Antidepressant and Anxiolytic Effects and Subacute Toxicity of the Aerial Parts of Psychotria ankasensis J.B.Hall (Rubiaceae) in Murine Models

Abstract

Background. The present study aimed at validating the traditional use and toxicity profile of a methanolic extract of the aerial parts of Psychotria ankasensis in alleviating depression and anxiety disorders. Method. The antidepressant effect of methanolic extract of Psychotria ankasensis (PAE 30, 100, and 300 mg/kg, p.o.) was assessed in mice using the forced swim test (FST) and the tail suspension test (TST). The plant's anxiolytic potential was also evaluated in mice using the elevated plus-maze (EPM) and the open field tests (OFT). The subchronic toxicity was assessed via oral administration of PAE at doses of 100, 300, and 1000 mg/kg in rats for 28 days. Results. PAE 100 and 300 mg/kg showed antidepressant-like properties by significantly (at least p < 0.05 ) decreasing the frequency and duration of immobility in FST and TST. PAE (100 and 300 mg/kg) also showed a significant (at least p < 0.05 ) anxiolytic effect in both EPM and OFT. In the EPM test, Emax for PAE and diazepam were 92.52 ± 40.11% and 85.95 ± 45.92%, respectively, whereas Emax was approximately 100% for both test drugs in the OFT. Subchronic administration of PAE did not reveal any toxic effects with respect to organ weight index, haematological, serum biochemical, and histopathological parameters. Conclusions. Methanolic extract of P. ankasensis exhibited antidepressant-like and anxiolytic-like effects devoid of significant toxicity at the doses tested in murine models.

Pharmacokinetics and Pharmacodynamics: A Comprehensive Analysis of the Absorption, Distribution, Metabolism, and Excretion of Psychiatric Drugs

“…The average inhibition constant (Ki) value for inhibiting the CYP2D6 enzyme is typically observed to be in the nanomolar range, specifically around 150 nM. This is analogous to the efficacy of quinidine (Ki = 30 nM), which is presently acknowledged as the most potent antagonist of CYP2D6 [ 45 ].…”

A Comprehensive Description of the Anatomy and Histochemistry of Psychotria capillacea (Müll. Arg.) Standl. and an Investigation into Its Anti-Inflammatory Effects in Mice and Role in Scopolamine-Induced Memory Impairment

“…Species of the genus Psychotria are used in popular medicine for pain-and inflammationrelated symptoms [5,6] and mental disorders [7]. According to a literature review of pharmacological studies carried out with extracts from leaves of this genus, these exhibit several biological effects, including anti-inflammatory and analgesic effects [8,9] and activities that protect the central nervous system [9][10][11]. Preliminary tests revealed that alkaloids (87% of which are indole alkaloids) were the major compounds responsible for the effects, in addition to triterpenes (12%), flavonoids (6%), and constituents of other classes; i.e., indole alkaloids (strictosidine and 5α-carboxystrictosidine) and triterpenes (pomolic acid and spinosic acid) isolated from P. nuda, which showed promising inhibitory activity against nitric oxide (NO) production [12]; alkaloids isolated from P. nemorosa (nemorosinoside G, serotonin and bufotenine), which displayed anticholinesterase activity [10]; nemoroside and fargesine, which were able to significantly extend the time of metallothionein induction, a process that is associated with reduced neurodegeneration of aged brain tissue [13]; vincosamide isolated from P. leiocarpa, which showed anti-inflammatory activity and AChE inhibitory effects [11]; alkaloids, obtucarbamate A, and the triterpene asperulosidic acid isolated from P. prainii, which showed anti-inflammatory activity [14] and strictosidinic acid isolated from P. Myriantha, which inhibited monoamine oxidase activity in the rat hippocampus [15].…”