| Summary: | 碩士 === 嘉南藥理科技大學 === 生物科技系暨研究所 === 91 === Microwave aqueous extracts (MAE) from twelve Chinese herbs and fifteen
commercial pure compounds were evaluated for their (1) melanin biosynthesis
anti-oxidative activities by tyrosinase inhibition, (2) nitric oxide (NO)
scavenging activities by SNP, (3) radical scavenging effects by the DPPH and (
4) peroxynitrite scavenging activities by the SNP / H2O2 / luminal
chemiluminescence’s methods. The results of our investigation show that
glycyrrhizae radix for the preliminary assay optimal tyrosinase inhibition (90.
73%) and NO scavenging effects (82.39%) of microwave Chinese herbs extracts
can be concluded that the duration of microwave radiation is 6 min, the
microwave energy is 720w. Our studies also show three Chinese herbs by MAE (
Ramulus mori, Glycyrrhizae radix and Cortex mori) exhibited high anti-
tyrosinase (SC50=0.3,0.9 and 3.11mg/ml, respectively) and NO scavenging
effect (SC50=0.238, 0.249 and 0.236mg/ml, respectively). On the other hands,
Acanthopanax senticosus (SC50=0.755, 0.713mg/ml, respectively) and Ginkgo
biloba (SC50=0.583, 0.756mg/ml, respectively) scavenged DPPH free radical and
peroxynitrite production, most effectively. Commercial pure compounds (such as
licorice-derived, flavonoids, antioxidants and tyrosinase inhibitors
compounds) were referenced index for their anti-tyrosinase, free radical
scavenging and antioxidant properties. The results indicated that under 100μM
concentration, Kojic acid against tyrosinase (63.14%), Hydroquinone scavenged
NO (40.17%), Catechin scavenged DPPH free radical (97.99%), and Quercetin
decreased peroxynitrite production (52.25%) present more effect for
bioactivities. Collectively, these data suggest that Chinese herbs by MAE
maybe extract some effect such as anti-oxidative and anti-tyrosinase.
Consequently, some detail bioactive mechanisms and MAE in order to isolate and
identify photochemical compounds, involved in some biological activities will
be studied.
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