Growth Inhibition of Grain Spoilage Fungi by Selected Herbs and Spices Essential Oils

Natural plant extracts are promising alternatives for chemical food additives and synthetic pesticides. In this study, essential oils of selected herbs and spices were tested for their antimicrobial activities against Aspergillus flavus and Aspergillus niger, two of the most common food spoilage  microorganisms. Agar disk diffusion assay was used for screening of the most effective essential oils, agar dilution assay was used to determine Minimum Inhibitory Concentration (MIC) of the essential oils and broth dilution assay was employed to the spore germination inhibition assay. Tests were also conducted to examine the effects of the essential oils for sorghum kernel protection against the tested fungi, and the optimal  protective dosages on the sorghum grains were also determined. From the preliminary tests, essential oils of Cinnamomum zeylanicum (Cinnamon) and Thymus schimperi (thymus) were found to be the most effective. However piper nigrum (black pepper) had no effect on the test organisms. In MIC, spore germination inhibition and grain protection assay, cinnamon essential oil was found to be superior where its MIC on the isolates was found to be 0.0156% and its optimum protective dosage on the sorghum grain was 5%. It inhibited spore germination at a concentration of 3ìL/mL. The effect of thymus oil was also very much comparable to these results (no significant difference at P>0.05). Finally, it was concluded that essential oil extracts of cinnamon and thymus can be a useful source of antifungal agents for protection of grain spoilage by fungi

Invivo Antimalarial Activity of Dodonaea Angustifolia Seed Extracts Against Plasmodium Berghei in Mice Model

Dodonaea angustifolia has a wide range of therapeutic applications against various diseases including malaria. This plant is traditionally used for  treatment of malaria in different countries including Ethiopia. However, the antimalarial effect and safety of D. angustifolia are not studied. The aim of this study was to evaluate antimalarial activity of Dodonaea angustifolia in Plasmodium berghei infected mice. In the present study, aqueous and hydroalcoholic extracts as well as solvent fractions of the aqueous extract of D. angustifolia seeds were investigated for their antimalarial activity using Peters’ 4-day suppressive test method. Different concentrations of the crude extracts and the fractions of the water extract, most active  extract, were orally administered to screen for their antimalarial activities. The extracts significantly inhibited parasitemia and prevented packed cell volume reduction (p <0.05) dose-dependently. Crude extracts and fractions of the aqueous extract of D. angustifolia seeds increased the survival time of infected mice. None of the extracts, however, prevented body weight loss. The aqueous extract of D. angustifolia was found to produce 35.79% parasite suppression. From this extract, three fractions were produced by solvent fractionation technique using butanol, chloroform and water and tested in vivo against P. berghei in mice. The butanol fraction was found to be the most active producing inhibition of 48.6% at 100 mg/kg. The test substance observed to be safe with no toxicity on the mice even at 4500 mg/kg. The results of the present work supported thetraditional use of the plant against malaria and confirmed the antimalarial activity of the plant. Moreover, antimalarial compounds can be isolated from this plant and tested against human malaria parasite in the future.Keywords: Malaria; Dodonaea angustifolia; Extracts; Plasmodium berghe

evaluation of Lathyrus sativus cultivated in Ethiopia for proximate composition, minerals, β-ODAP and anti-nutritional components

