Preventive Potential of Resveratrol in Carcinogen-Induced Rat Thyroid Tumorigenesis

Can Compounds of Natural Origin Be Important in Chemoprevention? Anticancer Properties of Quercetin, Resveratrol, and Curcumin-A Comprehensive Review

Malignant tumors are the second most common cause of death worldwide. More attention is being paid to the link between the body's impaired oxidoreductive balance and cancer incidence. Much attention is being paid to polyphenols derived from plants, as one of their properties is an antioxidant character: the ability to eliminate reactive oxygen and nitrogen species, chelate specific metal ions, modulate signaling pathways affecting inflammation, and raise the level and activity of antioxidant enzymes while lowering those with oxidative effects. The following three compounds, resveratrol, quercetin, and curcumin, are polyphenols modulating multiple molecular targets, or increasing pro-apoptotic protein expression levels and decreasing anti-apoptotic protein expression levels. Experiments conducted in vitro and in vivo on animals and humans suggest using them as chemopreventive agents based on antioxidant properties. The advantage of these natural polyphenols is low toxicity and weak adverse effects at higher doses. However, the compounds discussed are characterized by low bioavailability and solubility, which may make achieving the blood concentrations needed for the desired effect challenging. The solution may lie in derivatives of naturally occurring polyphenols subjected to structural modifications that enhance their beneficial effects or work on implementing new ways of delivering antioxidants that improve their solubility and bioavailability.

Research progress of plant-derived natural products in thyroid carcinoma

Thyroid carcinoma (TC) is a prevalent malignancy of the endocrine system, with a notable rise in its detection rate in recent decades. The primary therapeutic approaches for TC now encompass thyroidectomy and radioactive iodine therapy, yielding favorable prognoses for the majority of patients. TC survivors may necessitate ongoing surveillance, remedial treatment, and thyroid hormone supplementation, while also enduring the adverse consequences of thyroid hormone fluctuations, surgical complications, or side effects linked to radioactive iodine administration, and encountering enduring physical, psychosocial, and economic hardships. In vitro and in vivo studies of natural products against TC are demonstrating the potential of these natural products as alternatives to the treatment of thyroid cancer. This therapy may offer greater convenience, affordability, and acceptability than traditional therapies. In the early screening of natural products, we mainly use a combination of database prediction and literature search. The pharmacological effects on TC of selected natural products (quercetin, genistein, apigenin, luteolin, chrysin, myricetin, resveratrol, curcumin and nobiletin), which hold promise for therapeutic applications in TC, are reviewed in detail in this article through most of the cell-level evidence, animal-level evidence, and a small amount of human-level evidence. In addition, this article explores possible issues, such as bioavailability, drug safety.

Effects of Different Levels of Surgical Separation on Neck Bulge and Swallowing Disorders during Endoscopic Thyroidectomy

OBJECTIVE

Our study aims to compare the effects of different levels of access on postoperative neck bulge and swallowing disorder and provide a better level for endoscopic thyroidectomy.

MATERIALS AND METHODS

The patients were selected retrospectively between March 2021 to September 2021 by the Department of Thyroid Surgery, Third Affiliated Hospital of Zunyi Medical University. They were divided into two groups according to the level of the free flap during surgery: group A (the superficial cervical fascial level) and group B (the superficial deep cervical fascial level). Age, sex, body mass index, diameter of the primary lesion, postoperative neck bulge, and swallowing disorders and other complications were compared between the two groups.

RESULTS

A total of 40 patients who underwent endoscopic unilateral lobectomy plus central region lymph node dissection were enrolled in our study. Twenty in group A and 20 in group B. The age, gender, body mass index, diameter, and the proportion of benign and malignant primary lesions were not significantly different between the two groups ( P >0.05), and there was also no difference in thyroid function between the two groups ( P >0.05). No significant differences were observed in terms of bleeding and operation time during the operation ( P >0.05). There were also no statistical differences in terms of recurrent laryngeal nerve injury or hypoparathyroidism ( P >0.05). However, patients in group B were superior to those in group A in the occurrence of neck bulge and swallowing disorders ( P <0.05). These symptoms were most evident one month after surgery. Six months after the operation, only 4 patients in group B still complained of neck "swelling" and uncomfortable straining which did not resolve until 1 year after the operation. No statistical significance between long-term results and complication rates could be observed in either group.

