DOCKING AND CYTOTOXICITY STUDIES OF 2-VINYLCHROMONE DERIVATIVES ON HUMAN BREAST CANCER CELL LINES

Objective: Estrogen receptor (ER) is over-expressed in 70% of breast cancers. The ER has two isoforms, ERα and ERβ. The ER ligand binding domain (LBD) has been the target for hormone-responsive breast cancer. Due to tissue-specific effects currently available drugs for hormone positive breast cancer presents serious limitation. The dynamic and plastic nature of ER LBD plays a crucial role in ligand design that discriminates between the ER subtypes. Agents that selectively target ER isoform are a formidable challenge to researchers. The chromone scaffold is a privileged scaffold for exploration of anticancer agents. The objective of the present study was to evaluate the anticancer activity of a small library of 2-vinylchromones in human breast cancer cell lines MCF-7 and MDA-MB-231.Methods: The compounds were synthesized by the reported procedures. Docking studies of the substituted 2-vinylchromone was performed using GLIDE tool in Maestro 8.0. The compounds were evaluated for anticancer activity against MCF-7 (ERα positive), MDA-MB-231 (ERβ positive) and MRC-5 (ERα, β negative) cell lines using MTT assay.Results: The in silico studies indicated that substituted 2-vinylchromones, 1(a-c) and 2(a-b) exhibited comparable docking score at LBD of ERα and ERβ. However, the binding affinity of the compounds for the allosteric binding site in ERβ was negligible. The dose-dependent studies using MTT assay depicted that compounds 1(a-c) and 2(a-b) exhibited anticancer activity in ERα positive cell line MCF-7 as compared to ERβ positive cell line MDA MB 231. The most potent anticancer activity was observed for compound 2b against MCF-7 cells with IC50 value of 15.625 μg/ml.Conclusion: The present investigation indicated that 2-vinylchromone derivatives exhibited ER isoform selectivity and the presence of bulky group in 2-vinylchromones resulted in significantly higher cytotoxicity in ERα positive cell lines as compared to the ERβ positive cell line.Â

Regulation of Chronic Stress-Induced Changes in Hypothalamic-Pituitary-Adrenal Activity by the Basolateral Amygdala

Little is known about the role of the basolateral amygdala (BLA) in regulating hypothalamic-pituitary-adrenal (HPA) activity, particularly chronic stress-induced HPA activity. In the current studies, we examined the effects of manipulations of the BLA on HPA responses to the eighth restraint, to novel restraint after repeated cold, or to acute novel restraint alone. Excitotoxic lesions of the BLA, in general, inhibited HPA activity in both acute and chronically stressed animals.To examine the role of the BLA in chronic stress without affecting the response to the first stress, we injected the GABA agonist muscimol to temporarily inactivate the BLA prior to restraint in the same three groups of animals. In contrast to the lesion data, muscimol enhanced the HPA response to acute restraint and to novel restraint after repeated cold, but it did not affect responses to the eighth restraint. These data suggest that the BLA inhibits HPA responses to novel stress but is not important in animals repeatedly exposed to the same stressor. Future studies will focus on the neuro-anatomical substrates of BLA's effects on HPA activity including whether inputs from the pPVTh are important.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73378/1/annals.1314.050.pd

Reduced orexin system function underlies resilience to repeated social defeat stress

