Alpinetin promotes Bax translocation, induces apoptosis through the mitochondrial pathway and arrests human gastric cancer cells at the G2/M phase

Heat acclimation alleviates the heat stress-induced impairment of vascular endothelial cells

Heat acclimation (HA) is found to help decrease the incidence of heat-related illnesses such as heat syncope and exertional heat stroke. However, the response of vascular endothelial cells to HA remain to be elucidated. In this study, mouse brain microvascular endothelial cells (bEnd.3), human umbilical vein endothelial cells (HUVEC), and human aortic endothelial cells (HAEC) were selected. The cells were first subjected to HA at 40 ℃ for 2 h per day for 3 days, and then subjected to heat stress at 43 ℃ for 2 h or 4 h. After heat stress, HA-pretreated cells showed a significant increase in cell viability, cell integrity, a decrease in the proportion of S phase cells, cell apoptosis, and cytoskeletal shrinkage compared with the cells without HA pretreatment. Additionally, the expression of VEGF, ICAM-1, iNOS and EPO in HA-pretreated cells significantly increased. We also presented evidence that HA upregulated HSP70 and bcl-2, while downregulated p-p53 and bax. Notably, the suppression of HSP70 expression attenuated the protective role of heat acclimation. Furthermore, HA mitigated injuries in vital organs of mice exposed to heat stress. Conclusively, these findings indicated the HA can increase the vitality of vascular endothelial cells after heat stress, partially restore the function of vascular endothelial cells, and this protective effect may be related to the upregulation of HSP70 expression.

Flavonoids and Gastric Cancer Therapy: From Signaling Pathway to Therapeutic Significance

Gastric cancer (GC) is a prevalent gastrointestinal tumor characterized by high mortality and recurrence rates. Current treatments often have limitations, prompting researchers to explore novel anti-tumor substances and develop new drugs. Flavonoids, natural compounds with diverse biological activities, are gaining increasing attention in this regard. We searched from PubMed, Web of Science, SpringerLink and other databases to find the relevant literature in the last two decades. Using "gastric cancer", "stomach cancers", "flavonoid", "bioflavonoid", "2-Phenyl-Chromene" as keywords, were searched, then analyzed and summarized the mechanism of flavonoids in the treatment of GC. It was revealed that the anti-tumor mechanism of flavonoids involves inhibiting tumor growth, proliferation, invasion, and metastasis, as well as inducing cell death through various processes such as apoptosis, autophagy, ferroptosis, and pyroptosis. Additionally, combining flavonoids with other chemotherapeutic agents like 5-FU and platinum compounds can potentially reduce chemoresistance. Flavonoids have also demonstrated enhanced biological activity when used in combination with other natural products. Consequently, this review proposes innovative perspectives for the development of flavonoids as new anti-GC agents.

Phytochemicals and mitochondria: Therapeutic allies against gastric cancer

BACKGROUND

Mitochondria are the energy factories of cells with the ability to modulate the cell cycle, cellular differentiation, signal transduction, growth, and apoptosis. Existing drugs targeting mitochondria in cancer treatment have disadvantages of drug resistance and side effects. Phytochemicals, which are widely found in plants, are bioactive compounds that could facilitate the development of new drugs for gastric cancer. Studies have shown that some phytochemicals can suppress the development of gastric cancer.

METHODS

We searched for data from PubMed, China National Knowledge Infrastructure, Web of Science, and Embase databases from initial establishment to December 2021 to review the mechanism by which phytochemicals suppress gastric cancer cell growth by modulating mitochondrial function. Phytochemicals were classified and summarized by their mechanisms of action.

RESULTS

Phytochemicals can interfere with mitochondria through several mechanisms to reach the goal of promoting apoptosis in gastric cancer cells. Some phytochemicals, e.g., daidzein and tetrandrine promoted cytochrome c spillover into the cytoplasm by modulating the members of the B-cell lymphoma-2 protein family and induced apoptotic body activity by activating the caspase protein family. Phytochemicals (e.g., celastrol and shikonin) could promote the accumulation of reactive oxygen species and reduce the mitochondrial membrane potential. Several phytochemicals (e.g., berberine and oleanolic acid) activated mitochondrial apoptotic submission via the phosphatidylinositol-3-kinase/Akt signaling pathway, thereby triggering apoptosis in gastric cancer cells. Several well-known phytochemicals that target mitochondria, including berberine, ginsenoside, and baicalein, showed the advantages of multiple targets, high efficacy, and fewer side effects.

CONCLUSIONS

Phytochemicals could target the mitochondria in the treatment of gastric cancer, providing potential directions and evidence for clinical translation. Drug discovery focused on phytochemicals has great potential to break barriers in cancer treatment.

Comparative in silico and in vitro study of the stability and biological activity of an octapeptide from microalgae Isochrysis zhanjiangensis and its truncated short peptide

In this study, the structural characteristics and active sites of the octapeptide (IIAVEAGC), the pentapeptide (IIAVE) and tripeptide (AGC) were studied in silica and in vitro.

Alpinetin: a Dietary Flavonoid with Diverse Anticancer Effects

Cancer is  a global burden and mechanistically complex disease with a plethora of genetic, physiological, metabolic, and environmental alterations. The development of dietary nutraceuticals into cancer chemotherapeutics has emerged as a new paradigm in cancer treatment. Alpinetin (ALPI) is a novel flavonoid component of multiple edible and medicinal plants and possesses a wide range of biological and pharmacological activities including antibacterial, anti-hemostatic, anti-oxidative, anti-hepatotoxic, stomachic, immunosuppressive, and anti-inflammatory. Recently, ALPI has been reported as a bioactive dietary nutraceutical with promising anticancer activity in various human cancers through multiple mechanisms. The purpose of this review is to compile the data on natural sources of ALPI, and its anticancer activity including cellular targets and anticancer mechanism in various human cancers. Moreover, this review will set the stage for further design and conduct pre-clinical and clinical trials to develop ALPI into a lead structure for oncological therapy.

