Department of Chemistry and Biochemistry

Effects of Adsorbent Dosage and Particle Size on Fluoride Removal Using Calcium-Spiked Moringa oleifera Seed Powder

2026-06-15T12:35:20Z

Effects of Adsorbent Dosage and Particle Size on Fluoride Removal Using Calcium-Spiked Moringa oleifera Seed Powder Chavaregi, Geoffrey,; Lusweti, John; Keronei, Pius Access to safe drinking water remains a major challenge in fluoride-endemic regions, where excessive fluoride concentrations can lead to dental and skeletal fluorosis. This study evaluated the effects of adsorbent dosage, particle size, and particle size classification (mesh size) on the fluoride removal performance of Moringa oleifera seed powder (MOSP) in both calcium-spiked and non-spiked forms. A three-factor factorial batch adsorption experiment was conducted using initial fluoride concentration of 1ppm, dosages of 0.25–2.0 g/100 mL, particle sizes of <250 μm, 250–500 μm, and >500 μm, and mesh classifications of 20 (850 μm), 40 (425 μm), and 60(250 μm). Response variables included fluoride removal efficiency, residual fluoride concentration, and adsorption capacity (qe), measured using a fluoride ion-selective electrode. ANOVA and linear regression were applied to evaluate the dose and size response relationships. Results showed that calcium-spiked MOSP consistently outperformed non-spiked MOSP across all parameters. Fluoride removal efficiency increased with dosage, reaching 88.95% for spiked and 70.34% for non-spiked MOSP at 2.0 g. Finer particle sizes and smaller mesh fractions significantly enhanced removal efficiency and reduced residual fluoride levels, with spiked MOSP at ≤250 μm achieving 89.80% removal and residual fluoride below WHO guidelines. Regression analysis confirmed strong inverse relationships between particle size/mesh size and fluoride removal performance, and positive correlations with dosage. The improved performance of calcium-spiked MOSP is attributed to increased surface-active Ca2+ sites enabling precipitation of CaF2 and enhanced adsorption via electrostatic attraction and ion exchange. These findings indicate that calcium-spiked MOSP, optimally prepared at fine particle size and moderate dosage, is a viable, locally sourced defluoridation medium suitable for rural water treatment systems.

Fluoride Removal Efficiency of Calcium-spiked and Non-spiked Moringa Oleifera Seed Powder

2026-06-15T12:27:46Z

Fluoride Removal Efficiency of Calcium-spiked and Non-spiked Moringa Oleifera Seed Powder Chavaregi, Chavaregi; Lusweti, John; Keronei, Pius Fluoride contamination in drinking water remains a widespread public health concern, particularly in arid and semi-arid regions where groundwater is the primary source of potable water. Chronic exposure to elevated fluoride levels—commonly above the World Health Organization’s (WHO) recommended limit of 1.5 mg/L—can result in dental and skeletal fluorosis, affecting millions of people globally. Affordable and effective defluoridation technologies are urgently needed, especially in low-income rural settings. In this study, the fluoride removal efficiency of calcium-spiked and non-spiked Moringa oleifera seed powder was investigated through controlled laboratory batch adsorption experiments. Biosorbents were prepared by treating ground seed powder with 1% calcium chloride solution and characterised based on their performance across five fluoride concentrations (1-20 ppm). Key parameters such as removal efficiency, residual fluoride levels, and adsorption capacity (qe) were evaluated under consistent operating conditions (pH 7, 2 g/50 mL dose, mesh 40, 120 minutes). Results indicated that calcium-spiked Moringa oleifera powder significantly outperformed its non-spiked counterpart. At 1 ppm, the spiked adsorbent achieved 94.35 ±1.15% removal efficiency, compared to 81.45 ±1.35% for the non-spiked. At the highest tested concentration (20 ppm), the spiked biosorbent still removed 72.31 ±1.80% of fluoride, while the non-spiked removed only 54.21 ±1.95%. Linear regression models showed strong inverse correlations between fluoride concentration and removal efficiency (R2 > 0.99, p < 0.001). The spiked adsorbent also resulted in significantly lower residual fluoride concentrations, with final values closer to the WHO guideline. One-way ANOVA confirmed significant differences in adsorption capacity and efficiency between treatments (p < 0.001). These findings highlight the effectiveness of calcium modification in enhancing biosorption performance and suggest that calcium-spiked Moringa oleifera seed powder is a promising, low-cost, and environmentally friendly solution for mitigating fluoride contamination in drinking water.

