook PC, et al.

J Ethnopharmacol, 2011 Jan 27;133(2):881-7.
PMID: 21093571 DOI: 10.1016/j.jep.2010.11.026

Andrographis paniculata (AP), Centella asiatica (CA) and Orthosiphon stamineus (OS) are three popular herbs traditionally used worldwide. AP is known for the treatment of infections and diabetes and CA is good for wound healing and healthy skin while OS is usually consumed as tea to treat kidney and urinary disorders. Interaction of these herbs with human cytochrome P450 2C19 (CYP2C19), a major hepatic CYP isoform involved in metabolism of many clinical drugs has not been investigated to date.

Matched MeSH terms: Flavonoids/pharmacology
In vitro modulatory effects of flavonoids on human cytochrome P450 2C8 (CYP2C8)

Pang CY, Mak JW, Ismail R, Ong CE

Naunyn Schmiedebergs Arch Pharmacol, 2012 May;385(5):495-502.
PMID: 22307090 DOI: 10.1007/s00210-012-0731-5

The inhibitory effects of five flavonoids with distinct chemical classes (flavones [luteolin], flavonols [quercetin and quercitrin], and flavanones [hesperetin and hespiridin]) on cDNA-expressed CYP2C8 were investigated. CYP2C8 was co-expressed with NADPH-cytochrome P450 reductase in Escherichia coli and used to characterise potency and mechanism of these flavonoids on the isoform. Tolbutamide 4-methylhydroxylase, a high-performance liquid chromatography-based assay, was selected as marker activity for CYP2C8. Our results indicated that the flavonoids inhibited CYP2C8 with different potency. The order of inhibitory activities was quercetin > luteolin > hesperetin > hesperidin > quercitrin. All of these compounds however exhibited mechanism-based inhibition. A number of structural factors were found to be important for inhibition; these include the molecular shape (volume to surface ratio), the number of hydroxyl groups as well as glycosylation of the hydroxyl group. Quercetin was the most potent inhibitor among the flavonoids examined in this study, and our data suggest that it should be examined for potential pharmacokinetic drug interactions pertaining to CYP2C8 substrates in vivo.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext In vivo antitumor and antimetastatic effects of flavokawain B in 4T1 breast cancer cell-challenged mice

Abu N, Mohamed NE, Yeap SK, Lim KL, Akhtar MN, Zulfadli AJ, et al.

Drug Des Devel Ther, 2015;9:1401-17.
PMID: 25834398 DOI: 10.2147/DDDT.S67976

Flavokawain B (FKB) is a naturally occurring chalcone that can be isolated through the root extracts of the kava-kava plant (Piper methysticum). It can also be synthesized chemically to increase the yield. This compound is a promising candidate as a biological agent, as it is reported to be involved in a wide range of biological activities. Furthermore, FKB was reported to have antitumorigenic effects in several cancer cell lines in vitro. However, the in vivo antitumor effects of FKB have not been reported on yet. Breast cancer is one of the major causes of cancer-related deaths in the world today. Any potential treatment should not only impede the growth of the tumor, but also modulate the immune system efficiently and inhibit the formation of secondary tumors. As presented in our study, FKB induced apoptosis in 4T1 tumors in vivo, as evidenced by the terminal deoxynucleotidyl transferase dUTP nick end labeling and hematoxylin and eosin staining of the tumor. FKB also regulated the immune system by increasing both helper and cytolytic T-cell and natural killer cell populations. In addition, FKB also enhanced the levels of interleukin 2 and interferon gamma but suppressed interleukin 1B. Apart from that, FKB was also found to inhibit metastasis, as evaluated by clonogenic assay, bone marrow smearing assay, real-time polymerase chain reaction, Western blot, and proteome profiler analysis. All in all, FKB may serve as a promising anticancer agent, especially in treating breast cancer.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext Indonesian Mangrove Sonneratia caseolaris Leaves Ethanol Extract Is a Potential Super Antioxidant and Anti Methicillin-Resistant Staphylococcus aureus Drug

Audah KA, Ettin J, Darmadi J, Azizah NN, Anisa AS, Hermawan TDF, et al.

