PMID: 

Chem Biodivers. 2020 Mar 18. Epub 2020 Mar 18. PMID: 32187456

Abstract Title: 

Trifolium pratense (Red Clover) Improve SIRT1 Expression and Glycogen Content in High Fat Diet-Streptozotocin Induced Type 2 Diabetes in Rats.

Abstract: 

Flowering tops of Trifolium pratense L. (Fabaceae) are known for its traditional medicinal values. In present study, our aim was to investigate effect of standardized aqueous extract of flowering tops of Trifolium pratense L. on insulin resistance and SIRT1 expression in type 2 diabetic rats. Type 2 diabetes was induced by feeding high fat diet and administering low dose of streptozotocin. Diabetic animals were treated with standardized aqueous extract at three different doses. Parameters such as blood glucose, lipid profile, glycohemoglobin, insulin sensitivity, HOMA-IR and liver glycogen content were measured. Changes in morphology and expression of SIRT1 in pancreatic tissue were measured in histopathological and immunohistological studies. Aqueous extract treatment showed reduction in hyperglycemia and improved insulin sensitivity. Extract treatment also showed reduction in formation of glycated hemoglobin and improved liver glycogen level. Histopathological study revealed protecting effect of extract in pancreatic tissue against hyperglycemia induced damage. Treatment increased expression of SIRT1 in rat pancreatic tissue. Results indicate that the aqueous extract of Trifolium pratense had beneficial role in improving insulin sensitivity and SIRT1 expression.

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PMID: 

Phytother Res. 2006 Dec ;20(12):1096-9. PMID: 17078110

Abstract Title: 

Effects of isoflavones from red clover (Trifolium pratense) on skin changes induced by ovariectomy in rats.

Abstract: 

Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens improve skin in many ways. Among these, they increase collagen content, skin thickness and improve skin moisture. There is evidence that diets with high levels of phytoestrogenic isoflavones are associated with a low incidence of menopausal symptoms and osteoporosis. Plant extracts such as red clover, which contain high levels of isoflavones, have been used to reduce menopausal symptoms and have been shown to reduce bone loss in healthy women. In this study to investigate the effects of red clover isoflavones on skin aging, the histology of the skin, skin thickness and the amount of total collagen determined by a colorimetric method, were studied in ovariectomized rats after treatment for 14 weeks with a red clover extract standardized to contain 11% isoflavones determined by HPLC. In ovariectomized rats the thickness and keratinization of the epidermis were reduced; glands were less in number and vascularity was poor; the distribution and morphology of the collagen bundles and elastic fibers were altered. Whereas the skin of the ovariectomized rats treated with red clover isoflavones (20 and 40 mg of total isoflavones daily for 14 weeks) appeared well organized with a normal epidermis with uniform thickness and regular keratinization; vascularity, collagen and elastic fibers were well developed. The amount of collagen significantly increased in the treated group in comparison with the control group. These findings suggest that red clover isoflavones are effective in reducing skin aging induced by estrogen deprivation.

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PMID: 

Photochem Photobiol. 2001 Sep ;74(3):465-70. PMID: 11594062

Abstract Title: 

Isoflavonoid compounds from red clover (Trifolium pratense) protect from inflammation and immune suppression induced by UV radiation.

Abstract: 

Isoflavones derived from many edible plants have been reported to possess significant antioxidant, estrogenic and tyrosine kinase inhibitory activity. Genistein has been found previously to provide protection from oxidative damage induced by UV radiation both in vitro and following dietary administration. We have therefore examined the potential of a number of isoflavones from red clover (Trifolium pratense) and some metabolically related compounds to offer protection from UV irradiation in hairless mice by topical application after UV exposure. We show that whereas the primary isoflavones, daidzein, biochanin A and formononetin, were inactive, 20 microM lotions of genistein and the metabolites equol, isoequol and the related derivative dehydroequol had powerful potential to reduce the inflammatory edema reaction and the suppression of contact hypersensitivity induced by moderate doses of solar-simulated UV radiation. For equol the protection was concentration dependent and 5 microM equol markedly reduced the UV-induced inflammation but abrogated the UV-induced immunosuppression. Equol protected similarly from immunosuppression induced by the putative epidermal mediator, cis-urocanic acid (UCA), indicating a potential mechanism of action involving inactivation of this UV-photoproduct. Since immunosuppression induced by both UV radiation and by cis-UCA appears to be an oxidant-dependent response our observations support the actions of these topically applied isoflavones and their metabolites as antioxidants. They also indicate that lotions containing equol, unlike topical UV sunscreens, more readily protect the immune system from photosuppression than from the inflammation of the sunburn reaction, even when applied after exposure, and thus such compounds may have a future role as sun-protective cosmetic ingredients.