DETERMINATION OF DIABETIC WOUND HEALING, ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY OF Cyathula uncinulata CRUDE LEAF EXTRACT IN FRUCTOSE-INDUCED DIABETIC WISTAR RATS

2026-06-11T08:35:14Z

DETERMINATION OF DIABETIC WOUND HEALING, ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY OF Cyathula uncinulata CRUDE LEAF EXTRACT IN FRUCTOSE-INDUCED DIABETIC WISTAR RATS KILONZO, MUTUKU The treatment of a wound in a diabetic patient is difficult for clinicians and researchers since it often heals very slowly, due to lasting inflammation and is subject to prolonged oxidative stress. The current treatments have adverse side effects, are expensive, inaccessible and sometimes inefficient leading to death, infections, reduced quality of life and amputation. Therefore, there is a critical need for affordable, accessible and effective alternatives for diabetic wound management. C. uncinulata has been traditionally used in treatment of wounds and despite the wide spread use there is no scientific evidence to support it in the management of diabetic wounds. Therefore, this study aimed to investigate the phytochemicals, antioxidant activity and Wound healing (WH) features of C. uncinulata leaves extracts in fructose-induced diabetic Wistar rats. Phytochemical screening of the methanolic leaf extract showed higher presence of a high concentration of flavonoids, alkaloids and tannins, as compared to aqueous extract; methanolic extract was selected for in vivo studies. Thirty-five male rats were randomly assigned to seven groups. Two groups received topical methanolic extract, with one group treated with a low dose of 300 mg/kg and the other with a high dose of 600 mg/kg. One group was administered Floxapen (0.2 mL/day). The remaining groups served as controls, with some receiving a vehicle treatment or no treatment at all in this case diabetic control group. The rats were induced with a specific type of injury, which was then topically treated as per the experimental design. The low dose of 300 mg/kg was considered the lower dose, while 600 mg/kg represented the higher dose in the study. In vitro, the methanolic leaf extract showed significant antioxidant activity at all tested concentrations, comparable to ascorbic acid, as well as Hydrogen Peroxide (HP) scavenging, reducing power and catalase enzyme activity (P<0.05). Additionally, the methanolic leaf extract showed significant protection of albumin against protein denaturation at higher doses. In vivo studies, rats treated with the high dose of methanolic extract exhibited faster wound contraction, with their wounds completely healed by day 21. This outcome was similar to the group treated with the standard drug Floxapen, which also showed complete wound healing by the same time point. The Kaplan-Meier curves for the healing rate demonstrated that the treated groups healed faster than the control groups. According to this study’s findings, Cyathula uncinulata had the potential as one of the natural therapeutic agents for the management of diabetic patient wounds due to its antioxidant, anti-inflammatory, and WH properties. These effects indicated that further studies need to be conducted to identify and describe the molecules that act in this way.

