Chitosan Oligosaccharides
Chitosan is a by-product of the alkaline deacetylation of chitin. Chitin is a polysaccharide, the second most abundant naturally occurring polymer. It is found on the shells of arthropods such as crustaceans and insects (Hadrami, Hadrami, Adam, & Daayf, 2010). Chitin contains nitrogen that is used in pharmaceuticals. The production of chitosan from chitin involves four major steps that aims at removing protein and calcium components from the raw shells. The chitin is treated with about 40% of sodium hydroxide during the deprotenization and demineralization process to make chitosan. Chitosan is soluble in acidic solutions and precipitates in high pH environments. Its instability in acidic environments greatly affect its practical use. Several attempts to chemically modify chitosan have been made with the aim of overcoming the instability in acidic conditions. The physical and chemical properties of chitosan are dependent on its molecular weight and the degree of deacetylation (Sarmento & Neves, 2012). Chitosan has been linked to a number of biological and physiological activities in the human body. Studies carried out have shown its unique biological activities that include anti-oxidant, anti-inflammation, biological recognition, and enhancing immunity among others (Guo et al., 2018). This has resulted to chitosan being used to treat a number of illnesses. These illnesses include high cholesterol, crohns’ disease, kidney failure, dental cavities, and hyperphosphatemia (Liu, Xin, Liu, Zhang, & Li, 2017).
Other than the links in human biological and physiological activities, chitosan has shown great potential in agriculture regarding controlling of plants’ diseases. With the high demand of blemish free farm products that require high input, chitosan has allowed this achievement while ensuring the produce yields profits (Hadrami, Hadrami, Adam,, & Daayf, 2010). Chitosan has made this possible by reducing the disease levels and the spread of pathogens in plants. Additionally this has helped preserve the yield and quality of the produce. The chitosan molecules have exhibited toxicity and inhibit fungal growth and development (Xing, Zhu, Peng, & Qin, 2014). Fragments from chitosan elicit defense responses in the host plants in regards to microbial infections. The responses provided by chitosan include lignification, protein phosphorylation, membrane depolarization, and generation of reactive oxygen species among others. The toxicity demonstrates anti-viral, anti-bacterial, and ant-fungal properties that allow the protection of plants against several diseases. This has allowed for agricultural exploration since the diseases can now be controlled and the pests kept away. Chitosan is effective to both monocotyledons and dicotyledons by enhancing the plants’ defense responses (Xing, Zhu, Peng, & Qin, 2014).
Dosage in Humans in mg
The oral lethal dosage in humans is estimated to be 1330mg/kg (Sarmento & Neves, 2012). There are no adverse side effects that have been observed in human beings. The only side effects observed were mild transiently nausea and constipation. Individuals are always advised not to take chitosan with warfarin. This is because chitosan is known to be a blood thinner. Taking chitosan with warfarin exposes an individual to several risks such as bruising easily. Extensive research carried out on mice and rabbits conclude that an overdose of chitosan would result to death. This was after a mice was intravenously injected with 50mg/kg of chitosan, which resulted to its death (Liu, Xin, Liu, Zhang, & Li, 2017).
Parts Per Million for Agricultural Use
The antimicrobial activities exhibited
by chitosan depends on several factors. These factors include the plant in
question, the degree of polymerization, type of chitosan used, chemical
composition of the substrate, as well as the environmental factors (Hadrami,
Hadrami, Adam, & Daayf, 2010). In viruses and bacteria, the minimal
growth-inhibiting concentrations vary between 10-1000 parts per million. On
fungi, the minimal growth-inhibiting concentrations vary between 10-5000 parts
per million.
References
Guo, X., Sun, T., Zhong, R., Ma, L., You, C., Tian, M. Wang, C. (2018). Effects of Chitosan Oligosaccharides on Human Blood Components. Frontiers in Pharmacology, 9. doi:10.3389/fphar.2018.01412
Hadrami, A. E., Hadrami, I. E., Adam, L. R., & Daayf, F. (2010). Chitosan in Plant Protection. Marine Drugs, 8(4), 968-987. doi: 10.3390/md8040968
Liu, L., Xin, Y., Liu, J., Zhang, E., & Li, W. (2017). ). Inhibitory Effect of Chitosan Oligosaccharide on Human Hepatoma Cells in Vitro. African Journal of Traditional, Complementary and Alternative Medicines, 14(4), 272-277. doi:10.21010/ajtcam.v14i4.30
Sarmento, B., & Neves, J. D. (2012). Chitosan-Based Systems for Biopharmaceuticals: Delivery, Targeting and Polymer Therapeutics. Hoboken, NJ: John Wiley & Sons.
Xing, K., Zhu, X., Peng, X., & Qin, S. (2014). Chitosan antimicrobial and eliciting properties for pest control in agriculture: A review. Agronomy for Sustainable Development, 35(2), 569-588. doi:10.1007/s13593-014-0252-3
