Autophagy plays a pro-apoptotic role in arsenic trioxide-induced cell death of liver cancer.

OBJECTIVE: The effects of arsenic trioxide (As2O3) on hepatocellular carcinoma have been documented widely. Autophagy plays dual roles in the survival and death of cancer cells. Therefore, we investigated the exact role of autophagy in As2O3-induced apoptosis in liver cancer cells. METHODS: The viability of hepatoma cells was determined using the MTT assay with or without fetal bovine serum. The rate of apoptosis in liver cancer cells treated with As2O3 was evaluated using flow cytometry, Hoechst 33258 staining, and TUNEL assays. The rate of autophagy among liver cancer cells treated with As2O3 was detected using immunofluorescence, Western blot assay and transmission electron microscopy. RESULTS: Upon treatment with As2O3, the viability of HepG2 and SMMC-7721 cells was decreased in a time- and dose-dependent manner. The apoptosis rates of both liver cancer cell lines increased with the concentration of As2O3, as shown by flow cytometry. Apoptosis in liver cancer cells treated with As2O3 was also shown by the activation of the caspase cascade and the regulation of Bcl-2/Bax expression. Furthermore, As2O3 treatment induced autophagy in liver cancer cells; this finding was supported by Western blot, immunofluorescence of LC3-II and beclin 1, and transmission electron microscopy. In liver cancer cells, As2O3 inhibited the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway that plays a vital role in both apoptosis and autophagy. The PI3K activator SC-79 partially reversed As2O3-induced autophagy and apoptosis. Furthermore, inhibiting autophagy with 3-methyladenine partially reversed the negative effects of As2O3 on cell viability. Serum starvation increased autophagy and amplified the effect of As2O3 on cell death. CONCLUSION: As2O3 induces apoptosis and autophagy in liver cancer cells. Autophagy induced by As2O3 may have a proapoptotic effect that helps to reduce the viability of liver cancer cells. This study provides novel insights into the effects of As2O3 against liver cancer. Please cite this article as: Deng ZT, Liang SF, Huang GK, Wang YQ, Tu XY, Zhang YN, Li S, Liu T, Cheng BB. Autophagy plays a pro-apoptotic role in arsenic trioxide-induced cell death of liver cancer. J Integr Med. 2024; 22(3): 295-302.

Research on different compound combinations of Realgar-Indigo naturalis formula to reverse acute promyelocytic leukemia arsenic resistance by regulating autophagy through mTOR pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: In China, the Chinese patent drug Realgar-Indigo naturalis Formula (RIF) is utilized for the therapy of acute promyelocytic leukemia (APL). Comprising four traditional Chinese herb-Realgar, Indigo naturalis, Salvia miltiorrhiza, and Pseudostellaria heterophylla-it notably includes tetra-arsenic tetra-sulfide, indirubin, tanshinone IIa, and total saponins of Radix Pseudostellariae as its primary active components. Due to its arsenic content, RIF distinctly contributes to the therapy for APL. However, the challenge of arsenic resistance in APL patients complicates the clinical use of arsenic agents. Interestingly, RIF demonstrates a high remission rate in APL patients, suggesting that its efficacy is not significantly compromised by arsenic resistance. Yet, the current state of research on RIF's ability to reverse arsenic resistance remains unclear. AIM OF THE STUDY: To investigate the mechanism of different combinations of the compound of RIF in reversing arsenic resistance in APL. MATERIALS AND METHODS: The present study utilized the arsenic-resistant HL60-PMLA216V-RARα cell line to investigate the effects of various RIF compounds, namely tetra-arsenic tetra-sulfide (A), indirubin (I), tanshinone IIa (T), and total saponins of Radix Pseudostellariae (S). The assessment of cell viability, observation of cell morphology, and evaluation of cell apoptosis were performed. Furthermore, the mitochondrial membrane potential, changes in the levels of PMLA216V-RARα, apoptosis-related factors, and the PI3K/AKT/mTOR pathway were examined, along with autophagy in all experimental groups. Meanwhile, we observed the changes about autophagy after blocking the PI3K or mTOR pathway. RESULTS: Tanshinone IIa, indirubin and total saponins of Radix Pseudostellariae could enhance the effect of tetra-arsenic tetra-sulfide down-regulating PMLA216V-RARα, and the mechanism was suggested to be related to inhibiting mTOR pathway to activate autophagy. CONCLUSIONS: We illustrated that the synergistic effect of different compound combinations of RIF can regulate autophagy through the mTOR pathway, enhance cell apoptosis, and degrade arsenic-resistant PMLA216V-RARα.

