Mitraphylline is the major pentacyclic oxindolic alkaloid presented in Uncaria tomentosa. It has traditionally been used to treat disorders including arthritis, heart disease, cancer, and other inflammatory diseases. It is also present in the leaves of the tree Mitragyna speciosa, commonly known as kratom, herb which is traditionally used to treat withdrawal symptoms associated with opiate addiction. However, the specific role and the mechanism of action of mitraphylline is not clear. Current research is focusing on mitraphylline as a new promising anticancer and anti-inflammatory agent. Its antiproliferative and cytotoxic effects and in vivo efficacy to induce apoptosis has been studied in human breast cancer, sarcoma, bladder cancer as well as lymphoblastic leukaemia cell lines. As a new candidate for inflammatory disease therapies mitraphylline has been studied in vitro in LPS-activated human primary neutrophils and Its activity against cytokines involved in inflammation process was tested in a murine model in vivo. In mice mitraphylline inhibited around 50% of the release of interleukins 1α, 1β, 17, and TNF-α. It also reduced about 40% of the production of interleukin 4 (IL-4). Mitraphylline was stable in simulated gastric fluid but unstable in simulated intestinal fluid (13.6 % degradation) and was metabolized by human liver microsomes with half-live of 50 min.

Mitragynine is the main active alkaloid constituent of the plant Mitragyna speciosa Korth. Mitragyna speciosa Korth. (M. speciosa), from the Rubiaceae family, is a tropical medicinal plant native to Southeast Asia. In Malaysia, M. speciosa leaves are known as Ketum or Biak, and in Thailand as Kratom. M. speciosa has been historically used in Southeast Asia as a stimulant drug and in its traditional context as a remedy for various symptoms. Pharmacological activities are mainly mediated via opioid receptors as well as neuronal Ca2+ channels, expression of cAMP and CREB protein and via descending monoaminergic system. Mitragynine acted as a partial agonist at mu-opioid receptors, in contrast, at kappa-opioid receptors, mitragynine was a competitive antagonist, similarly, mitragynine acted as an antagonist at delta-mu-opioid receptors, but with very low potency. Experimental studies in animals have now shown that mitragynine has an addictive potential, however, only at higher doses. Human users in countries of frequent use with a traditional context report a rather low daily consumption with only mild side effects. Kratom and mitragynine can be instrumentalized to enhance physical work power and endurance. A major reason for Kratom consumption is its reported efficacy to replace opiates in chronic users. This makes the Kratom plant preparation and also the isolated compound mitragynine interesting options to treat opiate addiction. In August 2016, the US Drug Enforcement Administration announced plans to classify kratom and its mitragynine constituents as Schedule 1 controlled substances.