| Summary: | 碩士 === 國立陽明大學 === 生物藥學研究所 === 95 === Coconut nucifera L. (Palmae) is an useful and highly economic plant in the Torrid Zone. In Brazil traditional medicine, water extract of coconut husk was used for treatment of arthritis. The immuno-regulatory and hair-darkening activities of coconut water were reported in the ancient Chinese medicine books. In the present study, we elucidated the immunomodulatory and cell regeneration activities of coconut water.
Rheumatoid arthritis is an autoimmune disease resulted from the hyperactive Th1 response, which leads to chronic inflammation in joints and progressive cartilage destruction and bone erosion. In this study, we evaluated the therapeutic effect of coconut water on PGIA (proteoglycan induced arthritis) animal model. In the low-dose group, paw swollen was inhibited and the serum levels of total IgG, IgG1, and IgG2a were decreased. In the spleen lymphocyte proliferation assay, T cell proliferation activity was decreased in both low- and high-dose group.
We expected the bioactive compounds were not carbohydrates, thus we fed PGIA with decarbonhydrate coconut water extract (dCCWE) afterward. We found that arthritis accident rate and the degree of paw swollen in the low-dose groups (2 mg/kg/day) were decreased. In contrast, the high dose group (50 mg/kg/ady) developed is more severe arthritis earlier. IgG2a level in serum was decreased in both high- and low-dose groups, but lymphocyte proliferation activity and CD8+ T cell percentage of spleen decreased only occured in the high-dose group. CD8+ T cell plays the role in protection and immunomodulation of arthritis. We suggested that CD8+ T cell proliferation was inhibited by dCCWE resulting in arthritis severer and onset earlier. In contrast, dCCWE could regulate TH1 immune response and counteract with arthritis if CD8+ T cell proliferation activity was not inhibited by dCCWE.
Hair graying is a sign of aging. Recent studies indicated that the number of melanocyte stem cells in hair follicle decreased with age which leads to hair graying. In our study, dCCWE had no effect on proliferation and maturation of melanocyte stem cell. Gene expression level of TRP1 was upregulated by dCCWE. In vivo, dCCWE promoted hair growth but couldn’t reduce the area of graying hair in FIHG (free radicals induced hair gaying) animal model. We inferred that dCCWE induced the differentiation of melanocyte stem cells to certain stage but not melanocytes.
In the study, we demonstrated that dCCWE could protect PGIA mice from arthritis by down-regulation of Th1 immune response. However, dCCWE had no impact on hair graying, and dCCWE might be an effective natural medicine for rheumatoid arthritis therapy.
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