2
|
Berthold EC, Kamble SH, Raju KS, Kuntz MA, Senetra AS, Mottinelli M, León F, Restrepo LF, Patel A, Ho NP, Hiranita T, Sharma A, McMahon LR, McCurdy CR. The Lack of Contribution of 7-Hydroxymitragynine to the Antinociceptive Effects of Mitragynine in Mice: A Pharmacokinetic and Pharmacodynamic Study. Drug Metab Dispos 2022; 50:158-167. [PMID: 34759012 PMCID: PMC8969138 DOI: 10.1124/dmd.121.000640] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/05/2021] [Indexed: 02/03/2023] Open
Abstract
Kratom (Mitragyna speciosa), a Southeast Asian tree, has been used for centuries in pain relief and mitigation of opium withdrawal symptoms. Mitragynine (MTG), the major kratom alkaloid, is being investigated for its potential to provide analgesia without the deleterious effects associated with typical opioids. Concerns have been raised regarding the active metabolite of MTG, 7-hydroxymitragynine (7HMG), which has higher affinity and efficacy at µ-opioid receptors than MTG. Here we investigated the hotplate antinociception, pharmacokinetics, and tissue distribution of MTG and 7HMG at equianalgesic oral doses in male and female C57BL/6 mice to determine the extent to which 7HMG metabolized from MTG accounts for the antinociceptive effects of MTG and investigate any sex differences. The mechanism of action was examined by performing studies with the opioid receptor antagonist naltrexone. A population pharmacokinetic/pharmacodynamic model was developed to predict the behavioral effects after administration of various doses of MTG and 7HMG. When administered alone, 7HMG was 2.8-fold more potent than MTG to produce antinociception. At equivalent effective doses of MTG and 7HMG, there was a marked difference in the maximum brain concentration of 7HMG achieved, i.e., 11-fold lower as a metabolite of MTG. The brain concentration of 7HMG observed 4 hours post administration, producing an analgesic effect <10%, was still 1.5-fold higher than the maximum concentration of 7HMG as a metabolite of MTG. These results provide strong evidence that 7HMG has a negligible role in the antinociceptive effects of MTG in mice. SIGNIFICANCE STATEMENT: Mitragynine (MTG) is being investigated for its potential to aid in pain relief, opioid withdrawal syndrome, and opioid use disorder. The active metabolite of MTG, 7-hydroxymitragynine (7HMG), has been shown to have abuse potential and has been implicated in the opioid-like analgesic effect after MTG administration. The results of this study suggest a lack of involvement of 7HMG in the antinociceptive effects of MTG in mice.
Collapse
Affiliation(s)
- Erin C Berthold
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Shyam H Kamble
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Kanumuri S Raju
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Michelle A Kuntz
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Alexandria S Senetra
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Marco Mottinelli
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Francisco León
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Luis F Restrepo
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Avi Patel
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Nicholas P Ho
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Takato Hiranita
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Abhisheak Sharma
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Lance R McMahon
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| | - Christopher R McCurdy
- Department of Pharmaceutics, College of Pharmacy, (E.C.B., S.H.K., K.S.R., M.A.K., A.S.S., A.S., C.R.M.), Translational Drug Development Core, Clinical and Translational Science Institute (S.H.K., K.S.R., A.S., C.R.M.), Department of Medicinal Chemistry, College of Pharmacy (M.M., F.L., C.R.M.), and Department of Pharmacodynamics, College of Pharmacy, USA (L.F.R., A.P., N.P.H., T.H., L.R.M.) University of Florida, Gainesville, Florida
| |
Collapse
|
3
|
Hiranita T, Obeng S, Sharma A, Wilkerson JL, McCurdy CR, McMahon LR. In vitro and in vivo pharmacology of kratom. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2021; 93:35-76. [PMID: 35341571 DOI: 10.1016/bs.apha.2021.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Kratom products have been historically and anecdotally used in south Asian countries for centuries to manage pain and opioid withdrawal. The use of kratom products has dramatically increased in the United States. More than 45 kratom alkaloids have been isolated, yet the overall pharmacology of the individual alkaloids is still not well characterized. The purpose of this chapter is to summarize in vitro and in vivo opioid activities of the primary kratom alkaloid mitragynine and its more potent metabolite 7-hydroxymitragynine. Following are experimental procedures described to characterize opioid receptor activity; receptor binding and functional assays, antinociceptive assays, operant conditioning assays, and respiratory plethysmography. The capacity of kratom alkaloids to confer tolerance and physical dependence as well as their pharmacokinetic properties are also summarized. The data reviewed here suggest that kratom products and mitragynine possess low efficacy agonist activity at the mu-opioid receptor in vivo. In addition, kratom products and mitragynine have been demonstrated to antagonize the effects of high efficacy mu-opioid agonists. The data further suggest that 7-hydroxymitragynine formed in vivo by metabolism of mitragynine may be minimally involved in the overall behavioral profile of mitragynine and kratom, whereas 7-hydroxymitragynine itself, at sufficiently high doses administered exogenously, shares many of the same abuse- and dependence-related behavioral effects associated with traditional opioid agonists. The apparent low efficacy of kratom products and mitragynine at mu-opioid receptors supports the development of these ligands as effective and potentially safe medications for opioid use disorder.
Collapse
Affiliation(s)
- Takato Hiranita
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Samuel Obeng
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States; Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Abhisheak Sharma
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL, United States; Translational Drug Development Core, Clinical and Translational Sciences Institute, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Jenny L Wilkerson
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Christopher R McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, United States; Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL, United States; Translational Drug Development Core, Clinical and Translational Sciences Institute, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Lance R McMahon
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States.
| |
Collapse
|