Arecoline augments cellular proliferation in the prostate gland of male Wistar rats

Epigallocatechin-3-gallate Synergistically Enhanced Arecoline-Induced Cytotoxicity by Redirecting Cycle Arrest to Apoptosis

Carcinogens, such as arecoline, play a crucial role in cancer progression and continuous gene mutations by generating reactive oxygen species (ROS). Antioxidants can reduce ROS levels and potentially prevent cancer progression but may paradoxically enhance the survival of cancer cells. This study investigated whether epigallocatechin-3-gallate (EGCG), an antioxidant from green tea, could resolve this paradox. Prostate cancer cells (PC-3 cell line) were cultured and treated with arecoline combined with NAC (N-acetylcysteine) or EGCG; the combined effects on intracellular ROS levels and cell viability were examined using the MTT and DCFDA assays, respectively. In addition, apoptosis, cell cycle, and protein expression were investigated using flow cytometry and western blot analysis. Our results showed that EGCG, similar to NAC (N-acetylcysteine), reduced the intracellular ROS levels, which were elevated by arecoline. Moreover, EGCG not only caused cell cycle arrest but also facilitated cell apoptosis in arecoline-treated cells in a synergistic manner. These were evidenced by elevated levels of cyclin B1 and p27, and increased fragmentation of procaspase-3, PARP, and DNA. Our findings highlight the potential use of EGCG for cancer prevention and therapy.

Low-dose arecoline regulates distinct core signaling pathways in oral submucous fibrosis and oral squamous cell carcinoma

BACKGROUND

Betel nut chewing plays a role in the pathogenesis of oral submucous fibrosis (OSF) and oral squamous cell carcinoma (OSCC). As the major active ingredient of the betel nut, the effect of arecoline and its underlying mechanism to OSF and OSCC pathogenesis remain unclear.

METHODS

Next-generation sequencing-based transcriptome and dRRBS analysis were performed on OSF and OSCC cells under low-dose arecoline exposure. Functional analyses were performed to compare the different roles of arecoline during OSF and OSCC pathogenesis, and key genes were identified.

RESULTS

In this study, we identified that low-dose arecoline promoted cell proliferation of both NFs and OSCC cells via the acceleration of cell cycle progression, while high-dose arecoline was cytotoxic to both NFs and OSCC cells. We performed for the first time the transcriptome and methylome landscapes of NFs and OSCC cells under low-dose arecoline exposure. We found distinct transcriptome and methylome profiles mediated by low-dose arecoline in OSF and OSCC cells, as well as specific genes and signaling pathways associated with metabolic disorders induced by low-dose arecoline exposure. Additionally, low-dose arecoline displayed different functions at different stages, participating in the modulation of the extracellular matrix via Wnt signaling in NFs and epigenetic regulation in OSCC cells. After exposure to low-dose arecoline, the node roles of FMOD in NFs and histone gene clusters in OSCC cells were found. Meanwhile, some key methylated genes induced by arecoline were also identified, like PTPRM and FOXD3 in NFs, SALL3 and IRF8 in OSCC cells, indicating early molecular events mediated by arecoline during OSF and OSCC pathogenesis.

CONCLUSIONS

This study elucidated the contribution of low-dose arecoline to OSF and OSCC pathogenesis and identified key molecular events that could be targeted for further functional studies and their potential as biomarkers.

Betel Nut Arecoline Induces Different Phases of Growth Arrest between Normal and Cancerous Prostate Cells through the Reactive Oxygen Species Pathway

Prostate cancer (PCa) is a reproductive system cancer in elderly men. We investigated the effects of betel nut arecoline on the growth of normal and cancerous prostate cells. Normal RWPE-1 prostate epithelial cells, androgen-independent PC-3 PCa cells, and androgen-dependent LNCaP PCa cells were used. Arecoline inhibited their growth in dose- and time-dependent manners. Arecoline caused RWPE-1 and PC-3 cell cycle arrest in the G2/M phase and LNCaP cell arrest in the G0/G1 phase. In RWPE-1 cells, arecoline increased the expression of cyclin-dependent kinase (CDK)-1, p21, and cyclins B1 and D3, decreased the expression of CDK2, and had no effects on CDK4 and cyclin D1 expression. In PC-3 cells, arecoline decreased CDK1, CDK2, CDK4, p21, p27, and cyclin D1 and D3 protein expression and increased cyclin B1 protein expression. In LNCaP cells, arecoline decreased CDK2, CDK4, and cyclin D1 expression; increased p21, p27, and cyclin D3 expression; had no effects on CDK1 and cyclin B1 expression. The antioxidant N-acetylcysteine blocked the arecoline-induced increase in reactive oxygen species production, decreased cell viability, altered the cell cycle, and changed the cell cycle regulatory protein levels. Thus, arecoline oxidant exerts differential effects on the cell cycle through modulations of regulatory proteins.