Alpinetin: A Review of Its Pharmacology and Pharmacokinetics

Flavonoids isolated from medicinal herbs have been utilized as valuable health-care agents due to their virous biological applications. Alpinetin is a natural flavonoid that emerges in many widely used medicinal plants, and has been frequently applied in Chinese patent drugs. Accumulated evidence has demonstrated that alpinetin possesses a broad range of pharmacological activities such as antitumor, antiinflammation, hepatoprotective, cardiovascular protective, lung protective, antibacterial, antiviral, neuroprotective, and other properties through regulating multiple signaling pathways with low systemic toxicity. However, pharmacokinetic studies have documented that alpinetin may have poor oral bioavailability correlated to its extensive glucuronidation. Currently, the reported pharmacological properties and pharmacokinetics profiles of alpinetin are rare to be scientifically reviewed. In this article, we aimed to highlight the mechanisms of action of alpinetin in various diseases to strongly support its curative potentials for prospective clinical applications. We also summarized the pharmacokinetics properties and proposed some viable strategies to convey an appreciable reference for future advances of alpinetin in drug development.

Chiral Flavonoids as Antitumor Agents

Flavonoids are a group of natural products with a great structural diversity, widely distributed in plant kingdom. They play an important role in plant growth, development and defense against aggressors. Flavonoids show a huge variety of biological activities such as antioxidant, anti-inflammatory, anti-mutagenic, antimicrobial and antitumor, being able to modulate a large diversity of cellular enzymatic activities. Among natural flavonoids, some classes comprise chiral molecules including flavanones, flavan-3-ols, isoflavanones, and rotenoids, which have one or more stereogenic centers. Interestingly, in some cases, individual compounds of enantiomeric pairs have shown different antitumor activity. In nature, these compounds are mainly biosynthesized as pure enantiomers. Nevertheless, they are often isolated as racemates, being necessary to carry out their chiral separation to perform enantioselectivity studies. Synthetic chiral flavonoids with promising antitumor activity have also been obtained using diverse synthetic approaches. In fact, several new chiral bioactive flavonoids have been synthesized by enantioselective synthesis. Particularly, flavopiridol was the first cyclin-dependent kinase (CDK) inhibitor which entered clinical trials. The chiral pool approaches using amino acid as chiral building blocks have also been reported to achieve small libraries of chrysin derivatives with more potent in vitro growth inhibitory effect than chrysin, reinforcing the importance of the introduction of chiral moieties to improve antitumor activity. In this work, a literature review of natural and synthetic chiral flavonoids with antitumor activity is reported for the first time.

Preclinical Investigation of Alpinetin in the Treatment of Cancer-Induced Cachexia via Activating PPARγ

The ongoing loss of skeletal muscle is a central event of cancer cachexia, and its consequences include adverse effects on patient’s quality of life and survival. Alpinetin (Alp), a natural plant-derived flavonoid obtained from Alpinia katsumadai Hayata, has been reported to possess potent anti-inflammatory and antitumor activities. This study aimed to explore the therapeutic effect and underlying mechanism of Alp in the prevention of cancer cachexia. We found that Alp (25–100 μM) dose-dependently attenuated Lewis lung carcinoma–conditioned medium-induced C2C12 myotube atrophy and reduced expression of the E3 ligases Atrogin-1 and MuRF1. Moreover, Alp administration markedly improved vital features of cancer cachexia in vivo with visible reduction of the loss of tumor-free body weight and wasting of multiple tissues, including skeletal muscle, epididymal fat, and decreased expression of Atrogin-1 and MuRF1 in cachectic muscle. Alp suppressed the elevated spleen weight and serum concentrations of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. Further, Alp treatment remained protective against cancer cachexia in the advanced stage of tumor growth. Molecular docking results suggested that Alp was docked into the active site of PPARγ with the docking score of –7.6 kcal/mol, forming a hydrogen bond interaction with PPARγ protein amino acid residue HIS449 with a bond length of 3.3 Å. Mechanism analysis revealed that Alp activated PPARγ, resulting in the downregulated phosphorylation of NF-κB and STAT3 in vitro and in vivo. PPARγ inhibition induced by GW9662 notably attenuated the improvement of Alp on the above cachexia phenomenon, indicating that PPARγ activation mediated the therapeutic effect of Alp. These findings suggested that Alp might be a potential therapeutic candidate against cancer cachexia.

The investigation of the T-type calcium channel enhancer SAK3 in an animal model of TAF1 intellectual disability syndrome

T-type calcium channels, in the central nervous system, are involved in the pathogenesis of many neurodegenerative diseases, including TAF1 intellectual disability syndrome (TAF1 ID syndrome). Here, we evaluated the efficacy of a novel T-type Ca2+ channel enhancer, SAK3 (ethyl 8'-methyl-2', 4-dioxo-2-(piperidin-1-yl)-2'H-spiro [cyclopentane-1, 3'-imidazo [1, 2-a] pyridine]-2-ene-3-carboxylate) in an animal model of TAF1 ID syndrome. At post-natal day 3, rat pups were subjected to intracerebroventricular (ICV) injection of either gRNA-control or gRNA-TAF1 CRISPR/Cas9 viruses. At post-natal day 21 animals were given SAK3 (0.25 mg/kg, p.o.) or vehicle up to post-natal day 35 (i.e. 14 days). Rats were subjected to behavioral, morphological, electrophysiological, and molecular studies. Oral administration of SAK3 (0.25 mg/kg, p.o.) significantly rescued the behavior abnormalities in beam walking test and open field test caused by TAF1 gene editing. We observed an increase in calbindin-positive Purkinje cells and GFAP-positive astrocytes as well as a decrease in IBA1-positive microglia cells in SAK3-treated animals. In addition, SAK3 protected the Purkinje and granule cells from apoptosis induced by TAF-1 gene editing. SAK3 also restored the excitatory post synaptic current (sEPSCs) in TAF1 edited Purkinje cells. Finally, SAK3 normalized the BDNF/AKT signaling axis in TAF1 edited animals. Altogether, these observations suggest that SAK3 could be a novel therapeutic agent for TAF1 ID syndrome.

