This paper reports the in vitro anti-diabetic profile of certain medicinal plants traditionally used in Eritrea for the management of type 2 diabetes. The crude methanolic extracts and fractions of Meriandra dianthera...This paper reports the in vitro anti-diabetic profile of certain medicinal plants traditionally used in Eritrea for the management of type 2 diabetes. The crude methanolic extracts and fractions of Meriandra dianthera, Aloe camperi, a Polyherb and their fractions were investigated. The in vitro screening of the crude extracts has generally elicited a dose dependent α-glucosidase and α-amylase inhibition activities. M. dianthera displayed the highest α-glucosidase inhibitory activity (IC50: 0.074 ± 0.032 mg/mL) at the highest concentration tested (0.800 mg/mL) relative to A. camperi, the Polyherb and Acarbose (IC50: 0.37 ± 0.052, 0.56 ± 0.024 and 0.55 ± 0.029 respectively). The α-glucosidase inhibition activities of A. camperi and M. dianthera, except for the Polyherb and Acarbose, were significantly different (P < 0.05) at various ranges of concentrations (0.025 - 0.800 mg/mL). The percentage α-amylase inhibitions of M. dianthera, A. camperi, the Polyherb and Acarbose, at the highest concentrations (0.800 mg/mL), were 78.3%, 15.9%, 16.4%, and 82.9% respectively. A. camperi and the Polyherb displayed lower α-amylase inhibitory activities (IC50: 1.72 ± 0.06 and 2.57 ± 0.07 mg/mL respectively) compared to Acarbose and M. dianthera (IC50: 0.31 ± 0.01 and 0.43 ± 0.02 mg/mL respectively). For the α-amylase inhibition activity, even at lower concentrations (0.025 mg/mL), there were statistically significant differences (P < 0.01) among the values generated for all the extracts. The in vitro anti-diabetic screening of the fractions, at 0.800 mg/ml, displayed characteristic enzyme inhibition activities. Generally, the non-polar fractions showed higher enzyme inhibitory activities compared to the polar fractions. The most bioactive non-polar fractions, thus, were subjected to GC-MS analysis and presented various essential oils, fatty acid methyl esters (FAMEs) and benzoic acid derivatives in those plants.展开更多
There are many possible sources of ground water contamination and may include wastes from industrial chemical production, domestic wastewater and pesticide run off from agricultural lands. The groundwater is thus susc...There are many possible sources of ground water contamination and may include wastes from industrial chemical production, domestic wastewater and pesticide run off from agricultural lands. The groundwater is thus susceptible to chemical, physical and/or microbiological contamination and ultimately becomes a cause for diverse diseases borne from the contaminated water. It has been a common practice to cultivate vegetables, crops and animal feed grasses around Asmara using sewage and industrial effluents and there are likelihoods that contaminants in the wastewater used for irrigation would infiltrate to the nearby wells. It is believed that the groundwater around the wastewater irrigated area is not safe for domestic and agricultural applications. Thus, this study was conducted to evaluate the quality of the groundwater in order to safeguard the public health treats caused by using this water. Samples were collected from five locations around Mai-Bella and thus different physico-chemical parameters were investigated. The pH of the samples was measured by pH metric method;electrical conductivity (EC) and salinity by using conductometric method. Hardness was estimated by EDTA method;total alkalinity (TA) and bicarbonate concentrations by titrimetric methods. Chloride concentration was analyzed by titration against mercurial nitrate. Na and K were determined using flame photometric method. Fe, Mn, nitrate, nitrite, sulphates and ammonia were determined using spectrophotometric method. Chemical Oxygen Demand (COD) was determined using photometric method. Moreover, the concentrations of trace, major and heavy metals were analysed using Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES). The suitability of the groundwater for domestic and irrigation purposes was examined using WHO and FAO standards. Most of the physico-chemical parameters, except the temperature, pH, COD, Al, Cd, Cr, Cu and Zn, of the samples were found above the standard limits given by WHO. Similarly, the levels of toxic metals (Pb, As, Hg and Se) in all the water sources and Ni from two water sources were found above the permissible limit. Accordingly, the results signpost that most of the groundwater samples from the study sites are not suitable for drinking and irrigation purposes. Further studies related to the bacterial load would be appropriate to assess the health effects of all the water sources found around Mai-Bella.展开更多
