Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6035_Библиотеки_им_академика_М_И_Перельмана.pdf
353
Turk, D.; Guncar , G.; Marjetka Podobnik, M.; Turk, B. Revised definition of substrate binding sites of papain-
like cysteine proteases. Biol. Chem. 1998, 379, 137–147.
Turk, D.; GuncÏar, G. Lysosomal cysteine proteases (cathepsins): Promising drug targets. Acta Cryst. 2003,
D59, 203–213.
Turk, V.; Stoka, V.; Vasiljeva, O.; Renko, M.; Sun, T.; Turk, B. Turk, D. Cysteine cathepsins: From structure,
function, and regulation to new frontiers. Biochim. Biophys. Acta. 2012, 1824, 68–88.
Ulčakar, L.; Novinec, M. Inhibition of human cathepsins B and L by caffeic acid and its derivatives.
Biomolecules. 2021, 11, 31.
Utami, J. P .; Kurnianingsih, N.; Faisal, M. R. An in silico study of the cathepsin L inhibitory activity of bioactive
compounds in Stachytarpheta jamaicensis as a Covid-19 drug therapy. Makara J. Sci. 2022, 26, 25–36.
van der Linden, W. A.; Schulze, C. J.; Herbert, A. S.; Krause, T. B.; Wirchnianski, A. A.; Dye, J. M.; Chandran,
K.; Bogyo, M. Cysteine cathepsin inhibitors as anti-Ebola agents. ACS Infect. Dis. 2016, 2, 173–179.
Varughese, K. I..; Ahmed, F. R.; Carey, P. R.; Hasnain, S.; Huber, C. P.; Storer, A. C. Crystal structure of a
papain-E-64 complex. Biochem. 1988, 28, 1330–1332.
V asiljeva, T.; Reinheckel, C.; Peters, D.; Turk, V.; Turk, B. Emerging roles of cysteine cathepsins in disease and
their potential as drug targets. Curr. Pharm. Des. 2007, 13, 387–403.
Vidak, E.; Urban Javoršek, U.; Matej Vizovišek, M.; Turk, B. Cysteine cathepsins and their extracellular roles:
Shaping the microenvironment. Cells. 2019, 8, 264.
Vidal-Albalat, A.; González, F. V. Natural products as cathepsin inhibitors. In: Atta-ur-Rahman. (Ed.), Studies
in Natural Products Chemistry. Elsevier: Amsterdam, 2016, Vol. 50, pp. 179–213.
Villalvilla, A.; da Silva, J. A.; Largo, R.; Gualillo, O.; Vieira, P. C.; Herrero-Beaumont, G.; Gomez, R. 6-Shogaol
inhibits chondrocytes’ innate immune responses and cathepsin-K activity. Mol. Nutr. Food Res. 2014, 58,
256–266.
Wartmann, T.; Mayerle, J.; Kähne, T.; Sahin-Tóth, M.; Ruthenbürger, M.; Matthias, R.; Kruse, A.; Reinheckel,
T.; Peters, C.; Weiss, F. U.; Sendler, M.; Lippert, H.; Schulz, H. U.; Aghdassi, A.; Dummer, A.; Teller,
S.; Halangk, W.; Lerch, M. M. Cathepsin L inactivates human trypsinogen, whereas cathepsin L-deletion
reduces the severity of pancreatitis in mice. Gastroenterology. 2010, 138, 726–737.
Willstätter, R.; Bamann, E. Über die Proteasen der Magenschleimhaut. ErsteAbhandlungüber die Enzyme der
Leukocyten. Hoppe Seylers Z. Physiol. Chem. 1929, 180, 127–143.
Wisutsitthiwong, C.; Buranaruk, C.; Pudhom, K.; Palaga, T. The plant limonoid 7-oxo-deacetoxygedunin
inhibits RANKL-induced osteoclastogenesis by suppressing activation of the NF-κB and MAPK pathways.
Biochem. Biophys. Res. Commun. 2011, 415, 361–366.
Woo, J.-T.; Ono, H.; Tsuji, T. Cathestatins, new cysteine protease inhibitors produced by Penicillium citrinum.
Biosci. Biotechnol. Biochem. 1995, 59, 350–352.
Yamada, T.; Hiratake, J.; Aikawa, M.; Suizu, T.; Saito, Y.; Kawato, A.; Suginami, K.; Oda, J. Cysteine protease
inhibitors produced by the industrial koji mold, Aspergillus oryzae O-1018. Biosci. Biotechnol. Biochem.
1998, 62, 907.