Voltage-Dependent Anion Channels Influence Cytotoxicity of ME-344, a Therapeutic Isoflavone

ME-344 is a second-generation cytotoxic isoflavone with anticancer activity promulgated through interference with mitochondrial functions. Using a click chemistry version of the drug together with affinity-enriched mass spectrometry, voltage-dependent anion channels (VDACs) 1 and 2 were identified as drug targets. To determine the importance of VDAC1 or 2 to cytotoxicity, we used lung cancer cells that were either sensitive (H460) or intrinsically resistant (H596) to the drug. In H460 cells, depletion of VDAC1 and VDAC2 by small interfering RNA impacted ME-344 effects by diminishing generation of reactive oxygen species (ROS), preventing mitochondrial membrane potential dissipation, and moderating ME-344-induced cytotoxicity and mitochondrial-mediated apoptosis. Mechanistically, VDAC1 and VDAC2 knockdown prevented ME-344-induced apoptosis by inhibiting Bax mitochondrial translocation and cytochrome c release as well as apoptosis in these H460 cells. We conclude that VDAC1 and 2, as mediators of the response to oxidative stress, have roles in modulating ROS generation, Bax translocation, and cytochrome c release during mitochondrial-mediated apoptosis caused by ME-344. SIGNIFICANCE STATEMENT: Dissecting preclinical drug mechanisms are of significance in development of a drug toward eventual Food and Drug Administration approval.

Ephedrine causes retinal damage in SD rats associating with JAK2/STAT3 pathway

PURPOSE

Ephedrine has various side effects in the cardiovascular and nervous systems. However, the cellular mechanism of toxicity remains unknown, specifically on the retina. This study was to investigate effects of ephedrine on the retina and explore the underlying mechanisms.

METHODS

Sprague Dawley rats were treated with ephedrine (n = 10) or saline (n = 10) by oral gavage for seven days. The retinal morphology was evaluated by Toluidine blue staining. Apoptosis-related markers were detected in the retinal lysate. Enzyme-linked immunosorbent assays were used to measure neurotransmitters and oxidative stress markers. Real-time PCR and western blot were used to measure gene and protein expression, respectively.

RESULTS

Our results demonstrated that ephedrine induced apoptosis in the retina, increased dopamine level as well as oxidative stress, and down-regulated the Jak2/Stat3 gene expression as well as protein expression of p-JAK2/p-STAT3.

CONCLUSIONS

Our study indicated that ephedrine treatment caused retinal damage in SD rats, which may be associated with the JAK2/STAT3 pathway.

The cyclopeptide <alpha>-amatoxin induced hepatic injury via the mitochondrial apoptotic pathway associated with oxidative stress

In order to explore the role of apoptosis in alpha-amatoxin (α-AMA) induced liver injury and probable upstream activation signals, we established animal and cellular models, respectively, for this pathophysiological condition. To this end, we evaluated the survival rate and serum biochemical parameters in BALB/c mice exposed to α-AMA at different time periods, along with the levels of oxidative and antioxidant enzymes in the liver tissue of these mice and proteins involved in apoptosis-related pathways. Our results reveal that α-AMA-induced apoptosis occurs primarily through the mitochondrial apoptotic pathway and is associated with oxidative damage. Further, in order to verify the key nodes and important upstream activators in this apoptotic pathway, we estimated the levels of p53 protein and downstream mitochondrial apoptotic pathway-related proteins in L-02 cells, all of which were found to change significantly. We also found that the levels of total and mitochondrial reactive oxygen species (ROS) in L-02 cells increased with time. Collectively, our findings suggest that α-AMA affects many cellular processes, including the expression of p53 independent of transcription and the expression of Bax and Bcl-2, thereby activating the subsequent caspase cascade pathways. In addition, we identified ROS to be an upstream signaling molecule involved in the α-AMA-induced apoptosis of mouse liver cells and L-02 cells.

(Z)-7,4′-Dimethoxy-6-hydroxy-aurone- 4-O-β-glucopyranoside alleviates cerebral ischemia-reperfusion injury in rats associating with the regulation of JAK1/STAT1 signaling pathway

Inflammatory responses have been demonstrated to contribute to the neuronal death following cerebral ischemia. This study was to investigate the repairing effects and potential mechanisms of (Z)-7,4′-dimethoxy-6-hydroxy-aurone-4-O-β-glucopyranoside (DHAG), a compound with neuroprotective effects, on cerebral ischemia-reperfusion (I/R) injury in rats. Cerebral I/R model was established with middle cerebral artery occlusion method in Sprague Dawley rats and then rats were treated with DHAG (1 and 2 mg/kg) for 7 days. The volume of cerebral infarction was detected by triphenyltetrazolium chloride staining. The apoptosis in ischemic brain tissues was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Oxidative stress markers and inflammatory factors were detected by enzyme-linked immunosorbent assay. Protein expression was detected by Western blot. DHAG treatment significantly alleviated the cerebral I/R injury and decreased apoptosis in brain tissues. Moreover, DHAG treatment significantly inhibited oxidative stress and reduced inflammatory responses, associating with decreasing the protein expression of phosphorylated Janus kinase 1/phosphorylated signal transducer and transcriptional activator 1. These results demonstrated neuroprotective properties of DHAG and highlighted it as a potential therapeutic agent against injury of cerebral IR.