AQUEOUS FLUORIDE BIOSORPTION USING CALCIUM-SPIKED AND NON- SPIKED Moringa oleifera SEED POWDER: INFLUENCE OF DOSAGE, PARTICLE SIZE, AND PROCESS PARAMETERS

2026-06-03T12:48:43Z

AQUEOUS FLUORIDE BIOSORPTION USING CALCIUM-SPIKED AND NON- SPIKED Moringa oleifera SEED POWDER: INFLUENCE OF DOSAGE, PARTICLE SIZE, AND PROCESS PARAMETERS CHAVAREGI, GEOFFREY Excessive fluoride concentrations in drinking water pose serious public health risks, including dental and skeletal fluorosis, particularly in rural, semi-arid and arid regions of developing countries where groundwater is the primary source of potable water. Traditional defluoridation methods remain costly, chemically intensive, or environmentally unsustainable, prompting the search for low-cost, eco-friendly alternatives. Moringa oleifera seed powder (MOSP) has emerged as a promising biosorbent, though its native adsorption capacity remains limited. This study aimed to enhance fluoride removal efficiency by modifying MOSP with calcium (Ca-MOSP) and to evaluate the influence of key process parameters including adsorbent dosage,particle size,pH,contact time, temperature and initial fluoride concentration; adsorption equilibrium behaviour, kinetic rates, and thermodynamic properties. Batch experiments were conducted under controlled laboratory conditions using both calcium-spiked and non-spiked MOSP to assess the effect of dosage, particle size, contact time, pH, temperature, and initial fluoride concentration. The biosorption performance was analysed using Langmuir and Freundlich isotherm models, pseudo-first-order and pseudo-second-order kinetics, and thermodynamic parameters such as enthalpy (ΔH°), entropy (ΔS°), and Gibbs free energy (ΔG°). Results showed that calcium spiking significantly improved fluoride removal efficiency, with Ca-MOSP achieving over 90% removal under optimal conditions (2 g/50 mL dosage, 40 mesh size, pH 7-, and 120- minute contact time), compared to 78% for the non-spiked powder. Finer particle sizes led to increased surface area and binding site availability, while increased dosage improved performance up to a saturation threshold. Adsorption was found to be pH- dependent, with neutral pH offering the best removal efficiencies for both biosorbent types. The adsorption isotherm data fitted best with the Langmuir model, suggesting monolayer adsorption on homogeneous surfaces. Ca-MOSP exhibited a higher maximum adsorption capacity (q e = 4.98 mg/g) and affinity constant (Kₗ = 0.442 L/mg) than the non-spiked variant. Kinetic data followed the pseudo-second-order model, indicating chemisorption as the dominant uptake mechanism, with high R² values (>0.99) and strong agreement between experimental and theoretical adsorption capacities. Thermodynamic analysis confirmed that biosorption was endothermic (ΔH° = +28.45 kJ/mol for Ca-MOSP), spontaneous (ΔG° < 0), and associated with an increase in system randomness (ΔS° = +85.6 J/mol·K). Thus, calcium-modified Moringa oleifera seed powder offers a significantly enhanced, sustainable, and low-cost alternative for fluoride remediation in drinking water. The findings support its potential for practical application in areas with fluoride endemism, particularly in rural and resource-limited settings. Recommendations include adopting Ca-MOSP in decentralised treatment systems and optimising operational conditions for field deployment. Future research should explore regeneration potential, competing ion effects, and long-term performance in continuous- flow and field-scale systems.

GREEN TECHNOLOGY FOR WASTEWATER MANAGEMENT: UTILIZING RICE HUSKS, COCONUT SHELLS AND CLAY AS ADSORBENTS FOR BASIC DYE RHODAMINE B AND SELECTED HEAVY METALS

