Phytochemical Contents, Evaluation of Antiulcer, Antipyretic, Antinociceptive, and Anti-Inflammatory Activities of Artemisia absinthium L. (Asteraceae) Leaf Extract in Wistar Rats

Artemisia absinthium L.(wormwood) is popularly called ‘’Tazargaade’’ in northern Nigeria and is found in all parts of the country. The leaf is used to treat ulcers, fevers, pains and inflammations in Nigeria. The study was carried out aimed at analyzing the phytoconstituents of the leaf and evaluating the antiulcer, antipyretic, antinociceptive, and anti-inflammatory activities of A. absinthium extract in Wistar rats. Phytochemical analysis was carried out following standard procedures, the toxicity studies were carried out using the OECD methods, the antiulcer effect was evaluated using ethanol-induced, naproxeninduced and pyloric ligation-induced ulcer models, the antipyretic effect was evaluated using brewer’s yeast-induced pyrexia, the antinociceptive effect was evaluated using the acetic acid-induced and hot plate models, while the anti-inflammatory effect was determined using carrageenan-induced paw oedema in rats’ models at extract doses of 50-400 mg/kg body weight (p.o.). For the phytoconstituents, LC/MS and GC-MS were used to identify bioactive compounds. Various ulcer parameters were calculated from specific formulae for each model, while the abdominal writhing and volumes of paw oedema in rats were used to assess the potential of the extract in acetic acid and carrageenan-induced models respectively from 0 to 5 h. The phytochemical screening of leaf extract revealed the presence of saponins, flavonoids, carbohydrates, tannins, phenols and phytosterols while, the GC-MS and LC/MS analysis further confirmed three major bioactive compounds as cis-thujones, transsabinyl acetate, and β-thujone. An acute toxicity study of the extract showed that the plant was safe at a maximum dose of 2000 mg/kg b.w. (p.o.). There were no major histopathological defects observed on examination of vital organs, organ weights or biochemical changes in blood profiles, liver function parameters, and lipid profiles. There were no elevated values obtained as all the values fall within the acceptable ranges. Furthermore, the extract showed dose-dependent biological activities. The extract showed significant (p < 0.05) reductions in ulcer area, ulcer index, ulcer score, total acidity, and gastric volumes as well as increased percentage inhibition of ulceration (80.12 %) at the dose of 400 mg/kg b.w. when compared to the various control groups (p < 0.05). Similarly, significant antipyretic, antinociceptive and anti-inflammatory effects were observed in a dose-dependent fashion, with an average reduction in rectal temperature of 76.54 ±2.01℃ in pyrexia, 86.12 % inhibition of abdominal writhing in acetic acid-induced pain, and 82.14 % reduction in paw oedema within the study periods at the dose of 400 mg/kg b.w. (p.o.). There was a significant difference (p < 0.05) in the values obtained when compared to the standard drugs Our study showed that methanol leaf extract of A. absinthium possessed significant antiulcer, antipyretic, antinociceptive and anti-inflammatory activities in Wistar rats. These scientific findings further justify its use in Nigeria’s traditional medicine for the treatment of these ailments. However, there is the need to further investigate specific compound(s) responsible for these biological activities toward drug discovery.