15-hydroxy-6α,12-epoxy-7β,10αH,11βH-spiroax-4-ene-12-one exerts anti-tumor effects against osteosarcoma through apoptosis induction

Osteosarcoma is the most common type of malignant bone tumor, which has an overall survival rate of only 15-30%. The present study aimed to investigate the effects of 15-hydroxy-6α,12-epoxy-7β,10αH,11βH-spiroax-4-ene-12-one (HESEO), a compound extracted from the endophytic fungus Penicillium sp. FJ-1 isolated from Avicennia marina, on the proliferation of osteosarcoma cells and to explore its underlying mechanisms of action. Cell number was counted to measure the cell proliferation. JC-1 reagent was used to measure mitochondrial membrane potential. ELISA was used to measure the cytochrome c level and caspase activities. Apoptosis was detected by Annexin V-Propidium Iodide staining. Gene and protein expression were measured by reverse-transcription-PCR and western blot analysis, respectively. Additionally, the anti-tumor effects of HESEO were explored within a syngeneic osteosarcoma tumor model. The results suggested that HESEO significantly inhibited the proliferation of osteosarcoma cells and induced apoptosis of MG-63 cells, evidenced by their decreased mitochondrial membrane potential, and increased cytochrome c release, caspase activities and percentage of apoptotic cells. In addition, HESEO increased the expression of pro-apoptotic genes and proteins compared with control cells. The results indicated that HESEO may act through increasing p53 upregulated modulator of apoptosis expression. Furthermore, HESEO treatment significantly increased the survival time and decreased the tumor burden of osteosarcoma tumor-bearing mice compared with vehicle treatment. Furthermore, combined treatment with HESEO enhanced the effects of the chemotherapeutic agent methotrexate on a lung metastasis osteosarcoma model. These data suggested that HESEO could be developed as a potential anti-tumor agent against osteosarcoma.

Lysergic acid diethylamide causes mouse retinal damage by up-regulating p-JAK1/p-STAT1

Purpose: Lysergic acid diethylamide (LSD) is a powerful hallucinogen with high potential for abuse. There is far less known about its effects on the retina, especially the underlying mechanisms. This study was to investigate the acute toxicity of LSD on the retina of C57 mice and its mechanisms of action.Methods: C57 mice were treated with LSD at progressively increasing doses (0.2-1.2 mg/kg) intraperitoneally two times daily for 5 days, mice treated with saline served as negative control. Electroretinography (ERG) was used to test the function of the retina. Toluidine blue staining was used to detect the morphology of the retina. Enzyme-linked immunosorbent assay (ELISA) was used to measure the apoptosis-related factors. Real-time PCR and western blot techniques were used to measure expression changes of genes and proteins, respectively.Results: LSD treatment caused retinal damage, as shown by a decrease in ERG response and the loss of photoreceptor cells. LSD treatment also increased apoptosis through up-regulating the expression of p-JAK1/p-STAT1.Conclusions: Our study indicated that intraperitoneal administration of LSD-induced retinal damage of C57 mice, at least partially through regulating the JAK/STAT pathway.

6-Formyl-5-isopropyl-3-hydroxymethyl- 7-methyl-1H-indene mitigates methamphetamine-induced photoreceptor cell toxicity through inhibiting oxidative stress

As an extremely addictive psychostimulant drug and an illicit dopaminergic neurotoxin, methamphetamine (METH) conducts to enhance satisfaction, feelings of alertness through influencing monoamine neurotransmitter systems. Long-lasting exposure to METH causes psychosis and increases the risk of neurodegeneration. 6-Formyl-5-isopropyl-3-hydroxymethyl-7-methyl-1H-indene (FIHMI) is a novel compound with potent antioxidant properties. This study was to investigate whether FIHMI could mitigate METH-induced photoreceptor cell toxicity. METH-caused cell toxicity was established in 661W cells and protective effects of FIHMI at different concentrations (1-10 µM) was examined. FIHMI significantly attenuated the METH-caused cell damage in 661W cells, evidenced by increasing cell viability and mitochondrial membrane potential, decreasing cytochrome c release and DNA fragmentation, inhibiting activities of caspase 3/9, and changing expression of apoptosis-related protein. Furthermore, FIHMI treatment decreased mRNA expression of Beclin-1 and LC3B protein expression in METH-induced 661W cells suggesting autophagy is reduced. FIHMI decreased the oxidative stress through increasing protein expression of nuclear factor (erythroid-derived 2)-like 2. These data demonstrated FIHMI could inhibit oxidative stress, which may also play an essential role in the regulation of METH-triggered apoptotic response, providing the scientific rational to develop FIHMI as the therapeutic agent to alleviate METH-induced photoreceptor cell toxicity.

Systemic administration with tetrahydrocannabinol causes retinal damage in BALB/c mice

Recent years have seen substantial shifts in cultural attitudes towards cannabis for medical and recreational use. However, legalizing recreational marijuana may have adverse effects on individual and public health. As the most widely used illicit agent, cannabis is commonly reported to disrupt learning and memory. Unfortunately, the molecular mechanisms underlying behavioral impairment by cannabis abuse remain poorly understood. Tetrahydrocannabinol (THC), a major component in cannabis, causes short-term effects on the visual system, but little is known about persisting visual disturbances. This study was to investigate the effects of systemic administration with THC on retina and explore its underlying mechanisms. BALB/c mice were treated with 1 or 2 mg/kg THC intraperitoneally daily for 2 months, mice treated with vehicle as negative control. The retinal function was tested by electroretinography after THC treatment. Morphology and pathology changes of retina were detected by hematoxylin and eosin staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to detect the apoptosis in photoreceptor cells. Enzyme-linked immunosorbent assay was used to show the inflammatory responses and oxidative stress. mRNA and protein changes were measured by real-time polymerase chain reaction and Western blot to explore the underlying mechanisms. Results indicated that 2-month treatment with THC caused retinal damage, evidenced by its functional loss and increased apoptosis in photoreceptor cells through inducing inflammatory responses and oxidative stress. Our study demonstrated that systemic administration with THC caused toxic effects on retinas of BALB/c mice, suggesting the potential mechanisms for the retina damage caused by cannabis abuse.