Dissection of scientific compatibility of Chinese medicinal formula Realgar-Indigo naturalis as an effective treatment for promyelocytic leukemia from the perspective of toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Realgar-Indigo naturalis formula (RIF), a first-line drug for the treatment of acute promyelocytic leukemia (APL),is also a TCM formula entirely designed based on TCM theories. There have been studies that explain the scientific connotation of the compatibility of RIF from the perspective of pharmacodynamics. However, as one of the arsenic-containing preparations, the safety of realgar is widely concerned, and there has not been systematic studies to explain the scientific connotation of RIF from the perspective of toxicology. AIM OF THIS STUDY: Dissection of scientific compatibility of Chinese medicinal formula Realgar-Indigo naturalis as an effective treatment for promyelocytic leukemia from the perspective of toxicology. MATERIALS AND METHODS: We used normal mice and an APL model to explore (i) the effects of different components on intestinal permeability, (ii) the changes in intestinal flora, and (iii) toxic effects. At the same time, a bionic extraction method was used to study the effects of different components on the dissolution of soluble arsenic in realgar under the acidic environment in the stomach and the alkaline environment in the intestinal tract. RESULTS: Salvia miltiorrhiza Bunge can repair the intestinal mucosal barrier, maintain the homeostasis of intestinal flora, intervene in the dissolution process of realgar, reverse the increase in intestinal permeability and the disturbance of intestinal flora caused by realgar, and reduce toxicity. CONCLUSION: From the perspective of toxicology, we propose new insights into the definition of the roles of each component in the RIF formula, namely realgar is the monarch, Indigo naturalis is the minister, Salvia miltiorrhiza Bungeis the assistant.

Involvement of Mitochondrial Damage and Oxidative Stress in Apoptosis Induced by Betulin Plus Arsenic Trioxide in Neuroblastoma Cells.

BACKGROUND/AIM: Arsenic trioxide (As2O3), a potent toxin in traditional Chinese medicine, has been utilized as an anticancer agent in Chinese culture for over a millennium. Betulin, commonly extracted from the bark of birch trees, has been identified for its pharmacological properties, including antibacterial, anti-inflammatory, antitumor, and antiviral activities. The aim of this study was to determine the efficacy and underlying anticancer signaling cascade induced by As2O3 and betulin in neuroblastoma cells. MATERIALS AND METHODS: SK-N-SH cells were treated with As2O3 with or without betulin. Cell viability and apoptotic signaling were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, measurement of mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS), and quantitative western blotting analysis. Student's t-test in addition to one- or two-way analysis of variance was used to examine significant differences between comparison groups. RESULTS: The combined treatment of As2O3 plus betulin was more effective than single treatments in suppressing cell viability and induction of apoptosis, which correlated well with elevated ROS levels. The apoptotic signaling cascade of As2O3 plus betulin was revealed as ROS elevation and relative loss of MMP, leading to the cleavage of caspase-3 and -9. As2O3 plus betulin treatment also reduced the expression of BCL2 apoptosis regulator, BH3-interacting domain death agonist, and BCL2-like-1. CONCLUSION: The novel combination of As2O3 plus betulin has the potential to serve as a practical anti-neuroblastoma drug.