文摘This paper reports the in vitro anti-diabetic profile of certain medicinal plants traditionally used in Eritrea for the management of type 2 diabetes. The crude methanolic extracts and fractions of Meriandra dianthera, Aloe camperi, a Polyherb and their fractions were investigated. The in vitro screening of the crude extracts has generally elicited a dose dependent α-glucosidase and α-amylase inhibition activities. M. dianthera displayed the highest α-glucosidase inhibitory activity (IC50: 0.074 ± 0.032 mg/mL) at the highest concentration tested (0.800 mg/mL) relative to A. camperi, the Polyherb and Acarbose (IC50: 0.37 ± 0.052, 0.56 ± 0.024 and 0.55 ± 0.029 respectively). The α-glucosidase inhibition activities of A. camperi and M. dianthera, except for the Polyherb and Acarbose, were significantly different (P < 0.05) at various ranges of concentrations (0.025 - 0.800 mg/mL). The percentage α-amylase inhibitions of M. dianthera, A. camperi, the Polyherb and Acarbose, at the highest concentrations (0.800 mg/mL), were 78.3%, 15.9%, 16.4%, and 82.9% respectively. A. camperi and the Polyherb displayed lower α-amylase inhibitory activities (IC50: 1.72 ± 0.06 and 2.57 ± 0.07 mg/mL respectively) compared to Acarbose and M. dianthera (IC50: 0.31 ± 0.01 and 0.43 ± 0.02 mg/mL respectively). For the α-amylase inhibition activity, even at lower concentrations (0.025 mg/mL), there were statistically significant differences (P < 0.01) among the values generated for all the extracts. The in vitro anti-diabetic screening of the fractions, at 0.800 mg/ml, displayed characteristic enzyme inhibition activities. Generally, the non-polar fractions showed higher enzyme inhibitory activities compared to the polar fractions. The most bioactive non-polar fractions, thus, were subjected to GC-MS analysis and presented various essential oils, fatty acid methyl esters (FAMEs) and benzoic acid derivatives in those plants.
文摘There are many possible sources of ground water contamination and may include wastes from industrial chemical production, domestic wastewater and pesticide run off from agricultural lands. The groundwater is thus susceptible to chemical, physical and/or microbiological contamination and ultimately becomes a cause for diverse diseases borne from the contaminated water. It has been a common practice to cultivate vegetables, crops and animal feed grasses around Asmara using sewage and industrial effluents and there are likelihoods that contaminants in the wastewater used for irrigation would infiltrate to the nearby wells. It is believed that the groundwater around the wastewater irrigated area is not safe for domestic and agricultural applications. Thus, this study was conducted to evaluate the quality of the groundwater in order to safeguard the public health treats caused by using this water. Samples were collected from five locations around Mai-Bella and thus different physico-chemical parameters were investigated. The pH of the samples was measured by pH metric method;electrical conductivity (EC) and salinity by using conductometric method. Hardness was estimated by EDTA method;total alkalinity (TA) and bicarbonate concentrations by titrimetric methods. Chloride concentration was analyzed by titration against mercurial nitrate. Na and K were determined using flame photometric method. Fe, Mn, nitrate, nitrite, sulphates and ammonia were determined using spectrophotometric method. Chemical Oxygen Demand (COD) was determined using photometric method. Moreover, the concentrations of trace, major and heavy metals were analysed using Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES). The suitability of the groundwater for domestic and irrigation purposes was examined using WHO and FAO standards. Most of the physico-chemical parameters, except the temperature, pH, COD, Al, Cd, Cr, Cu and Zn, of the samples were found above the standard limits given by WHO. Similarly, the levels of toxic metals (Pb, As, Hg and Se) in all the water sources and Ni from two water sources were found above the permissible limit. Accordingly, the results signpost that most of the groundwater samples from the study sites are not suitable for drinking and irrigation purposes. Further studies related to the bacterial load would be appropriate to assess the health effects of all the water sources found around Mai-Bella.