CONCLUSION

In endoscopic thyroidectomy, the superficial cervical fascial level may be a better option for reducing postoperative neck bulge and swallowing disorders, which needs further validation by conducting a large sample study.

Mediterranean Diet and Thyroid: An Interesting Alliance

The Mediterranean diet, recognized as being cultural heritage by UNESCO, is mostly plant-based and includes a high consumption of whole-grain, fruit, and vegetables with a moderate consumption of alcohol during meals. Thus, it provides a small amount of saturated fatty acids and a high quantity of antioxidants and fiber. For this reason, it has been considered to have an important role in preventing cardiovascular diseases, chronic kidney diseases, type 2 diabetes mellitus, and cancer, but its relationship with thyroid function and diseases is still under debate. The aim of this review was to search for the possible correlation between the Mediterranean diet and thyroid function, and to critically evaluate the pathophysiological link between selected food intake and thyroid disorders.

Anticancer effects of natural phytochemicals in anaplastic thyroid cancer (Review)

Anaplastic thyroid cancer (ATC) is an aggressive and lethal malignancy having a dismal prognosis. Phytochemicals are bioactive components obtained from plants that have been proven useful to treat numerous diseases. Phytochemicals are also an important source of novel anticancer drugs and an important area of research due to the numerous available candidates that can potentially treat cancers. This review discusses naturally occurring phytochemicals and their derivatives that show promising anticancer effects in anaplastic thyroid cancer. Anticancer effects include cell growth inhibition, induction of apoptosis, promoting cell cycle arrest, suppressing angiogenesis, modulating autophagy, and increasing the production of reactive oxygen species. Phytochemicals are not only prospective candidates in the therapy of anaplastic thyroid cancer but also exhibit potential as adjuvants to improve the anticancer effects of other drugs. Although some phytochemicals have excellent anticancer properties, drug resistance observed during the use of resveratrol and artemisinin in different anaplastic thyroid cancer cell lines is still a problem. Anaplastic thyroid cancer cells have several biological, clinical, and drug-resistance features that differ from differentiated thyroid cancer cells. Phytochemicals such as resveratrol and quercetin exhibit different biological effects in anaplastic thyroid cancer and differentiated thyroid cancer. Tumor cells depend on increased aerobic glycolysis by mitochondrial oxidative phosphorylation to provide energy for their rapid growth, invasiveness, and drug resistance. Phytochemicals can alter signaling cascades, modulate the metabolic properties of cancer cells, and influence the mitochondrial membrane potential of anaplastic thyroid cancer cells. These findings enrich our knowledge of the anticancer effects of phytochemicals and highlight alternative therapies to prevent drug resistance in anaplastic thyroid cancer.

Bisphenol A drives di(2-ethylhexyl) phthalate promoting thyroid tumorigenesis via regulating HDAC6/PTEN and c-MYC signaling

Bisphenol A (BPA) and di-(2-ethylhcxyl) phthalate (DEHP) are exist widespread in the environment and produce adverse effect to human as environmental disruptors (EDCs). Epidemiological studies have found that the exposure of DEHP and BPA could increase the susceptibility to thyroid diseases including thyroid cancer and benign thyroid nodules. Due to the existence of multiple pollutants in our daily life, the mixed toxic effects of exposure and their interrelationships may distinguish from the exposure to a single chemical, so it is of great significance to explore the mixed toxic effect of DEHP and BPA co-exposure. Thyroid, as one of the target organs of EDCs, is prone to tumor occurrence, however, whether the mixture of BPA and DEHP will affect the occurrence of thyroid cancer is still obscure. We aim to investigate the effect of single or combined exposure to BPA and DEHP on the occurrence of thyroid cancer. An animal model of exposure to BPA and DEHP was firstly established to evaluate their effect on DMD-induced thyroid cancer. Additionally, human thyroid cancer cells BCPAP and thyroid cells Nthy-ori3-1 were used to further clarify some possible mechanisms of BPA and MEHP, the main metabolite of DEHP. Consequently, we found that BPA alone could increase the incidence of thyroid tumors in female rats compared with DEHP, and DEHP enhanced the effect of BPA on cancer promotion. BPA alone and in combination with DEHP mainly induced the expression of HDAC6, inhibited tumor suppressor gene PTEN upregulated the expression of oncogene c-MYC, and eventually elevate the susceptibility to thyroid tumors. Mechanistically, BPA alone and in combination with MEHP could significantly induce the proliferation of BCPAP cells depending on HDAC6, which could modulate H3K9ac to inhibit PTEN, activate AKT signaling pathway, and simultaneously upregulate the expression of c-MYC. Interestingly, we found that BPA alone and in combination with MEHP could significantly induce the proliferation of Nthy-ori3-1 cells independent on HDAC6 via activating ERK signaling pathway. Taken together, these findings not only provide new evidence of the promoting effect of BPA and DEHP on thyroid cancer but also discusses some possible mechanisms underlying these effects.