Molecules, 2022 Nov 30;27(23).
PMID: 36500458 DOI: 10.3390/molecules27238369

Methicillin-resistant Staphylococcus aureus (MRSA) is an S. aureus strain that has developed resistance against ß-lactam antibiotics, resulting in a scarcity of a potent cure for treating Staphylococcus infections. In this study, the anti-MRSA and antioxidant activity of the Indonesian mangrove species Sonneratia caseolaris, Avicennia marina, Rhizophora mucronata, and Rhizophora apiculata were studied. Disk diffusion, DPPH, a brine shrimp lethality test, and total phenolic and flavonoid assays were conducted. Results showed that among the tested mangroves, ethanol solvent-based S. caseolaris leaves extract had the highest antioxidant and anti-MRSA activities. An antioxidant activity assay showed comparable activity when compared to ascorbic acid, with an IC50 value of 4.2499 ± 3.0506 ppm and 5.2456 ± 0.5937 ppm, respectively, classifying the extract as a super-antioxidant. Moreover, S. caseolaris leaves extract showed the highest content of strongly associated antioxidative and antibacterial polyphenols, with 12.4% consisting of nontoxic flavonoids with the minimum inhibitory concentration of the ethanol-based S. caseolaris leaves extract being approximately 5000 ppm. LC-MS/MS results showed that phenolic compounds such as azelaic acid and aspirin were found, as well as flavonoid glucosides such as isovitexin and quercitrin. This strongly suggested that these compounds greatly contributed to antibacterial and antioxidant activity. Further research is needed to elucidate the interaction of the main compounds in S. caseolaris leaves extract in order to confirm their potential either as single or two or more compounds that synergistically function as a nontoxic antioxidant and antibacterial against MRSA.

Matched MeSH terms: Flavonoids/pharmacology
Influence of flavonoids from Sedum aizoon L. on mitochondrial function of Rhizopus nigricans in strawberry

Ge Q, Zhao S, Shao X, Wei Y, Chen J, Wang H, et al.

World J Microbiol Biotechnol, 2024 Apr 13;40(5):161.
PMID: 38613738 DOI: 10.1007/s11274-024-03967-3

Rhizopus nigricans (R. nigricans), one of the fungi that grows the fastest, is frequently discovered in postharvest fruits, it's the main pathogen of strawberry root rot. Flavonoids in Sedum aizoon L. (FSAL) is a kind of green and safe natural substance extracted from Sedum aizoon L. which has antifungal activity. In this study, the minimum inhibitory concentration (MIC) of FSAL on R. nigricans and cell apoptosis tests were studied to explore the inhibitory effect of FSAL on R. nigricans. The effects of FSAL on mitochondria of R. nigricans were investigated through the changes of mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), Ca2+ content, H2O2 content, cytochrome c (Cyt c) content, the related enzyme activity and related genes of mitochondria. The results showed that the MIC of FSAL on R. nigricans was 1.800 mg/mL, with the addition of FSAL (1.800 mg/mL), the mPTP openness of R. nigricans increased and the MMP reduced. Resulting in an increase in Ca2+ content, accumulation of H2O2 content and decrease of Cyt c content, the activity of related enzymes was inhibited and related genes were up-regulated (VDAC1, ANT) or down-regulated (SDHA, NOX2). This suggests that FSAL may achieve the inhibitory effect of fungi by damaging mitochondria, thereby realizing the postharvest freshness preservation of strawberries. This lays the foundation for the development of a new plant-derived antimicrobial agent.

Matched MeSH terms: Flavonoids/pharmacology
Inhibition of gastrointestinal release of acetylcholine by quercetin as a possible mode of action of Psidium guajava leaf extracts in the treatment of acute diarrhoeal disease

Lutterodt GD

J Ethnopharmacol, 1989 May;25(3):235-47.
PMID: 2747259

The electrically stimulated guinea-pig ileum and spontaneously contracting guinea-pig ileum preparations were employed in studies on the effects of an alcoholic extract and two flavonoid compounds, quercetin and quercetin-3-arabinoside, extracted from the leaves of Psidium guajava. The extract showed a morphine-like inhibition of acetylcholine release in the coaxially stimulated ileum, together with an initial increase in muscular tone, followed by a gradual decrease. The morphine-like inhibition was found to be due to quercetin, starting at concentrations of 1.6 micrograms/ml. The glycoside did not show any such action at concentrations of up to 1.28 mg/ml. The extract inhibited spontaneous contractions in the unstimulated ileum with a concentration-response relationship.

