| 摘要: | 本論文探討天然物對皮膚光保護作用的一系列探討，包括活體及試管內的試驗。本實驗中活體試驗部分，先將豬塗抹各種受測天然物 (包括nicotinamide、caffeine、L-ascorbic acid、saponin、berberine chloride、silymarin、薑黃素、樟芝萃取液、冬蟲夏草萃取液、靈芝萃取液及龍膽萃取液等) 後，利用紫外線B照射豬，觀察豬產生的紅斑指數是否有減少的現象，即表示是否具有光保護作用。以各種受試物最高濃度塗抹豬皮膚5天後，結果顯示對2倍最小紅斑劑量的紫外線能量，24小時產生紅斑抑制率，nicotinamide （51%）、L-ascorbic acid（86%）、saponin（55%）、berberine chloride（79.4%）及silymarin（86%）等有較佳的光保護作用。試管內試驗部分，是以一氧化氮清除作用、2,2-diphenyl-1-picrylhydrazyl (DPPH)自由基清除能力、2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+)清除作用、對liposome peroxidation系統之抗氧化作用等方法，測定各種受測物的抗氧化力。一氧化氮清除作用抑制率大於50%者，有L-ascorbic acid（99%）、berberine chloride（81.6%）、curcumin（57.4%）等。DPPH自由基清除能力抑制率大於50% 者，有L-ascorbic acid（100%）、saponin（70%）、silymarin（100%）、curcumin（79.7%）、樟芝萃取液（80%）及龍膽萃取液（61.3%）等。ABTS陽離子清除作用抑制率大於50%者，有L-ascorbic acid（100%）、saponin（96.3%）、 silymarin（100%）、curcumin（88%）、樟芝萃取液（100%）及龍膽萃取液（98.7%）等。對liposome peroxidation系統之抗氧化作用抑制率大於50%者，有saponin（100%）、berberine chloride（100%）、silymarin（93.5%）、curcumin（79%）、樟芝萃取液（100%）及龍膽萃取液（76.3%）等。綜合以上發現，有些受測物之光保護能力與其抗氧化能力略成相關性。試管內試驗也測定各種受測物之紫外線吸收光譜，發現nicotinamide、caffeine、L-ascorbic acid、saponin、berberine chloride、樟芝萃取液、冬蟲夏草萃取液、靈芝萃取液及龍膽萃取液等有紫外線C的吸收光譜。而berberine chloride兼具紫外線A及C的吸收光譜。又saponin和silymarin具有紫外線B的吸收光譜，具有紫外線A及紫外線B的吸收光譜或閉馬銗O護作用的機制之一。
The aim of this study was to investigate the photoprotection effects of a number of natural products through in vivo and in vitro assay. The study materials encompassed nicotinamide, caffeine, L-ascorbic acid, saponin, berberine chloride, silymarin, curcumin as well as extracts from Antrodia camphorata, Cordyceps sinensis, Genoderma and Gentian. For in vivo assay, these materials were topically applied to porcine skin. The porcine skin was subsequently irradiated with ultraviolet B (UVB) light. The extent of decrease in the erythema index was used as a measurement of the photoprotection effects. When observed the inhibition of erythema at 24 hours following irradiation with 2 minimal erythema dose (MED), nicotinamide (51%), L-ascorbic acid (85%), saponin (55%), berberine chloride (79.4%), and silymarin (86%) were found to have good photoprotection effects. For in vitro assays, nitric oxide (NO)-scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+) assay, and antioxidative effect on liposome peroxidation were used to evaluate the antioxidant capability of the study materials. L-Ascorbic acid (99%), berberine chloride (81.6%), and curcumin (57.4%) were shown to have NO-scavenging activity greater than 50%. L-Ascorbic acid (100%), saponin (70%), silymarin (100%), curcumin (79.7%), extracts from A. camphorate (80%), and Gentian extracts (61.3%) were found to have DPPH radical-scavenging activity greater than 50%. L-Ascorbic acid (100%), saponin (96.3%), silymarin (100%), curcumin (88%), extracts from A. camphorate (100%), and Gentian extracts (98.7%) were found to have ABTS•+ scavenging activity greater than 50%. Saponin (100%), berberine chloride (100%), silymarin (93.5%), curcumin (79%), extracts from A. camphorate (100%), and Gentian extracts (76.3%) were revealed to have antioxidative effect on liposome peroxidation greater than 50%. To sum up, the photoprotection effects in a number of the study materials were found to correlate with their antioxidant capability. The ultraviolet absorption spectra for the study materials were measured. Ultraviolet C (UVC) absorption was detected in nicotinamide, caffeine, L-ascorbic acid, berberine chloride as well as extracts from A. camphorata, C. sinensis, Genoderma and Gentian. Ultraviolet A and UVC absorption were simultaneously detected in berberine chloride. UVB absorption was detected in saponin and silymarin, which may play a role in their photoprotection effects. |