Yu, C.-M.; Curtis, J. M.; Walter , J. A.; Wright, J. L. C.; Ayer, S. W.; Kaleta, J.; Querengesser, L.; Fathi-Afshar, Z.
R. Potent inhibitors of cysteine proteases from the marine fungus Microascus longirostvis. J. Antibiot. 1995,
49, 395–397.
Y uan, L.; Li, Y. C.; Zou, C. Y.; Wang, C.; Gao, J.; Miao, C. X.; Ma, E. L.; Sun, T . M. Synthesis and in vitro antitumor
activity of asperphenamate derivatives as autophagy inducer. Bioorg. Med. Chem. Lett. 2012, 22, 2216–2220.
Yuan, L.; Sheng, L.; He, W.; Zou, C.; Hu, B.; Liu, J.; Ge, W.; Liu, Y.; Wang, J.; Ma, E. Discovery of novel
cathepsin inhibitors with potent anti-metastatic effects in breast cancer cells. Bioorg. Chem. 2018, 81, 672–680.
Zang, L.; Kagotani, K.; Nakayama, H.; Bhagat, J.; Fujimoto, Y.; Hayashi, A.; Sono, R.; Katsuzaki, H.;
Nishimura, N. Shimada, Y. 10-Gingerol suppresses osteoclastogenesis in RAW264.7 cells and zebrafish
osteoporotic scales. Front. Cell Dev. Biol. 2021, 9, 588093.
Zeng, G.-Z.; Pan, X.-L.; T an, N.-H.; Xiong, J.; Zhang, Y.-M. Natural biflavones as novel inhibitors of cathepsin
B and K. Eur. J. Med. Chem. 2006, 41, 1247–1252.
CHAPTER 15
Phytoestrogens in Drug Discovery: A Focus on Mechanisms of Action and Safety Assessment
BANCHA YINGNGAM
ABSTRACT
Compounds from plants with estrogen-mimicking properties, known as phytoestrogens,
show potential for medicinal uses in the field of drug research. They are garnering
more attention for their potential to modulate estrogen receptor responses and various
molecular pathways, making them beneficial for addressing issues such as symptoms
of menopause, bone density loss, and cancer. However, concerns persist regarding the
safety of phytoestrogens due to their potential unintended effects on reproductive health,
neuroendocrine function, and other physiological processes. This chapter presents a
summary of the ways phytoestrogens operate in drug discovery, especially emphasizing
their estrogenic effects and influence on cell signaling pathways. Additionally, safety
concerns associated with phytoestrogen use will be discussed, including potential adverse
effects and interactions with other medications. Finally , the chapter explores the potential
for developing safer and more effective phytoestrogen-based therapies, emphasizing the
importance of thorough safety assessment and clinical testing.
*
*Corresponding author
15.1 INTRODUCTION
In 1926, the term “phytoestrogen” was introduced, combining the Greek words “phyto”,
meaning plant, and “estrogen”, referring to the hormone responsible for female fertility
in vertebrates (Farhat et al., 2023). Phytoestrogen is classified as a functional term rather
than a structural term since its chemical structure does not belong to the steroid family.
These naturally occurring compounds have garnered attention in drug discovery due to
their potential therapeutic effects (Yingngam et al., 2021). Their form and/or function
bear resemblance to natural estrogen, and they can be identified in diverse plants, such
as soybeans (Glycine max L.), white clover (Trifolium repens L.), red clover (Trifolium
pratense L.), fennel (Foeniculum vulgare Mill.), flaxseed (Linum usitatissimum L.), white
356
Kwao Krua (Pueraria candollei Benth.), and Wan Chak Modlook (Curcuma comosa
Roxb.) (Yingngam et al., 2021; Ceccarelli et al., 2022; Warinsiriruk et al., 2022; Kiyama,
2023; Pourjafari et al., 2023). Phytoestrogens exhibit diverse biological activities, including
estrogenic (Yingngam et al., 2021), antiestrogenic (Kiyama, 2023), and antiandrogenic
effects (Pool et al., 2023), making them potential alternatives to hormone replacement
therapy for managing menopausal symptoms (Karimi et al., 2023). Additionally, research
suggests that phytoestrogens may reduce the likelihood of certain illnesses, including breast
cancer (Al-Thamiree Mezban and Fox, 2023), cardiovascular disease (Kiyama, 2023), and
osteoporosis (Mei et al., 2023), due to their estrogenic activity, which provides protective
effects against these conditions. However, the exact mechanisms of action and optimal
dosages for these potential health benefits are still under investigation. Furthermore, the
use of phytoestrogens in drug discovery extends beyond managing menopausal symptoms
and disease prevention (Xu et al., 2023). These compounds have been studied for their
potential therapeutic effects in a range of other conditions, including diabetes (Jain et al.,
2022; Kiyama, 2023), obesity (Kim et al., 2020), and neurological disorders (Rebe et al.,
2023; Xu et al., 2023), due to their anti-inflammatory and antioxidant properties (Y en et al.,
2023), which could contribute to their potential therapeutic effects in these conditions.
