Eddy Elkana Owaga

Dr. Eddy Elkana Owaga


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 February 2022 in Journal of Toxicology
Verified
Journal Article
Open access
PDF file
EWEliud Wafula
Eliud Wafula
CMChristabel N. Muhonja
Christabel N. Muhonja
JKJosiah O. Kuja
Josiah O. Kuja
EOEddy Elkana Owaga
Eddy Elkana Owaga
HMHuxley M. Makonde
Huxley M. Makonde
VKVirginia Kimani
Virginia Kimani
Cereals play an important role in global food security. Data from the UN Food and Agriculture Organization projects increased consumption of cereals from 2.6 billion tonnes in 2017 to approximately 2.9 billion tonnes by 2027. However, cereals are prone to contamination by toxigenic fungi, which lead to mycotoxicosis. The current methods for mycotoxin control involve the use of chemical preservatives. However, there are concerns about the use of chemicals in food preservation due to their effects on the health, nutritional quality, and organoleptic properties of food. Therefore, alternative methods are needed that are affordable and simple to use. The fermentation technique is based on the use of microorganisms mainly to impart desirable sensory properties and shelf-life extension. The lactic acid bacteria (LAB) are generally regarded as safe (GRAS) due to their long history of application in food fermentation systems and ability to produce antimicrobial compounds (hydroxyl fatty acids, organic acids, phenyllactic acid, hydrogen peroxide, bacteriocins, and carbon dioxide) with a broad range of antifungal activity. Hence, LAB can inhibit the growth of mycotoxin-producing fungi, thereby preventing the production of mycotoxins. Fermentation is also an efficient technique for improving nutrient bioavailability and other functional properties of cereal-based products. This review seeks to provide evidence of the potential of LAB from African fermented cereal-based products as potential biological agents against mycotoxin-producing fungi.

19 December 2023 in Antioxidants
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Journal Article
Open access
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JUJureeporn U-pathi
Jureeporn U-pathi
YYYen-Chia Yeh
Yen-Chia Yeh
CCChia-Wen Chen
Chia-Wen Chen
EOEddy Elkana Owaga
Eddy Elkana Owaga
RHRong-Hong Hsieh
Rong-Hong Hsieh
There are emerging concerns about the potential cerebral cortex injury from aspartame due to the accumulation of the various neurotoxic metabolic components in the central nervous system after long-term dietary exposure. The aim of this study was to evaluate the effect of oral aspartame consumption on cerebral cortex injury in the rat brain, and further evaluate the various underlying molecular mechanisms, with a special focus on oxidative stress, inflammation, mitochondrial dysfunction, and apoptosis pathways. Sprague Dawley rats (nineteen, female) were randomly sub-divided into three groups: (i) normal diet with vehicle: control group (five rats), (ii) low dose of aspartame group (LA): seven rats received 30 mg/kg body weight (bw) daily doses of aspartame, (iii) high dose of aspartame group (HA): seven rats received 60 mg/kg bw daily doses of aspartame. After 8 weeks, the LA and HA groups showed lower expression levels of brain-derived neurotrophic factor (BDNF), antioxidant enzyme activity (SOD2, CAT), antioxidant marker (Nrf2), inflammatory response (IκB), mitochondrial biogenesis (Sirt1, PGC1α, Nrf1, TFAM), mitochondrial DNA (mtDNA) copy number, and apoptosis-related proteins (Bax, Caspase-3) expressions. Aspartame administration also elevated oxidative stress levels (Malondialdehyde, MDA), 8-hydroxy-2-deoxy guanosine (8-OHdG), PGE2 and COX-2 expressions, pro-inflammatory cytokines (TNFα, IL6, IL1β), antioxidant marker expression (Keap1), inflammatory responses (iNOS, NFκB), and glial fibrillary acidic protein (GFAP) levels in the cerebral cortex of the rats, thereby contributing to the reduced survival of pyramidal cells and astrocyte glial cells of the cerebral cortex. Therefore, these findings imply that aspartame-induced neurotoxicity in rats’ cerebral cortex could be regulated through four mechanisms: inflammation, enhanced oxidant stress, decreased mitochondrial biogenesis, and apoptosis pathways.

