Sulfotransferase 1A1 as a Biomarker for Susceptibility to Carcinogenesis: From Molecular Genetics to the Role of Dietary Flavonoids

BACKGROUND

Sulfotransferase (SULT) 1A1 is a phase II metabolic enzyme that catalyzes sulfate conjugation of various phenolic compounds, including endogenous substances, such as estrogens and thyroid hormones, but also different xenobiotics. Although sulfation is classically considered as a detoxification event facilitating the excretion of more water soluble metabolites from the body, in some cases such bioconversion may also lead to bioactivation of promutagens, producing highly reactive intermediates which are capable of damaging DNA and promoting carcinogenesis. The most common polymorphism in SULT1A1 (Arg213His) has an important functional impact by affecting the capacity to sulfate diverse substrates and numerous case-control studies have shown associations between SULT1A1 variants and susceptibility to different malignancies. Several factors may significantly influence such relationships, including ethnicity, gender, parity, menopausal status, use of estrogen replacement therapy, exposure to tobacco smoke or occupational chemicals.

RESULTS AND CONCLUSION

In this review article, we show that one more important determinant should be considered as a stratifying factor in studies of possible associations between SULT1A1 variants and cancer risk, i.e., the dietary intake of different flavonoids. As sulfation of bioactive plant polyphenols can change their potential anticancer activities and, on the other hand, these phytochemicals are capable to behave also as potent SULT1A1 inhibitors, the regular dietary exposure of humans to these compounds can make a great contribution to the impact of sulfation capacity on individual susceptibility to carcinogenesis. The effect of specific flavonoids as well as their interactions with other factors on associations between SULT1A1 alleles and cancer risk certainly needs further thorough studies.

Anticancer potential of oroxylin A: from mechanistic insight to synergistic perspectives

Oroxylin A (OA), a well-known constituent of the root of Scutellariae plants, has been used in ethnomedicine already for centuries in treating various neoplastic disorders. However, only recent molecular studies have revealed the different mechanisms behind its action, demonstrating antiproliferative, anti-inflammatory, and proapoptotic effects, restricting also the spread of cancer cells to distant organs. A variety of cellular targets and modulated signal transduction pathways regulated by OA have been determined in diverse cells derived from different malignant tissues. In this review article, these anticancer activities are thoroughly described, representing OA as a potential lead structure for the design of novel more potent anticancer medicines. In addition, co-effects of this natural compound with conventional anticancer agents are analyzed and the advantages provided by nanotechnological methods for more efficient application of OA are discussed. In this way, OA might represent an excellent example of using ethnopharmacological knowledge for designing modern medicines.

Gut Microbiota-Assisted Synthesis, Cellular Interactions and Synergistic Perspectives of Equol as a Potent Anticancer Isoflavone

It is well known that, historically, plants have been an important resource of anticancer agents, providing several clinically approved drugs. Numerous preclinical studies have shown a strong anticancer potential of structurally different phytochemicals, including polyphenolic constituents of plants, flavonoids. In this review article, suppressing effects of equol in different carcinogenesis models are unraveled, highlighting the mechanisms involved in these anticancer activities. Among flavonoids, daidzein is a well-known isoflavone occurring in soybeans and soy products. In a certain part of population, this soy isoflavone is decomposed to equol under the action of gut microflora. Somewhat surprisingly, this degradation product has been shown to be more bioactive than its precursor daidzein, revealing a strong and multifaceted anticancer potential. In this way, it is important to bear in mind that the metabolic conversion of plant flavonoids might lead to products that are even more efficient than the parent compounds themselves, definitely deserving further studies.

Only pyrimidinoceptors are functionally expressed in mouse neuroblastoma cell lines

The ability of UTP, UDP, ATP, and ADP to influence inositol phospholipid hydrolysis in neuroblastoma origin cell lines was assessed. The mouse neuroblastoma lines N1E 115, Neuro 2a, and NB4 1A3 and the rat glioma/mouse neuroblastoma hybrid line NG108-15 gave robust responses to both UTP and UDP, which were essentially equipotent. Thus a range of cell lines of mouse neuroblastoma origin express a pyrimidine-selective P2Y receptor. The NG108-15 cells were the only cell type tested at which ATP and ADP displayed activity with EC50 values of greater than 100 microM, compared with values of 0.58 and 1.25 microM for UTP and UDP, respectively. In contrast to the cell lines derived from mouse neuroblastoma, the human neuroblastoma lines SH-SY5Y and SK-N-SH did not respond to any nucleotides, although both responded well to carbachol.