The efcacy and safety of phytoestrogens in drug discovery have been extensively
studied. Various mechanisms of action have been proposed, including the activation of
estrogen receptors (ERs), inhibition of aromatase activity, and modulation of steroid
hormone metabolism (Swathi Krishna et al., 2022). However, the use of phytoestrogens
as therapeutic agents remains controversial due to safety concerns and potential adverse
effects, particularly in hormone-sensitive tissues. In recent years, numerous studies have
focused on exploring the potential therapeutic benets of phytoestrogens in drug discovery,
investigating their interaction with ERs, modulation of hormone metabolism, and effects
on gene expression (Jing et al., 2023).
One of the most well-known mechanisms of action of phytoestrogens is their ability
to bind to ERs and mimic the effects of endogenous estrogen. This mechanism has been
extensively studied and is implicated in various potential therapeutic effects of phytoestrogens, including the management of menopausal symptoms (Chiba et al., 2022).
Moreover, certain studies have suggested that phytoestrogens may possess anticancer
properties by inhibiting the activity of the aromatase enzyme (Tanideh et al., 2023),
which is responsible for estrogen synthesis and serves as a target for many anticancer
drugs (Torrens-Mas and Roca, 2020).
Despite the potential benets of phytoestrogens, their use as therapeutic agents remains
a subject of controversy due to concerns regarding safety and potential adverse effects. Of
particular concern is the potential for phytoestrogens to increase the risk of breast cancer
or other hormone-sensitive cancers, as well as their potential to disrupt normal endocrine
system function (Chiba et al., 2022). It is important to acknowledge that the safety and
efcacy of phytoestrogens may vary depending on the individual and dosage administered.
Therefore, further research is necessary to gain a better understanding of the risks and
benets associated with phytoestrogens and to establish guidelines for their clinical use.
This chapter will provide an in-depth examination of how phytoestrogens work and
their safety assessment in the eld of drug discovery. It will address the challenges and
357
opportunities associated with developing phytoestrogen-based therapeutics, including
their potential applications in treating menopausal symptoms and other estrogen-related
disorders. The chapter will also highlight the latest research ndings and ongoing clinical
trials in this eld, aiming to present a thorough overview of the current knowledge.
Additionally , the chapter will discuss potential future directions for utilizing phytoestrogens
in drug discovery, shedding light on the opportunities and challenges that may emerge in
this rapidly evolving domain. However, the focus of this chapter excludes the discussion
of certain mycoestrogens, such as Fusarium spp. mycotoxins (specically zearalenone,
zearalanone, zearalenols, and zearalanols) that belong to the class of resorcyclic acid
lactones and possess estrogenic properties. These mycotoxins are produced as secondary
metabolites by fungi in plants and grasses.
15.2 PHYTOESTROGENS AND ESTROGEN RECEPTORS
ERs are nuclear receptors essential for numerous bodily functions, including growth,
development, and reproduction. The mechanism of action for ERs involves the induction
of transcription through ligand-receptor complexes that dimerize in the nucleus, acting
as ligand-induced transcription factors (Tanwar et al., 2021). ERs are composed of two
distinct regions: the domain that binds to DNA and the domain that binds to ligands
(Seo et al., 2023). There are two main subtypes of ERs, ERα and ERβ, with distinct
tissue distributions and functions (Ceccarelli et al., 2022). While ERα and ERβ share an
almost identical DNA-binding domain (DBD) of 97%, the overall amino acid sequences
of their ligand-binding domains exhibit only 56% and 18% similarity, respectively (Seo
et al., 2023). These receptors are encoded by separate genes located on chromosome 6
(6q25.1) and chromosome 14 (14q22-24) (Ceccarelli et al., 2022). Furthermore, they
exhibit distinct tissue distributions and functions (Qi et al., 2023). Upon estrogen binding
to ERα or ERβ, the receptors undergo a conformational change, facilitating dimerization
and binding to distinct DNA sequences known as estrogen response elements (EREs)
located in the promoters of the genes they target (Babiloni-Chust et al., 2022). This
process leads to the recruitment of coactivator proteins, initiating the transcription of
target genes (Ceccarelli et al., 2022).
