Related Experiment Video

Updated: Apr 20, 2026

Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
07:23

Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities

Published on: July 29, 2014

34.4K

Selective suppression of microglial activation by paeoniflorin attenuates morphine tolerance

C Jiang1,2, L Xu1,2, L Chen1,2

  • 1Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, China.

European Journal of Pain (London, England)
|November 18, 2014
PubMed
Abstract

Insights

Paeoniflorin, a natural compound, suppresses morphine-induced microglial activation, enhancing pain relief and reducing tolerance to morphine analgesia. This offers a potential strategy to improve opioid therapy.

Area of Science:

  • Neuroscience
  • Pharmacology
  • Immunology

Background:

  • Opioid analgesics, like morphine, lose effectiveness with repeated use due to antinociceptive tolerance.
  • Spinal cord microglia activation is a key mechanism driving morphine tolerance.
  • Paeoniflorin, a natural compound, is investigated for its potential to inhibit microglial activation and modulate morphine tolerance.

Purpose of the Study:

  • To investigate the effects of paeoniflorin on morphine-induced microglial activation.
  • To elucidate the underlying mechanisms of paeoniflorin's action in modulating morphine tolerance.
  • To evaluate paeoniflorin's potential to enhance morphine analgesia and attenuate tolerance.

Main Methods:

  • Utilized BV-2 microglia cell line for in vitro studies.
  • Assessed cytokine expression via quantitative polymerase chain reaction (qPCR).
  • Analyzed cell signaling pathways (p38 MAPK, NF-κB) using Western blot and immunohistochemistry.
  • Evaluated antinociceptive effects in Sprague-Dawley rats and CD-1 mice using Hargreaves' method and hot-plate test.

Main Results:

  • Morphine induced microglial activation (p38 MAPK phosphorylation, NF-κB translocation, pro-inflammatory cytokine release), which paeoniflorin inhibited.
  • Paeoniflorin co-administration potentiated morphine's analgesic effects by inhibiting spinal p38 MAPK/NF-κB signaling.
  • Paeoniflorin suppressed morphine-induced toll-like receptor-4 expression in both BV-2 cells and the spinal cord.

Conclusions:

  • Paeoniflorin directly inhibits morphine-induced microglial activation.
  • Paeoniflorin potentiates acute morphine analgesia and attenuates chronic antinociceptive tolerance.
  • Paeoniflorin represents a promising therapeutic agent for improving opioid efficacy and managing tolerance.

More Related Videos

Magnetic Isolation of Microglial Cells from Neonate Mouse for Primary Cell Cultures07:23

Magnetic Isolation of Microglial Cells from Neonate Mouse for Primary Cell Cultures

Published on: July 25, 2022

3.9K
Operant Protocols for Assessing the Cost-benefit Analysis During Reinforced Decision Making by Rodents07:05

Operant Protocols for Assessing the Cost-benefit Analysis During Reinforced Decision Making by Rodents

Published on: September 10, 2018

6.6K

Related Concept Videos

Analgesia and Pain Management01:25

Analgesia and Pain Management

Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...
3.3K
Opioid Analgesics: Synthetic and Semisynthetic Opioids01:15

Opioid Analgesics: Synthetic and Semisynthetic Opioids

Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...
1.5K
Opioid Receptors: Overview01:22

Opioid Receptors: Overview

Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2,...
7.2K
Desensitization and Tachyphylaxis01:20

Desensitization and Tachyphylaxis

Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
3.5K