2026-06-03T08:12:08Z

GREEN TECHNOLOGY FOR WASTEWATER MANAGEMENT: UTILIZING RICE HUSKS, COCONUT SHELLS AND CLAY AS ADSORBENTS FOR BASIC DYE RHODAMINE B AND SELECTED HEAVY METALS GICHUKI, JOHN Accumulation of heavy metals such as cobalt, copper, and lead and dyes such as rhodamine B (RB) released by various industries, poses a potential ecological risk of contamination due to their persistent nature and non-biodegradability. A remedial action is needed to mitigate this risk. A study was carried out to look into the possibility of eco-friendly and cost effective activated rice husk charcoal (ARC), coconut shell charcoal (ACC) and activated clay soil (ACS) in removal of heavy metals and rhodamine B dye from waste water. Three metal ions were selected, Cu2+, Co2+ and Pb2+ and were determined using atomic absorption spectrophotometer, AAS. The charcoal was obtained by burning rice husk and coconut shells which had been soaked in phosphoric acid in limited air. The ability of adsorbents to adsorb metal ions from water was investigated by carrying out batch experiment and varying parameters such as initial concentration, adsorbent dose, contact time, agitation speed, temperature and pH. Fourier Transform Infrared (FTIR) analysis detected presence of functional groups of Si-OH, Si-O, Si-O-Si, O-H and C=C in adsorbents upon activation which are responsible for adsorption. For the dye, a characteristic peak at 3200 cm-1 to 3070 cm-1 for aromatic stretch which was confirmed by a stretching vibration peak at around 1400 cm-1 was observed after adsorption. X-ray diffraction (XRD) data indicated that ACS was crystalline while ARC and ACC were amorphous. The X-ray fluorescence (XRF) results show that SiO2, Al2O3, and K2O were the main components where SiO2 were dominant especially in ARC and ACS. With Transmission emission spectroscopy (TEM) analysis, these nanostructures showed significantly different morphologies. Highly porous and hollow structures were visible in all cases though with differences. Brunauer, Emmett and Teller (BET) surface area and average pore diameter determination study showed that there was a relatively equal adsorption-desorption efficiency. This indicated that the adsorbents were highly reusable and that they had good stability. The efficiency of all the adsorbents towards the removal of heavy metals and dye increased with increase in temperature, time and surface area. Varying the pH showed that metals were adsorbed at a maximum pH of 6 while RB was highly adsorbed at pH 4. The equilibrium fitted the Langmuir equation well as compared to Freundrich. The R2 values for Langmuir ranged between 0.9928 to 0.9989 as compared to Freundlich which ranged between 0.9200 to 0.9671. The negative values of change in Gibb’s free energy (-1.55 to -0.581, -1.074 to -0.449 and -1.14 to -0.194 kJ mol-1 for ARC, ACC and ACS respectively) and positive values of change in enthalpy (32.034 to 37.562, 30.615 to 36.193 and 30.08 to 34.76 kJ mol-1 for ARC, ACC and ACS respectively) revealed the process to be spontaneous and endothermic. The use of a pseudo-second-order model, which indicates that chemical adsorption governed the process, allowed for a more accurate description of the adsorption process.

PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF Guizotia scabra LEAF, STEM BARK AND ROOT EXTRACTS FOR DENTAL CARIES CONTROL