Effects of Annurca Flesh Apple Polyphenols in Human Thyroid Cancer Cell Lines

Among natural macromolecules, the polyphenol extract from Annurca flesh (AFPE) apple could play a potential therapeutic role for a large spectrum of human cancer also by exerting antioxidant properties. Thyroid cancer is a common neoplasia in women, and it is in general responsive to treatments although patients may relapse and metastasize or therapy-related side effects could occur. In this study, we explored the effects of AFPE on papillary (TPC-1) and anaplastic (CAL62) thyroid cancer cell line proliferation and viability. We found that AFPE exposure induced a reduction of cell proliferation and cell viability in dose-dependent manner. The effect was associated with the reduction of phosphorylation of Rb protein. To study the mechanisms underlying the biological effects of AFPE treatment in thyroid cancer cells, we investigated the modulation of miRNA (miR) expression. We found that AFPE treatment increased the expression of the miR-141, miR-145, miR-200a-5p, miR-425, and miR-551b-5p. Additionally, since natural polyphenols could exert their beneficial effects through the antioxidant properties, we investigated this aspect, and we found that AFPE treatment reduced the production of reactive oxygen species (ROS) in CAL62 cells. Moreover, AFPE pretreatment protects against hydrogen peroxide-induced oxidative stress in thyroid cancer cell lines. Taken together, our findings suggest that AFPE, by acting at micromolar concentration in thyroid cancer cell lines, may be considered a promising adjuvant natural agent for thyroid cancer treatment approach.

The value of intraoperative nerve monitoring against recurrent laryngeal nerve injury in thyroid reoperations

Reoperative thyroidectomy is challenging for surgeons because of the higher incidence of recurrent laryngeal nerve (RLN) palsy. RLN identification is the gold standard during thyroidectomy; however, it is sometimes difficult to perform thyroid reoperations. In recent years, intraoperative nerve monitoring (IONM) has gained increased acceptance, and the use of IONM can be a valuable adjunct to visual identification. The aim of this study was to evaluate the value of IONM during thyroid reoperation.A total of 109 patients who met our criteria at the Affiliated Hospital of Hangzhou Normal University from January 2010 to June 2020 were retrospectively analyzed and divided into the IONM group and the visualization-alone group (VA group) according to whether neuromonitoring was used during the operation. The patients' characteristics, perioperative data, and intraoperative information including the RLN identification, time of RLNs confirmation, operative time, intraoperative blood loss, and the rate of RLN injury were collected.Sixty-five procedures (94 RLNs at risk) were performed in the IONM group, whereas 44 (65 RLNs at risk) were in the VA group. The rate of RLN identification was 96.8% in the IONM group and 75.4% in the VA group (P < .05). The incidence of RLN injury was 5.3% in the IONM group and 13.8% in the VA group (P > .05). The incidence of surgeon-related RLN injury rate was 0% in the IONM group compared to 7.7% in the VA group (P < .05), but the tumor-related or scar-related RLN injury rate between the 2 groups were not significantly different (4.3% vs 3.1%, 1.1% vs 3.1%, P > .05).IONM in thyroid reoperation was helpful in improving the RLN identification rate and reducing the surgeon-related RLN injury rate, but was ineffective in reducing the tumor-related and scar-related RLN injury rate. In the future, multicenter prospective studies with large sample sizes may be needed to further assess the role of IONM in thyroid reoperations.

