Gone with the weed: incidents of adolescent marijuana use in the United States, 1976-2021.

PURPOSE: This study sought to examine grouped and right-censored (GRC) counts of adolescent marijuana use and estimate its temporal trajectories and sociodemographic disparities over almost half a century. METHODS: After compiling 46 waves of nationally representative data from the Monitoring the Future (MTF) study from 1976 to 2021 (sample size = 491,348), we utilized an innovative modified Poisson (mixture) approach to analyze past-year marijuana use quantified by GRC counts. RESULTS: The overall reduction in incidence rates of marijuana use was attributable to an almost 40% reduction in the risk of marijuana use (with the proportion of at-risk adolescents at 51.36% in 1979 and 31.53% in 2021). Despite substantial changes over the study period, the recent incidence rates for at-risk individuals were similar to those in the early 1980s. Living in an intact family was a protective factor against adolescent marijuana use over time. CONCLUSIONS: The incidence rates of marijuana use among at-risk students, especially those from disadvantaged families, remained high over the study period. The modified Poisson (mixture) approach serves as the preferred tool for modeling GRC responses. It is essential to distinguish among risk, at-risk incidence, and overall incidence when assessing substance use and other risky behaviors.

[Pricking and cupping at Jianbo area combined with conventional acupuncture for scapulohumeral periarthritis of frozen stage: a randomized controlled trial].

OBJECTIVE: To compare the clinical effect of conventional acupuncture combined with pricking and cupping at Jianbo area and conventional acupuncture in the treatment of scapulohumeral periarthritis of frozen stage. METHODS: A total of 66 patients with scapulohumeral periarthritis of frozen stage were randomly divided into a combination group (31 cases) and an acupuncture group (35 cases, 1 case dropped off). Both groups were given functional exercise. Patients in the acupuncture group were treated with acupuncture at Jianyu (LI 15), Jianliao (TE 14), Binao (LI 14) and ashi point on the affected side, once every other day, three times a week, for a total of 4 weeks. On the basis of treatment in the acupuncture group, the patients in the combination group were treated with pricking and cupping at Jianbo area (the area surrounded by the 3 acupoints of Tianzong [SI 11], Naoshu [SI 10] and Jianzhen [SI 9]), once a week for 4 weeks. The University of California-Los Angeles (UCLA) shoulder joint score, visual analogue scale (VAS) score before treatment, after treatment and after 6 months of treatment completion (follow-up) and tenderness threshold before and after treatment, and the clinical effects of the two groups after treatment and in follow-up were evaluated. RESULTS: In the two groups, after treatment and in follow-up, the UCLA shoulder joint scores were higher than those before treatment (P<0.05), and the VAS scores were lower than those before treatment (P<0.05). In the combination group, after treatment and in follow-up, the UCLA shoulder joint score was higher than that of the acupuncture group (P<0.05), and the VAS score was lower than that of the acupuncture group (P<0.05). After treatment, the tenderness thresholds of the two groups were higher than those before treatment (P<0.05), and the tenderness threshold in the combination group was higher than that in the acupuncture group (P<0.05). After treatment and in follow-up, the cured and markedly effective rate of the combination group was 48.4% (15/31) and 51.6% (16/31) respectively, which was higher than 23.5% (8/34) and 23.5% (8/34) of the acupuncture group (P<0.05). CONCLUSION: Pricking and cupping in Jianbo area combined with conventional acupuncture can improve shoulder joint function and relieve shoulder joint pain in patients with scapulohumeral periarthritis of frozen stage, and the curative effect is better than that of single conventional acupuncture.

Analogues of natural products yaequinolones as potential inflammatory inhibitors: Design, synthesis and biological evaluation.

Inflammation is connected with a variety of diseases and there is still a need to develop more effective and safer anti-inflammatory drugs. Herein, we synthesized, resolved, and characterized eight enantiopure isomers of yaequinolone J1 (1), yaequinolone J2 (2), 4'-desmethoxyyaequinolone J1 (3), and 4'-desmethoxyyaequinolone J2 (4). The key synthetic steps were extended and 34 racemic analogues modified at the 4-aryl, the N-position, and the pyran ring were designed and synthesized. All the synthesized compounds were evaluated for their anti-inflammatory activities in RAW 264.7 cells of which 13 compounds showed significant inhibition of nitric oxide (NO) production at a concentration of 0.1 µM, which was more potent than that of indomethacin. Furthermore, compounds (-)-3, (-)-4, 5h, and 6g reduced the production of IL-6 in LPS-stimulated RAW 264.7 cells at a concentration of 50 nM. A preliminary SAR indicated that 3'-Br (5h), 4'-NO2 (6g) on 4-phenyl and 3-bromobenzyl (7f) on the N-position were the most effective substituents. This is the first report of the anti-inflammatory yaequinolone alkaloids and the present study provided evidence for exploiting this series of highly efficacious derivatives for new anti-inflammatory agents.