Grass pea (Lathyrus sativus L.) is one of the most important food legumes in  countries like Bangladesh, India and Ethiopia. The legume is nutritious, rich in protein (28-32%) and contains good quantities of essential amino acids. Consumption of Lathyrus sativus seeds has been associated for more than 2000 years with neurolathyrim caused by the nearotoxin ß-ODAP (ß-N-Oxalyl-L-α, ßdiaminopropionic acid) present in the seeds. In the present study, Lathyrus  sativus seed samples  collected from the traditional grass pea growing areas in the country were analyzed for characteristics such as crude protein (CP), ß-ODAP, catechin equivalents (CE), trypsin inhibitor activity (TIA), 100 seed weight, seed color and consumption habit of grass pea seeds. The CP content ranged from 272.9 g/kg -1 to 319.8 g/kg -1 dry matter, the lowest and highest CP being observed in samples collected from Grar Jarso and Akaki, respectively. There were higher variations between samples in ß-ODAP levels. On average, ß-ODAP level in  samples from Akaki was about twofold higher than those from Asgido. CE, which detects simple flavonoids as well as condensed tannins, was not more than 7.66 g/kg-1 dry matter in any sample. The TIA content did not differ significantly between the samples. The correlation coefficients indicated that, ß-ODAP, CE, TIA and 100 seed weight were positively correlated (p<0.05) with CP. In contrast, CE and TIA were negatively correlated (p<0.05) with ß-ODAP. The dietary interviews revealed that grass pea has diversified uses in Ethiopia both as human food and  feed or crop. The habit of consuming shiro wot (the Ethiopian traditional spiced soup-like dish), kik wot (sauce made of dehusked split seeds) kollo (roasted whole seeds), nifro (boiled whole seeds) or kitta (unlearned flat bread) prepared from grass pea alone is significantly higher (p<0.05) than the habit of consuming those food items prepared from grass pea mixed with other legumes. Further studies are  warranted to understand the reasons that influenced food choices of the housewives for establishing respective ways to improve healthy consumption habits.Key words: consumption habit, Lathyrus sativus, ß-ODAP, tannins, trypsin inhibitor activity. Le petit pois (Lathyrus sativus L.) est l’une des légumineuses alimentaires les plus importantes dans des pays tels que le Bangladesh, l’Inde et l’Ethiopie. Les légumineuses sont nutritives, riches en protéines (28-32%) et elles contiennent de  bonnes quantités d’acides aminés essentiels. La consommation des graines de Lathyrus sativus a été associée pendant plus de 2000 ans au neurolathyrime causé par le néarotoxine ß-ODAP (ß-N-Oxalyl-L-α, l’acide ß- diaminopropionique) présentdans les graines. Au cours de la présente étude, des échantillons de graines de Lathyrus sativus collectés à partir des  régions où pousse le petit pois traditionnel dans le pays ont été analysés pour trouver des caractéristiques telles que les   protéines à l’état brut (CP), ß-ODAP, des équivalents de catéchine (CE), l’activité inhibitrice de trypsine (AIT), le poids de la graine 100, la couleur de la graine et les habitudes liées à la consommation des graines de petits pois. Le contenu de CP variait entre 272.9 g/kg -1 et 319.8 g/kg -1 de matière sèche, le niveau le plus bas et le plus élevé de CP étant observés dans des échantillons collectés à Grar Jarso et à Akaki, respectivement. Il y avait des variations plus élevées entre les    échantillons dans les niveaux de ß-ODAP. En moyenne, la teneur en ß-ODAP dans les échantillons d’Akaki était presque le double de celle des échantillons d’Asgido. CE, qui détecte de simples flavonoïdes et des tanins condensés, ne constituait pas plus de 7.66 g/kg-1 de matière sèche dans n’importe quel échantillon. La teneur en AIT ne différait pas beaucoup entre les échantillons. Les coefficients des  corrélations indiquaient que les poids des graines de ß-ODAP, CE, AIT et 100 avaient des corrélations positives (p<0.05) avec CP. Par contre, CE et AIT avaient une corrélation négative (p<0.05) avec ß-ODAP. Les interviews sur les régimes alimentaires ont révélé qu’en Ethiopie le petit pois est utilisé de manières  diversifiées à la fois en tant qu’aliment humain et en tant que ration de nourriture ou culture. L’habitude de consommer le shiro wot (un plat   traditionnel éthiopien épicé qui ressemble à de la soupe), le kik wot (sauce faite de graines cassées et décortiquées), le kollo (des graines entières rôties), le nifro (des graines entières bouillies) ou le kitta (un pain plat désappris), préparés à partir de petit pois  uniquement, est beaucoup plus répandue (p<0.05) que l’habitude de consommer ces denrées alimentaires  préparées à partir du petit pois mélangé avec d’autres légumineuses. Des études plus approfondies s’imposent pour   comprendre les  raisons qui ont influencé les choix des aliments chez les femmes au foyer pour établir les moyens respectifs d’améliorer des habitudes alimentaires saines.Mots-clés: habitude alimentaire, Lathyrus sativus, ß-ODAP, tanins, activité inhibitrice de trypsine.