Chemopreventive mechanisms of amentoflavone: recent trends and advancements

In parallel to the continuous rise of new cancer cases all over the world, the interest of scientific community in natural anticancer agents has steadily been increased. In the past decades, numerous phytochemicals have been shown to possess a strong anticancer potential in preclinical conditions. One of such interesting compounds, derived from different plants such as ginkgo, hinoki, and St. John`s wort, is amentoflavone. In this review article, a wide range of anticancer properties of this natural biflavone are described, revealing its ability to suppress the malignant growth and lead tumor cells to apoptotic death, besides impeding also angiogenic and metastatic processes. Therefore, amentoflavone can be considered a potential lead compound for the development of novel anticancer drug candidates, definitely deserving further in vivo studies and also initiation of clinical trials. It is expected that this plant biflavone might be important, either alone or in combination with the current standard chemotherapeutics, in providing some alleviation for the continuous rise of global cancer burden.

Pyrimidinoceptor potentiation by ATP in NG108-15 cells

Regulation of inositol phospholipid hydrolysis by UTP and UDP in neuroblastoma x glioma hybrid cell line NG108-15 was potentiated in the presence of ATP. The effect of ATP was dose dependent and shifted the EC50 value for these uracil nucleotides up to three powers of magnitude, having no influence on the maximal value of the response. Adenine nucleotides (ADP, AMP, adenosine 5'-O-(3-thiotriphosphate) (ATPgammaS), beta,gamma-methyleneadenosine 5'-triphosphate (betagammaMeATP), 3'-O-(4-benzoyl)benzoyl ATP (BzATP) and 3'-deoxyadenosine 5'-O-(1-thio)triphosphate (dATPalphaS)) as well as adenosine, had no influence on the pyrimidinoceptor response. The potentiation effect was abolished by excess of EDTA. The results were in agreement with the hypothesis of pyrimidinoceptor affinity regulation via extracellular phosphorylation of the receptor protein, initiated by ATP. This mechanism may have physiological implication for functioning of uracil nucleotides as endogenous signaling molecules.

The Emergence of Mpox: Epidemiology and Current Therapeutic Options

The world recently witnessed the emergence of new epidemic outbreaks like COVID-19 and mpox. The 2022 outbreak of mpox amid COVID-19 presents an intricate situation and requires strategies to combat the status quo. Some of the challenges to controlling an epidemic include present knowledge of the disease, available treatment options, appropriate health infrastructures facilities, current scientific methods, operations concepts, availability of technical staff, financial funds, and lastly international policies to control an epidemic state. These insufficiencies often hinder the control of disease spread and jeopardize the health of countless people. Also, disease outbreaks often put a huge burden on the developing economies. These countries are the worst affected and are immensely dependent on assistance provided from the larger economies to control such outbreaks. The first case of mpox was reported in the 1970s and several outbreaks were detected thereafter in the endemic areas eventually leading to the recent outbreak. Approximately, more than 80,000 individuals were infected, and 110 countries were affected by this outbreak. Yet, no definite vaccines and drugs are available to date. The lack of human clinical trials affected thousands of individuals in availing definite disease management. This paper focuses on the epidemiology of mpox, scientific concepts, and treatment options including future treatment modalities for mpox.

Dual effect of nucleotides on P2Y receptors

The interaction of ADP, 2MeSADP, and ADPbetaS with the adenine nucleotide receptor P2Y1 in the hP2Y1-1321N1 cell line and of UDP with a receptor or receptors recognizing pyrimidine nucleotides in NG108-15 cells was studied over a wide range ofligand concentrations. Bell-shaped dose-response curves for stimulation of phosphoinositide hydrolysis were obtained in these cells. This dual behavior of the agonists studied was characterized by two dissociation constants, K(agon) and K(antag), which quantify the agonistic and antagonistic activity of these ligands and can be compared with the conventional EC50 and IC50 values, respectively. The data revealed a common pattern of agonistic and antagonistic behavior of nucleoside diphosphates and their derivatives at these two types of P2Y receptors, pointing to some similar properties of their nucleotide binding sites.