Egr-1 mediates low-dose arecoline induced human oral mucosa fibroblast proliferation via transactivation of Wnt5a expression

Background

Arecoline is an alkaloid natural product found in the areca nut that can induce oral submucous fibrosis and subsequent development of cancer. However, numerous studies have shown that arecoline may inhibit fibroblast proliferation and prevent collagen synthesis.

Results

High doses of arecoline (> 32 μg/ml) could inhibit human oral fibroblast proliferation, while low doses of arecoline (< 16 μg/ml) could promote the proliferation of human oral fibroblasts. Wnt5a was found to be both sufficient and necessary for the promotion of fibroblast proliferation. Egr-1 could mediate the expression of Wnt5a in fibroblasts, while NF-κB, FOXO1, Smad2, and Smad3 did not. Treatment with siRNAs specific to Egr-1, Egr inhibitors, or Wnt5a antibody treatment could all inhibit arecoline-induced Wnt5a upregulation and fibroblast proliferation.

Conclusions

Egr-1 mediates the effect of low dose arecoline treatment on human oral mucosa fibroblast proliferation by transactivating the expression of Wnt5a. Therefore, Egr inhibitors and Wnt5a antibodies are potential therapies for treatment of oral submucosal fibrosis and oral cancer.

Arecoline inhibits pineal-testis function in experimentally induced hypothyroid rats

Arecoline is known to cause endocrine dysfunction. In the current article role of arecoline on pineal-testis activity was investigated in hypothyroid rats induced by propylthiouracil (PTU). PTU treatment caused thyroid dysfunction ultrastructurally with a fall in T₃ and T₄ levels followed by a rise of thyroid stimulating hormone (TSH) level. Pineal activity was impaired by PTU treatment, as evident from degenerated synaptic ribbons and mitochondria of the pinealocytes with depletion of pineal and serum N-acetyl serotonin and melatonin levels. Leydig cell function was suppressed, evident from reduced smooth endoplasmic reticulum and depletion of testosterone level. Sex accessories function was impaired by showing scanty rough endoplasmic reticulum with depletion of fructose and sialic acid levels. Arecoline treatment that caused pineal dysfunction and testicular stimulation in control rats, suppressed both pineal and testis functions after PTU treatment. The findings suggest that arecoline inhibits pineal-testis function in experimentally induced hypothyroid rats.

Arecoline suppresses epithelial cell viability through the Akt/mTOR signaling pathway via upregulation of PHLPP2

Arecoline, the major active ingredient of the betel nut, is involved in the pathogenesis of oral submucous fibrosis. However, the underlying mechanism of this pathogenesis remains unclear. In this study, we found that arecoline suppresses the cell proliferation of the HaCaT epithelial cell and induces cell cycle arrest at the G1/S phase with an IC50 of 50 μg/mL. Furthermore, we found that arecoline reduces the protein level of cyclin D1, but it has no effect on its mRNA level and protein stability, implying that arecoline may modulate the translation of cyclin D1. We also observed the downregulation of the Akt/mTOR signaling pathway after treatment with arecoline, which may be related to the translation of cyclin D1. RNA-seq analysis identified that PHLPP2, the direct upstream target of Akt, is significantly upregulated after arecoline treatment. siRNA-mediated knockdown of PHLPP2 recovered the phosphorylation state of Akt, as well as attenuated the effect of arecoline on cell viability. Thus, our study revealed the crucial role of PHLPP2 in arecoline-induced cell viability suppression.

Arecoline ameliorates hyperthyroid condition in mice under cold stress

Betel nut of Areca catechu is chewed by millions of people for increased capacity to work and stress reduction, but it contains arecoline that causes hypothyroidism. The aim is to investigate the role of arecoline on thyroid activity in cold stress in mice. Arecoline treatment (10 mg/kg body wt/day, for 7 d) caused a reduction in thyroid weight and ultrastructural degeneration of thyro-follicular cells with depletion of T₃ and T₄ levels compared with the control mice. Cold stress (4 °C for 2 h, twice daily, for 7 d) stimulated thyroid activity ultrastructurally with an elevation of T₃ and T₄ levels. Arecoline treatment in cold stress suppressed thyroid activity by showing reversed changes to those of cold stress. In contrast, TSH concentrations were consistently increased under all experimental conditions. The findings suggest that cold stress causes hyperthyroidism which arecoline can ameliorate in mice.