Alpinetin Inhibits Oral Squamous Cell Carcinoma Proliferation via miR-211-5p Upregulation and Notch Pathway Deactivation

Background: The effect of alpinetin (ALP) on miR-211-5p level and function in oral squamous cell carcinoma (OSCC) remains unclear.Materials and methods: Human OSCC cell lines (CAL-27 and TCA-8113) and a mouse xenograft model with subcutaneously injected TCA-8113 cells were used. Effect of ALP treatment on cell viability, cell cycle distributions, and p-p53, p21, c-PARP, cyclin D1, NICD, HES1, and miR-211-5p expression levels was analyzed. Influence of ALP on tumor volume and weight was determined.Results: ALP treatment (at doses 400 and 500 µM) significantly decreased the viability of CAL-27 and TCA-8113 cells (P < 0.05). It upregulated the number of cells in G1 phase and miR-211-5p expression, increased p-p53, p21, and c-PARP levels, and decreased cyclin D1 levels. Furthermore, miR-211-5p mimic treatment increased the number of cells in G1 phase, and p53, p21, and c-PARP levels, and decreased cyclin D1 levels. Contrasting effects were observed under anti-miR-211-5p treatment. ALP downregulated NICD and HES1, whereas anti-miR-211-5p increased NICD and HES1 expression. ALP effects were alleviated in both cell lines under Jagged-1 overexpression plasmid treatment. Finally, ALP inhibited tumor growth and increased miR-211-5p expression in vivo.Conclusion: ALP-induced miR-211-5p upregulation and Notch pathway deactivation may be involved in its anti-proliferative effects in OSCC.

(3R)-5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one inhibited osteosarcoma growth by inducing apoptosis

As one of the leading causes of cancer-associated mortalities worldwide, the overall survival rate of osteosarcoma has stably remained at 15–30% for several decades. (3R)- 5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one (TIM), isolated from the whole plant of Selaginella moellendorffii Hieron., has been reported to have pharmacological activities. In the present study, the anti-proliferative effects of TIM against osteosarcoma were evaluated, and the underlying molecular mechanisms were explored. The results demonstrated that TIM inhibited proliferation and induced apoptosis in U2OS cells. Furthermore, the expression of the pro-apoptotic protein NOXA in the intrinsic apoptosis pathway was upregulated by TIM, while the expression of myeloid cell leukemia 1, an anti-apoptotic protein, was downregulated. In addition, TIM increased the protein expression of the endoplasmic reticulum stress markers inositol-requiring enzyme 1, activating transcription factor 6 and glucose-regulated protein 78. These results suggested that TIM induced ER stress response while activating intrinsic apoptosis. Furthermore, treating osteosarcoma tumor-bearing mice with TIM significantly inhibited the tumor growth in the xenograft animal model. Overall, the study results suggested that TIM may serve as a potential antitumor agent against osteosarcoma.

Long-Term Systemic Treatment With Methamphetamine Causes Retinal Damage in CD1 Mice

As a powerful psychostimulant with high potential for abuse, methamphetamine (Meth) could cause long-lasting abnormalities in retinas. The purpose of this study was to investigate the effects of systemic administration of Meth at low dose on retinal damage and understand the underlying mechanisms of pathology. CD1 mice were treated with 0.5 mg/kg or 1 mg/kg Meth by intraperitoneal injection daily for 2 months, mice treated with saline were used as negative control. Electroretinography (ERG) reflects the mass response of photoreceptor cells and was used to test the outer retinal function after Meth treatment. Toluidine blue staining was used to show the retinal morphology and evaluate the photoreceptor cell loss. Inflammatory factors were measured by enzyme-linked immunosorbent assay to show the inflammatory response. Terminal deoxynucleotidyl transferase dUTP Nick end labeling assay was used to detect the apoptosis-positive cells. Real-time polymerase chain reaction and Western blot were applied to measure the gene and protein change to explore the underlying mechanisms. Results demonstrated that retinal damage was caused by Meth treatment after 2 months, evidenced by loss of rod photoreceptor cells; decreased ERG amplitude; increased apoptotic photoreceptor cells, cytochrome-c release, caspase-3 activity, caspase-9 activity, and apoptosis-related protein expression; increased malondialdehyde level as well as nicotinamide adenine dinucleotide phosphate oxidase 4 protein expression; decreased anti-oxidative agents glutathione as well as superoxide dismutase levels; and increased production and gene expression of inflammatory factors. Our study indicated that systemic administration of Meth caused neurotoxic effects on CD1 mouse retinas, providing the potential mechanisms for the retina damage caused by Meth abuse.

Walnut ( Juglans regia) Peptides Reverse Sleep Deprivation-Induced Memory Impairment in Rat via Alleviating Oxidative Stress

The aim of this study was to determine the neuroprotective effects of walnut protein hydrolysates (WPH) against memory deficits induced by sleep deprivation (SD) in rat and further to identify and characterize the potent neuroprotective peptides against glutamate-induced apoptosis in PC12 cells. Results showed that a remarkable amelioration effect on behavioral performance in Morris water maze test was observed for WPH and its low molecular weight fraction WPHL, especially for WPHL. Additionally, a reduction of antioxidant defense (catalase, glutathione peroxidase (GSH-px), and superoxide dismutase (SOD)) and an increase of malondialdehyde content induced by SD were normalized in brain of rat after oral administration of WPH and WPHL. Then three neuroprotective peptides including GGW, VYY, and LLPF were identified from WPHL, which could protect PC12 cells against glutamate-induced apoptosis with relative cell viability of 78.29 ± 3.09%, 80.65 ± 1.74%, and 83.97 ± 3.06%, respectively, versus glutamate group 48.61 ± 3.99%. The possible mechanism underlying their protective effects of GGW and VYY could be related to their strong radical scavenging activity as well as their ability to reduce reactive oxygen species production and the depletion of SOD and GSH-px in PC12 cells. Notably, the marked neuroprotective effects of LLPF, which did not show obvious free-radical scavenging activity in vitro, could be attributed to its strong effects on inhibiting Ca²⁺ influx and mitochondrial membrane potential collapse. Additionally, all these peptides could regulate the expression of apoptosis-related proteins (Bax and Bcl-2). Therefore, walnut peptides might be regarded as the potential nutraceuticals against neurodegenerative disorders associated with memory deficits.

