Chronic exposure to low doses of estradiol-17ß increases blood pressure in young female rats: A possible role for central Endothelin-1

Association of indoor and outdoor short-term PM2.5 exposure with blood pressure among school children

The association between particulate matter and children's increased blood pressure is inconsistent, and few studies have evaluated indoor exposure, accounting for time-activity. The present study aimed to examine the association between personal short-term exposure to PM_2.5 and blood pressure in children. We conducted a panel study with up to three physical examinations during different seasons of 2018 (spring, summer, and fall) among 52 children. The indoor PM_2.5 concentration was continuously measured at home and classroom of each child using indoor air quality monitors. The outdoor PM_2.5 concentration was measured from the nearest monitoring station. We constructed a mixed effect model to analyze the association of short-term indoor and outdoor PM_2.5 exposure accounting for time-activity of each participant with blood pressure. The average PM_2.5 concentration was 34.3 ± 9.2 μg/m³ and it was highest in the spring. The concentration measured at homes was generally higher than that measured at outdoor monitoring station. A 10-μg/m³ increment of the up to previous 3-day mean (lag0-3) PM_2.5 concentration was associated with 2.7 mmHg (95%CI = 0.8, 4.0) and 2.1 mmHg (95%CI = 0.3, 4.0) increases in systolic and diastolic blood pressure, respectively. In a panel study comprehensively evaluating both indoor and outdoor exposures, which enabled more accurate exposure assessment, we observed a statistically significant association between blood pressure and PM_2.5 exposure in children.

Phenylethanol Glycosides Protect Myocardial Hypertrophy Induced by Abdominal Aortic Constriction via ECE-1 Demethylation Inhibition and PI3K/PKB/eNOS Pathway Enhancement

Phenylethanol glycosides (CPhGs) are the core material basis of pharmacological activity in Cistanche tubulosa and have a variety of pharmacological effects. However, it is unclear whether CPhGs have an ameliorative effect on pressure overload-induced myocardial hypertrophy. In this study, male SD rats weighing (200 ± 20) g were established cardiac hypertrophy models by abdominal aortic coarctation (AAC). After operation, the rats were gavaged with corresponding medicine for 6 weeks (CPhGs 125, 250, and 500 mg/kg/d and valsartan 8.3 mg/kg/d). Echocardiography, heart weight index (HWI), cross-sectional area of cardiomyocytes (CSCA), fibrosis area, plasma endothelin 1(ET-1), and proinflammatory factors levels were detected. Our results showed that different CPhGs dosage decreased left ventricular posterior wall thickness (LVPWT), left ventricular end-diastolic diameter (LVED), HWI, CSCA, fibrosis area, ET-1, proinflammatory factors, arterial natriuretic peptide (ANP), brain natriuretic peptide (BNP), endothelin converting enzyme 1(ECE-1) mRNA levels, cyclooxygenase 2 (COX-2), high mobility group box 1 (HMGB-1) protein levels, and ECE-1 demethylation level while increasing left ventricular ejection fractions (LVEF), left ventricular fractional shortening (LVFS), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), phosphorylated protein kinase B (p-PKB), and phosphorylated endothelial nitric oxide synthetase (p-eNOS). The indexes of CPhGs 250 and 500 mg/kg group were significantly different from AAC group; compared with valsartan group (AV), the indexes of CPhGs 500 mg/kg group were not significantly different. In conclusion, CPhGs ameliorated myocardial hypertrophy rats by AAC, which may be related to ECE-1 demethylation inhibition and PI3K/PKB/eNOS enhancement.

