The Protective Effect of Picroside II on Isoflurane-Induced Neuronal Injury in Rats via Downregulating miR-195

<b><i>Introduction:</i></b> Numerous pieces of evidence demonstrated that isoflurane induces hippocampal cell injury and cognitive impairments. Picroside II has been investigated for its anti-apoptosis and antioxidant neuroprotective effects. We aimed to explore the protective effects of picroside II and the role of microRNA-195 (miR-195) on isoflurane-induced neuronal injury in rats. <b><i>Methods:</i></b> The Morris water maze test was used to evaluate the effects of isoflurane on rats regarding escape latency and time in quadrant parameters. Real-time quantitative PCR was used to detect the expression levels of miR-195 and pro-inflammatory cytokines, including inter­leukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) mRNA, in the hippocampal tissues and neuronal cells. <b><i>Results:</i></b> The picroside II significantly improves isoflurane-induced higher escape latency and lower time spent in the quadrant compared with the control rats. Picroside II also promotes cell viability and suppresses cell apoptosis of isoflurane-induced neuronal cells. Besides, picroside II suppresses the expression of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and miR-195 in vivo and in vitro. Furthermore, overexpression of miR-195 abrogates the effects of picroside II on the expression of pro-inflammatory cytokines. The appropriate dose of picroside II is 20 mg/kg. <b><i>Conclusion:</i></b> Picroside II could protect the nervous system possibly through inhibiting the inflammatory response in the isoflurane-induced neuronal injury of rats. The protective effect of picroside II may be achieved by downregulating the expression of miR-195 and then inhibiting the inflammatory response.

Capturing Acyltransferase(s) Transforming Final Step in the Biosynthesis of a Major Iridoid Glycoside, (Picroside-II) in a Himalayan Medicinal Herb, Picrorhiza kurroa

BackgroundPicrorhiza kurroa has been reported as an age-old ayurvedic hepatoprotection to treat hepatic disorders due to the presence of iridoids such as picroside-II (P-II), picroside-I, and kutkoside. The acylation of catalpol and vanilloyl coenzyme A by acyltransferases (ATs) is critical step in P-II biosynthesis. Since accumulation of P-II occurs only in roots, rhizomes and stolons, uprooting of this critically endangered herb has been the only source of this compound. Recently, we reported that P-II acylation likely happen in roots, while stolons serve as the vital P-II storage compartment. Therefore, developing an alternate engineered platform for P-II biosynthesis require identification of P-II specific AT/s.Methods and results In that direction, egg-NOG function annotated 815 ATs from de novo RNA sequencing of tissue culture based ‘shoots-only’ system and nursery grown shoots, roots, and stolons varying in P-II content, were cross-compared in silico to arrive at ATs sequences unique and/or common to stolons and roots. Verification for organ and accession-wise upregulation in gene expression of these ATs by qPCR has shortlisted six putative ‘P-II-forming’ ATs. Further, six-frame translation, ab initio protein structure modelling and protein-ligand molecular docking of these ATs signified one MBOAT domain containing AT with preferential binding to the vanillic acid CoA thiol ester as well as with P-II., implying that this could be potential AT decorating final structure of P-II. ConclusionOrgan-wise comparative transcriptome mining coupled with reverse transcription real time qPCR and protein-ligand docking led to the identification of an acyltransferases, contributing to the final structure of P-II.

Picroside II prevents inflammation injury in mice with diabetic nephropathy via TLR4/NF-κB pathway

The purpose of this study was to investigate the therapeutic effects of picroside II on diabetic nephropathy and reveal the involved underlying signal pathway. Male Sprague–Dawley (SD) mice were used to construct an animal model of streptozotocin (STZ)-induced diabetic nephropathy. Body weight and fasting blood glucose values were recorded. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of proteinuria, blood urea nitrogen (BUN), serum creatinine (Scr), interleukin (IL)-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1) and necrosis factor alpha (TNF-α). Protein expression was determined using Western blotting test. Hema-toxylin and eosin (H&E) staining was used to examine the morphological changes in kidney tissues. Treatment with picroside II (10 and 20 mg/kg) increased the STZ-induced reduction in body weight of diabetic mice. It also reversed the elevation of fasting blood glucose in STZ-induced diabetic mice. The levels of proteinuria, BUN and Scr were significantly increased in STZ-induced diabetic mice and these increments were prevented by picroside II. The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced, and the morphological damage was lessened by Picroside II in mice with diabetic nephropathy. Besides, picroside II prevented the activation of TLR4/NF-κB pathway. This study proved that picroside II inhibited inflammatory response and prevented kidney injury in mice with diabetic nephropathy through modulation of TLR4/NF-κB pathway, indicating beneficial effect of picroside II on diabetic nephropathy.

