LKB1: An emerging therapeutic target for cardiovascular diseases.

Cardiovascular diseases (CVDs) are currently the most common cause of morbidity and mortality worldwide. Experimental studies suggest that liver kinase B1 (LKB1) plays an important role in the heart. Several studies have shown that cardiomyocyte-specific LKB1 deletion leads to hypertrophic cardiomyopathy, left ventricular contractile dysfunction, and an increased risk of atrial fibrillation. In addition, the cardioprotective effects of several medicines and natural compounds, including metformin, empagliflozin, bexarotene, and resveratrol, have been reported to be associated with LKB1 activity. LKB1 limits the size of the damaged myocardial area by modifying cellular metabolism, enhancing the antioxidant system, suppressing hypertrophic signals, and inducing mild autophagy, which are all primarily mediated by the AMP-activated protein kinase (AMPK) energy sensor. LKB1 also improves myocardial efficiency by modulating the function of contractile proteins, regulating the expression of electrical channels, and increasing vascular dilatation. Considering these properties, stimulation of LKB1 signaling offers a promising approach in the prevention and treatment of heart diseases.

Combined use of platelet-rich plasma and adipose tissue-derived mesenchymal stem cells shows a synergistic effect in experimental spinal cord injury.

Spinal cord injury (SCI) as a crippling disability causes tissue degeneration via neuron loss and fiber disruption. Some researchers have tried to reverse or minimize these changes. Platelet-rich plasma (PRP) is a biological product derived from peripheral blood containing a variety of growth factors. PRP has been extensively used in regenerative medicine. On the other hand, via secreting neuroprotective growth factors, mesenchymal stem cells (MSCs) have shown a promising potential in repairing central nervous system deficits. This study investigated the therapeutic effect of the combined use of MSCs and PRP in a rat model of SCI. We used real time-PCR method for evaluation of Bcl-2, Bax and caspase 3 expressions, TUNEL test for apoptotic cell death assessment, and neurofilament NF200 immunohistochemistry for examination of axonal regeneration. The results showed that co-treatment with MSCs and PRP efficiently alleviated the evaluated categories. Significant differences were observed in expression of Bcl-2 and caspase3, but not Bax, apoptotic index and the number of NF200 positive axons (for all P ≤ 0.01) between co-treatment animals compared with those treated with only MSCs or PRP. In conclusion, this study showed that combination of MSCs and PRP synergistically promotes their therapeutic effects in the SCI.

Genus Boswellia as a new candidate for neurodegenerative disorders.

Neurodegenerative diseases, characterized by progressive loss of neurons, share common mechanisms such as apoptotic cell death, mitochondrial dysfunction, inflammation, and oxidative stress. Genus Boswellia is a genus in the Burseraceae family. It comprises several species traditionally used for treatment of chronic inflammatory diseases, cerebral edema, chronic pain syndrome, gastrointestinal diseases, tumors, as well as enhancing intelligence. Many studies have been carried out to discover therapeutic approaches for neurodegenerative diseases such as Alzheimer's diseases, Parkinson's disease, Huntington's disease, multiple sclerosis and amyotrophic lateral sclerosis, stroke, and concomitant cognitive deficits. However, no curative treatment has been developed. This paper provides an overview of evidence about the potential of the Boswellia species and their main constituents, boswellic acids, as modulators of several mechanisms involved in the pathology of the neurodegenerative diseases. In vitro, animal, and clinical studies have confirmed that Boswellia species contain bioactive components that may enhance cognitive activity and protect against neurodegeneration. They exert the beneficial effects via targeting multiple pathological causes by antioxidative, anti-inflammatory, antiamyloidogenic, and anti-apoptotic properties. The Boswellia species, having neuroprotective potential, makes them a promising candidate to cure or prevent the neurodegenerative disorders.

Rheum turkestanicum reduces glutamate toxicity in PC12 and N2a cell lines.

Glutamate is considered to be responsible for the pathogenesis of many neurodegenerative diseases. Reactive oxygen species (ROS) production is considered to be involved in the glutamate-induced apoptosis process. In this study, we investigated the neuroprotective effects of Rheum turkestanicum in the glutamate-induced rat pheochromocytoma (PC12 cells) and mouse neuroblastoma (N2a) cell lines. Rutin as an antioxidant was used as positive control. Glutamate cytotoxicity was accompanied by an increment of malondialdehyde (MDA) content, ROS generation and apoptosis induction. However, pretreatment with the root extract of R. turkestanicum significantly reduced MDA content, ROS generation and apoptotic cell death. Also rutin at a dose of 100 µM reduced ROS production and protected against glutamate toxicity. Also the quantification of rutin in R. turkestanicum extract was achieved and was about 0.11% ± 0.01 w/w. All these findings indicated that R. turkestanicum protected PC12 and N2a cells against glutamate-induced oxidative cell death and apoptosis and might raise the possibility of R. turkestanicum usage as a neuroprotective agent.

Neuropsychological function in relation to dysmenorrhea in adolescents.