Arsenicum album Induces Cell Cycle Arrest and Apoptosis, and Inhibits Epithelial-Mesenchymal Transition in Hormone-Dependent MCF7 Breast Cancer Cells.

BACKGROUND: Arsenic trioxide (As2O3) has been in therapeutic use since the 18th century for various types of cancers including skin and breast; however, it gained popularity following FDA approval for its use against acute promyelocytic leukemia. This present work was designed to evaluate the anti-cancer potential of a homeopathic potency of arsenic trioxide (Arsenicum album 6C) in hormone-dependent breast cancer. METHODS: Breast cancer cells (MCF7) were treated with Arsenicum album (Ars 6C) to evaluate its anti-proliferative and apoptotic potential. We examined the effect of Ars 6C on the cell cycle, wound healing, reactive oxygen species (ROS) generation, and modulation of expression of key genes which are aberrant in cancer. RESULTS: Treating breast cancer cells with Ars 6C halted the cell cycle at the sub-G0 and G2/M phases, which could be attributed to DNA damage induced by the generation of ROS. Apoptotic induction was associated with upregulation of Bax expression, with concurrent downregulation of the Bcl-2 gene. Ars 6C was also seen to reverse epithelial to mesenchymal transition and reduce the migration of breast cancer cells. CONCLUSION: The findings suggest that Ars has significant anti-proliferative and apoptotic potential against breast cancer cells. Further studies are required to elucidate the mechanism by which Ars exerts its effect in the in vivo setting.

Combinatorial Effect of Arsenic and Herbal Compounds in Telomerase-Mediated Apoptosis Induction in Liver Cancer.

Tumour illness and its resistance against existing anticancer therapies pose a serious health concern globally despite the progressive advancement of therapeutic options. The prevailing treatment of HCC using numerous antitumor agents has inflated long-lived complete remissions, but a percentage of individuals still die due to disease recurrence, indicating a need for further exploration of possible anti-tumour regimes. We aim to boost the effectiveness of the HCC treatment by conducting current investigations evaluating the effect of arsenic trioxide (ATO) with different herbal compounds like quercetin and aloe-emodin against liver tumour via inhibition of telomerase, a pro-cancer enzyme. The anticancer activity of ATO with herbal compounds was investigated in human control liver cell line (Wrl-68) and cancer liver cell line (HepG2) at different time intervals. Viability and cytotoxicity in response to combinatorial drugs were assessed in vitro by trypan blue dye exclusion assay and MTT and WST assay. Apoptosis was analysed by annexin V/PI assay, and the expression of telomerase and apoptosis-regulating proteins was evaluated by immunoblotting and qRT-PCR. Arsenic trioxide in combination with quercetin and aloe-emodin reduced cell viability in cancerous cells compared to normal cells by inducing apoptosis, downregulating telomerase and Bcl-2 (anti-apoptotic protein) and upregulating the expression of Bax (pro-apoptotic protein). ATO exhibited significant anticancer effects due to the synergistic effects of quercetin and aloe-emodin in liver tumour cells. The current study data collectively suggest that a successful inhibition of cancer growth by the combination of ATO and tested herbal medicines against liver tumour growth is via the inhibition of telomerase activity.

Arsenic in medicine: past, present and future.

Arsenicals are one of the oldest treatments for a variety of human disorders. Although infamous for its toxicity, arsenic is paradoxically a therapeutic agent that has been used since ancient times for the treatment of multiple diseases. The use of most arsenic-based drugs was abandoned with the discovery of antibiotics in the 1940s, but a few remained in use such as those for the treatment of trypanosomiasis. In the 1970s, arsenic trioxide, the active ingredient in a traditional Chinese medicine, was shown to produce dramatic remission of acute promyelocytic leukemia similar to the effect of all-trans retinoic acid. Since then, there has been a renewed interest in the clinical use of arsenicals. Here the ancient and modern medicinal uses of inorganic and organic arsenicals are reviewed. Included are antimicrobial, antiviral, antiparasitic and anticancer applications. In the face of increasing antibiotic resistance and the emergence of deadly pathogens such as the severe acute respiratory syndrome coronavirus 2, we propose revisiting arsenicals with proven efficacy to combat emerging pathogens. Current advances in science and technology can be employed to design newer arsenical drugs with high therapeutic index. These novel arsenicals can be used in combination with existing drugs or serve as valuable alternatives in the fight against cancer and emerging pathogens. The discovery of the pentavalent arsenic-containing antibiotic arsinothricin, which is effective against multidrug-resistant pathogens, illustrates the future potential of this new class of organoarsenical antibiotics.