Chemomodulating Effects of Flavonoids in Human Leukemia Cells

Flavonoids, a diverse class of polyphenolic compounds, are well known for their anticancer properties. Moreover, it is generally accepted that these plant secondary metabolites can also sensitize malignant cells to conventional chemotherapeutic drugs and could thus be considered as potential adjunctive agents in cancer treatment. In this review article we show that besides potentiating the anticancer activity of standard chemotherapeutics by modifying the molecular events that are involved in cell growth, differentiation and apoptosis, flavonoids might also act as inhibitory modulators in human leukemia cells. The specific behavior of a certain flavonoid in such combination treatments is multifactorial being dependent on various aspects, including cellular context, molecular mechanisms of clinical drugs, temporal regimen of administration, as well as doses of agents. Based on the highly complex nature of leukemogenesis it is feasible that a multifaceted therapeutic approach is also required to cure this disease and therefore, combined chemotherapeutic schemes incorporating natural plant metabolites as chemosensitizing agents can represent a new attractive strategy for more successful treatment of leukemia patients in the future. However, as highlighted in this review, caution should be taken when affecting malignant cells concurrently with chemotherapeutic drugs and flavonoids as unwisely chosen combinations can lead to inadvisable results and sometimes even deteriorate the clinical outcomes.

Cytotoxic action of methylquercetins in human lung adenocarcinoma cells

Lung cancer is the malignant disorder associated with a high number of fatalities in women and men worldwide. Despite continuous improvements in diagnostic strategies and therapeutic modalities over the past decades, the prognosis and survival rate of patients suffering from lung cancer are still unsatisfactory and suggest the requirement for further molecular studies with different lung cancer models. In the present study, the anticancer action of two methylated metabolites of quercetin, isorhamnetin and tamarixetin, was assessed by studying their antiproliferative and apoptosis-inducing potential in human lung adenocarcinoma cell lines, A549 and HCC-44. Both methylquercetins decreased the viability of lung cancer cells at doses significantly lower than those effective for parent quercetin. The IC50 values measured for isorhamnetin were 26.6 and 15.9 µM in A549 and HCC-44 cells, respectively. For tamarixetin, the IC50 values were 19.6 and 20.3 µM in A549 and HCC-44 cells, respectively. These results were many-fold lower than the respective values for quercetin (72.2 and 107.6 µM for A549 and HCC-44 cells, respectively). Based on the activation of caspase family members, both metabolites induced apoptotic cell death in the tested cell lines, predominantly via the extrinsic pathway in A549 cells and in both intrinsic and extrinsic pathways in HCC-44 cells. As A549 and HCC-44 lines were originally established from a male and female patient, current data may suggst some gender differences in the action of quercetin derivatives. Addition of a methyl group in the 3'- or 4'-position of the B-ring of quercetin significantly increased the anticancer activity of this flavonol towards lung adenocarcinoma cells, which demonstrated that these compounds may be considered as potential novel candidates for the development of future chemotherapeutics in the fight against lung cancer.

Ampelopsin targets in cellular processes of cancer: Recent trends and advances

Cancer is being considered as a serious threat to human health globally due to limited availability and efficacy of therapeutics. In addition, existing chemotherapeutic drugs possess a diverse range of toxic side effects. Therefore, more research is welcomed to investigate the chemo-preventive action of plant-based metabolites. Ampelopsin (dihydromyricetin) is one among the biologically active plant-based chemicals with promising anti-cancer actions. It modulates the expression of various cellular molecules that are involved in cancer progressions. For instance, ampelopsin enhances the expression of apoptosis inducing proteins. It regulates the expression of angiogenic and metastatic proteins to inhibit tumor growth. Expression of inflammatory markers has also been found to be suppressed by ampelopsin in cancer cells. The present review article describes various anti-tumor cellular targets of ampelopsin at a single podium which will help the researchers to understand mechanistic insight of this phytochemical.

Are P2Y1 purinoceptors expressed in turkey erythrocytes?