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PMID: 

Biosci Biotechnol Biochem. 2011 ;75(5):914-8. Epub 2011 May 20. PMID: 21597196

Abstract Title: 

In vitro and in vivo melanogenesis inhibition by biochanin A from Trifolium pratense.

Abstract: 

Our previous study showed that a methanol extract from Trifolium pratense exerted potent inhibitory activity on melanogenesis in mouse B16 melanoma cells. In the present study, the active compound in this Chinese herb extract was isolated and identified as biochanin A by mass spectrum, (1)H-NMR, and (13)C-NMR analysis. The inhibitory effects of biochanin A on melanogenesis were investigated in vitro in cultured melanoma cells and in vivo in zebrafish and mice. Biochanin A dose-dependently inhibited both melanogenesis and cellular tyrosinase activity in B16 cells and in zebrafish embryos. Application of a cream containing 2% biochanin A twice daily to the skin of mice also increased the skin-whitening index value after 1 week of treatment, and the increase continued for another 2 weeks. Biochanin A was confirmed as a good candidate for use as a skin-whitening agent in the treatment of skin hyperpigmentation disorders.

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PMID: 

J Nat Prod. 2018 09 28 ;81(9):1962-1967. Epub 2018 Sep 10. PMID: 30199256

Abstract Title: 

Irilone from Red Clover ( Trifolium pratense) Potentiates Progesterone Signaling.

Abstract: 

The use of botanical dietary supplements is becoming increasingly popular for the alleviation of hormonal-based conditions such as hot flashes, premenstrual syndrome, and fertility. Estrogen and progesterone receptors (ER and PR) play an essential role in these processes. However, despite the fact that many therapies used to alleviate gynecological conditions act through PR-mediated mechanisms, few studies have investigated or identified any herbal natural product components that act on this receptor. In the current study, we used a progesterone response element (PRE)-luciferase (Luc) reporter assay to identify four phytoprogestins present in a standardized red clover ( Trifolium pratense) extract. We found that the component irilone (1) potentiated the effect of progesterone in both endometrial and ovarian cancer cell lines. In these cancers, progesterone action is generally associated with positive outcomes; thus the potentiating effect of 1 may provide entirely new strategies for enhancing progesterone signaling as a means of mitigating conditions such as fibroids and endometriosis. Formononetin (3) and biochanin A (4) exhibited mixed agonist activity, while prunetin (2) acted only as an antagonist. Collectively, these results suggest that the effects of red clover extract repeatedly observed in cultured cells and the inverse correlation between risk of various cancers and flavonoid intake may be due, in part, to altered progesterone signaling.

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PMID: 

Animals (Basel). 2020 Feb 25 ;10(3). Epub 2020 Feb 25. PMID: 32106487

Abstract Title: 

Biochanin A Inhibits Ruminal Nitrogen-Metabolizing Bacteria and Alleviates the Decomposition of Amino Acids and Urea In Vitro.

Abstract: 

Biochanin A is a naturally occurring flavonoid compound that is found in plant species such as red clover () and alfalfa (). Flavonoids have been reported to regulate ruminal fermentation, and the objective of this study was to evaluate the effects of biochanin A on ruminal microbial composition and nitrogen metabolism. The experiment was performed by in vitro batch culturing of a control (without biochanin A) and a biochanin A treatment. Following a 24-h incubation, gas production and the amounts of ammonia-nitrogen (NH-N), volatile fatty acid (VFA), and amino acids were measured. Microbial population using 16S rRNA gene sequence. We found that the addition of biochanin A significantly increased microbial gas production; but had no effect on VFA production. Biochanin A supplementation also resulted in reduced microbial urease activity with half the maximal inhibitory concentration of 320 nM and also inhibited the degradation rates of total amino acids, valine, lysine, methionine and leucine by 18%, 56%, 37%, 13%, and 12%, respectively. This inhibition of urease activity and amino acid decomposition resulted in a significant reduction in the NH-N concentration. High-throughput sequencing of the 16S rRNA sequence to monitor microbial composition showed that biochanin A significantly reduced the abundance of the proteolytic bacteriaand ureolytic bacteria, but increased the abundance of the lactic acid metabolizing bacteriaand. In conclusion, biochanin A reduced the production of ammonia by inhibiting proteolytic bacteria and their decomposition of urea and amino acids.