Tetra-arsenic tetra-sulfide enhances NK-92MI mediated cellular immunotherapy in all-trans retinoic acid-resistant acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is liable to induce disseminated intravascular coagulation and has a high early mortality. Although the combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has significantly improved the complete remission rate, there are still some patients developed drug resistance. Growing evidence suggests that natural killer (NK) cell-mediated immunotherapy as a new treatment can help slow the progression of hematological malignancies. Previous studies also indicated that some tumors exhibited excellent responsiveness to NK cells in vitro. However, many clinical trial results showed that the anti-tumor effect of NK cells infusion alone was not ideal, which may be related to the inactivation of infiltrating NK cells caused by strong immunosuppression in tumor microenvironment, but the specific mechanism remains to be further explored. In the present study, we demonstrated that low doses of tetra-arsenic tetra-sulfide (As4S4) not only enhanced the in vitro killing of NK-92MI against ATRA-resistant APL cells, but also strengthened the growth inhibition of xenografted tumors in APL mouse model. Mechanistically, As4S4 altered the expression of natural killer group 2 member D ligands (NKG2DLs) and cytokines in APL cells, and PD-1 in NK-92MI cells. In addition, database retrieval results further revealed the relationship between the differentially regulated molecules of As4S4 and immune infiltration and its impact on prognosis. In conclusion, our findings confirmed the potential of As4S4 as an adjuvant for NK-92MI in the treatment of ATRA-resistant APL.

Target RNA expression omics approach to reveal the liver detoxification effect induced by Chinese medicine prescription Niu Huang Jie Du against realgar overexposure to mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Niu Huang Jie Du prescription (NHJD) is a traditional Chinese medicine (TCM) widely used in patients suffering from excessive inner fire toxin (Huo Du Nei Sheng) syndrome, such as sore throat, gingival swelling, and pain, mouth and tongue sores, etc. This formula contains realgar (As4S4) which is one of the 28 toxic medicinal materials promulgated by the Chinese Ministry of Health. Many studies reported its toxicity on the liver and kidney, and the detoxification effect of NHJD. However, its detoxification mechanism is still unclear. AIM OF THE STUDY: To clarify the detoxification mechanism of NHJD to realgar, this study evaluated the detoxification effect of NHJD on realgar exposure in mice, and analyzed differences in mRNA expression profiles in liver tissues and associated functional predictions. MATERIAL AND METHODS: ICR mice were administered with NHJD, realgar, and CMC-Na as blank control for 12 weeks, respectively. Liver injury was evaluated by histopathologic examination and liver mRNA gene were sequenced by Illumina. Differentially expressed gene, functionally enrichment and protein association network analysis were conducted. RESULTS: 43 genes were screened out, among which 15 genes in the realgar group were decreased, but the extent of the decline has been restored in the NHJD group. The remaining 28 genes have exactly the opposite trends. Functional module analysis revealed that those detoxification function-related genes were primarily for positive regulation of glutathione metabolism, P450 on the metabolism of exogenous compounds, oxidative stress and immune-related, etc. CONCLUSIONS: The results indicated that realgar mainly causes liver damage by changing the common enzymes of drug metabolism, especially the expression of genes related to CYPs, GSTs family, oxidative stress, and complement immunity, while the TCM prescription NHJD has a regulatory effect on the abnormal expression of corresponding genes. Our results will provide some clues for the detoxification mechanism of arsenic-containing TCM prescriptions.

