beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity

• Published in: Pharmaceutical biology Vol. 52; no. 11; pp. 1478 - 1486
• Main Authors: Okoye, Nkeoma Nkasi, Ajaghaku, Daniel Lotanna, Okeke, Henry Nnaemeka, Ilodigwe, Emmanuel Emeka, Nworu, Chukwuemeka Sylvester, Okoye, Festus Basden C.
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare USA, Inc 01.11.2014; Taylor & Francis
• Subjects: Alstonia; Animals; Anti-Inflammatory Agents - chemistry; Anti-Inflammatory Agents - isolation & purification; Anti-Inflammatory Agents - therapeutic use; Apocyanaceae; Edema - drug therapy; Edema - pathology; egg albumen-induced paw edema; Female; leucocytes migration; Male; Mice; Oleanolic Acid - analogs & derivatives; Oleanolic Acid - chemistry; Oleanolic Acid - isolation & purification; Oleanolic Acid - therapeutic use; pentacyclic triterpene; Plant Bark; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - therapeutic use; Plant Stems; Rats; xylene-induced ear edema; Apocyanaceae; xylene-induced ear edema; egg albumen-induced paw edema; pentacyclic triterpene; leucocytes migration
• ISSN: 1388-0209; 1744-5116
• DOI: 10.3109/13880209.2014.898078

Abstract Context: Alstonia boonei De Wild (Apocyanaceae) is used in ethnomedicine for the management of malaria, ulcer, rhematic pain, toothache, and inflammatory disorders. Objective: To investigate the anti-inflammatory potential of β-amyrin and α-amyrin acetate isolated from the stem bark of Alstonia boonei using animal models. Materials and methods: Chromatographic purification of the crude methanol extract led to the isolation and structure elucidation of β-amyrin and α-amyrin acetate. Their anti-inflammatory activities were evaluated in rodents using egg albumen-induced paw edema and xylene-induced ear edema models. The gastric ulcerogenic, in vivo leucocyte migration, and RBC membrane stabilization tests were also investigated. Results: α-Amyrin acetate at 100 mg/kg showed significant (p < 0.05) inhibition of egg albumen-induced paw edema with % inhibition of 40 at the 5th hour. Oral administration up to 100 mg/kg did not produce significant (p > 0.01) irritation of the gastric mucosa while significant (p < 0.01) ulceration was recorded for indomethacin at 40 mg/kg compared with the negative control. At 100 μg/mL, both β-amyrin and α-amyrin acetate inhibited heat-induced hemolysis to as much 47.2 and 61.5%, respectively, while diclofenac sodium (100 μg/mL) evoked only 40.5% inhibition. Both compounds at 100 µg/ear produced significant (p < 0.01) inhibition of ear edema in mice by 39.4 and 55.5%, respectively. Also at 100 mg/kg (p.o.) α-amyrin acetate evoked 60.3% reduction in total leucocyte count and significant (p < 0.05) suppression (47.9%) of neutrophil infiltration. Discussion and conclusion: This study generally provided evidence of profound anti-inflammatory activity of β-amyrin and α-amyrin acetate isolated from the Alstonia boonei stem bark.