Phytocompounds modulating Aquaporins: Clinical benefits are anticipated

A series of plant-derived bioactive compounds belonging to the class of polyphenols, terpenes and capsaicinoids, interact with important pathophysiological pathways at a molecular, cellular and systemic level. Mechanisms of action include altering cell growth and differentiation, apoptosis, autophagy, inflammation, redox balance and metabolic and energy homeostasis. These effects might also involve the expression and function of Aquaporins (AQPs), a family of membrane channel proteins, involved in several body functions. The ultimate translational beneficial effect of such phytocompounds on AQPs in health and disease is a matter of intensive research. Results might provide novel therapeutic approaches to a number of human diseases. Here, we give an updated overview of this fast growing and promising field, discussing a number of phytocompounds and their action on AQPs and related potential clinical achievements.

Alpinetin inhibits proliferation and migration of ovarian cancer cells via suppression of STAT3 signaling

Natural bioactive components are increasingly being applied in cancer research. Alpinetin is a type of natural flavonoid primarily derived from Alpinia katsumadai Hayata, which exhibits anti‑bacterial and anti‑inflammatory properties. Therefore, it may possess anticancer potential and be employed therapeutically for different diseases. The aim of the present study was to investigate the anticancer effects of alpinetin on the SKOV3 ovarian cancer cell line. The effect of alpinetin treatment on SKOV3 cell proliferation, apoptosis, spheroid and colony formation were measured using Cell Counting kit‑8, cell apoptosis, 3D spheroid and colony formation assays, respectively. Analysis of the cell cycle was performed using flow cytometry. Western blot analysis was used to determine the protein expression levels of B‑cell lymphoma (Bcl)‑2, Bcl‑2‑associated X protein, cleaved caspase‑3, cleaved poly (ADP‑ribose) polymerase (PARP), cyclin D1, cyclin‑dependent kinase (CDK) 4, CDK6, signal transducer and activator of transcription (STAT) 3, phosphorylated (p)‑STAT3, c‑myc, survivin, tissue inhibitor of metalloproteinase (TIMP)‑1, TIMP‑2, matrix metalloproteinase (MMP)‑2 and MMP‑9. In addition, a wound healing assay was used to determine cancer cell migration. The results revealed alpinetin suppressed cell viability and induced apoptosis of SKOV3 cells in a dose‑ and time‑dependent manner, and cells were arrested in the G1 phase. Alpinetin treatment upregulated protein expression levels of Bax, cleaved caspase‑3 and PARP, and downregulated protein expression levels of Bcl‑2, cyclin D1, CDK4 and CDK6. Alpinetin also inhibited cell migration, through increased protein expression levels of TIMP‑1 and TIMP‑2, and decreased protein expression levels of MMP‑2 and MMP‑9. Alpinetin also significantly suppressed colony and spheroid formation by SKOV3 cells. In addition, the STAT3 pathway was suppressed as demonstrated by downregulation of p‑STAT3 and reduced expression of downstream factors, including c‑myc and survivin. Overall, these results indicated that alpinetin may have anticancer effects on human ovarian cancer by inhibiting the STAT3 signaling pathway.

Aquaporins as Targets of Dietary Bioactive Phytocompounds

Plant-derived bioactive compounds have protective role for plants but may also modulate several physiological processes of plant consumers. In the last years, a wide spectrum of phytochemicals have been found to be beneficial to health interacting with molecular signaling pathways underlying critical functions such as cell growth and differentiation, apoptosis, autophagy, inflammation, redox balance, cell volume regulation, metabolic homeostasis, and energy balance. Hence, a large number of biologically active phytocompounds of foods have been isolated, characterized, and eventually modified representing a natural source of novel molecules to prevent, delay or cure several human diseases. Aquaporins (AQPs), a family of membrane channel proteins involved in many body functions, are emerging among the targets of bioactive phytochemicals in imparting their beneficial actions. Here, we provide a comprehensive review of this fast growing topic focusing especially on what it is known on the modulatory effects played by several edible plant and herbal compounds on AQPs, both in health and disease. Phytochemical modulation of AQP expression may provide new medical treatment options to improve the prognosis of several diseases.

(3R)-5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one reduces lipoteichoic acid-induced damage in rat cardiomyoblast cells

Objective:

Infective endocarditis is usually caused by Streptococcus sanguinis and characterized by inflammatory responses in the endocardium. This study aimed to investigate if the new compound (3R)-5,6,7-trihydroxy-3-isopropyl-3-methylisochroman-1-one (TIM) isolated from Alpinia katsumadai Hayata could provide protection against lipoteichoic acid (LTA)-induced cell damage in embryonic rat heart cells (H9c2).

Methods:

LTA-induced cell damage was established in H9c2, and the protective effects of TIM against the cell damage were examined at different concentrations (0.1–2.5 µM). The inflammatory response and oxidative stress in H9c2 cells were also measured.

Results:

Treatment with TIM (0.1–2.5 µM) significantly decreased LTA-induced toxicity in H9c2 cells, which was indicated by increase in cell viability, elevation in the mitochondrial membrane potential, decrease in the release of cytochrome-c and DNA damage, inhibition of caspase-3/9 activities, and change in apoptosis-related protein expression in LTA-treated H9c2 cells. TIM treatment also significantly attenuated the redox imbalance in H9c2 cells by decreasing malondialdehyde and intracellular reactive oxygen species levels as well as by enhancing superoxide dismutase activities and glutathione levels by increasing nuclear factor (erythroid-derived 2)-like 2 protein expression. Moreover, TIM treatment decreased interleukin 1 β, interleukin 12, and tumor necrosis factor α levels by inhibiting nuclear factor kappa B protein expression.

Conclusion:

Our data indicated that TIM protected H9c2 cells against LTA-induced toxicity, at least partially through inhibiting the inflammatory response and oxidative stress, providing scientific rational to develop TIM to treat infective endocarditis.

