A critical Review on the Neuropharmacological Effects of Kratom: An Insight from the Functional Array of Identified Natural Compounds

Abstract

Kratom (Mitragyna speciosa Korth. Havil) has been considered a narcotic drug for years, barred by the law in many parts of the world, while extensive research over the past few decades proves its several beneficial effects some of which are still in ambiguity. In many countries, including Thailand, the indiscriminate use and abuse of Kratom have led to the loss of life. Nonetheless, researchers have isolated almost fifty pure compounds from Krat-om, most of which are alkaloids. The most prevalent compounds, mitragynine and 7-hydroxy mitragynine, are reported to display agonist morphine-like effects on human μ-opioid receptors and antagonists at κ- and δ-opioid receptors with multimodal effects at oth-er central receptors. Mitragynine is also credited to be one of the modulatory molecules for the Keap1-Nrf2 pathway and SOD, CAT, GST, and associated gene’s upregulatory cascades leading to play a pivotal role in neuroprotective actions while its long-high dose is evident to cause the neuronal disorder. Additionally, the anti-inflammatory, antioxidative, antibac-terial, and gastroprotective effects are well-cited. In this context, this review focuses on the research gap to resolve the ambiguities about the neuronal effects of kratom to demonstrate its prospects as a therapeutic target for neurodisorders connecting with other pharmacologi-cal effects.