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PMID: 

Clin Liver Dis. 2016 Aug ;20(3):595-606. Epub 2016 Apr 2. PMID: 27373619

Abstract Title: 

Infection and Alcoholic Liver Disease.

Abstract: 

Acute and chronic alcohol use leads to an impaired immune response and dysregulated inflammatory state that contributes to a markedly increased risk of infection. Via shared mechanisms of immune-mediated injury, alcohol can alter the clinical course of viral infections such as hepatitis B, hepatitis C, and human immunodeficiency virus. These effects are most evident in patients with alcoholic hepatitis and cirrhosis. This article provides an overview of alcohol's effect on the immune system and contribution to the risks and outcomes of specific infectious diseases.

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PMID: 

Dose Response. 2020 Jan-Mar;18(1):1559325820904799. Epub 2020 Mar 3. PMID: 32165873

Abstract Title: 

Apigenin Attenuates Allergic Responses of Ovalbumin-Induced Allergic Rhinitis Through Modulation of Th1/Th2 Responses in Experimental Mice.

Abstract: 

Background: Allergic rhinitis (AR) is an immunoglobulin E (IgE)-mediated immune-inflammatory response mainly affecting nasal mucosa. Apigenin, a flavonoid, has been documented to possess promising anti-allergic potential.Aim: To determine the potential mechanism of action of apigenin against ovalbumin (OVA)-induced AR by assessing various behavioral, biochemical, molecular, and ultrastructural modifications.Materials and Methods: Allergic rhinitis was induced in BALB/c mice (18-22 grams) by sensitizing it with OVA (5%, 500μL, intraperitoneal [IP] on each consecutive day, for 13 days) followed by intranasal challenge with OVA (5%, 5 μL per nostril on day 21). Animals were treated with either vehicle (distilled water, 10 mg/kg, IP) or apigenin (5, 10, and 20 mg/kg, IP).Results: Intranasal challenge of OVA resulted in significant induction (

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PMID: 

J Parasit Dis. 2020 Mar ;44(1):221-229. Epub 2019 Dec 2. PMID: 32174728

Abstract Title: 

Interaction of apigenin-7-O-glucoside with pyrimethamine againstgrowth.

Abstract: 

Apigenin-7-O-glucoside, a flavonoid glucoside known to inhibit cancer cell growth, fungi growth, both intra and extracellular reactive oxygen species generation, causing cell arrest and damage to the plasma membrane, was tested alone or in combination with a dihydrofolate inhibitor (pyrimethamine) against() growth. The anti-activity was carried out using a high throughput antiparasitic drug screening cell-based assay known as 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium, monosodium salt (WST-8) and fluorescence plate reader. The 50% effective concentration inhibition and 95% confidence interval values for individual and combination treatments againstwere 0.80 (0.38-1.29)µg/mL, 1.05 (0.275-2.029) µg/mL, and 0.40 (0-1.06) µg/mL for apigenin-7-O-glucoside, pyrimethamine, and apigenin-7-O-glucoside plus pyrimethamine, respectively. Interestingly, the apigenin-7-O-glucoside plus pyrimethamine combination showed an additive inhibition effect againstgrowth in vitro using the fractional inhibitory concentration index method. It was discovered that the apigenin-7-O-glucoside combination with pyrimethamine had a high selectivity index 62.5, which implies 62-fold inhibition activity against the parasite versus human foreskin fibroblast cell cytotoxicity. This new combination hit is novel and will have the potential for future effective, safe, and less costly anti-drug development, if its in vivo activity shows similar findings.

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