Quantification and pharmacokinetics of alpinetin in rat plasma by UHPLC-MS/MS using protein precipitation coupled with dilution approach to eliminate matrix effects

Alpinetin, a bioactive flavonoid, has attracted great attention due to its diverse therapeutic effects, namely anti-oxidant, anti-tumor and anti-inflammatory effects with low systemic toxicity. Various determination methods have been developed in quality control and plant chemistry areas. However, quantification and pharmacokinetics of alpinetin in biological matrix have not been studied. In the present research, a sensitive, efficient and reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of alpinetin in rat plasma was developed and validated. Plasma samples were processed with protein precipitation (PP) followed by a 5-fold acetonitrile/water (50:50, v/v) dilution to significantly decrease matrix effect which exited in one step PP method. Determination of alpinetin was conducted using positive electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. Results demonstrated that the method was precise (3.3%-12.3%), accurate (-5.8% to 10.8%) and linear in the range of 1-1000 ng/mL. The new developed method was subsequently applied to a pharmacokinetic research of alpinetin following oral and intravenous dosing to healthy Sprague-Dawley rats. Alpinetin was demonstrated rapid absorption after oral administration with an absolute bioavailability of ∼15.1% and extensive distribution after dosing.

Inhibition of coiled coil domain containing protein 69 enhances platinum-induced apoptosis in ovarian cancer cells

Cisplatin is a platinum-based drug that is used for the treatment of human gynecological cancers. However, molecular mechanisms of chemo-resistance in ovarian cancer are poorly understood. The aim of the study is to examine the role of coiled coil domain containing protein 69 (CCDC69) in the underlying mechanism of chemoresistance. Heavy CpG methylation (73.1% and 74.3%) was found in A2780 and A2780cis cells assessing by bisulfite sequencing. Restoration in the expression of CCDC69 was found in A2780 and A2780cis cells after 5-Aza-dC treatment. In fact, the expression levels of CCDC69 were about 3-4 fold higher in cisplatin-resistant A2780cis cells than its parental cisplatin-sensitive A2780 cells. When knockout CCDC69 in cisplatin-resistant A2780cis and SKOV3 cells by CRISPR/Cas9, the CCDC69 knockout cisplatin-resistant A2780cis and CCDC69 knockout SKOV3 cells were also shown increased sensitive to cisplatin treatment. Moreover, treating CCDC69 knockout A2780cis cells with cisplatin, abrogated G1 and G2/M arrest, increased of cleaved caspase 3&8, greater ΔΨm loss and higher levels of Bax were observed. When restoring CCDC69 expression in CCDC69 knockout A2780cis cells by transient transfection, it attenuated sensitivity to cisplatin. By immunoblotting, we found that depletion of CCDC69 increased p53 acetylation at K382 site and Bax mitochondrial redistribution. Additionally, inhibition of c-Myc enhanced cisplatin sensitivities in CCDC69 knockout A2780cis cells, overexpression of c-Myc reduced apoptosis in CCDC69 knockout SKOV3 cells. Our results showed that CCDC69 inhibition might interfere with the effectiveness of combination therapy with platinum drugs.

3,4-Methylenedioxymethamphetamine causes cytotoxicity on 661W cells through inducing macrophage polarization

The abuse of 3,4-methylenedioxymethamphetamine (MDMA), a psychedelic drug, can lead to a variety of disorders in neural system, including the death of retinal neural cells. MDMA at lower doses does not cause obvious cytotoxicity to photoreceptor cells, indicating potential indirect mechanisms which have not yet been elucidated. This study investigated the effect of MDMA at nontoxic concentration on macrophage activation state and its resultant toxicity to photoreceptor cells. Using a co-culture system, cytotoxicity was caused by MDMA on 661W cells after co-culturing with RAW264.7 macrophage. Results showed that MDMA induced the macrophages to M1 polarization, releasing more pro-inflammatory cytokines, upregulating the M1-related gene and protein expression. The phenotype, secretion pattern, and cytotoxicity of the macrophages treated by MDMA are comparable to those of the ones stimulated by IFNγ and LPS. Our study demonstrated that MDMA promoted macrophage polarization to M1 and induced inflammatory response, providing the scientific rationale for the photoreceptor cell damage caused by the MDMA abuse.

Methamphetamine Causes Photoreceptor Cell Damage Through Promoting Polarization of Macrophages and Inducing Inflammatory Response

Classically activated macrophages (M1) are proinflammatory effectors and closely related to the progression of neurotoxicity. As a powerful psychostimulant and addictive drug, methamphetamine (Meth) abuse could result in long-lasting abnormalities in retina. This study investigated the effect of Meth at nontoxic concentration on macrophage activation state and its resultant toxicity to photoreceptor cells. Results showed that cytotoxicity was caused by Meth on 661 W cells after coculturing with RAW264.7 macrophage. RAW264.7 cells tended to switch to the M1 phenotype, releasing more proinflammatory cytokines after treatment with Meth. Meth could also upregulate the M1-related gene and protein expression. Our study demonstrated that Meth promoted macrophage polarization from M0 to M1 and induced inflammatory response, providing the scientific rationale for the photoreceptor cell damage caused by the Meth abuse.

Paeoniflorin exerts neuroprotective effects against glutamate‑induced PC12 cellular cytotoxicity by inhibiting apoptosis

Paeoniflorin (PF) is an active ingredient of Radix Paeoniae, which is known to exert neuroprotective effects. However, the mechanims behind the neuroprotective effects of PF are not yet fully understood. The apoptosis of neurons plays an important role in the cerebral ischemia-induced cascade response. This study aimed to investigate neuroprotective effects of PF against glutamate‑induced PC12 cellular cytotoxicity and to determine whether these effects are mediated via the inhibition of apoptosis in vitro and the activity of mitochondrial apoptosis-associated proteins in PC12 cells. Exposure of the PC12 cells to glutamate induced cell morphological changes, significantly decreased cell viability and induced apoptosis, with similar results being observed from the Hoechst 33342 staining and Annexin V/PI staining experiments. Glutamate also increased the lactate dehydrogenase release by the PC12 cells. However, treatment with PF prevented these effects. Furthermore, PF inhibited Bax and Bad expression and increased Bcl-2 and Bcl-xL expression; it also decreased the levels of downstream protein (caspase-3 and caspase-9). Collectively, our results indicate that PF protects PC12 cells against glutamate-induced neurotoxicity possibly through the inhibition of the expression of mitochondrial apoptosis-associated proteins.

