This paper described the thermal activation of Ebenaeae Diospyros preusii seed (EDP) as a cost effective biosorbent for Cr(VI) removal. SEM, FTIR, TGA, BET and XRD were used to characterise both the thermally modified EDP (TM-EDP) and unmodified EDP (UM-EDP) biosorbents obtained from ground Diospyros preusii seed. The obtained experimental data were modelled using Langmuir, Dubinin-Radushkevich, Temkin, Flory–Huggins and Freundlich isotherm to determine the process of removal of this ion from aqueous solution. Batch adsorption method was employed in the evaluation of the adsorbent’s adsorption performance. pH effect, initial Cr(VI) concentration, temperature and contact time influence on adsorption were also evaluated. Thermal modification of the EDP was found to increase the surface area from 471.665 m²/g to 771.738 m²/g. The FTIR showed the existence of C = O, -C-H, C-O-O- and –OH functional groups on both the functionalized and unmodified EDP. The characterization also showed that the thermally modified adsorbent is amorphous with rough surfaces which enhances adsorption of the Cr(VI). The thermally modified precursor showed a better adsorption capacity revealing the benefit of thermal modification. From the isotherm plots, Langmuir model best described the process of removal of the Cr(VI) from the aqueous solution with determination coefficient (R²) value of 0.991 which showed that Cr(VI) adsorption unto the adsorbent followed physisorption mechanism. From the kinetic studies, it was concluded that the pseudo-second order most appropriately explained the adsorption process indicating chemisorption. An exothermic, chemosorptive and non-spontaneous adsorption process was identified by thermodynamics investigations. This study therefore revealed the adsorption capacity of the thermally modified EDP seed to be 51.11% at pH 4.

Over the years, the world has continued to be plagued by type 2 diabetes (T2D). As a lifestyle disease, obese individuals are at higher risk of developing the disease. Medicinal plants have increasingly been utilized as remedial agents for managing metabolic syndrome. The aim of the present study was to investigate the in vitro anti-hyperglycemic and anti-lipidemic potential of Croton gratissimus herbal tea infusion. The inhibitory activities of C. gratissimus on carbohydrate (α-glucosidase and α-amylase) and lipid (pancreatic lipase) hydrolyzing enzymes were determined, and the mode of inhibition of the carbohydrate digestive enzymes was analyzed and calculated via Lineweaver–Burk plots and Michaelis Menten’s equation. Its effect on Advanced Glycation End Product (AGE) formation, glucose adsorption, and yeast glucose utilization were also determined. High-performance liquid chromatography (HPLC) was used to quantify the possible phenolic compounds present in the herbal tea infusion, and the compounds were docked with the digestive enzymes. C. gratissimus significantly (p < 0.05) inhibited α-glucosidase (IC₅₀ = 60.56 ± 2.78 μg/mL), α-amylase (IC₅₀ = 35.67 ± 0.07 μg/mL), as well as pancreatic lipase (IC₅₀ = 50.27 ± 1.51 μg/mL) in a dose-dependent (15–240 µg/mL) trend. The infusion also inhibited the non-enzymatic glycation process, adsorbed glucose effectively, and enhanced glucose uptake in yeast cell solutions at increasing concentrations. Molecular docking analysis showed strong binding affinity between HPLC-quantified compounds (quercetin, caffeic acid, gallic acid, and catechin) of C. gratissimus herbal tea and the studied digestive enzymes. Moreover, the herbal tea product did not present cytotoxicity on 3T3-L1 cell lines. Results from this study suggest that C. gratissimus herbal tea could improve glucose homeostasis and support its local usage as a potential anti-hyperglycemic and anti-obesogenic agent. Further in vivo and molecular studies are required to bolster the results from this study.