AIMS: In the present study, we investigated the effects of mitragynine on spatial learning and synaptic transmission in the CA1 region of the hippocampus.
METHODS: Male Sprague Dawley rats received daily (for 12 days) training sessions in the Morris water maze, with each session followed by treatment either with mitragynine (1, 5, or 10 mg/kg; intraperitoneally), morphine (5 mg/kg; intraperitoneally) or a vehicle. In the second experiment, we recorded field excitatory postsynaptic potentials in the hippocampal CA1 area in anesthetized rats and assessed the effects of mitragynine on baseline synaptic transmission, paired-pulse facilitation, and long-term potentiation. Gene expression of major memory- and addiction-related genes was investigated and the effects of mitragynine on Ca2+ influx was also examined in cultured primary neurons from E16-E18 rats.
RESULTS/OUTCOMES: Escape latency results indicate that animals treated with mitragynine displayed a slower rate of acquisition as compared to their control counterparts. Further, mitragynine treatment significantly reduced the amplitude of baseline (i.e. non-potentiated) field excitatory postsynaptic potentials and resulted in a minor suppression of long-term potentiation in CA1. Bdnf and αCaMKII mRNA expressions in the brain were not affected and Ca2+ influx elicited by glutamate application was inhibited in neurons pre-treated with mitragynine.
CONCLUSIONS/INTERPRETATION: These data suggest that high doses of mitragynine (5 and 10 mg/kg) cause memory deficits, possibly via inhibition of Ca2+ influx and disruption of hippocampal synaptic transmission and long-term potentiation induction.
RECENT FINDINGS: Recent studies have been focused on the interactions of mitragynine, the most abundant alkaloid, and opioid-like effects. This has been driven by the harm that kratom products have produced in the Western world, in stark contrast to the lack of harm in Southeast Asian traditional use over centuries. Many users in the Western world ingest kratom for mood enhancement and/or to ween themselves from prescription or illicit opioids. Highly concentrated products and recreational use and misuse have resulted in individuals pushing doses to levels that have not been imagined or ever studied in animal, let alone humans.
SUMMARY: Kratom, as a preparation and how it is utilized is different around the world.
AIM OF THE STUDY: However, there are no scientific reports documented on the wound healing activities of this plant against Staphylococcus aureus infections in the Sprague Dawley male rat model. Thus, the present study was conducted to evaluate the wound healing potential of E. guineensis extract leaves.
MATERIALS AND METHODS: The crude extract was prepared in 10% (w/w) ointment and evaluated for wound healing activity using excision and infected wound models in Sprague Dawley rats. The wound healing activity was evaluated from wound closure rate, CFU reduction, histological analysis of granulation tissue and matrix metalloprotease expression.
RESULTS: The results show that the E. guineensis extract has potent wound healing ability, as manifest from improved wound closure and tissue regeneration supported by histopathological parameters. Assessment of granulation tissue every fourth day showed a significant reduction in the microbial count. The expression of matrix metalloproteinases was well correlated with the other results, hence confirming E. guineensis wound healing activity's effectiveness.
CONCLUSIONS: E. guineensis enhanced infected wound healing in rats, thus supporting its traditional use.