Discovery, total syntheses and potent anti-inflammatory activity of pyrrolinone-fused benzoazepine alkaloids Asperazepanones A and B from Aspergillus candidus.

Natural products are well established as an important resource and play an important role in drug discovery. Here, two pyrrolinone-fused benzoazepine alkaloids, (+)-asperazepanones A (1) and B (2) with a 6/7/5 ring system, together with the artifact (-)-asperazepanone A (1), were isolated from the coral-derived Aspergillus candidus fungus. Their structures including absolute configurations were elucidated by extensive spectroscopic methods, single crystal X-ray diffraction, and ECD calculations. Furthermore, total syntheses of (±)-1 and (±)-2 have been achieved starting from the commercially L-aspartic acid diethyl ester hydrochloride and monoethyl malonate in 7 and 8 steps, respectively. The key step in the syntheses was an intramolecular Friedel-Crafts reaction to build the unique tricyclic skeleton. Interestingly, (+)-2 not only showed obviously inhibitory activity against NO production, but also inhibited potent LPS-induced expression of TNF-α and IL-6 at the concentration of 0.1 µM. It thus represents a potentially promising lead for anti-inflammatory drug discovery.

Polysaccharides from Hemp Seed Protect against Cyclophosphamide-Induced Intestinal Oxidative Damage via Nrf2-Keap1 Signaling Pathway in Mice.

Hemp seed has been used as a traditional oriental medicine and health food in China for centuries. Polysaccharides from hemp seed (HSP) exhibit important properties of intestinal protection, but there are limited data on the specific underlying mechanism. The primary objective of this study was to investigate the protective effect of HSP on intestinal oxidative damage induced by cyclophosphamide (Cy) in mice. The results showed that pretreatment with HSP significantly increased the average daily gain, thymus index, spleen index, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity in serum and ileal homogenate and significantly reduced malondialdehyde (MDA) content in ileal homogenate. In addition, the expression levels of SOD, GSH-Px, Nrf2, heme oxidase-1 (HO-1), and quinoneoxidoreductase-1 (NQO1) mRNA in ileal homogenate were significantly increased. Western blot results showed that HSP significantly upregulated the expression of Nrf2 protein and downregulated the expression of Keap1 protein in the ileum. Collectively, our findings indicated that HSP had protective effects on intestinal oxidative damage induced by Cy in mice, and its mechanism might be related to the activation of Nrf2-Keap1 signaling pathway.

Lipophilic ferulic acid derivatives protect PC12 cells against oxidative damage via modulating ß-amyloid aggregation and activating Nrf2 enzymes.

Ferulic acid (FA) has been shown to have a neuroprotective effect on Alzheimer's disease induced by amyloid-beta (Aß) neurotoxicity. This work aims to ascertain the structure-activity relationship of FA and its alkyl esters (FAEs) for evaluating the antioxidant activities in PC12 cells and Aß1-42 aggregation inhibitory activities in vitro, as well as the signaling mechanisms against oxidative stress elicited by Aß1-42 in PC12 cells. Our data showed that alterations in the subcellular localization and cytotoxicity of FAEs caused by the lipophilicity of FA were crucial when evaluating their antioxidant capacities. Pre-treating cells with butyl ferulate (FAC4) significantly attenuated Aß1-42-evoked intracellular ROS formation. Besides, FAC4 exhibited the highest Aß1-42 aggregation inhibitory effectiveness. The molecular docking results showed that FAC4 binds to amide NH in Gln15 and Lys16 via a hydrogen bond. Notably, FAC4 could upregulate antioxidant defense systems by modulating the Keap1-Nrf2-ARE signaling pathway. Identification of the functions of FAEs could be useful in developing food supplements or drugs for treating AD.