Immune-mediated febrile response in female rats: Role of central hypothalamic mediators

Lipopolysaccharide (LPS) induces fever through cytokines like receptor-activator of nuclear factor κB ligand (RANKL), triggering mediators like prostaglandins (PG), endothelin-1 (ET-1), corticotrophin-releasing factor (CRF), substance P (SP) and endogenous opioids. LPS-induced fever is reduced in females compared with males except in ovariectomized (OVX) females which show increased fever mediated by PG. The present study aimed to identify the mediators involved in fever in intact and OVX female rats. Fever was induced with LPS (50 μg/kg) intraperitoneally or CRF (2.5 μg), ET-1 (1 pg), morphine (10 μg) and SP (500 ng) intracerebroventricularly in sham-operated and OVX rats. The role of RANKL was evaluated with osteoprotegerin (OPG, 1 μg, intracerebroventricularly). Expression of RANK, CRFI/II, ETB, μ-opioid (MOR) and NK1 receptors was evaluated by confocal microscopy. Besides LPS, only morphine induced fever in OVX rats while all mediators induced fever in sham-operated animals. OPG abolished LPS-induced fever in OVX but not sham-operated animals. Overall, fever involves similar central mediators in cycling females and males but only morphine induced fever in OVX females. Importantly, RANK/RANKL participates in LPS-induced fever in OVX females, as in males but not in cycling females.

Recent development in antihyperalgesic effect of phytochemicals: anti-inflammatory and neuro-modulatory actions

INTRODUCTION

Pain is an unpleasant sensation triggered by noxious stimulation. It is one of the most prevalent conditions, limiting productivity and diminishing quality of life. Non steroidal anti inflammatory drugs (NSAIDs) are widely used as pain relievers in present day practice as pain is mostly initiated due to inflammation. However, due to potentially serious side effects, long term use of these antihyperalgesic drugs raises concern. Therefore there is a demand to search novel medicines with least side effects. Herbal products have been used for centuries to reduce pain and inflammation, and phytochemicals are known to cause fewer side effects. However, identification of active phytochemicals of herbal medicines and clear understanding of the molecular mechanism of their action is needed for clinical acceptance.

MATERIALS AND METHODS

In this review, we have briefly discussed the cellular and molecular changes during hyperalgesia via inflammatory mediators and neuro-modulatory action involved therein. The review includes 54 recently reported phytochemicals with antihyperalgesic action, as per the literature available with PubMed, Google Scholar and Scopus.

CONCLUSION

Compounds of high interest as potential antihyperalgesic agents are: curcumin, resveratrol, capsaicin, quercetin, eugenol, naringenin and epigallocatechin gallate (EGCG). Current knowledge about molecular targets of pain and their regulation by these phytochemicals is elaborated and the scope of further research is discussed.

17β-estradiol and tamoxifen protect mice from manganese-induced dopaminergic neurotoxicity

Chronic exposure to manganese (Mn) causes neurotoxicity, referred to as manganism, with common clinical features of parkinsonism. 17β-estradiol (E2) and tamoxifen (TX), a selective estrogen receptor modulator (SERM), afford neuroprotection in several neurological disorders, including Parkinson's disease (PD). In the present study, we tested if E2 and TX attenuate Mn-induced neurotoxicity in mice, assessing motor deficit and dopaminergic neurodegeneration. We implanted E2 and TX pellets in the back of the neck of ovariectomized C57BL/6 mice two weeks prior to a single injection of Mn into the striatum. One week later, we assessed locomotor activity and molecular mechanisms by immunohistochemistry, real-time quantitative PCR, western blot and enzymatic biochemical analyses. The results showed that both E2 and TX attenuated Mn-induced motor deficits and reversed the Mn-induced loss of dopaminergic neurons in the substantia nigra. At the molecular level, E2 and TX reversed the Mn-induced decrease of (1) glutamate aspartate transporter (GLAST) and glutamate transporter 1 (GLT-1) mRNA and protein levels; (2) transforming growth factor-α (TGF-α) and estrogen receptor-α (ER-α) protein levels; and (3) catalase (CAT) activity and glutathione (GSH) levels, and Mn-increased (1) malondialdehyde (MDA) levels and (2) the Bax/Bcl-2 ratio. These results indicate that E2 and TX afford protection against Mn-induced neurotoxicity by reversing Mn-reduced GLT1/GLAST as well as Mn-induced oxidative stress. Our findings may offer estrogenic agents as potential candidates for the development of therapeutics to treat Mn-induced neurotoxicity.