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Chronic subcutaneous infusion of ouabain causes hypertension via central pathways involving angiotensin type 1 (AT1) receptor stimulation. The present study assessed plasma and tissue ANG I and II levels as well as AT1 receptor and angiotensin-converting enzyme (ACE) mRNA levels and binding densities by real-time PCR and in vitro autoradiography in relevant brain nuclei and peripheral tissues (heart and kidney) in rats at 1 and/or 2 wk after start of ouabain infusion at 50 μg/day. After 2 wk (but not after 1 wk), blood pressures significantly increased (+ 15 mmHg). At 2 wk, plasma ANG I and II levels were markedly suppressed by ouabain. In contrast, in the heart and kidneys, ANG I levels were not affected, and ANG II levels tended to decrease, whereas in the hypothalamus ANG II content clearly increased. At I wk, no changes in ACE and AT1 receptor densities were seen. After 2 wk, there were significant decreases in AT1 receptor mRNA and densities in the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and paraventricular nucleus (PVN). ACE densities decreased only in the OVLT and SFO, but ACE mRNA showed more variable responses (decrease in OVLT vs. increase in PVN). In the kidneys, at 2 wk both AT1 receptor and ACE densities were decreased, but mRNA abundance did not change. The heart showed no significant changes. The increase in hypothalamic ANG II content and associated decreases in central AT1 receptor and ACE densities support the involvement of the brain renin-angiotensin system in the central hypertensive mechanism of action of ouabain. [ABSTRACT FROM AUTHOR]

Pulicaria incisa sub. candolleana E. Gamal-Eldin (Asteraceae) was traditionally used by Bedouins as a refreshing tea and as hypoglycemic, in gastrointestinal ailments, sinusitis and headache. Recently a great correlation has been established between liver cirrhosis and gastrointestinal dysfunction reflected by abdominal bloating, pain, diarrhea, constipation, besides decreased food intake. So far, the hepatoprotective effect of P. incisa sub. candolleana E. Gamal-Eldin was not studied before although other Pulicaria species have previously shown hepatoprotective and antioxidant effects. In this study, we aimed to identify the phytochemical constituents of the P. incisa sub. candolleana E. Gamal-Eldin hydroethanolic extract (PICE), as well as to evaluate the hepatoprotective, anti-inflammatory and antioxidant activities in methotrexate (MTX)- intoxicated rats. Besides, the molecular interaction between the isolated compounds and cyclooxygenase-2 (COX-2) and phospholipase 2 (PLA-2) were assessed by in-silico screening. The main phytoconstituents were characterized using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Vacuum liquid chromatography (VLC) aided by preparative high-performance liquid chromatography (HPLC) were also used to isolate the major phenolics from the hydroethanolic extract. Their structures were elucidated using different spectroscopic analysis methods, including 1D and 2D nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI/MS). The hepatoprotective activity of three doses (100, 250, 500 mg/kg) of PICE in MTX-intoxicated rats was assessed and compared to silymarin as a standard. Additionally, in silico docking study on cyclooxygenase-2 (COX-2) and phospholipase 2 (PLA-2) was performed to justify the anti-inflammatory activity of the isolated compounds. Thirteen compounds were tentatively identified, including flavonoids and phenolic acids. Four main isolated compounds were identified as, eugenol-1- O - β -glucoside, 5- O -caffeoylquinic acid, 3, 5-di- O -caffeoylquinic acid and quercetin-3- O - β -glucoside. Treatment of MTX-intoxicated rats with the 250 mg/kg extract reversed the altered levels of biochemical markers of liver damage, ameliorated the oxidant status and reduced the inflammatory mediators, similar to treatment with silymarin. Quercetin-3- O - β -glucoside showed the best docking energy score of −19.12 kcal/mol against COX-2, forming four binding interactions with residues Leu 353, Arg 121, Tyr 356 and Ala 528, followed by 3,5-di- O -caffeoylquinic acid (−18.01 kcal/mol). This study reveals P. incisa sub. candolleana as a rich source of phenolics including flavonoids, supporting its anti-inflammatory and hepatoprotective effects and suggesting its usage as a promising candidate in inflammatory conditions. • Pulicaria incisa subspecies candolleana – a traditional medicine-showed thirteen compounds through LC/MS/MS. • Four major phenolics from the ethanolic extract were isolated and characterized. • Methotrexate intoxicated rat model confirmed the traditional uses with potential anti-inflammatory and hepatoprotective effects and which was useful in the protection of liver. • A docking study on cyclooxygenase-2 and phospholipase 2 demonstrated the anti-inflammatory activity of its constituents. [ABSTRACT FROM AUTHOR]