Exposure to stress increases the risk of developing affective disorders such as depression and post-traumatic stress disorder (PTSD). However, these disorders occur in only a subset of individuals, those that are more vulnerable to the effects of stress, whereas others remain resilient. The coping style adopted to deal with the stressor, either passive or active coping, is related to vulnerability or resilience, respectively. Important neural substrates that mediate responses to a stressor are the orexins. These neuropeptides are altered in the cerebrospinal fluid of patients with stress-related illnesses such as depression and PTSD. The present experi- ments used a rodent social defeat model that generates actively coping rats and passively coping rats, which we have previously shown exhibit resilient and vulnerable profiles, respectively, to examine if orexins play a role in these stress-induced phenotypes. In situ radiolabeling and qPCR revealed that actively coping rats expressed significantly lower prepro-orexin mRNA compared with passively coping rats. This led to the hypothesis that lower levels of orexins contribute to resilience to repeated social stress. To test this hypothesis, rats first underwent 5 d of social defeat to establish active and passive coping phenotypes. Then, orexin neurons were inhibited before each social defeat for three additional days using designer receptors exclusively activated by designer drugs (DREADDs). Inhibition of orexins increased social interaction behavior and decreased depressive-like behavior in the vulnerable population of rats. Indeed, these data suggest that lowering orexins promoted resilience to social defeat and may be an important target for treatment of stress-related disorders

Reduced orexin system function underlies resilience to repeated social defeat stress

Exposure to stress increases the risk of developing affective disorders such as depression and post-traumatic stress disorder (PTSD). However, these disorders occur in only a subset of individuals, those that are more vulnerable to the effects of stress, whereas others remain resilient. The coping style adopted to deal with the stressor, either passive or active coping, is related to vulnerability or resilience, respectively. Important neural substrates that mediate responses to a stressor are the orexins. These neuropeptides are altered in the cerebrospinal fluid of patients with stress-related illnesses such as depression and PTSD. The present experi- ments used a rodent social defeat model that generates actively coping rats and passively coping rats, which we have previously shown exhibit resilient and vulnerable profiles, respectively, to examine if orexins play a role in these stress-induced phenotypes. In situ radiolabeling and qPCR revealed that actively coping rats expressed significantly lower prepro-orexin mRNA compared with passively coping rats. This led to the hypothesis that lower levels of orexins contribute to resilience to repeated social stress. To test this hypothesis, rats first underwent 5 d of social defeat to establish active and passive coping phenotypes. Then, orexin neurons were inhibited before each social defeat for three additional days using designer receptors exclusively activated by designer drugs (DREADDs). Inhibition of orexins increased social interaction behavior and decreased depressive-like behavior in the vulnerable population of rats. Indeed, these data suggest that lowering orexins promoted resilience to social defeat and may be an important target for treatment of stress-related disorders

ANTIFUNGAL ACTIVITY OF BIPHENYL-2,6-DIETHANONE DERIVATIVES

Objective: The objective of the study was to evaluate the antifungal activity of biphenyl-2,6-diethanone derivatives against Cryptococcus neoformans.Methods: Antifungal activity of biphenyl derivatives were evaluated against C. neoformans. Zone of inhibition by disc diffusion method and minimum inhibitory concentration (MIC) using micro-broth dilution method was performed as per clinical and laboratory standard institute (CLSI). Melanin was extracted using 1M KOH, purified using 6M HCL and its reduction was assayed spectrophotometrically at 530 nm. Laccase activity was measured using L-DOPA as substrate and was assayed spectrophotometrically at 480 nm. Time kill assay was also performed to compare the antifungal potency of the test compound against azole drug.Results: Zone of inhibition of 12 mm diameter was estimated against C. neoformans. MIC80 of compound 1e was calculated as 50µg/ml. 63.67% decrease in melanization and 57.44% laccase activity reduction was determined. The Time-kill assay illustrated that the compound 1e inhibited the growth of C. neoformans cells in almost the same duration as observed in fluconazole.Conclusion: The outcome of in vitro antifungal studies indicated that compound 1e demonstrated maximum reduction of melanin and laccase activity in C. neoformans. In conclusion, biphenyl-2,6-diethanone derivatives possess significant antifungal property which can be explored further for lead generation.Â

Sex- and Stress-Dependent Effects on Dendritic Morphology and Spine Densities in Putative Orexin Neurons