2026-04-15T11:39:22Z

PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF Guizotia scabra LEAF, STEM BARK AND ROOT EXTRACTS FOR DENTAL CARIES CONTROL PAUL, ANJELINE JEPCHUMBA Medicinal plants offer promising alternatives for treating oral infections. This study investigated the phytochemical composition and antibacterial activity of Guizotia scabra tender leaf, stem bark, and root extracts against Streptococcus mutans and Streptococcus sobrinus, key pathogens in dental caries. Ethanol and acetone extracts were subjected to Standard laboratory tests for phytochemicals analysis, High- performance liquid chromatography (HPLC) for quantification of flavanoids, Fourier- transform infrared spectroscopy (FTIR) for determination of functional groups and antibacterial bioassays to assess antibacterial activity. Phytochemical tests revealed the presence of anthraquinones, alkaloids, terpenoids, flavonoids, steroids, saponins, and quinones. HPLC analysis confirmed the presence of myricetin and quercetin, with leaf extracts showing the highest concentrations (myricetin: 7.0013 ppm; quercetin: 0.901 ppm). Stem bark lacked myricetin but contained quercetin (2.4991 ppm), while root extracts had moderate levels of both (myricetin (2.0627 ppm) and quercetin (0.7027 ppm). FTIR spectra identified key functional groups, including O-H/N-H (3441 cm−1)1 linked to alkanoids (Quercetin ) (N-H /O-H group), C=O (1643 cm−1) which correlate to terpenoids, C-H/C-O (1396 cm−1) linked to alkaloids structure having N /O-H bond,2000 cm−1 to terpenoids /flavanoids and possible metal-ligand vibrations (538 cm−1). There is also a distinct C-N stretch (1250 cm−1) likely due to C-N stretching in alkaloids showed by leaf and root extracts. Antibacterial evaluation demonstrated that ethanol leaf extract had the highest inhibition against Streptococcus mutans (5.0 mm, 62.5%) and Streptococcus sobrinus (4.0 mm, 50%), followed by root extracts (3.0 mm, (37.5%) and 2.5 mm , (31.25%) respectively. Acetone extracts showed similar trends with the leaf extract at 4.6 mm, (57.5%) and 4.3 mm, (53.75%). However, commercial toothpastes showed superior inhibition (up to 7.0 mm, 87.5%) likely due to fluoride content and other additives. These findings suggest that Guizotia scabra possesses bioactive compounds with potential for natural oral healthcare applications. Further studies should optimize extraction; evaluate compound synergy, ensuring safety and efficacy for possible formulation of dental products.

PLASMID-MEDIATED ANTIBIOTIC RESISTANCE IN GRAM-NEGATIVE PATHOGENIC BACTERIA ISOLATED FROM RIVER SOSIANI AND WASTE WATER SYSTEMS IN UASIN GISHU COUNTY, KENYA

2026-04-15T11:17:02Z

PLASMID-MEDIATED ANTIBIOTIC RESISTANCE IN GRAM-NEGATIVE PATHOGENIC BACTERIA ISOLATED FROM RIVER SOSIANI AND WASTE WATER SYSTEMS IN UASIN GISHU COUNTY, KENYA AUMA, SHARON The widespread of bacteria resistance to antibiotics poses an immense threat to the public health. Aquatic ecosystems receive waste water which invariably contain different bacteria, chemicals and antibiotic residues that induces bacterial resistance to antibiotics, resulting into several treatments failures and deaths. Plasmid-mediated antibiotic resistance of bacteria through horizontal gene transfer has been reported to significantly cause resistance in susceptible bacteria. The current study identified antibiotic resistance genes present in gram-negative bacterial plasmids, isolated from River Sosiani and wastewater systems in Uasin Gishu County, Kenya. The sampling sites included Outspan-Nairobi bridge, Pioneer bridge, Moi Teaching and Referral Hospital, Eldoret prison, Kipkaren bridge, Huruma quarry influent, Huruma quarry effluent, Kipkenyo boundary influent and Kipkenyo boundary effluent. The study entailed bacteria isolation, identification, antibiotic susceptibility testing, plasmid DNA extraction and polymerase chain reaction of the antibiotic-resistant genes. Mean and standard deviations were analyzed using Microsoft Excel while Chi square was used to determine significant relationship existing between the phenotypic and genotypic resistance in bacteria. Most of the bacteria coliforms obtained were too numerous to count. A total of 10 gram-negative pathogenic bacteria species were detected, including Escherichia coli, Enterobacter aerogenes, Citrobacter freundii, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteriditis and Yersinia enterocolitica. All the 10 bacteria conferred resistance to penicillin, ampicillin, amoxicillin-clavulanic acid, ceftazidime, tetracycline, streptomycin and sulfamethoxazole-trimethoprim. Multi antibiotic resistance index was higher in E. aerogenes (0.83) but lower in Y. enterocolitica (0.58). Out of the nine antibiotic-resistant genes investigated, qepA and qnrA genes were present in the plasmids of all the 10 bacteria species, 70% of the total bacteria species had dfrA5, 70% had aadA1, 50% had blaKPC, 40% had mphA, 30% of the bacteria species had blaSHV and sul 1 genes (P≥1) while none of the bacterial plasmid DNA had AmpC gene. The study findings suggested that River Sosiani and the sampled wastewater systems contained different pathogenic bacteria and their plasmid-mediated antibiotic resistance genes which confer resistance to commonly used antibiotics. Therefore, effective waste disposal, continuous monitoring and proper pretreatments of water from River Sosiani and the sampled wastewater systems may reduce bacteria contamination and antibiotic resistance inducers, addressing challenges associated with antibiotic resistance in bacteria.