Protective effect of seleno-amino-oligosaccharide on oxidative damage of IPEC-1 cells by activating Keap1/Nrf2 signaling pathway.

The aim of the study was to investigate the antioxidant effect of seleno-amino-oligosaccharide (Se-AOS) on intestinal porcine epithelial cells (IPEC-1). MTT assay showed that Se-AOS had no effect on the viability of IPEC-1 cells up to a concentration of 9200 µg/L and Se-AOS significantly increased the viability of IPEC-1 cells compared to cells exposed to H2O2 alone. Se-AOS significantly increased the level of superoxide Dismutase (SOD) and decreased the levels of malonic dialdehyde (MDA) and lactate dehydrogenase (LDH) in IPEC-1 cells. The gene expression levels of different antioxidant enzymes dramatically increased by the pretreatment of Se-AOS compared to H2O2 treatment. In addition, the results indicated that Se-AOS up-regulated the intracellular Nrf2 and down-regulated the level of Keap1 by western blot. Taken together, these findings suggested that Se-AOS can protect IPEC-1 cells from oxidative damage through activating the Keap1/Nrf2 signaling pathway.

Low Molecular Seleno-Aminopolysaccharides Protect the Intestinal Mucosal Barrier of Rats under Weaning Stress.

Low molecular seleno-aminopolysaccharide (LSA) was synthesized with sodium selenite and low molecular aminopolysaccharide (LA), which is an organic selenium compound. This study is aimed to investigate the protective effect of LSA on the intestinal mucosal barrier in weaning stress rats by detecting the intestinal tissue morphology and function, mucosal thickness and permeability, the structure of MUC2, antioxidant index, the expression level of intracellular transcription factor NF-E2-related factor 2 (Nrf2), and its related factors. The results showed that LSA significantly increased the height of intestinal villi (p < 0.05) and increased the thickness of intestinal mucosa and the number of goblet cells, which indicated that LSA has a protective effect on the intestinal mucosal barrier that is damaged by weaning. Moreover, LSA significantly reduced the level of DAO, D-LA, and LPS compared with the weaning group (p < 0.05), which indicated that LSA reduced the intestinal damage and permeability of weaning rats. In addition, LSA could increase the number and length of glycans chains and the abundance of acid glycans structures in the MUC2 structure, which indicated that LSA alleviated the changes of intestinal mucus protein structure. LSA significantly increased the levels of GSH-Px, SOD, LDH, and CAT, while it decreased the level of MDA in serum and intestinal tissue, which suggested that LSA significantly enhanced the antioxidant capacity and reduced oxidative stress of weaning rats. RT-PCR results showed that LSA significantly increased the expression level of antioxidant genes (GSH-Px, SOD, Nrf2, HO-1), glycosyltransferase genes (GalNT1, GalNT3, GalNT7) and mucin gene (MUC2) in intestinal mucosa (p < 0.05). The results of western blot showed that the LSA activated the Nrf2 signaling pathway by down-regulating the expression of Keap1and up-regulating the expression of Nrf2, and protected the intestinal mucosa from oxidative stress. Overall, LSA could play a protective role in intestinal mucosal barrier of weaning rats by activating the Nrf2 pathway and alleviating the alnormal change of mucin MUC2.

Protective effect of polysaccharides of sea cucumber Acaudina leucoprocta on hydrogen peroxide-induced oxidative injury in RAW264.7 cells.

The aim of this experiment was to investigate the protective effects of polysaccharides of sea cucumber Acaudina leucoprocta (ALP) against hydrogen peroxide (H2O2) induced oxidative injury in RAW264.7 cells. Analysis of monosaccharide composition and structure of one fraction from ALP (ALPN) were analyzed by High Performance Liquid Chromatography (HPLC) and Fourier Transform Infrared Spectoscopy (FT-IR). The results showed that ALPN contain sulfate groups, which is sulfated polysaccharides. The results from MTT assay indicated that ALPN could markedly increase viability of cells compared with RAW264.7 cells exposed to H2O2. Moreover, ALPN significantly increased the levels of catalase (CAT), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD), decreased the production of malondialdehyde (MDA) and lactate dehydrogenase (LDH) in RAW264.7 cells. The data from RT-PCR showed that ALPN (300 µg/mL) could increase the gene expression levels of SOD1 and GPX1. ALPN could also observably increase the protein expression level of Nrf2 and decrease the protein expression level of Keap1 with western blot. Collectively, this study suggested that polysaccharides of sea cucumber Acaudina leucoprocta (ALP) could effectively protect RAW264.7 cells against H2O2-induced oxidative injury. This protection mechanism may be related to activation of the Nrf2/Keap1 signaling pathway.