We recently found that non-stressed female rats have higher basal prepro-orexin expression and activation of orexinergic neurons compared to non-stressed males, which lead to impaired habituation to repeated restraint stress at the behavioral, neural, and endocrine level. Here, we extended our study of sex differences in the orexin system by examining spine densities and dendritic morphology in putative orexin neurons in adult male and female rats that were exposed to 5 consecutive days of 30-min restraint. Analysis of spine distribution and density indicated that putative orexinergic neurons in control non-stressed females had significantly more dendritic spines than those in control males, and the majority of these were mushroom spines. This morphological finding may suggest more excitatory input onto orexin neurons in female rats. As orexin neurons are known to promote the hypothalamic–pituitary–adrenal response, this morphological change in orexin neurons could underlie the impaired habituation to repeated stress in female rats. Dendritic complexity did not differ between non-stressed males and females, however repeated restraint stress decreased total dendritic length, nodes, and branching primarily in males. Thus, reduced dendritic complexity of putative orexinergic neurons is observed in males but not in females after 5 days of repeated restraint stress. This morphological change might be reflective of decreased orexin system function, which may allow males to habituate more fully to repeated restraint than females. These results extend our understanding of the role of orexin neurons in regulating habituation and demonstrate changes in putative orexin cell morphology and spines that may underlie sex differences in habituation

Sex- and Stress-Dependent Effects on Dendritic Morphology and Spine Densities in Putative Orexin Neurons

We recently found that non-stressed female rats have higher basal prepro-orexin expression and activation of orexinergic neurons compared to non-stressed males, which lead to impaired habituation to repeated restraint stress at the behavioral, neural, and endocrine level. Here, we extended our study of sex differences in the orexin system by examining spine densities and dendritic morphology in putative orexin neurons in adult male and female rats that were exposed to 5 consecutive days of 30-min restraint. Analysis of spine distribution and density indicated that putative orexinergic neurons in control non-stressed females had significantly more dendritic spines than those in control males, and the majority of these were mushroom spines. This morphological finding may suggest more excitatory input onto orexin neurons in female rats. As orexin neurons are known to promote the hypothalamic–pituitary–adrenal response, this morphological change in orexin neurons could underlie the impaired habituation to repeated stress in female rats. Dendritic complexity did not differ between non-stressed males and females, however repeated restraint stress decreased total dendritic length, nodes, and branching primarily in males. Thus, reduced dendritic complexity of putative orexinergic neurons is observed in males but not in females after 5 days of repeated restraint stress. This morphological change might be reflective of decreased orexin system function, which may allow males to habituate more fully to repeated restraint than females. These results extend our understanding of the role of orexin neurons in regulating habituation and demonstrate changes in putative orexin cell morphology and spines that may underlie sex differences in habituation

Orexins Mediate Sex Differences in the Stress Response and in Cognitive Flexibility

BACKGROUND: Women are twice as likely as men to suffer from stress-related psychiatric disorders. However, the biological basis of these sex differences is poorly understood. Orexins are altered in anxious and depressed patients. Using a rat model of repeated stress, we asked whether orexins contribute to sex differences in outcomes relevant to stress-related psychiatric diseases. METHODS: Behavioral, neural, and endocrinal habituation to repeated restraint stress and subsequent cognitive flexibility was examined in adult male and female rats. In parallel, orexin expression and activation was determined in both sexes, and chromatin immunoprecipitation was used to determine transcription factors acting at the orexin promoter. DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) were used to inhibit orexin activation throughout repeated restraint to determine if the stress related impairments in females could be reduced. RESULTS: Female rats exhibited impaired habituation to repeated restraint with subsequent deficits in cognitive flexibility compared to male rats. Increased orexin expression and activation was observed in females compared to males. The higher expression of orexin mRNA in females was due to actions of glucocorticoid receptors on the orexin promoter, as determined by chromatin immunoprecipitation. Finally, inhibition of orexins using DREADDs in females throughout repeated restraint abolished their heightened HPA responsivity and reduced stress-induced cognitive impairments. CONCLUSIONS: The results demonstrate that orexins mediate the impairments in adaptations to repeated stress and in subsequent cognitive flexibility exhibited by female rats and provide evidence for a broader role for orexins in mediating functions relevant to stress related psychiatric diseases

