ABSTRACT
The leaves and stem of Sida acuta Burm.F. ( Malvaceae) are used in ethnomedicine for the treatment of fever, aches and pains, inflammation, worm infestation as well as to induce labour. Some Pharmacognostic characteristics such as the macroscopy, microscopy , chemomicroscopy and phytochemistry of the aerial parts of Sida acuta were studied; quantitative parameters were determined. The analgesic,anti-inflammatory, anti-ulcer and uterine muscle activity of Sida acuta were also studied in mice and rats.
Pharmacognostic evaluation was carried out using standard Pharmacognostic techniques. Analgesic activity was investigated by means of the acetic acid induced writhing, tail immersion and formalin test models. The carrageenan induced oedema and the mouse ear oedema tests were used in the study of anti-inflammatory activity; while the anti-ulcer activity was evaluated by means of the acetylsalicylic acid induced ulceration model. The effects of the aqueous and methanol extracts, as well as the saponin and alkaloidal fractions on the isolated uterus were determined.
The phytochemical analysis revealed the presence of alkaloids, flavonoids, cardiac and saponin glycosides. Chemomicroscopic tests showed the presence of lignin, starch, mucilage and calcium oxalate crystals. The results of the quantitative parameters (in % w/w + S.E.M) were as follows: Total ash value: 8.63 + 0.07, acid insoluble ash value: 0.65 + 0.06, water soluble ash value 2.09 + 0.18, moisture content 9.47 + 0.18, alcohol soluble extractive value 1.35 + 0.08 and water soluble extractive value 2.93 + 0.46. The crude ethanolic extract exhibited significant (p<0.001) analgesic and anti-inflammatory activities in mice as well as a marked protection against acetylsalicylic acid induced gastric mucosal ulceration in rats (p < 0.001). The saponin fraction and the aqueous and methanol extracts showed oxytocic activity, while the alkaloidal fraction showed uterine relaxant activity on the isolated uterus of rats. The results of this study have established vital Pharmacognostic characteristics for the genuine crude drug, as well as verified the claimed analgesic, anti-inflammatory, anti-ulcer, uterotonic and uterine relaxing activities of Sida acuta. The results thus supply the basis for the claimed uses of Sida acuta in ethnomedicine.
The work has also established that the aqueous extract as used in herbal medicine has oxytocic activity, and further that the alkaloidal fraction is tocolytic and therefore could be used in the treatment of threatened abortion.