OBJECTIVE: Hormonal variations during the menstrual cycle may affect emotional regulation. We aimed to investigate the association between dysmenorrhea (the severe abdominal pain and cramps associated with menstruation) and cognitive abilities, emotional function and sleep patterns in adolescent girls. Moreover, we evaluated the frequency of premenstrual syndrome (PMS) in our population and then divided them into 4 groups: subjects with only PMS; subjects with only dysmenorrhea; individuals with both PMS and dysmenorrhea and normal subjects. STUDY DESIGN: In this cross sectional study, 897 adolescent girls who had entered menarche were recruited. Of these, 35.9% had only dysmenorrhea, 14.9% had only PMS, 32.7% had both PMS and dysmenorrhea while 16.5% had no PMS and/or dysmenorrhea (Normal). We assessed the tests for cognitive, emotional function and sleep patterns were compared for these groups. RESULTS: Individuals in the dysmenorrhea group had significantly higher depression, aggression, insomnia, daytime sleepiness and sleep apnea scores compared to normal controls and the PMS group, but did not have significantly different cognitive ability (P value <0.05). These differences were strongly correlated to pain intensity (P<0.001). However, there were no significant differences between those with only PMS and control subjects with regard to cognitive ability, emotional function and sleep pattern tests. CONCLUSIONS: Dysmenorrhea is highly prevalent among adolescents and appears to be associated with depressive mood, a tendency to aggressive behavior and sleep disorders among adolescent girls.

Thymoquinone ameliorates renal damage in unilateral ureteral obstruction in rats.

BACKGROUND: It is well established that renin-angiotensin system (RAS) play a central role in pathophysiology of renal damage following unilateral ureteral obstruction (UUO). The present study investigated the effects of thymoquinone and RAS blockade on renal tissue damage and renal expression of angiotensin II after UUO in rats. METHODS: Forty male rats were divided to five groups: Sham-operated group, UUO group and rats with UUO treated with losartan, captopril and thymoquinone. The rats were evaluated two weeks after UUO by measuring renal oxidative stress, apoptosis and the expression of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein (MCP-1) and angiotensin II. RESULTS: Two weeks after UUO there was a significant increase in the number of renal apoptotic cells and renal malondialdehyde and TNF-α expression. In addition, renal total thiol content and the activity of antioxidant enzymes were significantly decreased in UUO group, compared with the sham group. Also, UUO was associated with upregulation in the expression of angiotensin II and MCP-1 in the obstructed kidney. Losartan, captopril and thymoquinone significantly improved oxidative damage, apoptosis and TNF-α expression and markedly decreased the upregulation of angiotensin II and MCP-1 compared with the UUO group. CONCLUSIONS: The current study suggests that thymoquinone is able to improve the UUO-induced renal tissue damage. These favorable actions of thymoquinone on UUO model in rat are comparable with the well-known RAS inhibitors captopril and losartan.

Beneficial Effects of Selective Orexin-A Receptor Antagonist in 4-aminopyridine-induced Seizures in Male Rats.

BACKGROUND: Orexins are excitatory neuropeptides which stimulate the central regulatory pathways. Orexins increase the penicillin-induced epileptic activity in rats. Orexin-A increases in different types of seizures and its elevated level is the characteristic feature in the epileptic children during polysomnography. Recently, the orexin receptor blockage has been reported to increase seizure threshold in mice; however, effect of the selective orexin-A receptor antagonist (SB-334867) on 4-aminopyridine (4-AP)-induced seizures has not been investigated. MATERIALS AND METHODS: We used the intraperitoneal injection of 4-AP to induce seizure in male rats. Under urethane anesthesia, SB-334867 (50 and 100 nmol) was injected stereotaxically into the ventral hippocampal commissure. Using video recording, the effects of SB-334867 on electroencephalogram and tonic-clonic convulsions were compared to those that received diazepam or dimethyl sulfoxide (DMSO). RESULTS: SB-334867 significantly decreased the duration of spike trains compared to DMSO-treated rats (P < 0.001) and reduced the duration of convulsive seizures (P < 0.05). Seizure onset was increased significantly by SB-334867, 50 nmol, compared to DMSO (P < 0.05) and diazepam (P < 0.01) treated rats. CONCLUSION: Antagonism of orexin-A receptor by a low-dose SB-334867 showed protective effects in 4-AP-induced seizure-like activities in anesthetized rats.

Effect of Salvia leriifolia Benth. root extracts on ischemia-reperfusion in rat skeletal muscle.

BACKGROUND: Salvia leriifolia have been shown to decrease ischemia-reperfusion (I/R) injury in brain tissues. In this study, the effects of S. leriifolia aqueous and ethanolic extracts were evaluated on an animal model of I/R injury in the rat hind limb. METHODS: Ischemia was induced using free-flap surgery in skeletal muscle. The aqueous and ethanolic extracts of S. leriifolia (100, 200 and 400 mg/kg) root and normal saline (10 ml/kg) were administered intraperitoneally 1 h prior reperfusion. During preischemia, ischemia and reperfusion conditions the electromyographic (EMG) potentials in the muscles were recorded. The markers of oxidative stress including thiobarbituric acid reactive substances (TBARS), total sulfhydryl (SH) groups and antioxidant capacity of muscle (using FRAP assay) were measured. RESULTS: In peripheral ischemia, the average peak-to-peak amplitude during ischemic-reperfusion was found to be significantly larger in extracts groups in comparison with control group. Following extracts administration, the total SH contents and antioxidant capacity were elevated in muscle flap. The MDA level was also declined significantly in test groups. CONCLUSION: It is concluded that S. leriifolia root extracts have some protective effects on different markers of oxidative damage in muscle tissue injury caused by lower limb ischemia-reperfusion.