Diet as a possible influencing factor in thyroid cancer incidence: the point of view of the nutritionist

The incidence of differentiated thyroid cancer has increased in the last decades all over the world. Different environmental factors are possible perpetrators of this exponential growth. Nutritional factors are among the main environmental factors studied for thyroid cancer in recent years. This review aims to overview the main dietary factors involved in thyroid cancer risk, providing specific nutrition recommendations from the endocrinological Nutritionist point of view. Among the single food, fish and shellfish are the primary natural source of iodine, selenium and vitamin D in the human diet. These nutrients are essential for the synthesis of thyroid hormones; however, their consumption is not consistently related to thyroid cancer risk. The high intake of fruit and vegetables, probably due to their vitamin and antioxidant content, shows a weak inverse association with thyroid cancer risk. Alcohol, meat, or other food groups/nutrients showed no significant effect on thyroid cancer. In conclusion, to date, no definite association among dietary factors, specific dietary patterns, and thyroid cancer, and its clinical severity and aggressiveness have been found. However, it is essential to underline that in the future, prospective studies should be carried out to precisely evaluate the qualitative and quantitative intake of nutrients by patients to establish with more confidence a potential correlation between food intake and the occurrence and development of thyroid cancer.

Resveratrol and its Nanoparticle suppress Doxorubicin/Docetaxel-resistant anaplastic Thyroid Cancer Cells in vitro and in vivo

Background: Docetaxel and doxorubicin combination has been widely used in anaplastic thyroid cancer/ATC treatment but often results in serious adverse effects and drug resistance. Resveratrol effectively inhibits ATC cell proliferation in vitro without affecting the corresponding normal cells, while its in vivo anti-ATC effects especially on the ones with docetaxel/doxorubicin-resistance have not been reported due to its low bioavailability. Nanoparticles with sustained-release and cancer-targeting features may overcome this therapeutic bottleneck. Methods: The resveratrol nanoparticles with sustained-release and IL-13Rα2-targeting capacities (Pep-1-PEG3.5k-PCL4k@Res) were prepared to improve the in vivo resveratrol bioavailability. Human THJ-16T ATC cell line was employed to establish nude mice subcutaneous transplantation model. The tumor-bearing mice were divided into four groups as Group-1, without treatment, Group-2, treated by 30 mg/kg free resveratrol, Group-3, treated by 30 mg/kg Pep-1-PEG3.5k-PCL4k@Res and Group-4, treated by 5 mg/kg docetaxel/5 mg/kg doxorubicin combination. TUNEL staining was used to detect the apoptotic cells in the tumor tissues. Docetaxel/doxorubicin resistant xenografts named as THJ-16T/R were isolated and subjected to 2D and 3D culture. The docetaxel/doxorubicin and resveratrol sensitivities of the original THJ-16T and THJ-16T/R cells were analyzed by multiple methods. Results: Docetaxel/doxorubicin and Pep-1-PEG3.5k-PCL4k@Res but not free resveratrol significantly delayed tumor growth (P < 0.01) and caused extensive apoptosis. The mice in docetaxel/doxorubicin-treated group suffered from weight loss (> 10%) and 2/3 of them died within 3 times of treatment and the chemotherapy was stop to avoid further animal loss. One week after drug withdrawal, the subcutaneous tumors regrew and the tumor volume increased 55.28% within 14 days. The cells isolated from the regrowing tumors (THJ-16T/R) were successfully cultured under 2D and 3D condition and underwent drug treatments. Compared with THJ-16T, the death rate of docetaxel/doxorubicin-treated THJ-16T/R population was lower (39.3% vs 18.0%), which remained almost unchanged in resveratrol-treated group (45.3% vs 49.3%). Conclusion: Resveratrol sustained-release targeting nanoparticles effectively inhibit in vivo ATC growth. Docetaxel/doxorubicin suppresses ATC xenografts but causes obvious side effects and secondary drug resistance that can be overcome by resveratrol.

Resveratrol Attenuates High-Fat Diet Induced Hepatic Lipid Homeostasis Disorder and Decreases m6A RNA Methylation