The Effect of Clerodendrum Myricoides Aqueous Extract on Blood, Liver and Kidney Tissues of Mice

Clerodendrum myricoides is a plant traditionally used for its medicinal value in many parts of the world including Ethiopia. Several human defects are treated in different regions of Ethiopia using the roots, leaves, twigs, fruits and root barks of Clerodendrum myricoides species. The objective of the present study is to investigate the effect of the aqueous extract of Clerodendrum myricoides root on different tissue of mice in chronic administration. The root of the plant were collected in Bale area, Ethiopia dried and crushed into powder and soaked in water to yield aqueous extract. The extract was then administered to mice at doses of 100 and 400mg/kg bw/day for six weeks and 1134mg/kg bw/day (LD50) once. The 400mg/kg bw/day and LD50 treated mice showed hypoactivity (abnormally diminished activity), grooming, prostration (submissively prone position), piloroerection (elevation of hairs) and irritation, while 100mg/kg bw/day treated mice showed no behavioral changes. The dose of 100mg/kg bw/day produced significant weight gain, while 400mg/kg bw/day produced significant weight lost in chronic administration. The extract increased only urea at the dose of 100mg/kg bw/day, whereas it increases most hematological and biochemical parameters at 400mg/kg bw/day. The extract, however did not show significant change in platelet, HGB and MCHC value at both doses. Several histopathological changes in liver and kidney were also observed at both doses of the extract. There were inflammation and hydropic degeneration of hepatocytes at both doses. The LD50 of the extract produced hemorrhages and congestion in the glomeruli of the kidney

Toxic effects of aqueous leaf extract of Vernonia bipontini vatke on blood, liver and kidney tissue of mice

The present paper evaluates the acute and chronic toxicity of aqueous crude leaf extract of Vernonia bipontini Vatke (V. bipontini V) in mice model. Leaves of the plant were collected from Bale, Ethiopia, dried under shade, crushed into powder and soaked in water to yield the extract. Lethal dose of aqueous leaf extract of the plant was determined using nine groups of mice to which the aqueous leaf extracts of V. bipontini V was administered at doses ranging from 1250 to 3250mg/kg. All animals were closely observed for any physical and behavioral alterations for acute toxicity evaluation. For long-term toxicity evaluation, animals were subjected to oral administration of the extract at 400 and 800mg/kg, at 24 hours intervals for 45 days. The treated animals survived for 45 days. Body weights of the mice were recorded. Blood sample was collected from experimental and control groups for hematological studies and biochemical analysis on the 46th day after anesthesia. The liver and kidney of each animal were taken and examined by light microscope for any anatomical abnormalities. The LD50 was found to be 2500.62±5.24 mg/kg. The extract had no significant effect on liver and kidney weights, hematological (RBC, WBC, platelet, Hgb, Hct, Mcv, Mcv and L) and biochemical parameters such as liver AST, ALT and ALP; and kidney urea at all doses (P>0.05). Light microscope examination of liver and kidney tissue of mice treated with 400 and 800mg/kg of the extract did not show structural abnormalities. The results suggest that the extract of this plant may be safe, even when administered at a dose of 800mg/kg for 45 days. This is in agreement with the traditional claim of the water preparation of V. bipontini Vatke leaves.Key words: V. bipontini Vatke, Swiss Albino mice, Hematological and Biochemical parameters

Toxicological evaluation of methanol leaves extract of Vernonia bipontini Vatke in blood, liver and kidney tissues of mice

Background: Various medicinal plants have been studied using modern scientific approaches. These plants have a variety of properties and various biological components that can be used to treat various diseases. However, harmful effects of plants are common clinical occurrence.Objective: This study was designed to investigate toxicological assessment of acute and chronic methanol leaf extract of Vernonia bipontini Vatke (V.bipontini V) on blood, liver and kidney tissues of mice.Methods: Lethal dose (LD) at which 50% of experimental mice died and long term toxicity of methanolic leaf extract of V. bipontini V were determined. Some hematological and biochemical parameters were evaluated. Then, liver and kidney tissues of each animal were taken and processed for light microscopy.Results: Almost all mice treated with 800mg/kg methanol leaf extract of V. bipontini V showed swellings on the left part of abdominal region related to location of spleen, mild diarrhea and enlargement of spleen. The LD50 of the methanol leaf extract of V. bipontini V was 2130.6±1.5mg/kg. Treatment with 800mg/kg body weight of methanol leaf extract significantly decreased body, liver and kidney weights, red blood cells (RBC), haemoglobin (Hgb), mean cell haemoglobin (Mch), Mchc, platelet and significantly increased serum aspartate transferance (AST), vatanine tranferance (ALT) and alkaline phosphate (ALP) levels while 400mg/kg dose had no effect on these parameters. The reduced organ weights did not correlate with loss of body weight at 800mg/kg of methanol leaf extract of the plant. Light microscope observations of liver tissue of mice treated with 800mg/kg of the methanol leaf extract revealed dilated sinusoids, nuclear enlargement, lots of bi-nucleation of hepatocytes, peripheral cramped chromatin, shrinkages (single cell death) of hepatocytes, fragmentation of hepatocytes while no histopathological changes were observed in liver and kidney of mice treated at 400mg/kg. Kidney tissue sections of mice did not show significant histopathological changes at 400mg/kg. However, at 800mg/kg kidney sections showed increased cellularity of glomerulus, urinary space obliteration and enlarged macula densa.Conclusion: This study suggests that the methanol leaf extract may have been phytotoxic to liver that resulted in a rise in serum AST, ALT and ALP levels.Key words: V. bipontini Vatke, Swiss Albino mice, liver, kidney, methanol, hematological and biochemica