Antibacterial Activity of the Tender Leaf, Stem Bark and Root Extracts of Guizotia Scabra against Streptococci Bacteria Using Bioassay

2026-03-16T07:56:06Z

Antibacterial Activity of the Tender Leaf, Stem Bark and Root Extracts of Guizotia Scabra against Streptococci Bacteria Using Bioassay Paul, Anjeline Jepchumba; Lagat, Grace; Lutta, Samuel Dental caries remains a major public health concern globally, largely attributed to bacterial pathogens such as Streptococcus mutans and Streptococcus sobrinus. The search for plant-based alternatives to synthetic oral care products has intensified in recent years. This study evaluated the antibacterial activity of ethanol and acetone extracts of Guizotia scabra leaf, stem bark and root against these key oral pathogens in comparison with commercial toothpastes. The ethanol leaf extract exhibited the highest activity against Streptococcus mutans with an inhibition zone of 5.0 mm (62.5%), followed by the root extract (3.0 mm, 37.5%) and stem extract (2.0 mm, 25.0%). Against Streptococcus sobrinus., the ethanol leaf extract recorded 4.0 mm (50.0%), root extract 2.5 mm (31.25%), and stem extract 1.5 mm (18.75%). Similarly, the acetone leaf extract demonstrated the highest inhibition against Streptococcus mutans (4.6 mm, 57.5%) and Streptococcus sobrinus. (4.3 mm, 53.75%), compared to the root extract (2.8 mm, 35.0%; 2.3 mm, 28.75%) and stem extract (1.9 mm, 23.75%; 1.7 mm, 21.25%). In contrast, commercial toothpaste brand 1 produced inhibition zones of 6.0 mm (75.0%) against both pathogens, while brand 2 showed 7.0 mm (87.5%) against Streptococcus mutans and 6.0mm (75.0%) against Streptococcus sobrinus. These findings demonstrate that Guizotia scabra extracts possess significant antibacterial activity, with leaf extracts showing the greatest potential. Although commercial toothpastes were more effective likely due to fluoride and other active ingredients. The results highlight the potential of Guizotia scabra as a natural complementary agent for dental caries prevention. Future research should explore its integration with fluoride or other natural antibacterials to enhance its efficacy. Keywords: Antibacterial Activity, Guizotia scabra, Streptococcus mutans & Streptococcus sobrinus bacteria, Bioassay.