MicroRNA-206 Downregulates Connexin43 in Cardiomyocytes to Induce Cardiac Arrhythmias in a Transgenic Mouse Model.

BACKGROUND: MicroRNAs (miRNAs) are critical modulators of various physiological and pathological processes, but their role in cardiac arrhythmias remains yet to be completely understood. Connexin43 (Cx43) is an important cardiac gap junction protein and a potential target of miR-206, and downregulation of Cx43 induces ventricular tachyarrhythmias. METHODS: We investigated the effects of miR-206 overexpression on the adult mouse heart and in cardiac arrhythmias. Luciferase activity assay was employed to validate Cx43 as a direct target of miR-206. Expression of Cx43 was measured in cardiac muscle cell line HL-1 securely expressing miR-206. An inducible miR-206 overexpression mouse model was established to evaluate the in vivo effect of miR-206 on Cx43 expression and cardiac rhythm. RESULTS: MiR-206 directly recognised 3'-untranslated region of Cx43 mRNA to inhibit its expression in HL-1 cells. Induction of miR-206 in the adult mouse heart suppressed Cx43 expression, particularly in the atria and ventricle. Importantly, miR-206 overexpression also induced abnormal heart-rate and PR interval, and shortened life-span in the experimental mice. CONCLUSIONS: In cardiomyocytes, miR-206 is a upstream regulator of Cx43, and its overexpression downregulates Cx43 to induce abnormal heart-rate and PR interval.

Interleukin-6 induced by YAP in hepatocellular carcinoma cells recruits tumor-associated macrophages.

Tumor-associated macrophages (TAMs) has been regarded as the most prominent component in tumor microenvironment. The correlation between TAM density and poor prognosis in Hepatocellular carcinoma (HCC) patients suggests a supportive role for TAMs in tumor progression. Here we employed a co-culture system to interrogate the molecular link between Yes-Associated Protein (YAP) and TAMs chemotaxis in HCC cells. We found that YAP activation was critical for the recruitment of TAMs towards HCC cells. Furthermore, cytokine array and quantitative RT-PCR analyses showed that IL-6 secreted by YAP-activated HCC cells might induce the TAMs recruitment. Interrupting YAP function by statins, the inhibitors of hydroxymethylglutaryl-CoA reductase, could robustly suppress the chemotaxis of TAMs. Together with our findings that the expression levels ofIL-6inhumanHCC tumors were highly correlated with the prognosis of HCC patients, the current study highlight the possibility of improving HCC treatment by targeting YAP-IL-6 mediated TAMs recruitment.

AKR1C1 Activates STAT3 to Promote the Metastasis of Non-Small Cell Lung Cancer.

Metastasis is the leading cause of mortality for human non-small cell lung cancer (NSCLC). However, it is difficult to target tumor metastasis because the molecular mechanisms underlying NSCLC invasion and migration remain unclear. Methods: GEO data analyses and IHC analyses were performed to identify that the expression level of AKR1C1, a member of human aldo-keto reductase family, was highly elevated in patients with metastasis or metastatic foci of NSCLC patients. Functional analyses (in vitro and in vivo) and quantitative genomic analyses were preformed to confirm the pro-metastatic effects of AKR1C1 and the underlying mechanisms. The correlation of AKR1C1 with the prognosis of NSCLC patients was evaluated using Kaplan-Meier analyses. Results: in NSCLC patients, AKR1C1 expression was closely correlated with the metastatic potential of tumors. AKR1C1 overexpression in nonmetastatic cancer cells significantly promoted metastasis both in vitro and in vivo, whereas depletion of AKR1C1 in highly metastatic tumors potently alleviated these effects. Quantitative genomic and functional analyses revealed that AKR1C1 directly interacted with STAT3 and facilitated its phosphorylation-thus reinforcing the binding of STAT3 to the promoter regions of target genes-and then transactivated these genes, which ultimately promoted tumor metastasis. Further studies showed that AKR1C1 might facilitate the interaction of STAT3 with its upstream kinase JAK2. Intriguingly, AKR1C1 exerted these pro-metastatic effects in a catalytic-independent manner. In addition, a significant correlation between AKR1C1 and STAT3 pathway was observed in the metastatic foci of NSCLC patients, and the AKR1C1-STAT3 levels were highly correlated with a poor prognosis in NSCLC patients. Conclusions: taken together, we show that AKR1C1 is a potent inducer of NSCLC metastasis. Our study uncovers the active function of AKR1C1 as a key component of the STAT3 pathway, which promotes lung cancer metastasis, and highlights a candidate therapeutic target to potentially improve the survival of NSCLC patients with metastatic disease.

