No evidence for the in vivo activity of aromatase-inhibiting flavonoids

Saarinen, Niina M.; Joshi, S. C.; Ahotupa, Markku; Li, Xiangdong; Ämmälä, Jenni; Mäkelä, Sari; Santti, Risto

doi:10.1016/s0960-0760(01)00098-x

Cited by 54 publications

(58 citation statements)

References 33 publications

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“…Another clinical study did not show any effect of chrysin on urinary testosterone levels [5]. Similar findings were made in a rat study [6].…”

Section: Introductionsupporting

confidence: 69%

Aromatase inhibition by bioavailable methylated flavones

Ta¹,

Walle²

2007

The Journal of Steroid Biochemistry and Molecular Biology

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Previous studies have shown chrysin, 7-hydroxyflavone and 7,4′-dihydroxyflavone to be the most potent flavonoid inhibitors of aromatase. However, very poor oral bioavailability is a major limitation for the successful use of dietary flavonoids as chemopreventive agents. We have recently shown that methylated flavones, including 5,7-dimethoxyflavone, 7-methoxyflavone and 7,4′-dimethoxyflavone, are much more resistant to metabolism than their unmethylated analogs and have much higher intestinal absorption. In this study, we examined these fully methylated flavones as potential aromatase inhibitors for the prevention and/or treatment of hormone-dependent cancers. Whereas 5,7-dimethoxyflavone had poor effect compared to its unmethylated analog chrysin, 7-methoxyflavone and 7,4′-dimethoxyflavone were almost equipotent to their unmethylated analogs with IC 50 values of 2 to 9 μM. Thus, some fully methylated flavones appear to have great potential as cancer chemopreventive/chemotherapeutic agents.

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“…Another clinical study did not show any effect of chrysin on urinary testosterone levels [5]. Similar findings were made in a rat study [6].…”

Section: Introductionsupporting

confidence: 69%

Aromatase inhibition by bioavailable methylated flavones

Ta¹,

Walle²

2007

The Journal of Steroid Biochemistry and Molecular Biology

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“…Bioactive effects have been reported among them, such as antioxidant, anti-inflammatory, anticancer and anti-aromatase (Olthof et al, 2001;Gülçin, 2006;Kim et al, 2011;Marrassini et al, 2011;Choo et al, 2012;Lu et al, 2012;Lee et al, 2013;Shu-Yao et al, 2013). However, in vivo effects (especially anticancer and anti-aromatase), of both flavonoid rich extracts and purified extracts are still debated (Saarinen et al, 2001;Moon et al, 2006;Genoux et al, 2011;Lephart, 2015). The works by Dhawan & Sharma (2002, 2003; Dhawan (2003) and review by Dhawan et al (2004), suggest that the compound known as BZF, which is described as a trisubstituted α-naphthoflavone isolated from the methanolic extract of P. incarnata, has a strong antiaromatase activity by restoring libido decline, sperm count and fertility in male rats exposed to substances such as cannabinoids, alcohol or nicotine.…”

Section: Discussionmentioning

confidence: 99%

Effect of Passiflora incarnata (L) extract on gonadal maturation in young tilapia (Oreochromis sp.)

Ramirez

López-Cardiel

Lezama

et al. 2017

lajar

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ABSTRACT. The effect of Passiflora incarnata's extract (PE) on gonadal maturation in young tilapia (Oreochromis sp.) was evaluated by administering feed supplemented with PE during the first 90 days immediately after yolk sac assimilation. One hundred and fifty fishes with 0.01 ± 0.003 g average body weight were randomly distributed in ten tanks with the following duplicated treatments: commercial feed (NAT), NAT with 60 mg kg -1 of 17-MT (MET), and NAT supplemented with 31.10 mg, 62.30 mg and 124.60 mg of PE g -1 (P1, P2, P3 respectively). There were no significant differences (P > 0.05) in the average body weight or in the male-female sex ratio between the experimental treatments (P1, P2, P3) and the control (NAT). Statistical differences in the gonadosomatic index (GSI) and the percentage distribution of gonadal maturation stages (PDGMS) were observed in females of P2 and P3. With respect to the females of NAT, the treatments P2 and P3 presented a lower GSI and a lower percentage of females in stage III (GSI: 1.11 ± 0.88, 1.04 ± 0.99 and 1.71 ± 0.72; PDGMS: 45, 30 and 80%, respectively). No significant differences in GSI or PDGMS were observed in the males. The results suggest that the observed differences in GSI and PDGMS in females are unrelated to antinutritional effects. Instead, these differences could be due to a possible antiestrogenic effect attributed to the possible anti-aromatase action of some of its compounds. Future research focusing on the use of PE for reproductive control in tilapia is suggested.

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“…Chrysin and 7,8-dihydroxyflavone have been proposed as aro- matase inhibitors (20). However, in vivo studies do not show proof of aromatase inhibitor activity by chrysin in rats or humans (21,22). Presumably, 7,8-dihydroxyflavone might not inhibit aromatase, either.…”

Section: Kinases a Binding Assay Demonstrated That Increasing Concenmentioning

confidence: 99%

A selective TrkB agonist with potent neurotrophic activities by 7,8-dihydroxyflavone

Jang

Liu²,

Yepes³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

609

595

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Brain-derived neurotrophic factor (BDNF), a cognate ligand for the tyrosine kinase receptor B (TrkB) receptor, mediates neuronal survival, differentiation, synaptic plasticity, and neurogenesis. However, BDNF has a poor pharmacokinetic profile that limits its therapeutic potential. Here we report the identification of 7,8-dihydroxyflavone as a bioactive high-affinity TrkB agonist that provokes receptor dimerization and autophosphorylation and activation of downstream signaling. 7,8-Dihydroxyflavone protected wild-type, but not TrkB-deficient, neurons from apoptosis. Administration of 7,8-dihydroxyflavone to mice activated TrkB in the brain, inhibited kainic acid-induced toxicity, decreased infarct volumes in stroke in a TrkB-dependent manner, and was neuroprotective in an animal model of Parkinson disease. Thus, 7,8-dihydroxyflavone imitates BDNF and acts as a robust TrkB agonist, providing a powerful therapeutic tool for the treatment of various neurological diseases.

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No evidence for the in vivo activity of aromatase-inhibiting flavonoids

Cited by 54 publications

References 33 publications

Aromatase inhibition by bioavailable methylated flavones

Aromatase inhibition by bioavailable methylated flavones

Effect of Passiflora incarnata (L) extract on gonadal maturation in young tilapia (Oreochromis sp.)

A selective TrkB agonist with potent neurotrophic activities by 7,8-dihydroxyflavone

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