alpha-Amyrin acetate

beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity.[Pubmed:25026352]

Pharm Biol. 2014 Nov;52(11):1478-86.

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 beta-amyrin and alpha-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 beta-amyrin and alpha-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: alpha-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 mug/mL, both beta-amyrin and alpha-Amyrin acetate inhibited heat-induced hemolysis to as much 47.2 and 61.5%, respectively, while diclofenac sodium (100 mug/mL) evoked only 40.5% inhibition. Both compounds at 100 microg/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.) alpha-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 beta-amyrin and alpha-Amyrin acetate isolated from the Alstonia boonei stem bark.

Antihyperglycaemic activity of alpha-amyrin acetate in rats and db/db mice.[Pubmed:19488928]

Nat Prod Res. 2009;23(9):876-82.

The article reveals the antihyperglycaemic activity of the alpha-Amyrin acetate (alpha-AA) isolated from the aerial roots of the Ficus bengalensis in normal and diabetic rats and model of type-2 diabetes, i.e. db/db mice. The oral administration of alpha-AA significantly improved the diabetic condition in streptozotocin-induced diabetic rats and in diabetic db/db mice at 50 mg kg(-1) dose level.

Brine shrimp cytotoxicity of crude methanol extract and antispasmodic activity of alpha-amyrin acetate from Tylophora hirsuta wall.[Pubmed:23773697]

BMC Complement Altern Med. 2013 Jun 17;13:135.

BACKGROUND: We have previously reported that aerial parts of Tylophora hirsuta have antispasmodic profile. The current work is an attempt for isolation of pharmacologically active compound(s) that contribute for its antispasmodic activity. METHODS: Preliminary phytochemical screening for crude methanol extract of Tylophora hirsuta (Th.Cr) is performed. Brine shrimp cytotoxicity of crude methanol extract is performed. Column chromatography was used for isolation of compounds. Mass spectroscopy, H(1) NMR and C(13) NMR were used for structural determination of compounds. alpha-Amyrin acetate was tried for possible spasmolytic activity in rabbit's jejunal preparations and KCl-induced contractions. RESULTS: Th.Cr tested positive for saponins, alkaloids, flavonoids and terpenoids. Compound 1 was isolated as alpha-Amyrin acetate. Compound 2 was heptaeicosanol. Crude methanol extract tested positive for brine shrimp cytotoxicity with LC(50) 492.33+/- 8.08 mg/ml. Compound 1 tested positive for antispasmodic activity on spontaneous rabbits' jejunum preparations with EC(50) (60 +/- 2) x 10(-5)M. The compound also tested positive on KCl induced contractions with EC(50) (72 +/- 3) x 10(-5)M. CONCLUSIONS: The present work confirms that alpha-Amyrin acetate is has antispasmodic profile and the relaxant effect may be attributed to alpha-Amyrin acetate which is a major compound.

Adult mortality and blood feeding behavioral effects of alpha-amyrin acetate, a novel bioactive compound on in vivo exposed females of Anopheles stephensi Liston (Diptera: Culicidae).[Pubmed:22167372]

Parasitol Res. 2012 Jun;110(6):2117-24.

The effect of alpha-Amyrin acetate on mortality and blood feeding behavior in females of Anopheles stephensi was assessed by in vivo exposure on treated guinea pig skin. In vivo exposure to alpha-Amyrin acetate caused mosquito knock down in the form of rapidly and normally reversible paralysis and the subsequent record at the end of a 24 h, revealed mortality rates of females increased from 0.0% (Control) to 76.9% at 1.6% alpha-Amyrin acetate, the highest concentration which implies the contact toxicity of the alpha-Amyrin acetate received through the sensitive parts of test species. The mean probing time responses significantly increased (P < 0.05) from 5.3 s (Control) to 22.9 s at 1.6% alpha-Amyrin acetate. The blood feeding rates and the mean engorgement times were significantly shorter when compared to the control. The mean blood feeding rates of exposed females decreased from 91.7% (control) to 41.5% at 0.8% alpha-Amyrin acetate concentrations, the mean engorgement time also decreased from 278.6 s (Control) to 158.7 s at 0.8% alpha-Amyrin acetate concentrations. Mean blood feeding rates and mean engorgement time were statistically significant (P < 0.05) from that of control. The mean fecundity levels significantly reduced from 96.2 (Control) to 65.95%. The shortened mean engorgement time and smaller blood meal size have played a more important role in decline of fecundity. In vivo exposure to alpha-Amyrin acetate caused increased mean probing time, decreased blood engorgement time and feeding rate and declined fecundity which reduce the overall survival and reproductive capacity of the malaria vector A. stephensi.