Studies have demonstrated that phytoestrogens can have both positive and negative
effects on ER signaling. Phytoestrogens exhibit estrogenic effects, which can be benecial
for conditions such as osteoporosis and menopausal symptoms. However, high doses of
phytoestrogens may disrupt the endocrine system and increase the risk of certain cancers
(Farhat et al., 2023). Additionally, the effects of phytoestrogens on ER signaling may
depend on the subtype of ER involved (Wang et al., 2021). For example, certain phytoes-
trogens, such as genistein and daidzein, show a greater binding preference for ERβ over
ERα, which might elucidate their selective inuence on distinct physiological activities
(Basu and Maier, 2018). Others, such as coumestrol and equol, have a higher afnity
for ERα (Wang et al., 2021). The impact of phytoestrogens on different physiological
processes can be inuenced by the relative expression and activity of ER subtypes in
various tissues (Cho et al., 2021). In breast tissue, for instance, ERα is the dominant subtype
358
associated with cell proliferation and tumor growth, while ERβ has a more protective role
(Morozova et al., 2022). Consequently, phytoestrogens with a higher afnity for ERβ may
provide breast tissue protection by inhibiting ERα activity and reducing cell proliferation.
Similarly, in the cardiovascular system, ERβ is more highly expressed than ERα, and
activation of ERβ has been shown to have protective effects on endothelial function and
decrease the risk of cardiovascular disease (Chen et al., 2020). Thus, phytoestrogens with
a higher afnity for ERβ may be advantageous for cardiovascular health.
There are signicant differences in the binding afnity of phytoestrogens for
ERs compared to endogenous estrogens. Endogenous estrogens, including estrone,
17β-estradiol, 16α-estriol, and estetrol (depicted in Figure 15.1), exhibit a stronger
binding afnity for ERα than for ERβ (Seo et al., 2023). Estrone is the main type observed
in postmenopausal women, while 17β-estradiol signicantly contributes to the functional
processes in premenopausal women. The placenta synthesizes 16α-estriol by transforming
dehydroepiandrosterone and its sulfate, which are derived from the adrenal glands of
both the fetus and the mother. The concentration of this hormone is maximized during
pregnancy. Last, the fetal liver also creates the fourth form, estetrol, during pregnancy
(Das et al., 2022). In contrast, phytoestrogens such as genistein and daidzein exhibit the
opposite pattern. The binding of endogenous estrogens induces a conformational change
that facilitates the recruitment of coactivator proteins and the activation of target genes
(Tanwar et al., 2021). In contrast, phytoestrogens bind to ERs in a slightly different
conformation, resulting in weaker recruitment of coactivators and less potent activation
of target genes (Khan et al., 2022). Furthermore, endogenous estrogens undergo metabolism by the liver and other tissues, leading to the formation of metabolites with varying
estrogenic activity. In contrast, phytoestrogens are metabolized differently, resulting in
the production of metabolites with distinct estrogenic activity from those produced by
endogenous estrogens (Khan et al., 2022).
To enhance reader comprehension, the author utilizes an in silico molecular docking
technique to illustrate the manipulation of the binding pocket of ERs and selected phytoes-
trogens. Specically, AutoDock Vina was employed in this study to conduct molecular
docking analyses on chosen isoavone aglycones (genistein and daidzein) with ERs
(Huey et al., 2012). The X-ray crystal structures of ERα (PDB code 1A52) and ERβ (PDB
code 2YJD) were retrieved from the Protein Data Bank (https://www.rcsb.org/). The
three-dimensional structures of genistein, daidzein, and 17β-estradiol were acquired from
PubChem (https://pubchem.ncbi.nlm.nih.gov/), and ChemDraw 3D (Cambridgesoft Inc.,
MA, USA) was utilized to perform energy minimization on these molecules. Subsequently ,
the docking study selected the pose with the lowest binding energy, and the interaction
between the ligands and receptors was evaluated using Accelrys Discovery Studio 4.1
software (http://accelrys.com).