Effect of autophagy-associated proteins on the arecoline-induced liver injury in mice

Arecoline can be used to treat diseases including glaucoma and tapeworm infection, however, long-term administration can cause severe adverse effects, including oral submucosal fibrosis, oral cancer, hepatic injury and liver cancer. Autophagy serves a role in these injuries. The present study established a mouse model of arecoline-induced hepatic injury and investigated the role of autophagy-associated proteins in this injury. The results indicated that the expression levels of the autophagy marker protein microtubule associated protein 1 light chain 3 B (MAP1LC3B) and autophagy-promoting protein beclin 1 were elevated in the injured hepatic cells, while the expression levels of a well-known negative regulator of autophagy, mammalian target of rapamycin (mTOR), were reduced. Following treatment of the hepatic injury with glutathione, the liver function improved and liver damage was reduced effectively. Compared with the control group, the expression levels of both MAP1LC3B and beclin 1 were significantly upregulated in the glutathione-treated mice, but the expression of mTOR was significantly downregulated. It may be concluded that in the process of protecting against arecoline-induced hepatic injury, glutathione cooperates with mTOR and beclin 1 to accelerate autophagy, maintaining stable cell morphology and cellular functions.

Arecoline cannot alter testicular dysfunction and pineal activation caused by noise in wistar rat

Millions of people consume betel nut for increased capacity to work and for stress reduction. The nut contains arecoline, which has multiple side effects on endocrine functions. Objective of the work is to investigate pineal-testicular responses to noise and after arecoline treatment in noise in rats. Noise exposure (100 dB, 6 h daily, 10 days) caused pineal stimulation ultrastructurally and at indoleamines level. Leydig cell dysfunction with fall of testosterone level and suppression of sex accessories were noticed. In contrast, pineal activity was inhibited and reproductive functions were stimulated after arecoline administration, confirmed from reversed changes to those of noise. Arecoline treatment in noise exposure showed same results as in noise both in pineal and in reproductive functions. It is concluded that noise causes testicular dysfunction probably by gonadotropin suppression induced by pineal melatonin in noise. Furthermore, arecoline cannot prevent it in noise in rats.

ARECOLINE CANNOT ALTER PINEAL-TESTICULAR RESPONSES TO METABOLIC STRESS IN WISTAR RATS

Context

Betel nut is consumed by millions of people for stress reduction and increased capacity to work. One of its components is arecoline which is useful for Alzheimer and schizophrenia; it also influences endocrine and gonadal functions.

Objective

Objective is to examine whether arecoline can influence pineal-testicular function in metabolic stress.

Design

Rats were deprived of food or water or treated them with arecoline, each separately for 5 days.

Subjects

Pineal and testis with sex accessories were studied.

Methods

Ultrastructural (pineal, testis, Leydig cells and prostate), hormonal (melatonin and testosterone) and other parameters (fructose and sialic acid) were examined. Pineal indoleamines were quantitated by fluorometric method; testosterone by ELISA, and carbohydrate fractions by spectrophotometric methods.

Results

Inanition/ water deprivation caused pineal stimulation ultrastructurally (with enlarged synaptic ribbons) and elevation of melatonin level, but reproductive dysfunction by ultrastructural degeneration of Leydig cells and prostate with fall of testosterone, fructose and sialic acid concentrations. Arecoline treatment showed reversed changes to those of metabolic stress, but arecoline treatment in metabolic stress showed same results as in metabolic stress.

Conclusion

The findings suggest that arecoline cannot alter the action of metabolic stress on pineal-testicular activity in rats.

Effect of sildenafil citrate in testosterone induced benign prostate hyperplasia rat model

Objective

Efficacy of treatments for benign prostate hyperplasia (BPH) is limited because the disease has complex etiopathogenesis. Recent studies have demonstrated the presence of phosphodiesterase-5 (PDE-5) receptors in prostate tissue. We investigated efficacy of sildenafil citrate in testosteron - induced BPH in rats.