Purpose: N 6-methyladenosine (m6A) mRNA methylation is affected by dietary factors and associated with lipid metabolism; however, whether the regulatory role of resveratrol in lipid metabolism is involved in m6A mRNA methylation remains unknown. Here, the objective of this study was to investigate the effect of resveratrol on hepatic lipid metabolism and m6A RNA methylation in the liver of mice. Methods: A total of 24 male mice were randomly allocated to LFD (low-fat diet), LFDR (low-fat diet + resveratrol), HFD (high-fat diet), and HFDR (high-fat diet + resveratrol) groups for 12 weeks (n = 6/group). Final body weight of mice was measured before sacrificing. Perirhemtric fat, abdominal and epididymal fat, liver tissues, and serum were collected at sacrifice and analyzed. Briefly, mice phenotype, lipid metabolic index, and m6A modification in the liver were assessed. Results: Compared to the HFD group, dietary resveratrol supplementation reduced the body weight and relative abdominal, epididymal, and perirhemtric fat weight in high-fat-exposed mice; however, resveratrol significantly increased average daily feed intake in mice given HFD. The amounts of serum low-density lipoprotein cholesterol (LDL), liver total cholesterol (TC), and triacylglycerol (TAG) were significantly decreased by resveratrol supplementation. In addition, resveratrol significantly enhanced the levels of peroxisome proliferator-activated receptor alpha (PPARα), peroxisome proliferator-activated receptor beta/delta (PPARβ/δ), cytochrome P450, family 4, subfamily a, polypeptide 10/14 (CYP4A10/14), acyl-CoA oxidase 1 (ACOX1), and fatty acid-binding protein 4 (FABP4) mRNA and inhibited acyl-CoA carboxylase (ACC) mRNA levels in the liver. Furthermore, the resveratrol in HFD increased the transcript levels of methyltransferase like 3 (METTL3), alkB homolog 5 (ALKBH5), fat mass and obesity associated protein (FTO), and YTH domain family 2 (YTHDF2), whereas it decreased the level of YTH domain family 3 (YTHDF3) and m6A abundance in mice liver. Conclusion: The beneficial effect of resveratrol on lipid metabolism disorder under HFD may be due to decrease of m6A RNA methylation and increase of PPARα mRNA, providing mechanistic insights into the function of resveratrol in alleviating the disturbance of lipid metabolism in mice.

STAT3 signaling statuses determine the fate of resveratrol-treated anaplastic thyroid cancer cells

BACKGROUNDS

Anaplastic thyroid cancer/ATC is highly lethal malignancy without reliable chemotherapeutic drug. Resveratrol possesses anti-ATC activities but encounters resistance in some cases due to certain unknown reason(s).

OBJECTIVE

Because signal transducer and activator of transcription/STAT3 signaling is critical for ATC cell survival and the main molecular target of resveratrol, its roles in determining the fates of resveratrol-treated ATC cells were investigated here.

METHODS

Human THJ-11T, THJ-16 and THJ-21T ATC cell lines were treated by 100 μM resveratrol and their growth, statuses of STAT3 signaling and STAT3-related gene expression were examined. The relevance of STAT3 activation with resveratrol resistance was elucidated using STAT selective inhibitor AG490. Leukemia inhibitory factor/LIF expression and phosphorylated-STAT3/p-STAT3 nuclear translocation in ATC tissues were immunohistochemically analyzed.

RESULTS

Resveratrol inhibited proliferation, p-STAT3 nuclear translocation as well as LIF and STAT3 expression of THJ-16T and THJ-21T but not THJ-21T cells which showed LIF upregulation and more frequent p-STAT3 nuclear translocation. AG490 significantly prevent p-STAT3 nuclear translocation, and reversed the resveratrol tolerance of THJ-11T cells. Immonohistochemical staining revealed 14.3% (4/28) of LIF and 3.6% (1/28) of p-STAT3 detection in noncancerous ATC-surrounding tissues, which increased to 89.5% (17/19) and 52.6% (10/19) respectively among ATC specimens. The correlative analysis indicated the relevance of LIF expression and STAT3 activation (r= 0.825; P< 0.01).

CONCLUSIONS

The status of STAT3 activation and LIF expression are closely correlated with the therapeutic effect of resveratrol on ATCs. Frequent LIF upregulation and STAT3 activation are the unfavorable factors of ATCs and the potential targets of anti-ATC therapy.

Geraniin Protects PC12 Cells Against Aβ25-35-Mediated Neuronal Damage: Involvement of NF-κB and MAPK Signaling Pathways

β-amyloid peptide (Aβ) has been considered a critical factor that is associated with the development of oxidative stress and neuroinflammation in the pathogenesis of Alzheimer's disease. This study was performed to evaluate the effect of geraniin on Aβ_25-35-caused oxidative damage and neuroinflammatory response, and its underlying mechanism. Geraniin protected pheochromocytoma12 (PC12) cells from Aβ_25-35-mediated cell death by reducing oxidative stress and restoring cell cycle dysregulation. Moreover, geraniin markedly attenuated Aβ-triggered DNA injury that was partially associated with decreases in caspase-3 activity. Moreover, the compound significantly downregulated the release of neuroinflammatory factors. Upregulation of nuclear factor-κB activity was suppressed by geraniin, which was due to suppression of JNK, ERK1/2, and the p38 mitogen-activated protein kinase (MAPK) pathway. This was the first study to support further understanding of geraniin as a promising agent against neurotoxicity in the reduction of oxidative stress and neuroinflammation.

