Rapid recovery of high content phytosterols from corn silk

Improvement and prediction of the extraction parameters of lupeol and stigmasterol metabolites of Melia azedarach with response surface methodology

BACKGROUND

Melia azedarach is known as a medicinal plant that has wide biological activities such as analgesic, antibacterial, and antifungal effects and is used to treat a wide range of diseases such as diarrhea, malaria, and various skin diseases. However, optimizing the extraction of valuable secondary metabolites of M. azedarach using alternative extraction methods has not been investigated. This research aims to develop an effective, fast, and environmentally friendly extraction method using Ultrasound-assisted extraction, methanol and temperature to optimize the extraction of two secondary metabolites, lupeol and stigmasterol, from young roots of M. azedarach using the response surface methodology.

METHODS

Box-behnken design was applied to optimize different factors (solvent, temperature, and ultrasonication time). The amounts of lupeol and stigmasterol in the root of M. azedarach were detected by the HPLC-DAD. The required time for the analysis of each sample by the HPLC-DAD system was considered to be 8 min.

RESULTS

The results indicated that the highest amount of lupeol (7.82 mg/g DW) and stigmasterol (6.76 mg/g DW) was obtained using 50% methanol at 45 °C and ultrasonication for 30 min, and 50% methanol in 35 °C, and ultrasonication for 30 min, respectively. Using the response surface methodology, the predicted conditions for lupeol and stigmasterol from root of M. azedarach were as follows; lupeol: 100% methanol, temperature 45 °C and ultrasonication time 40 min (14.540 mg/g DW) and stigmasterol 43.75% methanol, temperature 34.4 °C and ultrasonication time 25.3 min (5.832 mg/g DW).

CONCLUSIONS

The results showed that the amount of secondary metabolites lupeol and stigmasterol in the root of M. azedarach could be improved by optimizing the extraction process utilizing response surface methodology.

Production, Characterization, Delivery, and Cholesterol-Lowering Mechanism of Phytosterols: A Review

Phytosterols are natural plant-based bioactive compounds that can lower blood cholesterol levels and help prevent cardiovascular diseases. Consequently, they are being utilized in functional foods, supplements, and pharmaceutical products designed to improve human health. This paper summarizes different approaches to isolate, purify, and characterize phytosterols. It also discusses the hypolipidemic mechanisms of phytosterols and their impact on cholesterol transportation. Phytosterols have a low water-solubility, poor chemical stability, and limited bioavailability, which limits their utilization and efficacy in functional foods. Strategies are therefore being developed to overcome these shortcomings. Colloidal delivery systems, such as emulsions, oleogels, liposomes, and nanoparticles, have been shown to be effective at improving the water-dispersibility, stability, and bioavailability of phytosterols. These delivery systems can be used to incorporate phytosterols into a broader range of cholesterol-lowering functional foods and beverages. We also discuses several issues that need to be addressed before these phytosterol delivery systems can find widespread commercial utilization.

Protective effect of Geophila obvallata (Shumach) Didr leaf extract and its fractions against cadmium-induced nephrotoxicity in male Wistar rats