ANTIOXIDANT AND ANTIDIABETIC PROPERTIES OF Mondia whitei ROOT EXTRACT IN STREPTOZOTOCIN-INDUCED DIABETIC WISTAR RATS

2026-03-13T10:22:01Z

ANTIOXIDANT AND ANTIDIABETIC PROPERTIES OF Mondia whitei ROOT EXTRACT IN STREPTOZOTOCIN-INDUCED DIABETIC WISTAR RATS GITAU, KENNEDY KAMAU The rising global prevalence of diabetes mellitus (DM) and its complications presents a major health challenge and is exacerbated by the lack of a definitive cure and the side effects of existing treatments, thus, highlighting the need for safer and more sustainable anti-diabetic agents. This study investigated Mondia whitei root extract as an alternative therapeutic option for DM. While traditional medicine suggests that M. whitei possesses antioxidant and anti-diabetic properties, scientific validation is limited. This research aimed to address this gap. Qualitative phytochemicals analysis of crude root extract of M. whitei was done and it’s in vitro antioxidant properties evaluated through 2,2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP) assays. DM was induced in twenty-four male Wistar rats by a single intraperitoneal injection of 65 mg/Kg body weight (bwt) of streptozotocin (STZ). Animals were randomly assigned to five groups each containing six subjects; Group I (normal control, saline), Group II (diabetic control, saline), Group III (diabetic rats 200 mg/Kg bwt extract treatment), Group IV (diabetic rats 400 mg/Kg bwt extract treatment), and Group V (diabetic rats 100 mg/Kg bwt metformin treatment). Treatments were orally administered for 21 days. Fasting body weights and blood sugar levels were measured weekly. After 21 days, animals were sacrificed and their blood and liver tissue samples collected followed by serum lipid profile, liver and kidney function indices analysis. Liver malondialdehyde (MDA) levels were measured, and liver and plasma’s ferric-reducing capacity were evaluated. Statistical analysis was performed using R software, with paired Student’s t-test and ANOVA determining statistical significance at 95% confidence level. The qualitative phytochemical analysis of the crude M. whitei root extract revealed the presence of saponins, phenols, tannins, alkaloids, flavonoids, glycosides, coumarins, steroids, and terpenoids, while anthraquinones were not detected. The extract significantly scavenged DPPH radical and reduced ferric ions in vitro. M. whitei also showed significant hypoglycemic, hypolipidemic and significantly reduced serum gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). M. whitei treatment also significantly increased liver and blood plasma capacity to reduce ferric ions as well as protected liver tissues from lipid peroxidation as indicated by significantly reduced levels of MDA. However, M. whitei showed no significant serum urea and creatinine levels decrease. In conclusion, the phytochemical-rich M. whitei root extract demonstrated anti-diabetic, antioxidant, hypolipidemic and hepatoprotective effects in STZ-induced diabetic rats, highlighting its potential as a natural candidate for the management of DM and its complications.

Fluoride distribution in selected foodstuffs from Nakuru County, Kenya, and the risk factors for its human overexposure

2026-03-06T06:23:28Z

Fluoride distribution in selected foodstuffs from Nakuru County, Kenya, and the risk factors for its human overexposure Nelima, Delphine; Wambu, Enos W.; Kituyi, John L. Critical data on the impacts of fluoride (F) in food systems along the Eastern Africa Rift Valley System (EARS) is needed for public health risk assessment and for the development of strategies for ameliorating its deleterious effects among the affected communities. Long-term F overexposure causes dental and skeletal fluorosis, and leads to neurotoxicity, which impacts several important body functions. Investigating F exposure pathways is of essence to inform and safeguard public health of the affected communities. The current study assessed the F levels in potatoes (Solanum tuberosum L.), beans (Phaseolus vulgaris L.) and garden peas (Possum sativa) from Nakuru County, Kenya, by potentiometric analysis using F ion-selective electrodes. It then evaluated the risk factors for excessive human exposure to F through contaminated foodstuffs. The mean F levels in the potatoes (8.50 ± 4.70 mg/kg), beans (8.02 ± 4.12 mg/kg) and peas (4.99 ± 1.25 mg/kg) exceeded recommended dietary allowances (RDA) level of 4 mg/kg endorsed by US Institute of Medicine for the different categories of people. The F distribution trends in beans and potatoes reflected the environmental patterns of F contamination of the study area but the spatial extent Fin the peas indicated existence of partial resistance of the pea plants to environmental F uptake. The results indicated that both the beans and the potatoes were more liable to accumulating greater amounts of F from the environment than garden peas and that all the three foodstuffs contained high F levels that posed greater risk of F overexposure and its deleterious impacts among the young children, male populations, and in people of greater body weight and high physical activity levels.