Realgar (α-As4S4) Treats Myelodysplastic Syndromes through Reducing DNA Hypermethylation.

DNA hypermethylation is an epigenetic modification that plays a critical role in the oncogenesis of myelodysplastic syndromes (MDS). Aberrant DNA methylation represses the transcription of promotors of tumor suppressor genes, inducing gene silencing. Realgar (α-As4S4) is a traditional medicine used for the treatment of various diseases in the ancient time. Realgar was reported to have efficacy for acute promyelocytic leukemia (APL). It has been demonstrated that realgar could efficiently reduce DNA hypermethylation of MDS. This review discusses the mechanisms of realgar on inhibiting DNA hypermethylation of MDS, as well as the species and metabolisms of arsenic in vivo.

Sub-chronic exposure to realgar induces liver injury via upregulating the TXNIP/NLRP3 pathway and disturbing bile acid homeostasis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Realgar is a traditional Chinese medicine used in China for a long history. Long-time or excessive use of realgar causes liver injury. However, its underlying mechanism is not fully clarified. AIM OF THE STUDY: In this study, we investigated the toxic effect of sub-chronic exposure to realgar on mice liver, and further revealed its underlying mechanism focused on the TXNIP/NLRP3 pathway and bile acid homeostasis. MATERIAL AND METHODS: Mice were divided into control and different doses of sub-chronic realgar exposed groups. Total arsenic levels in the blood and liver were determined by atomic fluorescence spectrometry. The effect of realgar on liver function was evaluated by biochemical analysis and histopathological examination. Assay kits were applied for the measurement of oxidative stress indexes, MPO and plasma inflammatory cytokines. The mRNA and proteins involved in the TXNIP/NLRP3 and NF-κB pathways were determined by RT-qPCR, western blot, Immunofluorescence and Immunohistochemistry. UHPLC/MS/MS was used for the quantitative analysis of bile acids (BAs) in mice plasma, liver and urine. The genes related to BAs metabolism were measured by RT-qPCR. RESULTS: Sub-chronic exposure to realgar led to arsenic accumulation and caused oxidative damage and inflammatory infiltration in mouse liver, finally resulting in liver injury. Realgar treatment activated the NF-κB pathway and significantly upregulated the TXNIP/NLRP3 pathway in mouse liver. Realgar altered the metabolic balance of BAs, which is related to the abnormal expression of BAs transporters and enzymes. CONCLUSION: Sub-chronic exposure to realgar caused liver injury in mouse, and the mechanism may involve the upregulation of the TXNIP/NLRP3 pathway and disordered BAs homeostasis.

PML/RARA destabilization by hyperthermia: a new model for oncogenic fusion protein degradation?

In this issue, Maimaitiyiming and colleagues demonstrate thermic stress-induced PML/RARA oncogenic fusion protein destabilization driven by corepressor aggregation. Hyperthermia synergizes with PML/RARA degradation by ATO and may circumvent ATO-resistance in historical APL patients. This novel approach could be extended to other corepressor-associated oncogenic fusion proteins.

Arsenic Dispensing Powder Promotes Erythropoiesis in Myelodysplastic Syndromes via Downregulation of HIF1A and Upregulation of GATA Factors.

