Abstract

Viscum album (Mistletoe) is a semi-parasitic plant which grows on the stems of other tree species. This present study was carried out to investigate the phytochemical composition, acute toxicity, analgesic, antiinflammatory and tonic properties of Viscum album, which was soxhlet-extracted using ethanol as solvent.Qualitative phytochemical analysis of ethanol extract of Viscum album showed the presence of saponins, alkaloids, flavonoids, phenolics, tannins, terpenes, glycosides and steroids. Quantitative screening yielded high result for flavonoids (6.93mg/100g), followed by alkaloids, saponins, tannins, steroids phenols, terpenes and glycosides yielding (6.39, 5.81, 4.38, 3.12, 2.76, 1.95 and 0.94)mg/100g respectively. Acetic acid-induced writhing model was employed for analgesic activity assay and aspirin was used as standard control. Oral administration of (400 and 800mg/kg b.w) significantly reduced the nociceptive responses induced by acetic acid by (80.34±0.67 and 58.95±2.25) % respectively. The antiinflammatory activity was screened using a phlogistic agent, egg albumin-induced rat paw edema, using aspirin (100mg/kg) as reference control. It was observed that administration of (200 and 400mg/kg) of extract significantly inhibited inflammatory response by (58.22±8.24 and 58.73±4.40) % respectively at the end of 120min of the assay. The tonic profile of the extract was screened on laboratory water bath, using an isolated rabbit jejunum. First, the effects of different concentrations of ethanol extract of Viscum album(300, 600 and 1200) µg/ml were assayed and it was found to reduce the basal contractions (15.00±0.41, 14.00±0.41 and 16.00±0.58)mm to (2.75±0.48, 2.00±0.41 and 1.75±0.25)mm respectively, which represent (81.74, 85.68 and 88.93)% respectively. Then the effects of same concentration of extract 300µg/ml was examined on different concentrations of acetylcholine (3.33, 6.66 and 13.32)µg/ml and was shown to inhibit the excitatory activity of acetylcholine from (17.00±0.41, 21.75±0.48 and 21.75±0.48)mm to (2.25±0.25, 6.50±0.29 and 6.50±0.29)mm, which represent (86.75, 79.29 and 70.05)% respectively. Furthermore, results of the effects of same concentration of atropine on acetylcholine induced contraction had no significant effect, but began inhibiting acetylcholine activity upon increased concentrations of atropine. The reduction in the contractile response to acetylcholine, following supposed blockade of cholinergic receptors by plant extract was far more considerable than atropine in rabbit jejunum. These results indicate that the ethanol extract of Viscum album is a potent analgesic, antiinflammatory and tonic compound. These findings further suggest that the analgesic, antiinflammatoryeffects and the relaxing effects of theethanol extract of Viscum album on jejunal contractions may in fact be due to the presence of the phytoconstituents present. However, further research on the isolation and characterization of the responsible phytochemicals is pertinent.