Since the beginning of purinoceptor research turkey erythrocytes have been widely used as the model systems for studying the pharmacology of P2Y1 nucleotide receptors. In this report the statistical analysis of the activity parameters of several purinoceptor agonists and antagonists in the turkey erythrocytes and P2Y1 receptor transfected cells is presented. As a results of this analysis several differences in the ligand activity orders measured in these biological systems were found. These data indicate that the receptors expressed in turkey erythrocytes and P2Y1 transfected cells are probably not the same. Whether it has to do with co-expression of several purinoceptor subtypes in turkey erythrocytes or novel P2Y receptors needs the further investigation.

Autophagy Induction by Scutellaria Flavones in Cancer: Recent Advances

In parallel with a steady rise in cancer incidence worldwide, the scientific community is increasingly focused on finding novel, safer and more efficient modalities for managing this disease. Over the past decades, natural products have been described as a significant source of new structural leads for novel drug candidates. Scutellaria root is one of the most studied natural products because of its anticancer potential. Besides just describing the cytotoxic properties of plant constituents, their molecular mechanisms of action in different cancer types are equally important. Therefore, this review article focuses on the role of the Scutellaria flavones wogonin, baicalein, baicalin, scutellarein and scutellarin in regulating the autophagic machinery in diverse cancer models, highlighting these molecules as potential lead compounds for the fight against malignant neoplasms. The knowledge that autophagy can function as a dual-edged sword, acting in both a pro- and antitumorigenic manner, further complicates the issue, revealing an amazing property of flavonoids that behave either as anti- or proautophagic agents.

'Strain effect' descriptors for ATP and ADP derivatives with modified phosphate groups

Semiempirical AM1 calculations were carried out for quantum chemically optimized conformations of ATP and ADP and their modified phosphate derivatives with the oxygen atoms intervening between phosphorus atoms substituted by imido or methylene groups or the double-bonded oxygen atoms substituted by sulfur. In addition to the calculation of conventional geometric and energetic parameters, the effect of these substitutions was quantified in terms of conformational 'strain energy'. The latter has been defined as the energy of transformation of the parent nucleotide (ATP or ADP) from the optimum conformation to the conformation optimized for its phosphate-modified analog. The results of calculations revealed that conformational 'strain' of phosphate-modified nucleotides depends not only on the nature of the substituent but also on its position. The respective effect had the largest magnitude when the substitution was made between two terminal phosphorus atoms. Given that the 'strain energy' characterizes the geometrical aspects of the interaction of nucleotide molecules with receptors and enzymes, an attempt was made to correlate it with the corresponding biological activities. Such correlation was significant in the case of highly specific binding sites for universal ligands like ATP.

Ace I/D polymorphism is associated with habitual physical activity in pubertal boys

We investigated the association between the angiotensin I-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphism and physical activity levels in boys at early pubertal stage (calendar age 12.04 ± 0.77 years). Body composition by DXA, pubertal stage and cardiovascular fitness on cycle ergometer were measured in addition to 7-day accelerometry. DNA was separated from the whole blood. Sedentary behaviour level was significantly lower in DD subjects compared to I allele carriers. A significant main effect of the D allele was found on total physical activity (F 1,256 = 5,453; p = 0.020; η (2) = 0.021] and on light physical activity (F 1,256 = 4.74; p = 0.030; η (2) = 0.018). Adding screen time as a covariate did not change ACE I/D polymorphism effect on total physical activity levels (F 2,256 = 3,326; p = 0.041; η (2) = 0.025). Carriers of the D allele had significantly higher light physical activity (F 1,256 = 4,710; p = 0.031; η (2) = 0.20), with screen time as covariate. In conclusion, ACE gene has a significant effect on sedentary, light and total physical activity levels in healthy 12-year-old boys.

Molecular Evolution of Severe Acute Respiratory Syndrome Coronavirus 2: Hazardous and More Hazardous Strains Behind the Coronavirus Disease 2019 Pandemic and Their Targeting by Drugs and Vaccines

Within almost the last 2 years, the world has been shaken by the coronavirus disease 2019 (COVID-19) pandemic, which has affected the lives of all people. With nearly 4.92 million deaths by October 19, 2021, and serious health damages in millions of people, COVID-19 has been the most serious global challenge after the Second World War. Besides lost lives and long-term health problems, devastating impact on economics, education, and culture will probably leave a lasting impression on the future. Therefore, the actual extent of losses will become obvious only after years. Moreover, despite the availability of different vaccines and vaccination programs, it is still impossible to forecast what the next steps of the virus are or how near we are to the end of the pandemic. In this article, the route of molecular evolution of the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is thoroughly compiled, highlighting the changes that the virus has undergone during the last 2 years and discussing the approaches that the medical community has undertaken in the fight against virus-induced damages.