ERα has a molecular weight of 66 kDa and consists of 595 amino acids, while ERβ
weighs 59 kDa and has 530 amino acids. The amino acid sequences of ERα and ERβ in
humans are 44% identical. ERs can be divided into six functional domains: A/B, C, D
(hinge region), E (ligand binding domain), and F. The A/B domains of ERα and ERβ share
only 17% homology. The C-terminal domain contains a conserved DBD with approxi-
mately 94% similarity between ERα and ERβ. The D domain serves as a hinge region and
359
has a nuclear localization signal with approximately 36% homology. The E domain, or
ligand-binding domain, plays a role in transactivation functions and shares a 59% struc-
tural resemblance between ERα and ERβ. Differences in ligand binding cavities between
the two ER subtypes are due to specic amino acid positions. The F domain, with 18%
homology between ERα and ERβ, protects the receptors against proteolysis. ERα acts as
an activator, while ERβ inhibits ERα activity by forming a heterodimer. The ligand-binding
pocket of ERα is characterized by specic amino acids, while ERβ has a smaller binding
pocket with different key amino acid residues (Das et al., 2022).
FIGURE 15.1 Chemical structures of three types of estrogens: estrone (E1), 17β-estradiol (E2), 16α-estriol
(E
), and estetrol (E4). (ChemDraw 20.1.1).
3
⏎
Figure 15.2 illustrates the binding results of genistein and daidzein to the ER binding
pockets. Based on the ranking of ligand binding energy, the best conformation is achieved
with 17β-estradiol, followed by genistein and daidzein. In ERα, the 4′-hydroxyl of genistein
forms hydrogen bonds with Glu353 and Ar g394, while the 7-hydroxyl group interacts with
His524 (binding energy = −9.40 kcal/mol). Similarly, in ERβ, the 4′-hydroxyl of genistein
forms hydrogen bonds with Glu305/Arg346, and the 7-hydroxyl group interacts with
His475 (binding energy = −9.20 kcal/mol) (Figure 15.2a). In contrast, daidzein adopts an
opposite orientation, forming hydrogen bonds between its 7-hydroxyl and Glu353/Arg394
and between its 4′-hydroxyl and His524 in ERα (binding energy = −9.30 kcal/mol). In ERβ,
hydrogen bonds are observed between the 4′-hydroxyl of daidzein and His475 and between
its 7-hydroxyl group and Glu305/Arg346 (binding energy = −8.50 kcal/mol) (Figure 15.2b).
360
The absence of a hydroxyl group adjacent to the carbonyl group in daidzein accounts for
this difference from genistein. Additionally, 17β-estradiol can bind to both ER binding
pockets through its 3- and 17-hydroxyls, similar to genistein, with the lowest binding ener-
gies of −10.70 and −9.80 kcal/mol for ERα and ERβ, respectively (Figure 15.2c). These
docking results suggest that the mechanism of action of both phytoestrogens could be
attributed to weak interactions involving hydrogen bonds and van der Waals forces.
FIGURE 15.2 The molecular binding mode of genistein (a), daidzein (b), and 17β-estradiol (c) within the
active sites of ERα (left side) and ERβ (right side). (Accelrys Discovery Studio 4.1).
⏎
361
15.3 NONESTROGEN RECEPTOR-MEDIATED EFFECTS OF PHYTOESTROGENS
Phytoestrogens exhibit a range of biological effects beyond their actions as ER agonists
or antagonists. They can influence other signaling pathways critical for cell growth,
differentiation, and survival, including mitogen-activated protein kinase (MAPK),
phosphatidylinositol 3-kinase/serine/threonine kinase (PI3K/AKT), WNT, and G
protein-coupled ER. The following are a few examples of the non-ER-mediated effects
of phytoestrogens on these signaling pathways.
15.3.1 MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) PATHWAY
The mitogen-activated protein kinase (MAPK) pathway is a key intracellular signaling
pathway that regulates various cellular processes, including proliferation, differentiation,
and apoptosis. Phytoestrogens have been demonstrated to activate the MAPK pathway
through the ER and other signaling intermediaries. One primary mechanism by which
phytoestrogens activate the MAPK pathway is through ER phosphorylation. Upon
binding to phytoestrogens, the ER undergoes a conformational change that activates
downstream signaling intermediaries such as growth factor receptor-bound protein 2 and
Src homology 2 domain-containing protein. These intermediaries then activate the RasRaf-MEK-extracellular signal-regulated kinase (ERK) cascade, leading to the activation
of MAPKs, such as ERK 1/2. Activated MAPKs translocate to the nucleus and phosphorylate various transcription factors, resulting in the expression of downstream target
genes involved in cell proliferation, differentiation, and survival. Phytoestrogen-induced
activation of the MAPK pathway regulates the expression of genes related to cell cycle
progression (e.g., cyclin D1) as well as apoptosis and survival (e.g., Bcl-2 and AKT).