Post-operative wound infiltration with dexmedetomidine and magnesium sulphate as adjuvant to levobupivacaine for lumbar laminectomy: a prospective, double blinded, randomized controlled study

Background: Wound infiltration with local anaesthetic is safe and effective technique for providing postoperative analgesia following lumbar laminectomy. The objective of this study was to compare the efficacy of local wound infiltration on postoperative analgesia with levobupivacaine, levobupivacaine plus magnesium sulphate and levobupivacaine plus dexmedetomidine in patient undergoing lumbar laminectomy.Methods: Ninety adult patients were randomly allocated into three groups. After the completion of lumbar laminectomy, the drug was locally infiltrated into the paravertebral muscles on either side. Group L received 10 ml of 0.5% levobupivacaine plus 10 ml normal saline, group LM received 10 ml of 0.5% levobupivacaine plus 500 mg magnesium sulphate (1 ml) plus 9 ml normal saline, group LD received 10 ml of 0.5% levobupivacaine plus 50 µg dexmedetomidine (0.5 ml) plus 9.5 ml normal saline. Postoperative visual analogue scale (VAS) pain score at 0, 1, 2, 4, 6, 8, 12 and 24 hours, time to first rescue analgesic drug and its total dose, quality of recovery score (QoR) and side effects were noted.Results: Postoperative VAS was significantly higher in group L as compared to group LM and LD (p<0.05). The time to first rescue analgesic drug was significantly longer in group LD (11.07±7.20 hr) than group LM (6.20±2.64 hr) and group L (3.93±2.70 hr) (p<0.001). The QoR score was significantly better in group LD as compared to group LM and L postoperatively (<0.01).Conclusions: Addition of magnesium sulphate or dexmedetomidine to levobupivacaine for local wound infiltration demonstrated enhanced postoperative analgesia.

Need to rethink before prescribing acetaminophen in malnourished patients? Acetaminophen-induced liver injury in a malnourished cancer patient in palliative care department

Acetaminophen toxicity is one of the major causes of acute liver failure worldwide. Due to wide availability and perception regarding safety, it also remains the commonest drug used in cancer pain settings. Incidental detection of acute liver failure during the hospital course may be observed in cachexia cancer patients. N-acetyl cysteine (NAC) can be used as a rescue drug in case of liver injury as manifested clinically or from altered lab values. There are only a few cases reported of acetaminophen toxicity in malnourished subjects. This case report can provide insight into the importance of reduction of dosage of acetaminophen in cachectic patients. A 47-year-old female patient with no known comorbidities was diagnosed with locally advanced squamous cell carcinoma mid-oesophagus. She was advised best supportive care and was referred to the palliative medicine department where she presented with complaints of central chest pain and absolute dysphagia. General examination revealed a body weight of around 30 kg, Body Mass Index (BMI) of 14.5, and performance status of 4. Her analgesics included an injection of tramadol 50 mg twice daily and an injection of paracetamol 1 g thrice daily. During the course of her stay in the hospital routine examinations revealed an acute rise in the liver enzymes, aspartate transaminase (AST) was 1526 U/L, and alanine transaminase (ALT) was 1880 U/L, compared to the previous day values (on admission to the department the AST and ALT values were 38 and 40 U/L, respectively). Acute liver injury due to paracetamol overdose was suspected. N-acetyl cysteine was initiated according to the 21-hour protocol. Later liver enzymes declined and the patient improved clinically and was discharged home in a stable condition. This case report underlines the importance of cautious dose reduction of acetaminophen in chronic pain patients with less than 50 kg to not more than 2 g per day for the prevention of acute liver failure