Resveratrol Inhibits the Tumorigenesis of Follicular Thyroid Cancer via ST6GAL2-Regulated Activation of the Hippo Signaling Pathway

Follicular thyroid carcinoma (FTC) is a common endocrine malignancy with highly aggressive features. In this study, next-generation sequencing technology was used to identify aberrant expression of sialyltransferase (ST) family members in FTC. Aberrant high expression of alpha-2,6-sialyltransferase 2 (ST6GAL2) was demonstrated to promote tumorigenesis of FTC in vitro and in vivo. Furthermore, ST6GAL2 promoted tumorigenesis by inactivating the Hippo signaling pathway. Resveratrol is a native compound extracted from Vitis species, and many studies have confirmed its protective cardiovascular and antineoplastic effects. Here we found that resveratrol can inhibit the tumorigenesis of FTC by suppressing the expression of ST6GAL2, further activating the Hippo pathway. In summary, this study revealed the role of the ST6GAL2-Hippo signaling pathway in FTC tumorigenesis and indicated that resveratrol, a commonly found antineoplastic compound, could inhibit tumorigenesis of FTC by regulating the abovementioned pathways.

BRCA1/P53: Two strengths in cancer chemoprevention

Increasing emphasis has been given to prevention as a feasible approach to reduce the cancer burden. However, for its clinical success, further advances are required to identify effective chemopreventive agents. This review affords a critical and up-to-date discussion of issues related to cancer prevention, including an in-depth knowledge on BRCA1 and p53 tumor suppressor proteins as key molecular players. Indeed, it compiles the most recent advances on the topic, highlighting the unique potential of BRCA1 and p53 germline mutations as molecular biomarkers for risk assessment and targets for chemoprevention. Relevant evidences are herein provided supporting the effectiveness of distinct pharmacological agents in cancer prevention, by targeting BRCA1 and p53. Moreover, the rationale for using germline mutant BRCA1- or p53-related cancer syndromes as model systems to investigate effective chemopreventive agents is also addressed. Altogether, this work provides an innovative conception about the dependence on p53 and BRCA1 co-inactivation in tumor formation and development, emphasizing the relationship between these two proteins as an encouraging direction for future personalized pharmacological interventions in cancer prevention.

Impacts of resveratrol versus platelet-rich plasma for treatment of experimentally lithium-induced thyroid follicular cell toxicity in rats. A histological and immunohistochemical study

Lithium (Li) is used for the treatment and prophylaxis of mental disorders, associated with many serious hazards. Resveratrol (RSV) has various beneficial therapeutic effects. Platelet-rich plasma (PRP) is a new promising curative tool. This study aimed to assess the impacts of RSV versus PRP on lithium-induced thyroid follicular cell toxicity in adult male rats. Forty-nine adult male rats were divided into four groups: group I: control rats; group II: lithium-treated rats; group III: lithium- and resveratrol-treated rats; group IV: lithium and PRP-treated rats. Thyroid specimens were taken and processed for histological and immunohistochemical methods. Morphometrical studies and statistical analysis were done. Group II showed distorted thyroid follicles, significantly increased collagen fibers, and highly positive P53 immunostaining (P < 0.01). Ultrastructural examination showed dilated rough endoplasmic reticulum and damaged mitochondria. Groups III and IV exhibited significant amelioration of the histological and electron microscopic changes mentioned previously. PRP remedy was more effective than RSV for treatment of Li-induced thyroid follicular cell toxicity.

