Cell and Tissue Journal

Abstract Introduction: Plant-derived exosome-like nanoparticles (PDENs) are nano-sized vesicles released by plant cells. They contain a lipid bilayer membrane and carry bioactive molecules such as proteins, lipids, nucleic acids, and secondary metabolites. Due to their low toxicity and natural drug delivery potential, they have gained attention for therapeutic applications. Plant extracts are also rich in phenolic compounds and flavonoids with known antioxidant and antimicrobial effects. The rising problem of antibiotic resistance in pathogens like Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes has created an urgent need for new natural agents.
Aim: This study aimed to isolate and characterize exosomes from ginger, lavender, onion, and lemon, and to compare their antioxidant and antibacterial activities with those of aqueous extracts from the same plants.
Materials and methods: Fresh ginger, lavender, onion, and lemon were used for the preparation of plant extracts and exosome isolation. For aqueous extraction, 2 g of ginger and lavender samples were homogenized with 20 mL of distilled water and incubated in a water bath at 70°C for 90 minutes. The mixtures were centrifuged at 3000 × g for 10 minutes, and the supernatants were filtered and stored at 4°C until analysis. Exosomes were isolated using the Exosun Exosome Isolation Kit (EXOSUN Company). Plant materials were homogenized, filtered, and subjected to differential centrifugation. The resulting supernatants were processed according to the manufacturer's instructions using buffers A and B. Due to the acidic nature of lemon juice, modification of the protocol was required by increasing the concentration of buffer A to facilitate exosome precipitation. Protein concentration of isolated exosomes was determined using the Bradford assay with bovine serum albumin (BSA) as the standard. Exosome morphology was characterized by transmission electron microscopy (TEM). The antioxidant activity of extracts and exosomes was evaluated using the Ferric Reducing Antioxidant Power (FRAP) assay. Samples were analyzed in 96-well microplates, and absorbance was measured at 570 nm. Antibacterial activity was assessed against Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes using the disk diffusion method. Sterile blank disks were impregnated with plant extracts or exosome preparations at concentrations of 25, 50, and 100 mg/mL and placed on Mueller-Hinton agar plates inoculated with bacterial suspensions adjusted to a 0.5 McFarland standard. Gentamicin and vancomycin served as positive controls. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined using the broth microdilution method in 96-well microplates. All experiments were performed in triplicate. Statistical analyses were conducted using SPSS version 27, applying one-way ANOVA followed by Tukey’s post hoc test, with p <0.05 considered statistically significant.
Results: TEM confirmed successful isolation of exosome-like vesicles from all plants. Bradford assay indicated protein-containing nanoparticles. FRAP analysis showed that lavender had the highest antioxidant capacity. Plant extracts generally showed greater antioxidant activity than their corresponding exosomes. Antibacterial testing revealed that exosomes from all four plants had no detectable antibacterial effect. Similarly, aqueous extracts of ginger, lavender, and onion showed no inhibition. However, lemon extract exhibited significant antibacterial activity against all three bacteria. MIC values of lemon extract were 3.12 mg/mL for S. aureus, 6.25 mg/mL for S. pyogenes, and 50 mg/mL for E. coli. Inhibition zones for S. aureus reached 22 mm at 100 mg/mL. Gram-positive bacteria were more susceptible than Gram-negative E. coli.
Discussion:The spread of antibiotic-resistant pathogens has increased the need for new treatments. In this study, exosomes isolated from ginger, lavender, onion, and lemon showed no antibacterial activity, while among aqueous extracts, only lemon extract displayed good antibacterial properties. The lack of activity in aqueous lavender extract compared to alcoholic extracts in previous reports may be due to solvent differences affecting phenolic compound extraction. Aqueous ginger extract also showed no effect, which contrasts with some alcoholic extracts. However, lavender exosomes demonstrated the highest antioxidant capacity among all samples, highlighting their potential for antioxidant applications.
Conclusion: Although plant-derived exosomes from these four species did not show antibacterial effects under the tested conditions, lemon aqueous extract exhibited promising antimicrobial activity, especially against Gram-positive bacteria. Lavender exosomes showed the strongest antioxidant potential. These findings suggest that lemon extract could serve as a natural antibacterial agent, while lavender-derived exosomes and extracts may be valuable sources of natural antioxidants. Further in vivo studies are needed to explore their efficacy and safety.

