Background Plants are able to deliver a huge number of differing bioactive compounds which may supplement the requirements of the human body by acting as natural antioxidants. Antioxidants are mindful for the defense component of the life form against the pathologies related to the assault of free radicals. The main purpose of this study was to investigate the qualitative phytochemical composition of Vernonia amygdalina leaf extract and its antioxidant activity. Method The powdered plant sample was successively extracted with aqueous, methanol and ethanol solvents using Soxhlet apparatus. The antioxidant activities of the crude leaf extract were determined using 1, 1- diphenyl-2-picryl hydrazyl (DPPH) radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical, phosphomolybdate (PM) and hydrogen peroxide (H2O2) scavenging assay. All the examinations were drained triplicates and average values of each test were taken. Results Phytochemical investigation of the plant revealed that the three solvent extracts contained numerous bioactive compounds namely alkaloids, tannins, saponins, phenols, terpenoids, steroids, glycosides and sugars. The result showed that, the leaf extracts of V. amygdalina obtained from methanol extract exhibit the maximum antioxidant activity compared ethanol and aqueous extracts. The IC50 values of DPPH assay for the H2O, MeOH and EtOH extracts were 111.4, 94.92 and 94.83 μg/ml; of ABTS assay were 334.3, 179.8 and 256.9 μg/ml; of H2O2 assay were 141.6, 156 and 180.6 μg/ml, respectively. The maximum radical scavenging activity was obtained in DPPH assay while the lowest scavenging activity was obtained in ABTS assay method. The data obtained in the in vitro models clearly suggest that methanol extract has higher antioxidant activity due to a higher presence of phenolic constituents in the extract. Conclusion This study revealed that V. amygdalina leaf has a noteworthy antioxidant and free radical scavenging activity mitigating the traditional use of the plant for different aliments.

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The fatty acids, cholesterol compositions and the ratio between unsaturated and saturated fatty acids are important parameters for the determination of the nutritional value of certain oils. Most oils sold in our markets are claimed they are cholesterol- free and their fatty acid profile is unknown. To determine the cholesterol and fatty acid profile of commercially sold vegetable oils in three places, twelve oil samples were analyzed for their cholesterol and fatty acid compositions. Cholesterol was detected in most sample oils except in nigger seed and peanut oils. Locally produced Sunflower oil has significantly (p < 0.05) highest cholesterol concentration (24.31±0.85) while Modjo oil has the least concentration (0.78± 0.16 mg/l). High saturated fatty acids were found in palm oil (43.87) with predominant presence of palmitic acid. Oleic acid (C16:0) is the predominant one in sunflower oil. Hamaressa and Modjo oils contained 46.12%, 16.7% Erucic acid (C20:1) respectively. Linoleic acid (C18:2 6c) was predominant in soybean oils (52.45–59.54%), corn oil (61.73%) and sunflower oil (43.54%). The highest percentage composition of alpha-linolenic acid was found in Hamaressa oil (1.27%) followed by Modjo oil (0.5%). Sesame, peanut and sunflower ( high oleic acid) oils were found to be better for salad and cooking purposes than other oils due to lower saturated and higher monounsaturated fatty acid contents. In general, the research output disclosed the quantity of cholesterol detected in sample oils contradicts the label of cholesterol claimed by most of the producers and marketers.

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The purpose of this study was to conduct characterization of the Delanta natural opals obtained from different mining sites. Characteristics of opals mined from different geological locality were examined. Six opal samples were collected from the main mining sites found in different localities from Delanta district and characterized using Fourier infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and inductively coupled plasma optical emission spectroscopy characterization techniques. The scanning electron microscope micrographs showed that all the samples have relatively semi-ordered (semi-crystalline) structural surface morphologies composed of tiny spherical particles. The performed X-ray diffraction analysis showed that the samples have main peaks at 20.0°, 21.72°, 36.9°, 44.0°, and 56.85° with 2 θ values between 10° and 60°. The five diffraction peaks are characteristic peak positions of opal-CT. The Fourier infrared spectroscopy data indicated that the prominent absorption bands for cristobalite at 620 and 520 cm−1 were absent from the spectrum. Instead, three bands in the low frequency region centered at 470, 791, and 1100 cm−1 were observed because of the absorptions of the silicate framework (Si-O) vibrations. red−1−1 Moreover,spectra feature of molecular water and silanol (Si-OH) groups with broadabsorption band centered around 3447 cm-1 andthe O-H stretching vibration of watermolecules and water bending vibration withan absorption band centered around 1634 cm-1were observed.. These values were consistently comparable with literature data. The inductively coupled plasma optical emission spectroscopy analysis showed that four main impurities (>500 parts per million) were Ca (∼1,750–4,730 parts per million), Al (∼1,990–4,319  parts per million, K (∼1,670–3,895 parts per million), and Na (∼595–3,723 parts per million). In general, this study revealed that all opal samples taken from six mining sites in Delanta district were found to be opal-CT as per the results of X-ray diffraction and Fourier infrared spectroscopy investigations.