Traditional Chinese Medicine (TCM) is a practical medicine based on thousands of years of medical practice in China. Arsenic dispensing powder (ADP) has been used as a treatment for MDS patients with a superior efficacy on anemia at Xiyuan Hospital of China Academy of Chinese Medical Sciences. In this study, we retrospectively analyzed MDS patients that received ADP treatment in the past 9 years and confirmed that ADP improves patients' anemia and prolongs overall survival in intermediate-risk MDS patients. Then, we used the MDS transgenic mice model and cell line to explore the drug mechanism. In normal and MDS cells, ADP does not show cellular toxicity but promotes differentiation. In mouse MDS models, we observed that ADP showed significant efficacy on promoting erythropoiesis. In the BFU-E and CFU-E assays, ADP could promote erythropoiesis not only in normal clones but also in MDS clones. Mechanistically, we found that ADP could downregulate HIF1A in MDS clones through upregulation of VHL, P53 and MDM2, which is involved in two parallel pathways to downregulate HIF1A. We also confirmed that ADP upregulates GATA factors in normal clones. Thus, our clinical and experimental studies indicate that ADP is a promising drug to promote erythropoiesis in both MDS and normal clones with a superior outcome than current regular therapies. ADP promotes erythropoiesis in myelodysplastic syndromes via downregulation of HIF1A and upregulation of GATA factors.

Hypoxia enhances the cytotoxic effect of As4S4 on rat ventricular H9c2 cells through activation of ubiquitin-proteasome system.

BACKGROUND: As4S4 is widely used in Chinese traditional medicine compound. However, based on some recent studies, we found that the cardiotoxicity risk of using As4S4 in ischemic heart disease patients may be increased. To study this potential risk, we compared the effects of As4S4 on rat ventricular H9c2 cell line with or without hypoxic pretreatment, and to elucidate mechanisms of c-Cbl mediated ubiquitination/degradation of integrin ß1. METHODS: The present study was conducted on rat ventricular H9c2 cell line in the absence or presence of hypoxic pretreatment for 6 h followed by As4S4 treatment for 24 h. Following As4S4 treatment, cell viability assay, flow cytometric quantification of apoptotic cells, caspase-3 activity assay and DAPI staining were conducted. Western blotting was carried out to detect expressions of ubiquitination related proteins. In addition, the ubiquitination/degradation of integrin ß1 and the role of c-Cbl in it was evaluated by immunoprecipitation and immunoblot assay. RESULTS: The viability of cells with hypoxic pretreatment followed by As4S4 treatment was decreased significantly, apoptosis rate and the activity of caspase-3 were increased than As4S4 treatment alone. The ubiquitin-proteasome degradation pathway induced by As4S4 was further enhanced by hypoxic pretreatment. The results of IP and immunoblot assay showed hypoxic enhanced down-regulation effect of As4S4 on integrin ß1 probably through c-Cbl activation. CONCLUSIONS: This study demonstrated that the hypoxia enhanced cytotoxicity of As4S4 on H9c2 cells may through increasing the ubiquitin-proteasome degradation of integrin ß1 mediated by the E3 ligase c-Cbl. The results provide an important clue that, in patients with ischemic heart disease, use of As4S4 may be associated with increased cardiotoxicity. We believe that the results worth to be further illuminated by in vivo and clinical research.

Pnictogens in medicinal chemistry: evolution from erstwhile drugs to emerging layered photonic nanomedicine.

Pnictogens (the non-metal phosphorus, metalloids arsenic and antimony, and metal bismuth) possess diverse chemical characteristics that support the formation of extended molecular structures. As witnessed by the centuries-old (and ongoing) clinical utilities, pnictogen-based compounds have secured their places in history as "magic bullet" therapeutic drugs in medicinal contexts. Moreover, with the development of recent metalloproteomics and bio-coordination chemistry, the pnictogen-based drugs functionally binding to proteins/enzymes in biological systems have been underlaid for "drug repurposing" with promising opportunities. Furthermore, advances in the modern materials science and nonotechnology have stimulated a revolution in other newly discovered forms of pnictogens-phosphorene, arsenene, antimonene, and bismuthine (layered pnictogens). Based on their favorable optoelectronic properties, layered pnictogens have shown dramatic superiority as emerging photonic nanomedicines for the treatment of various diseases. This tutorial review outlines the history and mechanism of action of ancient pnictogen-based drugs (e.g., arsenical compounds in traditional Chinese medicine) and their repurposing into modern therapeutics. Then, the revolutionary use of emerging layered pnictogens as photonic nanomedicines, alongside assessments of their in vivo biosafety, is discussed. Finally, the challenges to further development of pnictogens are set forth and insights for further exploration of their appealing properties are offered. This tutorial review may also provide some deep insights into the fields of integrated traditional Chinese and Western medicines from the perspective of materials science and nanotechnology.

