Abstract:
Aim: In-Vitro and In-Vivo safety and anti-asthmatic activity of stem bark extracts of
Prunus africana and Warburgia ugandensis against induced asthma in BALB/c mice.
Methodology: Cytotoxicity on Vero E6 cells were investigated using MTT assay. Acute
toxicity was determined by administering single oral gavages of extracts to five groups of
BALB/c at 500, 889.56, 1581.64, 2812.15 and 5000mg/kg body weight doses. Efficacy
against induced asthma was determined by assaying heart blood serum for ovalbumin
specific immunoglobulin E (IgE) antibodies and quantification of eosinophil proportion in
Bronchoalveolar lavage fluid (BALF). Eight sensitized groups were used, 2 were controls,
3 were treated with P. africana extract and 3 with W. ugandensis; each treatment group
received one dose concentration of 125, 250 or 500mg/kg body weight of either plant
extracts.
Results: P. africana CC50 was 104.08μg/ml while W. ugandensis had CC50 > 250 μg/ml.
In acute toxicity, mortality and signs of toxicity were recorded within 24 hours and the
mice monitored for 14 days. There was 20%, 60% and 100% mortality within 24 hours for
mice that received P. africana extracts at 1581.64, 2812.15 and 5000mg/kg body weight respectively. Lethal dose (LD50) for P. africana was 2201.207mg/kg body weight. W.
ugandensis extracts had no mortality recorded and the LD50 was >5000mg/kg body
weight. Treatment with P. africana extracts at 500mg/kg body weight reduced the IgE and
BALF Eosinophil to 0.100±0.0001 and 2.80±0.20 respectively which were significantly
different from positive controls P<0.05. W. ugandensis extracts at the same concentration
reduced the IgE and BALF eosinophils to 0.134±0.00016 and 3.80±0.20 respectively and
were significantly different from positive controls P<0.05.
Conclusion: The results attested that P. africana and W. ugandensis stem bark extracts
have anti-asthmatic property though there is need for further validation of anti-asthmatic
chemical compounds to augment the findings.
