PROJECT SUMMARY/ABSTRACT This project is submitted under NIH Exploratory/Developmental Research Grant Program Number: PA- 20-195. Mitragyna speciosa Korth., commonly known as kratom, is a tree native to Southeast Asia. The leaves of kratom and its commercially available products are self-prescribed to treat pain, enhance mood, and mitigate opioid withdrawal symptoms. According to reports, there are more than 15 million kratom consumers in the United States, including childbearing age females. Women with a history of opioid intake consume kratom to treat their pain and opioid withdrawal symptoms during pregnancy with a belief that herbal replacement of traditional opioids will be safer for their child. According to published case reports and discussions with neonatal medicine specialists, exposure to kratom may affect fetal development and opioid withdrawal symptoms have been observed in neonates. However, most mothers that consume kratom during pregnancy have a history of illicit substance intake and there is no clear scientific evidence if kratom can be directly connected to withdrawal symptoms in newborns. There is an urgent need to understand if kratom alkaloids can cross the placental barrier and lead to serious withdrawal symptoms in newborns. We believe it is important to assess the in utero effects of not only mitragynine and 7-hydroxymitragynine, but also the traditional kratom preparation (as a lyophilized tea) and a commercially used product (OPMS Gold). In rats, we will establish the fetal exposure and metabolism of mitragynine and metabolites along with other major kratom alkaloids. We can simultaneously quantify eleven kratom alkaloids and/or mitragynine along with its three major metabolites in biological matrices. In a pharmacokinetic-based Specific Aim 1, we will establish the fetal exposure of kratom alkaloids after oral doses of mitragynine, lyophilized tea and commercially used product (OPMS Gold). We will check the systemic excretion of mitragynine, 7-hydroxymitragynine and other kratom alkaloids through fetal urine by analyzing the amniotic fluid. We will establish a multi-compartmental pharmacokinetic model to describe the concentration- time data for mothers and fetuses. In a pharmacodynamic-based Specific Aim 2, we will test if in utero exposure of kratom alkaloids leads to withdrawal symptoms in newborns. We will evaluate naltrexone precipitated opioid withdrawal symptoms in pups immediately after birth. We will also perform immunohistochemistry studies for withdrawal-specific biomarkers (NR2B, Arc, GFAP and C-fos). After 2 years, we will establish a direct relationship between kratom intake during pregnancy and its consequences on newborns. If deemed reasonable, a blanket warning can be issued to stop the use of kratom during the gestation period and further studies will be performed to evaluate the effect of in utero exposure of kratom on long-term memory and learning capacity of progeny.

PROJECT NARRATIVE Conventional opioids (prescription and illicit) are being replaced by the herbal supplement kratom (Mitragyna speciosa) during pregnancies, and multiple clinical cases have been associated with serious withdrawal symptoms in newborns presumably due to in utero kratom exposure. There is an urgent need to mechanistically investigate if kratom intake during pregnancy results in neonatal abstinence syndrome (NAS) as an outcome. A combination of systemic pharmacokinetic and pharmacodynamic studies are proposed in this R21 proposal to identify risks (or benefits) of kratom use during pregnancy.