Abstract Introduction: Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer in polyvinyl chloride (PVC) products, including medical devices such as syringes, IV tubing, blood bags, respiratory circuits, and dialysis equipment. Due to its weak physical bonding to the PVC matrix and lack of covalent interactions, DEHP can leach into biological fluids upon contact. This becomes particularly concerning during prolonged clinical exposure, as it allows the compound to enter the bloodstream and potentially affect sensitive tissues, including bone marrow. Bone marrow-derived mesenchymal stem cells (BMSCs) are multipotent progenitors with the ability to differentiate into osteoblasts, playing a vital role in bone remodeling and regeneration. Given their sensitivity to environmental toxins, DEHP exposure represents a significant risk to BMSC viability and osteogenic function. Evidence suggests that DEHP disrupts osteogenesis by inducing oxidative stress and downregulating essential genes involved in matrix formation and mineralization. Curcumin (Cur), a bioactive polyphenol extracted from the rhizome of Curcuma longa, possesses strong antioxidant, anti-inflammatory, and cytoprotective properties. It is nontoxic, affordable, and widely available, making it a promising candidate for counteracting xenobiotic-induced oxidative damage. This study explores whether Curcumin can mitigate DEHP’s deleterious effects on BMSCs during osteogenic differentiation.
Aim: We hypothesize that co-treatment with Cur will ameliorate DEHP-mediated disruption in cell viability, antioxidant capacity, and osteogenic marker expression.
Materials and Methods: BMSCs were isolated from adult male Wistar rats under sterile conditions and cultured to passage three. Cells were divided into four experimental groups and exposed for 21 days to the following treatments: (1) control, (2) DEHP (100 μM), (3) Curcumin (0.1 μM), and (4) DEHP + Curcumin. The cells were cultured in osteogenic differentiation medium throughout the treatment period. Cell viability was assessed using the tetrazolium-based MTT assay. Osteogenic differentiation was evaluated via Alizarin Red staining for mineral deposition, calcium quantification, and alkaline phosphatase (ALP) activity measurement. Oxidative stress was assessed by quantifying intracellular malondialdehyde (MDA) levels, a lipid peroxidation marker. Antioxidant enzyme activity for catalase (CAT) and superoxide dismutase (SOD) was measured spectrophotometrically. Total antioxidant capacity (TAC) was evaluated using commercial kits. For molecular analysis, total RNA was extracted from cells and reverse-transcribed into complementary DNA (cDNA). Semi-quantitative PCR was performed to measure expression levels of osteogenic differentiation-related genes: Smad1, Bmp2, Bmp7, Runx2, Alp, Col-1A1, and Osteocalcin (Oc). Gapdh served as the internal control. Data were statistically analyzed using ANOVA with Tukey’s post-hoc test. A threshold of p < 0.05 was considered statistically significant.
Results DEHP treatment caused a marked reduction in BMSC viability (p < 0.0001), confirming its cytotoxicity. Cells co-treated with Curcumin showed a significant restoration in viability (p < 0.01), indicating Cur’s protective effects. Alizarin Red staining revealed diminished extracellular matrix mineralization in DEHP-treated cells, with corresponding reductions in calcium content and ALP activity. Notably, Curcumin co-treatment restored all markers to levels comparable to those seen in control cells. ALP, an early osteogenic marker, showed complete recovery, underlining Cur’s efficacy in preserving bone-forming potential. Gene expression analysis demonstrated that DEHP downregulated osteogenic genes (Smad1, Bmp2, Bmp7, Runx2, Col-1A1, Oc). Co-treatment with Curcumin significantly reversed this suppression, elevating transcript levels to near control values. These results suggest a transcriptional rescue linked to improved redox homeostasis. Oxidative stress measurements indicated that DEHP increased MDA levels while suppressing CAT and SOD activity, as well as total antioxidant capacity (p < 0.0001). Curcumin treatment effectively reduced MDA concentrations (p < 0.05), and boosted CAT and SOD activity (p < 0.01). TAC was significantly elevated in Curcumin-treated groups (p < 0.0001), indicating improved redox balance and defense against oxidative damage.
Conclusion: This study provides strong evidence that DEHP impairs BMSC viability and osteogenic differentiation primarily through oxidative stress mechanisms. Curcumin co-treatment mitigates DEHP-induced cellular damage, restores osteogenic function, and enhances antioxidant defenses. These findings highlight Curcumin’s potential as a therapeutic agent to counteract phthalate toxicity in clinical contexts involving prolonged exposure to DEHP-containing materials.