11 February 2023 in Bacteria
Verified
Journal Article
Open access
PDF file
MIMarie Lys Irakoze
Marie Lys Irakoze
EWEliud Wafula
Eliud Wafula
EOEddy Elkana Owaga
Eddy Elkana Owaga
Traditional preparation of African indigenous vegetables (AIVs) such as African black nightshade (Solanum nigrum) and African spiderplant (Cleome gynandra) involves either boiling and discarding the first water or lengthy boiling. Fermentation is considered a better alternative processing technique due to the enhanced retention of phytochemical contents and sensory properties. However, little is known about the impact of lactic acid fermentation on the phytochemical content, antioxidant capacity, sensory acceptability and microbial safety of the African black nightshade and African spiderplant. This study aimed to ferment AIVs using combined starter cultures (Lactobacillus fermentum and Lactococcus lactis) and further determine their effect on the phytochemical content (phenolic compounds and flavonoids), antioxidant capacity, sensory acceptability and microbial safety of the vegetables. There was a marked increase in phenol and flavonoid contents in all fermented vegetables (p < 0.05). The highest phenol content was 228.8 mg/g GAE (gallic acid equivalent) in the starter-culture-inoculated African black nightshade, while flavonoid content was 10.6 mg/g QE (quercetin equivalent) in the same. Starter-culture-inoculated AIVs presented significantly higher antioxidant capacity with a 60–80% radical scavenging activity compared to levels in uninoculated batches (p < 0.05). Fermented vegetables were more liked than the boiled vegetables and were microbiologically safe. In conclusion, lactic fermentation of AIVs increased phytochemical contents (phenolic compounds and flavonoids), maintained antioxidant capacity and improved product safety and sensory acceptability. Therefore, fermentation and consumption of the African indigenous vegetables are to be encouraged.

17 May 2020 in Nutrients
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Journal Article
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CCChing-Chien Chang
Ching-Chien Chang
CCChia-Wen Chen
Chia-Wen Chen
EOEddy Elkana Owaga
Eddy Elkana Owaga
WLWan-Ting Lee
Wan-Ting Lee
TLTing-Ni Liu
Ting-Ni Liu
RHRong-Hong Hsieh
Rong-Hong Hsieh
High-strength or long-duration exercise can lead to significant fatigue, oxidative stress, and muscle damage. The purpose of this study was to examine the effect of mangosteen concentrate drink (MCD) supplementation on antioxidant capacity and lactate clearance in rats after running exercise. Forty rats were divided into five groups: N, non-treatment; C, control; or supplemented with MCD, including M1, M5, and M10 (0.9, 4.5, and 9 mL/day) for 6 weeks. The rats were subjected to 30 min running and exhaustive-running tests using a treadmill. The blood lactate; triglyceride; cholesterol and glucose levels; hepatic and muscular malonaldehyde (MDA) levels; and antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), were analyzed. The results of this study demonstrated that MCD supplementation can increase GPx and CAT activities, alleviate oxidative stress in muscle, and increase lactate clearance, and is thereby beneficial to reduced muscle fatigue after exercise.