Matched MeSH terms: Flavonoids/pharmacology*
Inhibition of prostaglandin E(2) production by synthetic minor prenylated chalcones and flavonoids: synthesis, biological activity, crystal structure, and in silico evaluation

Rullah K, Mohd Aluwi MF, Yamin BM, Abdul Bahari MN, Wei LS, Ahmad S, et al.

Bioorg Med Chem Lett, 2014 Aug 15;24(16):3826-34.
PMID: 25027933 DOI: 10.1016/j.bmcl.2014.06.061

The discovery of potent inhibitors of prostaglandin E2 (PGE2) synthesis in recent years has been proven to be an important game changer in pharmaceutical industry. It is known that excessive production of PGE2 triggers a vast array of biological signals and physiological events that contributes to inflammatory diseases such as rheumatoid arthritis, atherosclerosis, cancer, and pain. In this Letter, we report the synthesis of a series of minor prenylated chalcones and flavonoids which was found to be significantly active in suppressing the PGE2 production secreted by lipopolysaccharide-induced mouse macrophage cells (RAW 264.7). Among the compounds tested, 14b showed a dose-response inhibition of PGE2 production with an IC50 value of 2.1 μM. The suppression upon PGE2 secretion was not due to cell death since 14b did not reduce the cell viability in close proximity to the PGE2 inhibition concentration. The obtained atomic coordinates for the single-crystal XRD of 14b was then applied in the docking simulation to determine the potential important binding interactions with murine COX-2 and mPGES-1 putative binding sites.

Matched MeSH terms: Flavonoids/pharmacology*
Inhibitory activity of cyclohexenyl chalcone derivatives and flavonoids of fingerroot, Boesenbergia rotunda (L.), towards dengue-2 virus NS3 protease

Kiat TS, Pippen R, Yusof R, Ibrahim H, Khalid N, Rahman NA

Bioorg Med Chem Lett, 2006 Jun 15;16(12):3337-40.
PMID: 16621533

Boesenbergia rotunda (L.) cyclohexenyl chalcone derivatives, 4-hydroxypanduratin A and panduratin A, showed good competitive inhibitory activities towards dengue 2 virus NS3 protease with the Ki values of 21 and 25 microM, respectively, whilst those of pinostrobin and cardamonin were observed to be non-competitive. NMR and GCMS spectroscopic data formed the basis of assignment of structures of the six compounds isolated.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext Inhibitory effects of acetylmelodorinol, chrysin and polycarpol from Mitrella kentii on prostaglandin E₂ and Thromboxane B₂ production and platelet activating factor receptor binding

Saadawi S, Jalil J, Jasamai M, Jantan I

Molecules, 2012;17(5):4824-35.
PMID: 22538486 DOI: 10.3390/molecules17054824

Acetylmelodorinol, chrysin and polycarpol, together with benzoic acid, benzoquinone and stigmasterol were isolated from the leaves of Mitrella kentii (Bl.) Miq. The compounds were evaluated for their ability to inhibit prostaglandin E₂ (PGE₂) and thromboxane B₂ (TXB₂) production in human whole blood using a radioimmunoassay technique. Their inhibitory effect on platelet activating factor (PAF) receptor binding to rabbit platelet was determined using ³H-PAF as a ligand. Among the compounds tested, chrysin showed a strong dose-dependent inhibitory activity on PGE(2) production (IC₅₀ value of 25.5 µM), which might be due to direct inhibition of cyclooxygenase-2 (COX-2) enzymatic activity. Polycarpol, acetylmelodorinol and stigmasterol exhibited significant and concentration-dependent inhibitory effects on TXB₂ production with IC₅₀ values of 15.6, 19.1 and 19.4 µM, respectively, suggesting that they strongly inhibited COX-1 activity. Polycarpol and acetylmelodorinol showed strong dose-dependent inhibitory effects on PAF receptor binding with IC₅₀ values of 24.3 and 24.5 µM, respectively.

