Methanolic Crude Extract of Hagenia abyssinica Possesses Significant Antidiarrheal Effect: Evidence for In Vivo Antidiarrheal Activity

Background. Hagenia abyssinica is one of the most commonly used medicinal plants for the treatment of diarrhea in Ethiopia. Therefore, this study aimed to evaluate the antidiarrheal effect of methanol crude extract of H. abyssinica leaves in mice. Methods. Acute toxicity testing was conducted using Organization for Economic Cooperation and Development guidelines. The antidiarrheal activity of the crude extract of H. abyssinica was investigated using three animal models such as small intestine transit, enteropooling, and castor oil-induced diarrhea models. The extract was administered at three different doses (100, 200, and 400 mg/kg) to the test groups, while the positive control group received 3 mg/kg of loperamide and the negative control group received 10 ml/kg of vehicle (distilled water). Results. The crude extract of H. abyssinica did not exhibit death at the limit dose (2 g/kg) throughout the observation period. In the castor oil-induced model, the crude extract at a dose of 200 and 400 mg/kg exhibited a significant ( P < 0.05 ) antimotility effect as compared to the negative control. The crude extract revealed a significant reduction in the volume and weight of intestinal contents at 200 and 400 mg/kg doses of the extract. Moreover, the highest antidiarrheal index (ADI) was obtained with the dose of 400 mg/kg of crude extract, which was comparable to the standard drug. Conclusion. The crude extract of Hagenia abyssinica possesses antidiarrheal activity and supports the traditional use of H. abyssinica for the management of diarrhea.

In Vitro α-Amylase and α-Glucosidase Inhibitory and Antioxidant Activities of the Crude Extract and Solvent Fractions of Hagenia abyssinica Leaves

Background. The leaves of Hagenia abyssinica have been used in the management of diabetes mellitus in Ethiopian folk medicine. Thus, this study is aimed at investigating the in vitro α-amylase and α-glucosidase inhibitory and antioxidant activities of the crude extract and solvent fractions of H. abyssinica leaves. Methods. The in vitro α-amylase and α-glucosidase inhibitory and antioxidant activities of the plant extract were assessed using 3,5-dinitrosalicylic acid (DNSA), p-nitro-phenyl-a-D glucopyranoside (p-NPG), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, respectively. Each value of percent inhibition of α-amylase, α-glucosidase, and DPPH scavenging effect was presented as means ± SEM ( n = 3 ). Results. The α-amylase inhibitory activity of the crude extract and solvent fractions was found to be concentration-dependent. The strongest activity was exhibited by the crude extract at the highest concentration with a percentage inhibition of 74.52% (IC50, 14.52 μg/ml) followed by water fraction 68.24% (IC50, 16.31 μg/ml), ethyl acetate fraction 61.57% (IC50, 18.73 μg/ml), and chloroform fraction 56.87% (IC50, 21.57 μg/ml) of H. abyssinica leaves. In the α-glucosidase inhibition assay, the maximum activity was exhibited by the aqueous fraction 62.54% (IC50, 11.67 μg/ml) followed by ethyl acetate fraction 54.97% (IC50, 15.89 μg/ml), crude extract 46.79% (IC50, >16.5 μg/ml), and chloroform fraction 36.44% (IC50, >16.5 μg/ml). In the antioxidant assay, the crude extract exhibited the highest antioxidant activity 86.36% (IC50, 10.25 μg/ml) followed by water fraction 78.59% (IC50, 13.86 μg/ml), ethyl acetate fraction 71.58% (IC50, 16.34 μg/ml), and chloroform fraction 63.65% (IC50, 18.83 μg/ml). Conclusion. This study has revealed that H. abyssinica leaves possess noticeable in vitro α-amylase and α-glucosidase inhibitory and antioxidant activities.

Evaluation of In Vivo Antidiarrheal Activity of Solvent Fractions of Hagenia abyssinica (Rosaceae) in Swiss Albino Mice