Material and methods

The rats were divided into three groups. Each groups had 7 rats. Group 1 was control group. Testosteron propionate 3 mg/kg/day was injected subcutaneously for two weeks in Group 2. The same procedure was done for Group 3 and sildenafil citrate was added to water at daily doses of 2 mg/kg for two weeks. The rats were euthanized with intraperitoneal pentobarbital. The body weights were measured and the prostates were removed.

Results

The mean weights of rats were 288±31.93, 345±23.23 and 294±32.86 g in Groups 1, 2 and 3, respectively. The mean prostate weights of rats were 0.74±0.18, 1.3±0.13 and 0.72±0.24 g in Groups 1, 2, and 3, respectively. Group 2 had statistically significantly higher prostate weights than the other groups (p<0.01). Relative prostate weight is calculated with ratio of prostate weight to body weight. BPH group showed an increase in relative prostate weight compared with other groups with significant difference (p=0.036 and p=0.040). There was statistical difference for acinar area between Group 2 and the others, no significant difference of number of acini, interstitial space and epithelial thickness. Group 2 has more papillary projections per acini than the other groups.

Conclusion

Favourable effect of sildenafil citrate on dimensions of prostate but not all on histological parameters was observed. We expect that PDE-5 inhibitors might be a treatment option for BPH patients if the studies support our findings in the future.

DUAL ACTION OF ARECOLINE ON ADRENAL FUNCTION AND GLUCOSE-GLYCOGEN HOMEOSTASIS IN METABOLIC STRESS IN MICE

Background

People chew betel nut (Areca catechu) for physical work and stress reduction, but it contains arecoline, which has both therapeutic value and untoward effects on endocrine and gonadal functions.

Objective

Aim of the present study is to investigate its role on adrenal with its target in metabolic stress in mice.

Materials and methods

Mice were deprived of water / food, each for 5 days / treated with arecoline (10 mg / kg body wt daily for 5 days) / arecoline after water or food deprivation, for 5 days each.

Results

Water or food-deprivation caused adrenocortical hyperactivity, evident from abundance of enlarged mitochondria and smooth endoplasmic reticulum (SER) with elevation of corticosterone level (C: 68.31 ± 2.30, WD: 159.31 ± 4.10 / FD: 194.12 ± 3.40 μg/ mL). Arecoline treatment alone or in water deprivation (C: 68.31 ± 2.30, AR: 144.50 ± 4.33, AR+WD: 194.42 ± 3.35 μg/ mL) / food deprivation (AR + FD: 180.89 ± 4.51 μg/ mL) stress also stimulated adrenocortical activity as recorded in metabolic stress. In contrast, adrenomedullary activity was not altered following water/ food deprivation. Arecoline treatment alone or in metabolic stress suppressed adrenomedullary activity by showing depletion of chromaffin granules (E/NE?), epinephrine (E) and norepinephrine (NE) concentrations. Both the stress decreased blood glucose and liver glycogen levels. Arecoline treatment decreased blood glucose level, with a rise in liver glycogen level, but elevated blood glucose level in water deprivation unlike in starvation.

Conclusion

Arecoline alone or in metabolic stress involves adrenal and probably other endocrine glands (pancreas, posterior pituitary and rennin-angiotensin system) to maintain homeostasis in metabolic stress in mice.

Arecoline aggravates hypothyroidism in metabolic stress in mice

Millions of people consume betel nut for increased capacity of work. It contains arecoline which is highly toxic and has several untoward side effects on endocrine functions. In this article, the role of arecoline on thyroid function under metabolic stress was investigated in mice. Water or food-deprivation, each for 5 days, caused ultrastructural degeneration of thyro-follicular cells, evident from pycnotic nuclei, scanty rough endoplasmic reticulum and mitochondria followed by depletion of blood serum T₃ and T₄ levels with alteration of TSH level as compared with control. Thyroid activity was also suppressed ultrastructurally as well as at hormonal level after arecoline administration. Further, arecoline treatment in water deprivation or food deprivation stress also caused thyroid dysfunction beyond that of metabolic stress, as evident from further ultrastructural degeneration of thyrocytes and depletion of thyroid hormones in mice. The findings suggest that arecoline aggravates hypothyroid condition in metabolic stress in mice.

