RESUMO
Warburgia ugandensis (W. ugandensis) is known by various names, including the East African greenheart, pepper bark tree, and Ugandan greenheart, and has a rich history of extensive use in the treatment of a host of human diseases in many African countries. This review is based on the botany and ethnopharmacological potentials of W. ugandensis for the treatment of pneumonia, asthma, malaria, candidiasis, skin infections, human immunodeficiency virus opportunistic infections, diarrhea, and measles given the common use in the management of these diseases. Extracts from W. ugandensis have strong antimicrobial activities against a broad spectrum of pathogens mainly because of the presence of abundant terpenoids, drimane, and coloratane type sesquditerpenoids amongst which are ugandensial, warburganal, mukaadial, and other secondary metabolites, such as tannins, flavonoids, saponins, steroids, and mannitol. This group of compounds gives the plant a high therapeutic value. Based on the review, there is a need for identification and isolation of the highly therapeutic phytochemical constituents and a drive for more preclinical and clinical trials to validate the safety and efficacy of the extracts. This gives basis for the potential development of new therapeutic drugs from the plant.
RESUMO
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.