Methamphetamine causes neurotoxicity by promoting polarization of macrophages and inflammatory response

Macrophages, especially their activation state, are closely related to the progression of neurotoxicity. Classically activated macrophages (M1) are proinflammatory effectors, while alternatively activated macrophages (M2) exhibit anti-inflammatory properties. As a powerful addictive psychostimulant drug, coupled with its neurotoxicity, methamphetamine (Meth) abuse may lead to long-lasting abnormalities in the neuronal system. The present study investigated the effect of Meth at subtoxic concentration on macrophage activation state and its underlying toxicity to neuronal cells. PC12 and Murine RAW264.7 cells were coincubated with Meth to test its toxicity. 3-(4,5-Dimethylthiazol)-2,5-diphenyltetrazolium-bromide, enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot assays were performed to evaluate the toxicity, cytokine secretion, gene, and protein expression. Results showed that cytotoxicity was enhanced on PC12 cells after coculturing with RAW264.7 stimulated with Meth. RAW264.7 macrophages tended to switch to the M1 phenotype, releasing more nitric oxide and proinflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)-12, and IL-1β, while decreasing the release of anti-inflammatory cytokine IL-10 after treatment with Meth. Meth upregulated the gene expression of IL-6, IL-1β, and TNFα and downregulated the expression of Arg-1, IL-10, and KLF4. Meth could also upregulate the protein expression of IL-1β and TNF α and downregulate the expression of Arg-1 and KLF4. However, the abovementioned effects induced by Meth were abolished by the addition of dopamine receptor D3 antagonist. In conclusion, our study demonstrated that Meth promoted macrophage polarization from M0 to M1 and enhanced inflammatory response, which provided the scientific rationale for the neurotoxicity caused by the chronic use of Meth.

Alpinetin inhibits lung cancer progression and elevates sensitization drug-resistant lung cancer cells to cis-diammined dichloridoplatium

OBJECTIVE

Alpinetin is a novel flavonoid that has demonstrated potent antitumor activity in previous studies. However, the efficacy and mechanism of alpinetin in treating lung cancer have not been determined.

METHODS

We evaluated the impact of different doses and durations of alpinetin treatment on the cell proliferation, the apoptosis of lung cancer cells, as well as the drug-resistant lung cancer cells.

RESULTS

This study showed that the alpinetin inhibited the cell proliferation, enhanced the apoptosis, and inhibited the PI3K/Akt signaling in lung cancer cells. Moreover, alpinetin significantly increased the sensitivity of drug-resistant lung cancer cells to the chemotherapeutic effect of cis-diammined dichloridoplatium. Taken together, this study demonstrated that alpinetin significantly suppressed the development of human lung cancer possibly by influencing mitochondria and the PI3K/Akt signaling pathway and sensitized drug-resistant lung cancer cells.

CONCLUSION

Alpinetin may be used as a potential compound for combinatorial therapy or as a complement to other chemotherapeutic agents when multiple lines of treatments have failed to reduce lung cancer.

Heat stress induced apoptosis is triggered by transcription-independent p53, Ca(2+) dyshomeostasis and the subsequent Bax mitochondrial translocation

In this study, We demonstrated that Bax mitochondrial translocation plays a vital role in the initiation of the mitochondrial signaling pathway upon activation by heat stress. In addition, both p53 mitochondrial translocation and Ca²⁺ signal mediated MPTP opening activate Bax mitochondrial translocation. Employing pifithrin-α (a p53 mitochondrial translocation inhibitor) and CsA (a permeability transition pore (MPTP) inhibitor), we found that heat stress induced Bax mitochondrial translocation was significantly inhibited in cells pretreated with both PFT and CsA. Furthermore, we demonstrated that generation of reactive oxygen species (ROS) is a critical mediator in heat stress induced apoptosis and that the antioxidant MnTBAP significantly decreased heat stress induced p53 mitochondrial translocation and Ca²⁺ signal mediated MPTP opening, as well as the subsequent Bax mitochondrial translocation and activation of the caspase cascade. Taken together, our results indicate that heat stress induces apoptosis through the mitochondrial pathway with ROS dependent mitochondrial p53 translocation and Ca²⁺ dyshomeostasis, and the ensuing intro Bax mitochondrial translocation as the upstream events involved in triggering the apoptotic process observed upon cellular exposure to heat stress.

X609, a novel manassantin A derivative, exhibits antitumor activity in MG-63 human osteosarcoma cells in vitro and in vivo

Manassantin A has been well-established as an inhibitor of HIF-1. In the present study, a new manasantin A derivative, X609, with decreased stereochemical complexity, rendering it amenable to a simplified synthesis scheme, was synthesized and was found to increase HIF-1 inhibitory activity. X609 exhibited antiproliferative activity in a broad spectrum of tumor cell lines, via HIF-1-dependent mechanisms. X609 may induce apoptosis in MG-63 cells through activation of the mitochondrial pathway. Oral administration of X609 significantly inhibited the growth of human osteosarcomas implanted into nude mice. In light of the results of the present study, it may be possible to develop X609 for use as a novel antitumor agent, which targets human osteosarcoma.

(2R,3S)-Pinobanksin-3-cinnamate improves cognition and reduces oxidative stress in rats with vascular dementia

This study investigated the neuroprotective effects of (2R,3S)-pinobanksin-3-cinnamate (PNC) in rats with occlusion-damaged bilateral common carotid arteries. Administration with PNC (5 and 10 mg/kg/day) for 5 weeks significantly improved the behavioral performance of rats with vascular dementia, as showed in the Morris water maze test by shortening the escape latency and latency of crossing, completing more platform crossings, as well as spending more time in the target zone. Further evaluations found that PNC could markedly decrease malondialdehyde levels, enhance superoxide dismutase activity and glutathione levels, and decrease the release of cytochrome c as well as the activities of caspases. Moreover, PNC increased Nrf2 and anti-apoptotic bcl-2 protein expression, while Nox1 and pro-apopotic bax protein expression was decreased. PNC may exert its neuroprotective effects through counteracting oxidative stress and has the potential to treat vascular dementia.