Antitumor Effect of Various Phytochemicals on Diverse Types of Thyroid Cancers

Thyroid cancers developed from the tissues of the thyroid gland are classified into papillary (PTC), follicular (FTC), medullary (MTC), and anaplastic thyroid cancer (ATC). Although thyroid cancers have been generally known as mild forms of cancer, undifferentiated MTC and ATC have a more unfavorable prognosis than differentiated PTC and FTC because they are more aggressive and early metastatic. A variety of therapies such as surgery, radiotherapy, and chemotherapy have been currently used to treat thyroid cancer, but they still have limitations including drug resistance or unfavorable side effects. Phytochemicals are plant-derived chemicals having various physiological activities that are expected to be effective in cancer treatment. In this review, anticancer efficacy of phytochemicals, such as resveratrol, genistein, curcumin, and other substances in each type of thyroid cancer was introduced with their chemopreventive mechanisms. English articles related with thyroid cancer and anti-thyroid cancer of phytochemicals were searched from PubMed and Google Scholar. This article mainly focused on in vitro or animal studies on phytochemicals with anti-thyroid cancer activity. These various phytochemicals have been shown to induce apoptosis in all types of thyroid cancer cells, inhibit cell proliferation and invasion, and to be helpful in enhancing the effect of radioiodine therapy that is a typical therapy to thyroid cancer. These results suggest that thyroid cancer can be more effectively treated by the combinations of phytochemicals and the existing therapies or substances.

Resveratrol Reverses Retinoic Acid Resistance of Anaplastic Thyroid Cancer Cells via Demethylating CRABP2 Gene

Background: Cellular retinoic acid binding protein 2 (CRABP2) mediates retinoic acid/RA anti-cancer pathways. Resveratrol effectively reverses RA tolerance and upregulates CRABP2 expression of anaplastic thyroid cancer cell line THJ-11T. As DNA methylation is responsible for CRABP2 silencing, the CRABP2 methylation status of THJ-11T cells and the demethylating effect of resveratrol on this gene are elucidated. Materials and methods: The statuses of CRABP2 expression and methylation and the levels of DNA methyltransferases (DNMTs) DNMT1, DNMT3A, and DNMT3B of THJ-11T cells were examined before and after resveratrol treatment via multiple experimental methods. The human medulloblastoma UW228-2 cell line was cited as the control of CRABP2 methylation and gemcitabine as the demethylator control. Results: RT-PCR, immunocytochemical staining and Western blotting showed that resveratrol significantly increased the CRABP2 expression and RA sensitivity of THJ-11T and UW228-2 cells. Bisulfite sequencing showed five CpG methylation sites at the CRABP2 promoter region of both cell lines, which were partially (3/5) demethylated by resveratrol and totally (5/5) by gemcitabine. DNMT1, DNMT3A, and DNMT3B were reduced in UW228-2 cells and DNMT1 and DNMT3A were reduced in THJ-11T cells after resveratrol treatment in a time-related fashion. Conclusion: Resveratrol is able to erase CRABP2 methylation and can thereby increase the RA sensitivity of THJ-11T and UW228-2 cells. This study demonstrates the additional value of the natural polyphenolic compound resveratrol as a demethylator in cancer treatments.

Resveratrol suppresses colon cancer growth by targeting the AKT/STAT3 signaling pathway

Colon cancer is a common type of cancer worldwide and accounts for a significant number of cancer‑related deaths. Although surgical techniques and treatment strategies for colon cancer have advanced over the past two decades, the prognosis has not improved considerably. Resveratrol, a natural stilbene compound, possesses antioxidant, cardioprotective and anticancer properties. However, the role of resveratrol in colon cancer has not been fully elucidated. The present study demonstrated that resveratrol inhibited cell proliferation and colony growth in DLD1 and HCT15 colon cancer cells, but did not affect normal colon epithelial cells. The resveratrol‑mediated inhibition of cell proliferation correlated with an induction of apoptosis and with G1 phase cell cycle arrest in colon cancer cells. Additionally, resveratrol treatment decreased the protein expression levels of cyclin D1, cyclin E2 and BCL2 apoptosis regulator, while it increased BCL2 associated X and tumor protein p53, all of which are involved in the regulation of cell cycle and apoptosis. Notably, the results obtained from in silico computational screening identified AKT serine/threonine kinase 1 (AKT1) and AKT2 as novel targets of resveratrol. Computational docking suggested that there are three or four possible hydrogen bonds in the active pocket of AKT1 and AKT2 that contribute to the mode of action of resveratrol. The present study confirmed that resveratrol bound to AKT1 and AKT2 with a pull‑down assay. Furthermore, knockdown of AKT1 and AKT2 inhibited cell proliferation and colony growth, by attenuating cell cycle progression and increasing apoptosis in colon cancer cells, effects that were similar to those caused by resveratrol treatment. Taken together, the present results suggest that the targeting effects of resveratrol to AKT1 and AKT2 may be a potent strategy for chemoprevention or therapy for colon cancer.