Furthermore, the MAPK pathway interacts with other intracellular signaling pathways,
such as the PI3K/AKT pathway and the WNT pathway. Activation of the MAPK pathway
by phytoestrogens can influence these pathways, leading to the modulation of various
cellular processes (Anjum et al., 2022).
Several phytoestrogens have been reported to activate the MAPK pathway (Ramachan-
dran et al., 2022). Genistein, an isoavone found in soybeans and soy products, was shown
to activate the MAPK pathway in osteoblasts, resulting in increased cell proliferation and
differentiation, according to a review article by W u and Liu (2022). The study suggests that
genistein may have potential benets for bone health. However, while these studies indicate
the ability of phytoestrogens to activate the MAPK pathway , their effects on human health
are still under investigation and not fully understood. Further research is necessary to fully
comprehend the role of phytoestrogens in human health and disease.
15.3.2 PI3K/AKT PATHWAY
The PI3K/AKT signaling pathway plays a critical role in cancer development by promoting
cell growth, proliferation, and survival (Issinger and Guerra, 2021). Both estrogens and
362
phytoestrogens have been shown to activate this pathway, resulting in various biological
effects (Huang et al., 2023). The pathway is initiated by the binding of extracellular ligands
to their respective receptors, such as ERs. This binding activates the receptor, leading
to the recruitment and activation of PI3K, which phosphorylates phosphatidylinositol
4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
PIP3 then recruits and activates AKT, which phosphorylates several downstream targets,
including mTOR, GSK-3β, and FOXO transcription factors (Issinger and Guerra, 2021;
Zhao et al., 2021; Yang et al., 2022).
Dysregulation of this pathway has been observed by inhibiting the activity of PI3K
and AKT, resulting in decreased cell proliferation and increased cell death (Issinger and
Guerra, 2021). For instance, a study by Kuang et al. (2021) demonstrated that coumestrol
from soy blocks the mTOR/PI3K/AKT signaling pathway in skin cancer SKEM-5 cells.
The study showed that the activity of phosphorylated proteins (p-mTOR, p-PI3K, and
p-AKT) was dose-dependently inhibited, while the activity of nonphosphorylated mTOR,
PI3K, and AKT remained largely unaffected. This suggests that coumestrol modulates the
mTOR/PI3K/AKT signaling pathway in a specic manner in skin carcinoma cells.
15.3.3 WNT PATHWAY
The WNT signaling pathway plays a crucial role in regulating cellular processes, including
proliferation, differentiation, and apoptosis. Estrogen has been found to modulate this
pathway by binding to its receptors and inducing the expression of WNT tar get genes (Nie
et al., 2020). One way estrogen regulates the WNT pathway is by promoting the stabiliza-
tion and accumulation of β-catenin, a key component of the pathway (Sharma and Nam,
2019). In the absence of WNT ligands, β-catenin is degraded by a destruction complex
that includes APC, GSK3β, and axin. Estrogen inhibits the activity of GSK3β, leading to
the cytoplasmic accumulation of β-catenin, which can then translocate to the nucleus and
activate WNT target genes (Bhukhai et al., 2012; Nie et al., 2020). Estrogen also interacts
with other components of the WNT pathway , including receptors and downstream ef fectors
(Qiu et al., 2020; Luo et al., 2022).
Some phytoestrogens, such as genistein, resveratrol, and 8-prenylgenistein (from G.
max, Vitis vinifera and Herba epimedii), have been shown to activate the WNT pathway
(Qiu et al., 2020; Luo et al., 2022). Genistein inhibits GSK-3β, leading to the cytoplasmic
accumulation of β-catenin (Luo et al., 2022), while resveratrol activates the WNT coreceptor
LRP6 (Elseweidy et al., 2021). 8-Prenylgenistein exhibits stronger osteogenic activity than
genistein, mediating its effects by inducing the WNT/β-catenin and ERα-associated PI3K/
AKT signaling pathways (Qiu et al., 2020).
ASPP 049, a diarylheptanoid found in C. comosa, has been shown to exhibit estrogen-
like activity and results in the ER/AKT/GSK-3β-dependent activation of the WNT/β-catenin
signaling pathway, which is associated with bone cell proliferation and differentiation.
This suggests the potential use of ASPP 049 as an osteogenic agent to protect against
osteoporosis in postmenopausal women (Bhukhai et al., 2012). Additionally, it may be
used as a dietary supplement to prevent bone loss. The activation of the WNT pathway