In vivo anti-malarial activity of hydroalcoholic extracts from Asparagus africanus Lam. in mice infected with Plasmodium berghei

Background: Malaria is a major public health problem in the world in general and developing countries in particular, causing an estimated 1-2 million deaths per year, an annual incidence of 300-500 million clinical cases and more than 2 billion people are at risk of infection from it. But it is also becoming more difficult to treat malaria due to the increasing drug resistance. Therefore, the need for alternative drugs is acute. Objective: The This study aims at investigating the in vivo antiplasmodial activity of extracts of the roots and area parts from traditionally used medicinal plant, named Asparagus africanus (Liliaceae). Methods: A rodent malaria parasite, Plasmodium berghei, which was maintained at the Ethiopian Health and Nutrition Research Institute (EHNRI) laboratory, was inoculated into Swiss albino mice. The mice were infected with 1x107 parasites intraperitoneally. The extracts were administered by an intra gastric tube daily for four days starting from the day of parasite inoculation. The control groups received the same amount of solvent (vehicle) used to suspend each dose of the herbal drug. Chloroquine was used as a standard drug, and was administered through the same route. Results: Extracts from the roots and aerial parts of A.africanus were observed to inhibit Plasmodium berghei parasitaemia in the Swiss albino mice by 46.1% and 40.7% respectively. Conclusion: The study could partly confirm the claim in Ethiopian traditional medicine that the plant has therapeutic values in human malaria. There is, thus, the need to initiate further in-depth investigation by using different experimental models. The Ethiopian Journal of Health Development Vol. 20 (2) 2006: 112-11

Immunogenicity and efficacy of non-adjuvant tissue culture-based rabies vaccine produced in Ethiopia

Rabies is 100% fatal, but it is preventable. More than 95% of human rabies cases occur in improperly treated individuals. This is partly due to the fact that modern post-exposure rabies prophylaxis is expensive and therefore not readily available in many endemic regions. Nervous tissue vaccine has been in use for more than 100yrs. These vaccines have now been superseded in purity, potency, immunogenicity and safety. The efficacy and immunogenicity of inactivated tissue culture rabies vaccine, produced in Ethiopia was evaluated. Twelve experimental dogs from local breed were duly conditioned during a quarantine period and assigned to two groups randomly. Animals in group I (cases) were vaccinated subcutaneously with 1 ml of our experimental vaccine. Dogs in group II served as non-vaccinated controls. The immune response of each dog was monitored for 90 days. On the day 90 after final sampling, all dogs were challenged in the masseter muscle with a rabies street virus of canine origin. To evaluate the titer of the rabies virus neutralizing antibodies (VNA), sera were analyzed by Fluorescent Antibody Virus Neutralization (FAVN) Test. Geometric Mean Titers (GMT) to rabies virus was determined at days 7, 15, 21, 30, 60 and 90. Geometric mean titers were equal to 1.59, 1.73, 2.19, 3.58, 3.17 and 3.35 IU/ml respectively. All dogs showed VNA titers higher than the 0.5 IU/ml mandated WHO recommended threshold. All vaccinated dogs, survived the challenge. In contrast, 83.3% of dogs in the control (non-vaccinated group), developed rabies and died. This study indicated that cell culture-based anti-rabies developed inhouse, with no adjuvant is efficacious and immunogenic

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses