Fluoride levels and its safety in Tea (Camellia sinensis) and Khat (Catha edulis) imported and produced in Ethiopia

The fluoride contents of sixteen(16) different packed tea leaves (Camellia sinensis) available in Ethiopian market and ten(10) samples of Khat leaves (Catha edulis) obtained from different localities were assessed using fluoride ion selective electrode. Amounts measured varies from 33.29 to 946 μg/gm on dried weight basis (DW) with an average value of 321.27±234.1 in tea samples and 13 to 20.01 μg/gm with a mean quantity of 14.94 ±1.45 in khat Samples. Based on the common practice of drinking tea three times a day by most people which is usually prepared using six grams of tea leaves and 100 to 200 gm chewing of khat leaves for those habitual users, possible daily intake of fluoride is calculated to be 1972.62 μg and 224.1-448.2 μg from tea and khat respectively based on the average fluoride quantity data from all the samples investigated. These values alone are within acceptable range of RDA (recommended daily allowance) of 2-4 mg fluorine by World Health Organization (WHO) except in one Ethiopian brand of tea where in its possible consumption the RDA limit was surpassed. Although dental problems were commonly reported in habitual khat chewers, the fluoride content of this plant is insignificant thus the chemical principle associated with such problems might be due to other ingredient(s) than fluorine. However the contribution of these plants to the overall dietary fluoride exposure should not be undermined and attention should be given to that of high values reported in tea leaves. Therefore drinking tea in areas with high fluoride levels from water sources should be cautioned to avoid the potential acute and chronic effects of fluoride.Key Words: Fluoride, Tea, Khat, Ethiopia, Ion selective electrod

Levels of essential and toxic metals in Ethiopian khat, (Catha Edulis Forsk.)

Khat chewing is a common habit in East Africa and Arabian Peninsula. However, detail of in-organic elemental content of this plant is scarcely known. Samples of khat (Catha edulis) were collected from different parts ofEthiopia. The leaf parts, which are chewed, were separated and air dried at room temperature. The dried samples were grounded to a fine size by the use of stainless steel mills. One gram was mineralized for metal analysis via digestion in aqua regia under reflux. Spiking was performed to check the accuracy of the digestion procedure. Recoveries varied from 84.5 % to 109.6 %. Thirteen metal concentrations were measured by Flame Atomic Absorption/Emission Spectrometer and Graphite Furnace Atomic Absorption Spectrometer employing an external calibration curve. Levels of metals (mg/kg) on Dried Weight Basis were recorded as follows; Cu: 5.11-9.55 Cd: 0.03-6.54 Pb: non detectable to 1.57 Zn: 4.15-89.3 Mn:6.45-20 K: 5929.65-10948 Na: 218.2-842.25 Li: 0.1-0.85 Al: 2448.15-8556.45 Ba: 12.13-1479 Mg: 1798.5.5-3098.75 Fe: 260.95-1551.8 Ca: 2190.9- 10985.8. The possible consumption for the measured elements by chewing khat on regular basis lies within the recommended daily allowance (RDA) except for Al, Fe and Ba. Detection of toxic elements like Cd and Pb in khat plant samples investigated might be related to possible introduction of artificial contaminants to the ecosystem of Ethiopia. But the quantities found are in very small amounts thus there should not be an alarm  although usual precautions of keeping the environment safe from artificial hazards is necessary. The levels of the analyzed elements in khat that surpassed the RDA i.e. Barium may expose the khat users to damages toheart, blood vessels and nervous system, Iron may facilitate growth of certain pathogenic microorganisms and Aluminium also had unconfirmed correlations under study with neuro-disorders.Key Words: Khat, Catha edulis, Metals, Flame Atomic Absorption/Emission Spectrometer (FAAS), Graphite Furnace Atomic Absorption Spectrometer (GFAAS), Ethiopia

Liver Cirrhosis of Unknown Etiology and Its Predictors in Eastern Ethiopia

Background: The global burden of liver cirrhosis is increasing, with 2.1 million incident cases and nearly 1.5 million deaths in 2019. Despite the enormous progress in our understanding of the etiology of liver cirrhosis, significant cases of the disease have been reported in Eastern Ethiopia due to unidentified causes. Hence, this study aimed to identify predictors of liver cirrhosis of unknown etiology in Eastern Ethiopia. Methods: A score of 7 out of 11 possible points on the ultrasound-based cirrhosis scale was used as a diagnostic criterion to include 127 liver cirrhosis patients. The study participants’ demographic, dietary, lifestyle, and clinical data were gathered using a structured questionnaire and standardized reporting forms. The associations between the outcome (known and unknown etiology) and indepen-dent variables were modeled using binary logistic regression analysis. Results: The etiology of liver cirrhosis was known in only 23% of patients and attributed to hepatitis B virus (21%), hepatitis C virus (0.8%), and alcohol abuse (0.8%). Sorghum consumption as a staple food (adjusted odds ratio (AOR) =3.8; 95% CI: 1.2, 12.5), splenomegaly (AOR = 4.0; 95% CI: 1.1, 14.4), and a family history of liver disease (AOR = 0.24; 95% CI: 0.06, 0.91) were significantly associated with liver cirrhosis of unknown etiology. Conclusion: Sorghum consumption was found to be the determinant factor of liver cirrhosis of unknown etiology, suggesting it as a possible source of exposure to aflatoxin B1

Regulation of Amyloid Precursor Protein Processing by the Beclin 1 Complex

Autophagy is an intracellular degradation pathway that functions in protein and organelle turnover in response to starvation and cellular stress. Autophagy is initiated by the formation of a complex containing Beclin 1 (BECN1) and its binding partner Phosphoinositide-3-kinase, class 3 (PIK3C3). Recently, BECN1 deficiency was shown to enhance the pathology of a mouse model of Alzheimer Disease (AD). However, the mechanism by which BECN1 or autophagy mediate these effects are unknown. Here, we report that the levels of Amyloid precursor protein (APP) and its metabolites can be reduced through autophagy activation, indicating that they are a substrate for autophagy. Furthermore, we find that knockdown of Becn1 in cell culture increases the levels of APP and its metabolites. Accumulation of APP and APP C-terminal fragments (APP-CTF) are accompanied by impaired autophagosomal clearance. Pharmacological inhibition of autophagosomal-lysosomal degradation causes a comparable accumulation of APP and APP-metabolites in autophagosomes. Becn1 reduction in cell culture leads to lower levels of its binding partner Pik3c3 and increased presence of Microtubule-associated protein 1, light chain 3 (LC3). Overexpression of Becn1, on the other hand, reduces cellular APP levels. In line with these observations, we detected less BECN1 and PIK3C3 but more LC3 protein in brains of AD patients. We conclude that BECN1 regulates APP processing and turnover. BECN1 is involved in autophagy initiation and autophagosome clearance. Accordingly, BECN1 deficiency disrupts cellular autophagy and autophagosomal-lysosomal degradation and alters APP metabolism. Together, our findings suggest that autophagy and the BECN1-PIK3C3 complex regulate APP processing and play an important role in AD pathology

Cell type-specific over-expression of chromosome 21 genes in fibroblasts and fetal hearts with trisomy 21

BACKGROUND: Down syndrome (DS) is caused by trisomy 21 (+21), but the aberrations in gene expression resulting from this chromosomal aneuploidy are not yet completely understood. METHODS: We used oligonucleotide microarrays to survey mRNA expression in early- and late-passage control and +21 fibroblasts and mid-gestation fetal hearts. We supplemented this analysis with northern blotting, western blotting, real-time RT-PCR, and immunohistochemistry. RESULTS: We found chromosome 21 genes consistently over-represented among the genes over-expressed in the +21 samples. However, these sets of over-expressed genes differed across the three cell/tissue types. The chromosome 21 gene MX1 was strongly over-expressed (mean 16-fold) in senescent +21 fibroblasts, a result verified by northern and western blotting. MX1 is an interferon target gene, and its mRNA was induced by interferons present in +21 fibroblast conditioned medium, suggesting an autocrine loop for its over-expression. By immunohistochemistry the p78(MX1 )protein was induced in lesional tissue of alopecia areata, an autoimmune disorder associated with DS. We found strong over-expression of the purine biosynthesis gene GART (mean 3-fold) in fetal hearts with +21 and verified this result by northern blotting and real-time RT-PCR. CONCLUSION: Different subsets of chromosome 21 genes are over-expressed in different cell types with +21, and for some genes this over-expression is non-linear (>1.5X). Hyperactive interferon signaling is a candidate pathway for cell senescence and autoimmune disorders in DS, and abnormal purine metabolism should be investigated for a potential role in cardiac defects

Perinatal asphyxia: current status and approaches towards neuroprotective strategies, with focus on sentinel proteins

Delivery is a stressful and risky event menacing the newborn. The mother-dependent respiration has to be replaced by autonomous pulmonary breathing immediately after delivery. If delayed, it may lead to deficient oxygen supply compromising survival and development of the central nervous system. Lack of oxygen availability gives rise to depletion of NAD+ tissue stores, decrease of ATP formation, weakening of the electron transport pump and anaerobic metabolism and acidosis, leading necessarily to death if oxygenation is not promptly re-established. Re-oxygenation triggers a cascade of compensatory biochemical events to restore function, which may be accompanied by improper homeostasis and oxidative stress. Consequences may be incomplete recovery, or excess reactions that worsen the biological outcome by disturbed metabolism and/or imbalance produced by over-expression of alternative metabolic pathways. Perinatal asphyxia has been associated with severe neurological and psychiatric sequelae with delayed clinical onset. No specific treatments have yet been established. In the clinical setting, after resuscitation of an infant with birth asphyxia, the emphasis is on supportive therapy. Several interventions have been proposed to attenuate secondary neuronal injuries elicited by asphyxia, including hypothermia. Although promising, the clinical efficacy of hypothermia has not been fully demonstrated. It is evident that new approaches are warranted. The purpose of this review is to discuss the concept of sentinel proteins as targets for neuroprotection. Several sentinel proteins have been described to protect the integrity of the genome (e.g. PARP-1; XRCC1; DNA ligase IIIα; DNA polymerase β, ERCC2, DNA-dependent protein kinases). They act by eliciting metabolic cascades leading to (i) activation of cell survival and neurotrophic pathways; (ii) early and delayed programmed cell death, and (iii) promotion of cell proliferation, differentiation, neuritogenesis and synaptogenesis. It is proposed that sentinel proteins can be used as markers for characterising long-term effects of perinatal asphyxia, and as targets for novel therapeutic development and innovative strategies for neonatal care

Evaluation of the Diuretic Activity and Phytochemical Screening of Different Solvent Fractions of the Rhizomes of Rumex abyssinicus Jacq (Polygonaceae) in Rats

Rumex abyssinicus J. (Polygonaceae) is a widely spread medicinal plant used traditionally to treat a variety of diseases, including hypertension. Previous study confirmed the diuretic effect of the aqueous and 80% methanol crude extracts of the plant, of which the 80% methanol extract produced a better diuresis. The aim of this study was to investigate which solvent fraction(s) of the 80% methanol extract would be responsible for the diuretic effect of the plant. Diuretic activity was examined in adult male rats, which were orally administered with aqueous, methanol and ethyl acetate fractions of 80% methanol extract of R. abyssinicus at doses of 250, 500 and 750 mg/kg; furosemide (10 mg/kg) or vehicle. Total urine output and electrolyte content of the urine was computed over 24 h period and compared with the standard and negative controls. Phytochemical composition of the fractions was also investigated using standard tests. The methanol (p<0.01) and ethyl acetate (p<0.001) fractions induced a significant diuresis at the lower dose (250 mg/kg) compared to the aqueous fraction, which produced a notable effect only at its higher dose. Both fractions also increased urinary electrolyte excretion significantly (p<0.001) at their highest doses. Whilst the ethyl acetate fraction increased urine output comparably to that of furosemide, the methanol fraction showed the highest saluretic effect. These findings collectively indicate that an increase in urine volume is observed with decreasing polarity of the fractions. This suggests that the diuretic activity of the plant might be mostly due to active principles contained in the less polar fractions.Keywords: Rumex abyssinicus, Furosemide, Diuretic Activity, Electrolytes, Solvent Fraction

The Essential Oil of Myrtus communis L. Produces a Non-Sedating Anxiolytic Effect in Mice Models of Anxiety

The myrtle shrub (Myrtus communis L., Myrtaceae) is rich in essential oils used in Ethiopian traditional medicine for the treatment of a variety of ailments, including anxiety. Anxiety is a common disorder that attacks many people in society and often accompanied by physiological sensations such as tachycardia, chest pain, shortness of breath, and insensitivity. The present study was undertaken to evaluate the anxiolytic effect of the essential oil of M. communis using different models of anxiety. Swiss Albino mice of either sex were randomly divided into six groups. Tween 80 (5%, v/v) in distilled water was administered to Group I and served as control. Group II was given diazepam (0.5 mg/kg, orally) suspended in Tween 80 and served as standard. Group III-VI were given the essential oil at doses of 50, 100, 200 and 400 mg/kg, respectively. Animals were then subjected to different anxiety tests, including elevated plus maze (EPM), stair case and open field. Parameters, among others, percentage of time spent in each arm and arm entries, number of steps climbed and number of rears, and number of crossings were then measured. Data were presented as mean ± SEM and analyzed by ANOVA followed by Tuckey posthoc test. In EPM studies, the essential oil at both 100 mg/kg (p<0.01) and 200 mg/kg (p<0.05), as well as diazepam (p<0.01) produced a significant increase in percentage of open arm time compared to controls. In the staircase setting, rearing was significantly decreased with 100 mg/kg (p<0.01) and 200 mg/kg (p<0.05) of the oil, and diazepam (p<0.05) relative to controls. However, at doses of 50 mg/kg and 400 mg/kg no detectable changes were noted on the measured parameters in both EPM and stair case models. The total number of entries into open field was comparable in all groups. At a dose of 100 mg/kg, the essential oil of M. communis showed better anxiolytic activity than the standard drug. The possible mechanism by which the oil showed the activity could be through GABA-related mechanisms. The present work, therefore, holds up the traditional use of the plant for the treatment of anxiety.Keywords: Myrtus communis, essential oil, anxiety, elevated plus maze, stair case, open fiel

Screening of the Antidepressant-like Activity of Two Hypericum Species Found in Ethiopia

The widespread use of Hypericum perforatum for the treatment of mild to moderate depression has prompted screening of the antidepressant-like effect of other species of the genus. The present study was designed to assess the antidepressant-like activity of the 80% methanol extract of Hypericum quartinianum and Hypericum revolutum in behavioral despair model. Eighty percent methanol extract of H. quartinianum and H. revolutum was investigated using learned helplessness models of depression such as tail suspension test (TST), forced swimming tests (FST) and avoidance tests. In addition, locomotor activity was investigated with open field test (OFT). Mice (for TST, avoidance test and OFT) and rats (for FST) were randomly assigned into different groups and treated with distilled water (control), imipramine 64 mg/kg (standard) and extract (200 mg/kg and 400 mg/kg). At 200 and 400 mg/kg, H. revolutum was effective in reducing immobility time in the TST (43.84%, p<0.01 and 49.08%, p<0.01, respectively) and FST (33.7%, p<0.05 and 38.4%, p<0.01, respectively). Similarly, H. quartinianum also showed anti-immobilty effect at 200 (30.67%, p<0.01) and 400 mg/kg (41.19%, p<0.01) in TST. However, only the larger dose produced significant anti-immobility effect in FST (35.3%, p<0.05). Moreover, both extracts at the doses used significantly decreased the escape failure (p<0.01) and increased the intertrial crossing (p<0.05 and p<0.01) during the resting periods in the avoidance task in a shuttle box. In OFT, the tested crude extracts did not significantly alter locomotor activity, suggesting that it is very unlikely that the observed antidepressant effects are false positives. These observations together provide evidence that the 80% methanolic extract of leaves of H. quartinianum and H. revolutum display antidepressant-like actions in established models of behavioral despair without affecting locomotion.Keywords: Hypericum quartinianum, Hypericum revolutum, depression, antidepressant-like activit