19 July 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
TCTai-Ling Chueh
Tai-Ling Chueh
ZWZih-Ling Wang
Zih-Ling Wang
YNYi Jing Ngu
Yi Jing Ngu
PLPo-Lin Lin
Po-Lin Lin
EOEddy Elkana Owaga
Eddy Elkana Owaga
RHRong-Hong Hsieh
Rong-Hong Hsieh
Effective weight management interventions involve a combination of behavioral strategies focusing on dietary changes. Tracing the change through mobile apps has been proven to be a valuable platform for facilitating weight management in many countries. However, the effectiveness of mobile app-based dietary intervention on weight management in Taiwan remains to be determined. By using the designated mobile app, this study aimed to assess the efficacy of the diet intervention, which is based on a 2:1:1 portion control plate and a flexible low-carbohydrate (FLC) diet. This 8-week retrospective cohort study involved 10,297 participants who were divided into two groups: the intervention group (joined an 8-week diet intervention program with the daily diet record assessed by registered dietitians) and the control group (voluntarily using the app without instructional materials or coaching). After eight weeks of intervention, the intervention group showed a higher weight loss percentage (−4.78% vs. −1.54%), body mass index (BMI) (−1.26 kg/m2 vs. 0.69 kg/m2), and diet record completeness (73.52% vs. 28.91%) compared with the control group. With respect to gender, male participants showed higher baseline weight and higher weight loss (−6.02%) in the intervention group. In the intervention group, 2871 participants (33.4%) lost less than 4% of their weight, 5071 participants (58.9%) lost 4–8% of their body weight, and 662 participants (7.7%) lost >8% of their weight. Compared to the low-effectiveness group (weight lost 8%) had a significantly higher diet record completeness (91.61 ± 15.99 vs. 55.81 ± 32.92), dietary compliance (green light %) (88.93 ± 9.9 vs. 77.75 ±17.5), protein intake % (26.34 ± 2.85 vs. 23.49 ± 3.56), and fat intake % (49.66 ± 6.36 vs. 44.05 ± 7.37). Most importantly, the high-effectiveness group had a lower carbohydrate intake % (24.1 ± 7.86 vs. 32.46 ± 9.61). The results remained significant after being stratified by gender. This study found that the use of online applications plus the intervention of dietitians is beneficial for short-term weight loss. The composition of nutrients and dietary compliance also significantly impacted weight loss.

26 June 2026 in Antioxidants
Verified
Journal Article
Open access
PDF file
MSMing-Hung Shen
Ming-Hung Shen
PLPei-hsuan LU
Pei-hsuan LU
TTTING-YU TSAI
TING-YU TSAI
EOEddy Elkana Owaga
Eddy Elkana Owaga
YTYi-Sheng Tsai
Yi-Sheng Tsai
RHRong-Hong Hsieh
Rong-Hong Hsieh
Global plastic production has led to widespread contamination by micro- and nanoplastics, with polystyrene nanoplastics (PSNPs) increasingly being detected in human biological samples, including blood and cardiac tissue. Given the critical role of mitochondria in cardiac energy metabolism, this study investigated whether 100 nm PSNPs interact with mitochondria and affect mitochondrial function in H9c2 cardiomyoblasts. Cellular uptake and intracellular distribution were examined, followed by an evaluation of mitochondrial ultrastructure, intracellular and mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential, mitochondrial dynamics and mitophagy-related gene expression, mitochondrial DNA copy number, and metabolic function. PSNPs were internalized but did not directly localize to mitochondria within 24 h. No significant cytotoxicity, increase in intracellular or mitochondrial ROS production, or alteration in basal metabolic activity was observed. However, PSNP exposure resulted in intracellular accumulation, an altered mitochondrial ultrastructure characterized by crista loosening and vacuole-like structural changes. These changes were accompanied by reduced mitochondrial membrane potential; the upregulation of mitochondrial dynamics-related genes, including optic atrophy 1 (Opa1) and dynamin-related protein 1 (Drp1); the suppression of PTEN-induced kinase 1 (PINK1)/Parkin RBR E3 ubiquitin protein ligase (Parkin)-mediated mitophagy-related genes; and decreased maximal respiratory capacity. Lactate production and the extracellular acidification rate remained unchanged, suggesting that compensatory glycolysis was not activated. These findings indicate that PSNP exposure induces early mitochondrial structural and functional alterations without substantial cell damage, suggesting a potential reduction in cardiac adaptive capacity under PSNP-induced stress conditions.