Matched MeSH terms: Flavonoids/pharmacology
Fulltext Investigation into the Molecular Mechanisms underlying the Anti-proliferative and Anti-tumorigenesis activities of Diosmetin against HCT-116 Human Colorectal Cancer

Koosha S, Mohamed Z, Sinniah A, Alshawsh MA

Sci Rep, 2019 03 26;9(1):5148.
PMID: 30914796 DOI: 10.1038/s41598-019-41685-1

Diosmetin (Dis) is a bioflavonoid with cytotoxicity properties against variety of cancer cells including hepatocarcinoma, breast and colorectal (CRC) cancer. The exact mechanism by which Dis acts against CRC however, still remains unclear, hence in this study, we investigated the possible molecular mechanisms of Dis in CRC cell line, HCT-116. Here, we monitored the viability of HCT-116 cells in the presence of Dis and investigated the underlying mechanism of Dis against HCT-116 cells at the gene and protein levels using NanoString and proteome profiler array technologies. Findings demonstrated that Dis exhibits greater cytotoxic effects towards HCT-116 CRC cells (IC50 = 3.58 ± 0.58 µg/ml) as compared to the normal colon CCD-841 cells (IC50 = 51.95 ± 0.11 µg/ml). Arrests of the cells in G2/M phase confirms the occurrence of mitotic disruption via Dis. Activation of apoptosis factors such as Fas and Bax at the gene and protein levels along with the release of Cytochrome C from mitochondria and cleavage of Caspase cascades indicate the presence of turbulence as a result of apoptosis induction in Dis-treated cells. Moreover, NF-ƙB translocation was inhibited in Dis-treated cells. Our results indicate that Dis can target HCT-116 cells through the mitotic disruption and apoptosis induction.

Matched MeSH terms: Flavonoids/pharmacology*
Fulltext Involvement of salicylic acid on antioxidant and anticancer properties, anthocyanin production and chalcone synthase activity in ginger (Zingiber officinale Roscoe) varieties

Ghasemzadeh A, Jaafar HZ, Karimi E

Int J Mol Sci, 2012 Nov 13;13(11):14828-44.
PMID: 23203096 DOI: 10.3390/ijms131114828

The effect of foliar application of salicylic acid (SA) at different concentrations (10-3 M and 10-5 M) was investigated on the production of secondary metabolites (flavonoids), chalcone synthase (CHS) activity, antioxidant activity and anticancer activity (against breast cancer cell lines MCF-7 and MDA-MB-231) in two varieties of Malaysian ginger, namely Halia Bentong and Halia Bara. The results of high performance liquid chromatography (HPLC) analysis showed that application of SA induced the synthesis of anthocyanin and fisetin in both varieties. Anthocyanin and fisetin were not detected in the control plants. Accordingly, the concentrations of some flavonoids (rutin and apigenin) decreased significantly in plants treated with different concentrations of SA. The present study showed that SA enhanced the chalcone synthase (CHS) enzyme activity (involving flavonoid synthesis) and recorded the highest activity value of 5.77 nkat /mg protein in Halia Bara with the 10-5 M SA treatment. As the SA concentration was decreased from 10-3 M to 10-5 M, the free radical scavenging power (FRAP) increased about 23% in Halia Bentong and 10.6% in Halia Bara. At a concentration of 350 μg mL-1, the DPPH antioxidant activity recorded the highest value of 58.30%-72.90% with the 10-5 M SA treatment followed by the 10-3 M SA (52.14%-63.66%) treatment. The lowest value was recorded in the untreated control plants (42.5%-46.7%). These results indicate that SA can act not only as an inducer but also as an inhibitor of secondary metabolites. Meanwhile, the highest anticancer activity against MCF-7 and MDA-MB-231 cell lines was observed for H. Bara extracts treated with 10-5 M SA with values of 61.53 and 59.88%, respectively. The results suggest that the high anticancer activity in these varieties may be related to the high concentration of potent anticancer components including fisetin and anthocyanin. The results thus indicate that the synthesis of flavonoids in ginger can be increased by foliar application of SA in a controlled environment and that the anticancer activity in young ginger extracts could be improved.

Matched MeSH terms: Flavonoids/pharmacology
Isolation and identification of antibacterial and cytotoxic compounds from the leaves of Muntingia calabura L

Sufian AS, Ramasamy K, Ahmat N, Zakaria ZA, Yusof MI

J Ethnopharmacol, 2013 Mar 7;146(1):198-204.
PMID: 23276785 DOI: 10.1016/j.jep.2012.12.032

Muntingia calabura (Elaeocarpaceae) is one of the most common roadside trees in Malaysia. Its leaves, barks, flowers and roots have been used as a folk remedy for the treatment of fever, incipient cold, liver disease, as well as an antiseptic agent in Southeast Asia. The aim of this study is to isolate and identify the antibacterial and cytotoxic compounds from the leaves of Muntingia calabura L.

Matched MeSH terms: Flavonoids/pharmacology*

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