Background. Ethiopia has several medicinal plants that have been used for their antidiarrheal activity. Hagenia abyssinica is the most commonly used medicinal plant for the management of diarrhea in Ethiopia. Thus, this study's aim is to investigate the antidiarrheal effect of solvent fractions of H. abyssinica. Methods. Antidiarrheal activity of extract fractions obtained from different solvents was evaluated by using small intestine transit, enteropooling, and castor oil-induced diarrhea animal models. In all animal models, the solvent fractions treated groups were treated with three different doses (100 mg/kg, 200 mg/kg, and 400 mg/kg) of the solvent fractions, while the negative control group was treated with a vehicle (distilled water), and positive control group was treated with loperamide. Results. The acute toxicity test revealed that the LD50 of H. abyssinica is > 2000 mg/kg. In castor oil-induced, the solvent fractions of H. abyssinica (at 200 mg/kg and 400 mg/kg) significantly ( P < 0.05 –0.001) prolonged the stool frequency, reduced the weight of feces, and delayed diarrheal onset time as compared with the negative control group. The fractions produced a significant ( P < 0.05 ) antimotility effect at the doses of 200 mg/kg and 400 mg/kg as compared to the negative control. All solvent fractions at the middle and higher doses showed a statistically significant dose-dependent reduction in the volume of intestinal contents and weight of the feces. However, the solvent fractions of H. abyssinica at a dose of 100 mg/kg failed to produce a statistically significant activity in all parameters (number of wet feces, the onset of diarrhea, and number of total feces) when compared with the negative control group. Conclusion. The extract fractions obtained from different solvents have shown significant antidiarrheal activity. Thus, this finding supports the claimed traditional use of H. abyssinica leaves for the treatment of diarrhea.

Bee flora diversity in different vegetation communities of Gesha-Sayilem forest in Kaffa Zone, south-western Ethiopia

Tropical Afromontane forest has the potential for honey production. The main objective of the study was to identify major bee floras and its diversity in different vegetation communities of Gesha-Sayilem forest. Bee flora data were collected systematically from 90 plots with subplots for shrubs and herbaceous species. In addition, pollen traps having 16% pollen trapping efficiency were fitted at the entrance of beehives for pollen load collection. Shannon-Wiener diversity index; species richness and Shannon’s evenness were employed to determine diversity of bee flora. The result showed that 93 bee plant species belongings to 43 families were identified of which Asteraceae the most abundant family was followed by Lamiaceae, Fabaceae, Acanthaceae and Rubiaceae. The analysis of bee forage diversity using Shannon-Wiener diversity index (H) found in 5 different plant communities showed that plant communities one, two, and three have the highest bee flora diversity 3.2, 3.2, and 3.5, respectively. The dominant bee plants in community one were (Ilex mitis and Syzygium guineens), community two (Pouteria adolfi-friederici and Schefflera abyssinica), Community three (Millettia ferruginea and Sapium ellipticum), community four (Hagenia abyssinica and Dombeya torrida), community five (Schefflera-volkensi and Maesa lanceolata). Sorensen similarity coefficient showed that communities 1, 2, 3, and 5 are more similar to each other while community four is less similar. On the other hand, the beta diversity for communities 1, 2, 3, and 5 were 0.25, 0.27, 0.39, and 0.28 respectively while community four has a higher beta diversity index (0.71) indicating low similarity with the rest of the plant communities. In conclusion community 1, 2 and 3 has a high diversity of bee flora and therefore, integration of these communities with beekeeping is recommended.

Modeling the Impact of Climate Change on the Distribution of Hagenia Abyssinica in Ethiopia

Research Highlights: Hagenia abyssinica is geographically localized, poor regenerated and endangered species in Ethiopia. Ethiopia has been experiencing variability of rainfall and rise in temperature due to the climate change. This study has hypothesized that the suitable areas for the species will be narrowed by the year 2070. Background and Objective The prediction of species distribution models help to implement appropriate conservation actions. The aim of this research was to identify the current and likely future distribution range and suitable areas for the species, and to determine the presence of H. absyssinica in risk in a short-term future. Material and method: To this end, occurrence data, bioclim variables, soil, elevation, and land cover map of Ethiopia were used. MaxEnt was used to predict distribution. Climate change impacts on the distribution of the species was performed using bioclimatic variables of the future climate data, 2070 (average for 2061-2080) was obtained from IPPC5 (CMIP5) at 30 seconds (1km) spatial resolution. The climate data was projected from GCMs, downscaled and calibrated using rcp4.5. Results: Both current and likely future distribution models were excellent and significantly better than random performance. This study has computed 59987 km2 to be the low impact area for the species under current conditions and will remain habitat under future climates and 39025 km2 area has been identified as the possible high impact areas or declining habitat. The model has also determined that 1238724 km2 of the areas are unsuitable at present and for future climates. The current study found that 15751 km2 of the area will be modified as a new suitable area for H. abyssinica due to climate change. Conclusion: Species distribution modeling is essential for the implementation of conservation actions that are compatible with the inevitable changing climatic conditions of the country.