Phytochemical, analgesic and anti-inflammatory studies of the methanol leaf extract of Commiphora mollis (Oliv.) Engl. (Burseraceae)

Abstract

Introduction: Commiphora mollis is used in African traditional medicine as analgesic, anti-inflammatory, antibacterial, anti-fungi, anti-oxidant as well as cytotoxic and cytostatic agent.
Objective: To carry out phytochemical, analgesic and anti-inflammatory studies on the methanol leaf extract of Commiphora mollis.
Methods: The powdered leaf material of Commiphoral mollis was extracted with methanol and partitioned using hexane, chloroform and ethylacetate. The methanol leaf extract was subjected to preliminary phytochemical screening while the fractions were studied using column chromatography for the isolation of compounds. The structure of the isolated compound was established by spectral analysis using UV, IR, 1D and 2D NMR spectroscopy. The methanol leaf extract was also subjected to acute toxicity, analgesic and anti- inflammatory studies using animal models.
Results: The preliminary phytochemical screening of the methanol leaf extract revealed the presence of terpenes, flavonoids, tannins, saponins and carbohydrates. The column chromatography of the chloroform and ethylacetate fractions led to the isolation of a  curcuminiod compound. The results of intrapretoneal LD50 were 1385.64 mg/kg in mice and 3807.8 mg/kg in rats. The analgesic studies were carried out at doses of 75, 150 and 300 mg/kg body weight i.p. using acetic acid-induced writhing and thermally-induced pain in mice. The extract significantly P<0.05 inhibited the acetic acid-induced writhing in mice with highest protection (89.40%) produced at the dose (300 mg/kg) which compare well with the standard drug piroxicam (10 mg/kg). The extract also significantly (P<0.05) increased the reaction time in a dose dependant manner to the thermal stimulus. The extract at 150 mg/kg body weight i.p showed 2.5 ± 0.43 seconds reaction time which was greater than the standard drug pentazocine at 10mg/kg (2.17 ± 0.31 seconds). The carrageenan-induced paw oedema test was employed in investigating the antiinflammatory activity in rats at doses of 150, 300 and 600 mg/kg body weight i.p. The extract inhibited hind paw oedema at all doses tested. The standard drug ketoprofen produces (91.30%) inhibition which is  greater than that of the test groups (40, 50 and 60% respectively).
Conclusion: The results indicated that the methanol leaf extract possess significant dose dependant analgesic activity (P < 0.05) and significant (P < 0.05) anti-inflammatory activity. Thus, the traditional use of the plant for treatment of pain and inflammation is justified in this study.

Keywords: Curcuminoid, Commiphora mollis, Analgesic, Anti-inflammatory, Phytochemical constituents.