A Conantokin Peptide Con-T[M8Q] Inhibits Morphine Dependence with High Potency and Low Side Effects

Natural products as the therapeutic strategies for addiction

World Drug Report 2023 concluded that 296 million people abused drugs, 39.5 million became addiction and 494,000 died as a direct or indirect result of addiction. Addiction has become a growing problem that affects individuals, their families, societies, countries and even the world. However, treatment for addiction is only limited to some developed countries because of the high cost, difficult implementation, and time consuming. Therefore, there is an urgent need to develop a low-cost, effective drug for the development of addiction treatment in more countries, which is essential for the stability and sustainable development of the world. In this review, it provided an overview of the abuse of common addictive drugs, related disorders, and current therapeutic regimen worldwide, and summarized the mechanisms of drug addiction as reward circuits, neuroadaptation and plasticity, cognitive decision-making, genetics, and environment. According to their chemical structure, 43 natural products and 5 herbal combinations with potential to treat addiction were classified, and their sources, pharmacological effects and clinical trials were introduced. It was also found that mitragine, ibogine, L-tetrahydropalmatine and crocin had greater potential for anti-addiction.

Endogenous opiates and behavior: 2021

This paper is the forty-fourth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2021 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonizts and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Marine natural products

Covering: January to December 2021This review covers the literature published in 2021 for marine natural products (MNPs), with 736 citations (724 for the period January to December 2021) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1425 in 416 papers for 2021), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. An analysis of the number of authors, their affiliations, domestic and international collection locations, focus of MNP studies, citation metrics and journal choices is discussed.

Peptide antagonists of NMDA receptors: Structure-activity relationships for potential therapeutics

The N-methyl-D-aspartate (NMDA) receptors are heteromeric cation channels involved in memory, learning, and synaptic plasticity. The dysfunction associated with NMDA receptors results in neurodegenerative conditions. The conantokins comprise a family of Conus venom peptides that induce sleep upon intracranial injection into young mice and are known to be NMDA receptor antagonists. This work comprehensibly documents the conantokins that have been characterized to date, focusing on the biochemistry, solution structures in the presence or absence of divalent cations, functions as selective NMDA receptor antagonists, and structure-activity relationships. Furthermore, the applications of conantokins as potential therapeutics for certain neurological conditions, including neuropathic pain, epilepsy, and ischaemia that are linked to NMDA receptor dysfunction are reviewed.

Pain modulation induced by electronic wrist-ankle acupuncture: A functional near-infrared spectroscopy study

BACKGROUND

As a new technology, electronic wrist-ankle acupuncture (E-WAA) combines the advantages of wrist-ankle acupuncture and transcutaneous electrical nerve stimulation, but the analgesic effect and mechanism need to be clarified. The purpose of this study was to identify the pain modulation caused by E-WAA by evaluating the response of the prefrontal cortex (PFC) from the perspective of neurophysiology.

METHODS

Fifty male volunteers (age 25.00 ± 1.05 years) with trapezius myofascial pain syndrome were randomly allocated into intervention group (E-WAA treatment) or sham control group at a 1:1 ratio. An outcome evaluation system was used to induce tenderness on the Jianjing point and record the pain value. A multichannel functional near-infrared spectroscope was used to detect the PFC activation during tenderness before and after treatment to demonstrate the neuromodulation mechanism. A general linear model and t-test (p < 0.05) were used to analyze the difference in the oxyhemoglobin (HbO) concentration and pain value.

RESULTS

In the intervention group, the pain value of volunteers decreased significantly (p = 0.017) after E-WAA treatment, whereas there was no statistical difference (p = 0.082) in the sham group. Before treatment, the frontopolar (FP) and dorsolateral prefrontal cortex (DLPFC) were the activation areas of the PFC. The E-WAA treatment then suppressed the activation of the two areas. The HbO concentration of the FP and DLPFC changed from a sharp rise during tenderness to not changing with tenderness stimulation.

CONCLUSION

The results demonstrated that the E-WAA have a great analgesic effect. The FP and DLPFC were relative to the analgesia neuromodulation induced by the E-WAA.