Cyclooxygenase-2 in cancer: A review

Cyclooxygenase-2 (COX-2) is frequently expressed in many types of cancers exerting a pleiotropic and multifaceted role in genesis or promotion of carcinogenesis and cancer cell resistance to chemo- and radiotherapy. COX-2 is released by cancer-associated fibroblasts (CAFs), macrophage type 2 (M2) cells, and cancer cells to the tumor microenvironment (TME). COX-2 induces cancer stem cell (CSC)-like activity, and promotes apoptotic resistance, proliferation, angiogenesis, inflammation, invasion, and metastasis of cancer cells. COX-2 mediated hypoxia within the TME along with its positive interactions with YAP1 and antiapoptotic mediators are all in favor of cancer cell resistance to chemotherapeutic drugs. COX-2 exerts most of the functions through its metabolite prostaglandin E2. In some and limited situations, COX-2 may act as an antitumor enzyme. Multiple signals are contributed to the functions of COX-2 on cancer cells or its regulation. Members of mitogen-activated protein kinase (MAPK) family, epidermal growth factor receptor (EGFR), and nuclear factor-κβ are main upstream modulators for COX-2 in cancer cells. COX-2 also has interactions with a number of hormones within the body. Inhibition of COX-2 provides a high possibility to exert therapeutic outcomes in cancer. Administration of COX-2 inhibitors in a preoperative setting could reduce the risk of metastasis in cancer patients. COX-2 inhibition also sensitizes cancer cells to treatments like radio- and chemotherapy. Chemotherapeutic agents adversely induce COX-2 activity. Therefore, choosing an appropriate chemotherapy drugs along with adjustment of the type and does for COX-2 inhibitors based on the type of cancer would be an effective adjuvant strategy for targeting cancer.

Inhibition of NF-κB Signaling Pathway by Resveratrol Improves Spinal Cord Injury

Spinal cord injury (SCI) can have a significant impact on an individual’s life. Herein, we discuss how resveratrol improves SCI by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. Evidences show resveratrol suppresses NF-κB signaling pathway to exert its beneficial effects on various diseases. NF-κB signaling pathway plays a significant role in the pathophysiological mechanisms of SCI including increase in inflammation, augmentation of damage caused by free radicals and lipid peroxidation as well as facilitation of apoptosis and axonal demyelination. We also discuss mechanisms between resveratrol and NF-κB signaling pathway in the wake of SCI, which can be potential targets for resveratrol to treat SCI.

The Synergistic Effects of Resveratrol combined with Resistant Training on Exercise Performance and Physiological Adaption

The comprehensive studies done on resveratrol (RES) support that this polyphenol has multiple bioactivities and is widely accepted for dietary supplementation. Furthermore, regular exercise is known to have benefits on health and is considered as a form of preventive medicine. Although the vast majority of prior studies emphasize the efficacy of aerobic exercise in promoting physiological adaptions, other types of exercise, such as resistance exercise and high-intensity interval training (HIIT), may achieve similar or different physiological outcomes. Few studies have looked into the effectiveness of a combinational, synergistic approach to exercise using a weight-loading ladder climbing animal platform. In this study, ICR mice were allocated randomly to the RES and training groups using a two-way ANOVA (RES × Training) design. Exercise capacities, including grip strength, aerobic performance, and anaerobic performance, were assessed and the physiological adaptions were evaluated using fatigue-associated indexes that were implemented immediately after the exercise intervention. In addition, glycogen levels, muscular characteristics, and safety issues, including body composition, histopathology, and biochemistry, were further elucidated. Synergistic effects were observed on grip strength, anaerobic capacities, and exercise lactate, with significant interaction effects. Moreover, the training or RES may have contributed significantly to elevating aerobic capacity, tissue glycogen, and muscle hypertrophy. Toxic and other deleterious effects were also considered to evaluate the safety of the intervention. Resistance exercise in combination with resveratrol supplementation may be applied in the general population to achieve better physiological benefits, promote overall health, and promote participation in regular physical activities.