tetrahydro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency (IC50s = 74 nM and >100 μM, respectively) compared to the companion harmala alkaloids also found in B. caapi: harmaline dro-Harmine (THH) is a fluorescent indole alkaloid extracted from B. caapi, a woody vine that is used to produce a psychoactive beverage, ayahuasca, which has been ritually ingested for medicoreligious purposes throughout South America since pre-Columbian times. THH inhibits monoamine oxidase (MAO)-A and MAO-B with much weaker potency