Realgar increases defenses against infection by Enterococcus faecalis in Caenorhabditis elegans.

ETHNOPHARMACOLOGICAL RELEVANCE: Realgar has been used in traditional remedies for a long history in China and India. It is clinically used to treat diverse cancers, especially acute promyelocytic leukemia (APL), chronic myelogenous leukemia (CML) in China. However, paradoxic roles of realgar to increase or decrease immunity are reported. It is urgent to address this question, due to immune depression can be strongly benefit to cancer development, but detrimental to patients. AIM OF THE STUDY: This present work is to explore whether realgar promote or suppress immune responses, and shed light on its mode of action. Our results should provide cues for rational strategy to explore realgar for clinical use. MATERIAL AND METHODS: Infection model in vivo was established by using Enterococcus faecalis to attack Caenorhabditis elegans, then realgar was used to treat the infected worms to investigate its effects on infectivity and the underlying mechanism. Killing analysis was carried out to test whether realgar can mitigate worm infection. Thermotolerance resistance analysis was used to evaluate if realgar functions hormetic effect. Quantification of live E. faecalis in nematode intestine was employed to ascertain if realgar alleviate the bacterial load in worm gut. Quantitative real-time PCR (qRT-PCR) was used to test the expression of antibacterial effectors. Western blot was used to test the effect of realgar on the expressions of p38 and phospho-p38 in worms infected by E. faecalis. RESULTS: Realgar alleviated the infected worms in strains of N2, glp-4, and daf-2, but failed in sek-1, glp-4; sek-1, and daf-2; daf-16 when p38 MAPK or daf-16 was blocked or inactivated. Western blot assay demonstrated that realgar increased the expression of phosph-p38. Thermotolerance assay showed that realgar played a hormetic role on nemtodes, triggered protective response and reduced bacterial load after realgar treatment for 120 h qRT-PCR demonstrated that realgar significantly increased antibacterial effectors, thus leading to pathogen elimination. CONCLUSION: Realgar increased defenses against E. faecalis in C. elegans by inducing both immune responses and protective responses. It was regulated by p38 MAPK pathway and DAF-16.

Radixin modulates the function of outer hair cell stereocilia.

The stereocilia of the inner ear sensory cells contain the actin-binding protein radixin, encoded by RDX. Radixin is important for hearing but remains functionally obscure. To determine how radixin influences hearing sensitivity, we used a custom rapid imaging technique to visualize stereocilia motion while measuring electrical potential amplitudes during acoustic stimulation. Radixin inhibition decreased sound-evoked electrical potentials. Other functional measures, including electrically induced sensory cell motility and sound-evoked stereocilia deflections, showed a minor amplitude increase. These unique functional alterations demonstrate radixin as necessary for conversion of sound into electrical signals at acoustic rates. We identified patients with RDX variants with normal hearing at birth who showed rapidly deteriorating hearing during the first months of life. This may be overlooked by newborn hearing screening and explained by multiple disturbances in postnatal sensory cells. We conclude radixin is necessary for ensuring normal conversion of sound to electrical signals in the inner ear.

[Preliminary study of Realgar and arsenic trioxide on gut microbiota of mice].