Cadmium (Cd) is a known nephro-toxicant. This research determined the ameliorative effects of Geophila obvallata crude methanol extract (Me70) and its fractions on Cd-induced nephrotoxicity in Wistar rats. Male rats were randomly allocated to nine (9) groups of six (6) rats each. Group I was given normal water and feed only. Group II received 0.3 mg Cd/L only for two weeks. Groups III, IV, V, VI and VII were pre-exposed to aqueous, ethyl acetate, hexane, butanol and chloroform fractions of Me70, each at a dose of 50 mg/kg bwt for fourteen (14) days prior to treatment with 0.3 mg Cd/L for a further two weeks. Group VIII was pre-exposed to Me70 at a dose of 50 mg/kg bwt for fourteen (14) days, prior to administration of 0.3 mg Cd/L for fourteen (14) days, while group IX received 50 mg/kg.bwt of Me70 only for fourteen (14) days. The treatments were administered daily for twenty-eight (28) days via oral gavage. Cadmium levels in the kidney tissues of Cd-treated rats increased significantly while their body weights decreased relative to control. The levels of kidney function markers in the plasma, lipid peroxidation levels, catalase activity, metallothionine (MT-1) and kidney injury molecule-1 (KIM-1) mRNA were increased significantly, while glutathione (GSH) levels, activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-s-transferase (GST), and levels of nuclear factor erythroid-2-related factor 2 (Nrf-2), peroxisome proliferator-activated receptor -gamma coactivator- 1-alpha (PGC-1α), heme oxygenase-1 (HO-1) and NADH quinone oxidoreductase-1 (NQ-O1) were decreased significantly in rats treated with Cd-only. Overall, pre-treatment with Me70 produced better protection from the toxic effects of cadmium induction in experimental rats.

Increment of Lysosomal Biogenesis by Combined Extracts of Gum Arabic, Parsley, and Corn Silk: A Reparative Mechanism in Mice Renal Cells

Gum Arabic (GA), parsley, and corn silk have been traditionally used for renal failure patients worldwide. This study aimed at probing the mechanism of the combined extracts, namely, GA (3 g/kg/day), parsley (1 g/kg/day), and corn silk (200 mg/kg/day), as nephroprotective agents in mice after amikacin (1.2 g/kg) single dose through exploration of their action on G-protein coupled receptors (GPR) 41 and 43 and the ensuing lysosomal biogenesis. Western blotting was employed for renal levels of bcl-2-associated X protein (BAX) and cytosolic cathepsin D; cell death markers, nuclear transcription factor EB (TFEB), and lysosomal associated membrane protein-1 (LAMP-1); and lysosomal biogenesis indicators. Liquid chromatography–mass spectrometry (LC-MS) and docking were also employed. After amikacin treatment, BAX and cathepsin D levels were upregulated while LAMP-1 and nuclear TFEB levels were inhibited. The combined extracts inhibited BAX and cytosolic cathepsin D but upregulated LAMP-1 and nuclear TFEB levels. Docking confirmed GPR modulatory signaling. The combined extracts showed GPR signal modulatory properties that triggered lysosome synthesis and contributed to reversing the adverse effects of amikacin on renal tissues.

Advances in various techniques for isolation and purification of sterols

Plants consist of triterpenoids such as phytosterols (PT) (C₂₉H₅₀O) with steroidal nuclei, including sitosterol, stigmasterol, brassicasterol and campesterol. They are hydrophobic but soluble in alcohol and other organic solvents and are isolated from industrial waste deodorizer distillates of various edible oil industries. They exist as free PT or their ester derivatives in soybean, rice, wheat, oat, cottonseed and corn fiber, and other cereals and grains. Conventional isolation techniques such as solvent extraction, distillation, evaporative fractionation, saponification and chemical esterification are employed for isolation and purification of PT. The present article reviews the various advanced separation techniques like solvent crystallization, supercritical fluid extraction, high speed counter-current chromatography and enzymatic process as strategic methods to isolate and purify sterols.

Enhanced Biosorption of Nickel Ions on Immobilized Surface-Engineered Yeast Using Nickel-Binding Peptides

Three nickel-binding peptides were screened from a phage peptide library and displayed separately or in combination with surface-engineered Saccharomyces cerevisiae EBY100. The sorption of nickel ions on the surface of yeast cells increased with the increasing number of nickel Ni(II)-binding peptides displayed. The combined expression of the three peptides by EBY100/pYD1-N123 demonstrated the highest sorption of Ni(II) (2.603 ± 0.004 g g^-1, dry weight) and an enhanced sorption capacity of 60.15%, compared to S. cerevisiae EBY100. An orthogonal test for yeast immobilization was designed. A maximum sorption capability of 68.62% was observed for a treatment at 25°C with 2.0% calcium chloride and 3.0% sodium alginate.