MDM2 promotes epithelial-mesenchymal transition and metastasis of ovarian cancer SKOV3 cells.

BACKGROUND: Metastasis accounts for the most lethal reason for the death of ovarian cancer patients, but remains largely untreated. Epithelial-mesenchymal transition (EMT) is critical for the conversion of early-stage ovarian tumours into metastatic malignancies. Thus the exploration of the signalling pathways promoting EMT would open potential opportunities for the treatment of metastatic ovarian cancer. Herein, the putative role of MDM2 in regulating EMT and metastasis of ovarian cancer SKOV3 cells was investigated. METHODS: The regulatory effects by MDM2 on cell motility was emulated by wound-healing and transwell assays. The effects on EMT transition and Smad pathway were studied by depicting the expression levels of epithelial marker E-cadherin as well as key components of Smad pathway. To evaluate the clinical relevance of our findings, the correlation of MDM2 expression levels with the stages of 104 ovarian cancer patients was investigated by immunohistochemistry assay. RESULTS: We demonstrate that MDM2 functions as a key factor to drive EMT and motility of ovarian SKOV3 cells, by facilitating the activation of TGF-ß-Smad pathway, which results in the increased transcription of snail/slug and the subsequent loss of E-cadherin levels. Such induction of EMT is sustained in either E3 ligase-depleted MDM2 or E3 ligase inhibitor HLI-373-treated cells, while being impaired by the N-terminal deletion of MDM2, which is also reflected by the inhibitory effects against EMT by Nutlin-3a, the N-terminal targeting agent. The expression levels of MDM2 is highly correlated with the stages of the ovarian cancer patients, and the higher expression of MDM2 together with TGFB are closely correlated with poor prognosis and predict a high risk of ovarian cancer patients. CONCLUSIONS: This study suggests that MDM2 activates Smad pathway to promote EMT in ovarian cancer metastasis, and targeting the N-terminal of MDM2 can reprogram EMT and impede the mobility of cancer cells.

Inactivation of hypoxia-induced YAP by statins overcomes hypoxic resistance tosorafenib in hepatocellular carcinoma cells.

Sorafenib is a multikinase inhibitor used as a first-line treatment for advanced hepatocellular carcinoma (HCC), but it has shown modest to low response rates. The characteristic tumour hypoxia of advanced HCC maybe a major factor underlying hypoxia-mediated treatment failure. Thus, it is urgent to elucidate the mechanisms of hypoxia-mediated sorafenib resistance in HCC. In this study, we found that hypoxia induced the nuclear translocation of Yes associate-Protein (YAP) and the subsequent transactivation of target genes that promote cell survival and escape apoptosis, thereby leading to sorafenib resistance. Statins, the inhibitors of hydroxymethylglutaryl-CoA reductase, could ameliorate hypoxia-induced nuclear translocation of YAP and suppress mRNA levels of YAP target genes both in vivo and in vitro. Combined treatment of statins with sorafenib greatly rescued the loss of anti-proliferative effects of sorafenib under hypoxia and improved the inhibitory effects on HepG2 xenograft tumour growth, accompanied by enhanced apoptosis as evidenced by the increased sub-G1 population and PARP cleavage. The expression levels of YAP and its target genes were highly correlated with poor prognosis and predicted a high risk of HCC patients. These findings collectively suggest that statins utilization maybe a promising new strategy to counteract hypoxia-mediated resistance to sorafenib in HCC patients.

Nuclear translocation and activation of YAP by hypoxia contributes to the chemoresistance of SN38 in hepatocellular carcinoma cells.