Cucurbitacins as Potent Chemo-Preventive Agents: Mechanistic Insight and Recent Trends

Cucurbitacins constitute a group of cucumber-derived dietary lipids, highly oxidized tetracyclic triterpenoids, with potential medical uses. These compounds are known to interact with a variety of recognized cellular targets to impede the growth of cancer cells. Accumulating evidence has suggested that inhibition of tumor cell growth via induction of apoptosis, cell-cycle arrest, anti-metastasis and anti-angiogenesis are major promising chemo-preventive actions of cucurbitacins. Cucurbitacins may be a potential choice for investigations of synergism with other drugs to reverse cancer cells' treatment resistance. The detailed molecular mechanisms underlying these effects include interactions between cucurbitacins and numerous cellular targets (Bcl-2/Bax, caspases, STAT3, cyclins, NF-κB, COX-2, MMP-9, VEGF/R, etc.) as well as control of a variety of intracellular signal transduction pathways. The current study is focused on the efforts undertaken to find possible molecular targets for cucurbitacins in suppressing diverse malignant processes. The review is distinctive since it presents all potential molecular targets of cucurbitacins in cancer on one common podium.

Mechanistic insight into anti-COVID-19 drugs: recent trends and advancements

The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) has been established now to be a deadly disease afflicting the whole world with worst consequences on healthcare, economy and day-to-day life activities. Being a communicable disease, which is highly pathogenic in humans, causing cough, throat infection, breathing problems, high fever, muscle pain, and may lead to death in some cases especially those having other comorbid conditions such as heart or kidney problems, and diabetes. Finding an appropriate drug and vaccine candidate against coronavirus disease (COVID-19) remains an ultimate and immediate goal for the global scientific community. Based on previous studies in the literature on SARS-CoV infection, there are a number of drugs that may inhibit the replication of SARS-CoV-2 and its infection. Such drugs comprise of inhibitors of Angiotensin-Converting Enzyme 2 (ACE2), transmembrane Serine Protease 2 (TMPRSS2), nonstructural protein 3C-like protease, nonstructural RNA-dependent RNA polymerase (RdRp) and many more. The antiviral drugs such as chloroquine and hydroxychloroquine, lopinavir and ritonavir as inhibitors for HIV protease, nucleotide analogue remdesivir, and broad-spectrum antiviral drugs are available to treat the SARS-CoV-2-infected patients. Therefore, this review article is planned to gain insight into the mechanism for blocking the entry of SARS-CoV-2, its validation, other inhibition mechanisms, and development of therapeutic drugs and vaccines against SARS-CoV-2.

Ginnalin A and hamamelitannin: the unique gallotannins with promising anti-carcinogenic potential

Tannins are secondary metabolites that belong to the family of polyphenolic compounds and have gained a huge interest among researchers due to their versatile therapeutic potential. After lignin, these are the second most abundant polyphenols found in almost every plant part like stem, bark, fruit, seed, leaves, etc. Depending upon their structural composition, these polyphenols can be divided into two distinct groups, namely condensed tannins and hydrolysable tannins. Hydrolysable tannins can be further divided into two types: gallotannins and ellagitannins. Gallotannins are formed by the esterification of D-glucose hydroxyl groups with gallic acid. The gallolyl moieties are bound by a depside bond. The current review focuses mainly on the anti-carcinogenic potential of recently discovered gallotannins, ginnalin A, and hamamelitannin (HAM). Both of these gallotannins possess two galloyl moieties linked to a core monosaccharide having anti-oxidant, anti-inflammatory, and anti-carcinogenic abilities. Ginnalin A is found in plants of the genus Acer whereas HAM is present in witch hazel plants. The biosynthetic pathway of ginnalin A along with the mechanism of the anti-cancer therapeutic potential of ginnalin A and HAM has been discussed. This review will certainly help researchers to work further on the chemo-therapeutic abilities of these two unique gallotannins.