Ziziphus abyssinica root bark extract ameliorates paracetamol-induced liver toxicity in rats possibly via the attenuation of oxidative stress.

Ziziphus abyssinica root bark is widely used in folk medicine to manage liver diseases, particularly, jaundice but its effect on paracetamol-induced liver toxicity (PILT) has not yet been validated. This study explored the ameliorative effect of ethanolic root bark extract of Ziziphus abyssinica (ZAE) against PILT in rats. The flavonoid and phenolic content of ZAE was evaluated using Folin-Ciocalteau and aluminium trichloride colorimetric methods, respectively. Antioxidant activity of ZAE was determined in vitro by evaluating its ferrous reducing antioxidant capacity (FRAC) as well as DPPH and nitic oxide (NO) radicals scavenging activities. Sprague-Dawley rats were assigned to six groups (n = 6) and administered with normal saline (10 mL/kg, p.o.), N-acetylcysteine (50 mg/kg, i.p.) and ZAE (30, 100, and 300 mg/kg, p.o.) respectively for seven days after which they received paracetamol (PCM, 3000 mg/kg, p.o.). Animals were sacrificed 48 h after paracetamol administration under light anaesthesia and assessed for liver toxicity and oxidative stress. Total flavonoid and phenolic contents of ZAE were 1313.425 µg/mL quercetin equivalence and 268.31 µg/mL gallic acid equivalence respectively. ZAE exhibited marked FRAC as well as DPPH and NO radical scavenging activities with IC50s of 80.41 ± 1.56, 67.56 ± 1.11 and 7.11 ± 1.48 µg/mL respectively. ZAE and N-acetylcysteine significantly (p < 0.05) reduced the paracetamol-mediated elevation of serum total bilirubin, proteins and activity of liver enzymes (AST, ALP, and ALT). Similarly, ZAE increased hepatic glutathione, total thiols and catalase activity of the paracetamol intoxicated rats. Morphological changes associated with the paracetamol hepatotoxicity were also ameliorated by ZAE. Overall, the hepatoprotective effect of ZAE may be related to its antioxidant property.

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

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 subacute 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, E max for PAE and diazepam were 92.52 ± 40.11% and 85.95 ± 45.92%, respectively, whereas E max was approximately 100% for both test drugs in the OFT. Subacute 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.