The aim of this paper was to observe the effect of Realgar and arsenic trioxide on gut microbiota. The mice were divided into low-dose Realgar group(RL), medium-dose Realgar group(RM), high-dose Realgar group(RH), and arsenic trioxide group(ATO), in which ATO and RL groups had the same trivalent arsenic content. Realgar and arsenic trioxide toxicity models were established after intragastric administration for 1 week, and mice feces were collected 1 h after intragastric administration on day 8. The effects of Realgar on gut microbiota of mice were observed through bacterial 16 S rRNA gene sequences. The results showed that Lactobacillus was decreased in all groups, while Ruminococcus and Adlercreutzia were increased. The RL group and ATO group were consistent in the genera of Prevotella, Ruminococcus, and Adlercreutzia but different in the genera of Lactobacillus and Bacteroides. Therefore, the effects of Realgar and arsenic trioxide with the same amount of trivalent arsenic on gut microbiota were similar, but differences were still present. Protective bacteria such as Lactobacillus were reduced after Realgar administration, causing inflammation. At low doses, the number of anti-inflammatory bacteria, such as Ruminococcus, Adlercreutzia and Parabacteroides increased, which can offset the slight inflammation caused by the imbalance of bacterial flora. At high doses, the flora was disturbed and the number of Proteobacteria was increased, with aggravated intestinal inflammation, causing edema and other inflammatory reactions. Based on this, authors believe that the gastrointestinal reactions after clinical use of Realgar may be related to flora disorder. Realgar should be used at a small dose in combination with other drugs to reduce intestinal inflammation.

Modern traditional Chinese medicine: Identifying, defining and usage of TCM components.

TCM-based medications have been used for millennia in China and have always been "different" from current Western-based medicines in that they frequently are still mixtures of predominately plant products. From the early 20th Century, there has been a move to identify both the actual compounds in these mixes, and then over the past approximately 50years, to utilize early information for current diseases, with an example being artemisinin for treatment of malaria. Since that discovery, Western scientists, together with their Chinese counterparts, have begun to investigate how TCM compositions can be utilized to discover new agents, sometimes the actual TCM-based compound(s) but also by utilizing the pharmacophores from such preparations that have utility in human diseases. The examples in this review include artemisinin derivatives and their manifold bioactivities, indirubins and derivatives as antitumor agents, arsenicals predominately as treatment for leukemia, though extending into other cancer types. Finally, there are sections discussing the use of current computerized techniques that combine metabolomics, mass spectroscopy/HPLC, and network pharmacology with the aim of identifying the "active principles" in relevant TCM preparations and finally how high content screening can be utilized in conjunction with the other analytical techniques.

Melatonin triggers the anticancer potential of phenylarsine oxide via induction of apoptosis through ROS generation and JNK activation.

Melatonin, a safe endogenous hormone and a natural supplement, has recently been recognized to have antiproliferative effects and the ability to sensitize cells to other anticancer therapies. Phenylarsine oxide (PAO) has anticancer potential but it is considered as a toxic agent. In this study we combined melatonin to reduce the toxicity while securing the anti-cancer effects of PAO. Cell viability was determined by MTT assay, whereas cytotoxic assays were performed using an LDH cytotoxicity assay kit. Cell cycle analysis, Annexin V/PI staining, the mitochondrial membrane potential (MMP), mitochondrial calcium and reactive oxygen species (ROS) generation were analyzed using flow cytometry. Sytox stained cells were visualized by fluorescence microscopy and the expression of proteins was detected by western blotting. Melatonin increased the anticancer potential of PAO by decreasing the cell viability and increasing LDH release in various cancer cells. The mode of cell death was determined to be typical apoptosis, as evidenced by Annexin V/PI-stained cells, PARP cleavage, and caspase-3 activation, and with significant modulations in the expression of proapoptotic, antiapoptotic and cell cycle-related proteins. ROS generation played a critical role in induction of cell death by this combined treatment, which is validated by reversal of cytotoxicity upon cotreatment with NAC. Furthermore, the activation of MAPKs, especially JNK, contributed to the induction of cell death, accompanied by endoplasmic reticulum stress and autophagy, affirmed by the abrogation of cytotoxicity after JNK-IN-8 and TUDCA application. Melatonin showed promising potential as a chemotherapeutic agent in combination with PAO to achieve a better anticancer response.