Picroside II Improves Severe Acute Pancreatitis-Induced Hepatocellular Injury in Rats by Affecting JAK2/STAT3 Phosphorylation Signaling

Picroside II is an important ingredient agent in Traditional Chinese medicine and hoped to reduce hepatocellular injury caused by severe acute pancreatitis (SAP). An SAP-induced hepatocellular injury model was established in rats by using pentobarbital sodium. 27 rats were divided into 3 groups: the sham group (SG), model group (MG), and Picroside groups (PG). SAP-induced hepatocellular injury was assessed using hematoxylin and eosin staining. We measured hepatocellular enzymes (amylase (AMY), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)), oxidative stress factors (superoxidase dismutase (SOD) and malondialdehyde (MDA)), and inflammatory factors (tumor necrosis factor α (TNF-α), interleukin- (IL-) 6, and IL-10), apoptotic factors (BAX and cleaved caspase 3), and inflammatory signaling (Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3), p-JAK2, and p-STAT3) in hepatocellular tissues. The SAP-induced hepatocellular injury model was successfully established. Picroside II treatment repaired hepatocellular injury by reducing the activities of AMY, ALT, and AST; reducing the levels of MDA, TNF-α, IL-1, IL-6, p-JAK2, p-STAT3, BAX, and cleaved caspase 3; and increasing the levels of SOD and IL-10. Picroside II exerted protective function for the SAP-induced hepatocellular injury model. Picroside II improved SAP-induced hepatocellular injury and antioxidant and anti-inflammatory properties by affecting JAK2/STAT3 phosphorylation signaling.

Advances in Ethnobotany, Synthetic Phytochemistry and Pharmacology of Endangered Herb Picrorhiza kurroa (Kutki): A comprehensive review (2010-2020)

: Picrorhiza kurroa Royle ex Benth. (Family: Plantaginaceae) is a well-recognized an Ayurvedic herb. It is commonly called “Kutki” or “Kurro” and ‘Indian gentian’. Iridoid glycosides are the plant’s bioactive constituents and accountable for the bitter taste and medicinal properties of the plant. The iridoid glycosides such as picrosides and other active metabolites of the plant exhibited many pharmacological activities like hepatoprotective, antioxidant, anti-inflammatory, anticancer, immunomodulator, anti-ulcerative colitis, antimicrobial etc. This review aims to provide updated information on the ethnobotany, synthetic phytochemistry, pharmacological potential, safety and toxicology of P. kurroa and its active metabolites. Indiscriminate exploitation, ecological destruction of natural habitats, slower plant growth and unawareness regarding cultivation and uprooting of plants has brought kutki as an endangered status. So, various techniques used for the conservation and production of bioactive metabolites from P. kurroa have also been reported. Information on the plant has been collected from Science Direct, Google Scholar, PubMed, Scopus by using ‘Picrorhiza kurroa’, ‘Picroside-‘, ‘Picroside-II’, ‘Picroliv’, ‘Immunomodulator’ keywords. All studies on ethnobotany, phytochemistry and pharmacology of plant from 2010- 2020 were comprised in this review article. The possible directions for the future research have also been outlined in brief in review article.

Pharmacokinetics of Picroside I, II, III, IV in Rat Plasma by UPLCMS/ MS

Background: Modern pharmacological studies show that rhizoma coptidis has protective effects on the liver, gallbladder, kidney, cerebral ischemia-reperfusion, local hypoxia injury, antiinflammatory, bone injury, nerve cells and myocardial cells. The effective components have been isolated from picroside I, II, III and IV. Introduction: A selective and sensitive ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed for the simultaneous quantitative determination of picroside I, II, III and IV in rat plasma to aid the pharmacokinetics studies. Method: Sprague-Dawley (SD) rats were orally administered with 10 mg/kg, intravenously injected with 1 mg/kg for the mixture of picroside I, II, III and IV. The biological samples were collected at 0.083 3 h, 0.25 h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 24 h. A UPLC BEH C18 column (2.1 mm×50 mm, 1.7 μm) was used for chromatographic separation with the mobile phase consisting of acetonitrile and 0.1% formic acid by gradient elution. The flow rate was 0.4 mL/min. Multiple reaction monitoring (MRM) transitions were m/z 491.1→147.1 for picroside I, m/z 511.1→234.9 for picroside II, m/z 537.3→174.8 for picroside III and m/z 507.3→163.1 for picroside IV in negative ion mode. Result: The inter-day precision was less than 13%, the intra-day precision was less than 15%. The accuracy ranged from 89.4% to 111.1%. Recovery was higher than 79.1%, and the matrix effect ranged from 96.2% to 109.0%. Conclusion: The sensitive, rapid and selective UPLC-MS/MS method can be applied to the pharmacokinetic study of picroside I, II, III and IV in rats.