A protective role of arecoline hydrobromide in experimentally induced male diabetic rats

Objectives. Arecoline, the most potent and abundant alkaloid of betel nut, causes elevation of serum testosterone and androgen receptor expression in rat prostate, in addition to increase in serum insulin levels in rats, leading to insulin resistance and type 2 diabetes-like conditions. This study investigated the role of arecoline on the reproductive status of experimentally induced type 1 diabetic rats. Methods. Changes in the cellular architecture were analyzed by transmission electron microscopy. Blood glucose, serum insulin, testosterone, FSH, and LH were assayed. Fructose content of the coagulating gland and sialic acid content of the seminal vesicles were also analyzed. Results. Arecoline treatment for 10 days at a dose of 10 mg/kg of body weight markedly facilitated β-cell regeneration and reversed testicular and sex accessory dysfunctions by increasing the levels of serum insulin and gonadotropins in type 1 diabetic rats. Critical genes related to β-cell regeneration, such as pancreatic and duodenal homeobox 1 (pdx-1) and glucose transporter 2 (GLUT-2), were found to be activated by arecoline at the protein level. Conclusion. It can thus be suggested that arecoline is effective in ameliorating the detrimental effects caused by insulin deficiency on gonadal and male sex accessories in rats with type 1 diabetes.

The hepatotoxicity and testicular toxicity induced by arecoline in mice and protective effects of vitamins C and e

Arecoline is a major alkaloid of areca nuts which are widely chewed by southeast Asian and it manifests various toxic effects in different organs of human and animals. In this work, mature mice were treated by vitamins C plus E, arecoline, or both daily for four weeks. The results showed that arecoline significantly increased the levels of serum alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and significantly decreased the levels of reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) in the liver tissues. Additionally, the body weight, testis weight, sperm counts, motility and normal sperms also were significantly decreased. The supplement of vitamins C and E can bring the activities of ALP and GPT to normal levels and partially restore the sperm counts compared to the arecoline-treated group but have no other positive effects. In conclusion, the vitamins C and E partially attenuated the arecoline-induced hepatotoxiciy but basically had on protective effects against the arecoline-induced testicular toxicity.

A review of the systemic adverse effects of areca nut or betel nut

Areca nut is widely consumed by all ages groups in many parts of the world, especially south-east Asia. The objective of this review is to systematically review and collate all the published data that are related to the systemic effects of areca nut. The literature search was performed by an electronic search of the Pubmed and Cochrane databases using keywords and included articles published till October 2012. We selected studies that covered the effect of areca nut on metabolism, and a total of 62 studies met the criteria. There is substantial evidence for carcinogenicity of areca nut in cancers of the mouth and esophagus. Areca nut affects almost all organs of the human body, including the brain, heart, lungs, gastrointestinal tract and reproductive organs. It causes or aggravates pre-existing conditions such as neuronal injury, myocardial infarction, cardiac arrhythmias, hepatotoxicity, asthma, central obesity, type II diabetes, hyperlipidemia, metabolic syndrome, etc. Areca nut affects the endocrine system, leading to hypothyroidism, prostate hyperplasia and infertility. It affects the immune system leading to suppression of T-cell activity and decreased release of cytokines. It has harmful effects on the fetus when used during pregnancy. Thus, areca nut is not a harmless substance as often perceived and proclaimed by the manufacturers of areca nut products such as Pan Masala, Supari Mix, Betel quid, etc. There is an urgent need to recognize areca nut as a harmful food substance by the policy makers and prohibit its glamorization as a mouth freshener. Strict laws are necessary to regulate the production of commercial preparations of areca nut.

Oral delivery of taurocholic acid linked heparin-docetaxel conjugates for cancer therapy

We have synthesized taurocholic acid (TCA) linked heparin-docetaxel (DTX) conjugates for oral delivery of anticancer drug. The ternary biomolecular conjugates formed self-assembly nanoparticles where docetaxel was located inside the core and taurocholic acid was located on the surface of the nanoparticles. The coupled taurocholic acid in the nanoparticles had enhanced oral absorption, presumably through the stimulation of a bile acid transporter of the small intestine. The oral absorption profile demonstrated that the concentration of the conjugates in plasma is about 6 fold higher than heparin alone. An anti-tumor study in MDA-MB231 and KB tumor bearing mice showed significant tumor growth inhibition activity by the ternary biomolecular conjugates. Ki-67 histology study also showed evidence of anticancer activity of the nanoparticles. Finally, noninvasive imaging using a Kodak Molecular Imaging System demonstrated that the nanoparticles were accumulated efficiently in tumors. Thus, this approach for oral delivery using taurocholic acid in the ternary biomolecular conjugates is promising for treatment of various types of cancer.