Antioxidant and Antibacterial Activities of Chitosan-Phloroglucinol Conjugate

Abstract

In an effort to develop biopolymer-based antioxidant and antibacterial materials, a chitosan-phloroglucinol conjugate was prepared and cellular antioxidant activity and minimum inhibitory concentration against foodborne pathogens and methicillin-resistant Staphylococcus aureus (MRSA) evaluated. The chitosan-phloroglucinol conjugate showed higher antioxidant activities than the unmodified chitosan (P < 0.05). The chitosan-phloroglucinol conjugate showed 62.29% reactive oxygen species scavenging activity, 56.11% lipid peroxidation inhibition activity, and 2.21-fold increase of glutathione expression in mouse macrophage cells. Additionally, the chitosan-phloroglucinol conjugate exhibited higher antibacterial activities than the unmodified chitosan, and the chitosan-phloroglucinol conjugate showed fourfold higher antibacterial activities against MRSA and clinical isolates and twofold higher activities against foodborne pathogens compared to the unmodified chitosan.

Antioxidant and Cytoprotective Effects of Lotus (Nelumbo nucifera) Leaves Phenolic Fraction

“…Chang liver cells were grown in a 96-well plate and labeled with 20 μM of 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) dye and left in the dark for 20 min, followed by the addition of 0~0.1 μg/mL of EAF and incubation for 1 h. Thereafter, the cells were washed with PBS, followed by the addition of 650 μM H 2 O 2 to each well. Fluorescence due to oxidative formation of 2′,7′-dichlorofluorescein (DCF) by ROS was measured after 30, 60, and 90 min at excitation and emission wavelengths of 485 and 528 nm, respectively ( 18 ). The percentage of fluorescence intensity (ROS generation) was compared with that of the control cells without the EAF treatment, which were arbitrarily assigned a value of 100%.…”

Antioxidant Properties and Redox-Modulating Activity of Chitosan and Its Derivatives: Biomaterials with Application in Cancer Therapy

“…31,40 To enhance water solubility of chitosan by disrupting inter-and intramolecular hydrogen bonding, a number of researchers proposed the synthesis of chitosan derivatives with improved solubility. Their antioxidant activities were proved by experiments conducted in both cell free 13,31,[41][42][43][44] and cell environment.…”

“…[58][59][60][61] Many studies suggest that due to their redox metabolism, cancer cells are characterized with increased ROS generation, as well as overexpression of antioxidant enzymes in response to the permanent oxidative stress, in comparison to normal cells. 13,[62][63][64][65][66] But at the same time, there are many evidences that have shown that mitochondria and producing ROS are key regulators for induction of cancer cell death. [67][68][69][70][71][72] Natural products have played a pivotal rule in guiding researchers to develop efficient anticancer agents.…”

“…It is known that it exhibits versatile biological properties, including biodegradability, biocompatibility, and a less toxic nature. 12,13 As a biomaterial, chitosan elicits a negligible immune response, after implantation, injection, topical application, or ingestion in the mammalian system. 14,15 The natural cationic polysaccharide possesses attractive hemostatic properties.…”

“…It has been reported that chitosan stimulates the host immune system against viral and bacterial infection. 13,16,17 Because of its biological properties, including antioxidant, antibacterial, anticancer, anti-inflammatory, and immunostimulatory activities, the biopolymer has been used in a wide variety of pharmaceutical, biomedical, food industry, health, and agricultural applications and has been classified as a new physiologically bioactive material. 13,[18][19][20][21][22][23] In this mini-review, we will focus on the antioxidant properties, redox-regulatory activities of chitosan and its derivatives, and their application as anticancer agents.…”