Although hypoxia is a prominent feature contributing to the therapeutic resistance of hepatocellular carcinoma cells (HCC) against chemotherapeutic agents, including the Topoisomerase I inhibitor SN38, the underlying mechanism is not fully understood and its understanding remains a major clinical challenge. In the present study, we found that hypoxia-induced nuclear translocation and accumulation of YAP acted as a survival input to promote resistance to SN38 in HCC. The induction of YAP by hypoxia was not mediated by HIF-1α because manipulating the abundance of HIF-1α with CoCl2, exogenous expression, and RNA interference had no effect on the phosphorylation or total levels of YAP. The mevalonate-HMG-CoA reductase (HMGCR) pathway may modulate the YAP activation under hypoxia. Combined YAP inhibition using either siRNA or the HMGCR inhibitor statins together with SN38 treatment produced improved anti-cancer effects in HCC cells. The increased anti-cancer effect of the combined treatment with statins and irinotecan (the prodrug of SN-38) was further validated in a human HepG2 xenograft model of HCC in nude mice. Taken together, our findings identify YAP as a novel mediator of hypoxic-resistance to SN38. These results suggest that the administration of SN28 together with the suppression of YAP using statins is a promising strategy for enhancing the treatment response in HCC patients, particularly in advanced stage HCC cases presenting hypoxic resistance.

[Sunitinib suppresses migration of ovarian cancer cells through negative modulation of TGF-ß-mediated epithelial-mesenchymal transition].

OBJECTIVE: To investigate the effect of sunitinib on the migration of ovarian cells and its mechanism of the negative regulation TGF-ß mediated of epithelial-mesenchymal transition(EMT) by sunitinib to inhibit ovarian cancer metastasis. METHODS: The migration of human ovarian cancer cells SKOV3 was evaluated by wound-healing and transwell assays. The effects of sunitinib on TGF-ß-induced E-cadherin expression was assessed by Western-blotting, real time RT-PCR and immunofluorescence assay. The protein levels of Snail and the transcriptional activity of Smad in sunitinib-treated cells were examined by Western-blotting and SBE-luciferase assay. RESULTS: Sunitinib suppressed the migration of SKOV3 cells in a concentration-dependent manner. TGF-ß stimulation reduced E-cadherin protein level, which was attenuated by sunitinib. Sunitinib inhibited the up-regulation of Snail protein level induced by TGF-ß treatment. The SBE reporter was constructed by linking the Smad-binding elements promoter upstream of luciferase reporter gene. A remarkable increment of transcriptional activity of Smads complexes was observed in SKOV3 cells exposed to TGF-ß, which was significantly prohibited by sunitinib. CONCLUSION: Sunitinib can inhibit the migration of SKOV3 cells and attenuate the down-regulation of E-cadherin protein level induced by TGF-ß. Sunitinib can abolish TGF-ß-induced up-regulation of Snail protein and decrease the transcriptional activity of Smad complexes. The results indicate that sunitinib suppresses migration of ovarian cancer cells through negative modulation of TGF-ß-mediated epithelial-mesenchymal transition.

Melatonin reverses the decreases in hippocampal protein serine/threonine kinases observed in an animal model of autism.

Lower global cognitive function scores are a common symptom of autism spectrum disorders (ASDs). This study investigates the effects of melatonin on hippocampal serine/threonine kinase signaling in an experimental ASD model. We found that chronic melatonin (1.0 or 5.0 mg/kg/day, 28 days) treatment significantly rescued valproic acid (VPA, 600 mg/kg)-induced decreases in CaMKII (Thr286), NMDAR1 (Ser896), and PKA (Thr197) phosphorylation in the hippocampus without affecting total protein levels. Compared with control rats, the immunostaining of pyramidal neurons in the hippocampus revealed a decrease in immunolabeling intensity for phospho-CaMKII (Thr286) in the hippocampus of VPA-treated rats, which was ameliorated by chronic melatonin treatment. Consistent with the elevation of CaMKII/PKA/PKC phosphorylation observed in melatonin-treated rat, long-term potentiation (LTP) was enhanced after chronic melatonin (5.0 mg/kg) treatment, as reflected by extracellular field potential slopes that increased from 56 to 60 min (133.4 ± 3.9% of the baseline, P < 0.01 versus VPA-treated rats) following high-frequency stimulation (HFS) in hippocampal slices. Accordingly, melatonin treatment also significantly improved social behavioral deficits at postnatal day 50 in VPA-treated rats. Taken together, the increased phosphorylation of CaMKII/PKA/PKC signaling might contribute to the beneficial effects of melatonin on autism symptoms.