scholarly journals Anti-proliferative Activity of Some Oleanolic Acid Derivatives with Potent Topoisomerase Inhibitory Activity on B16 Melanoma Cells

2020 ◽  
Vol 9 (1) ◽  
pp. 26-28
Author(s):  
Ahmed Ashour ◽  
Ryuichiro Kondo ◽  
Kuniyoshi Shimizu

Our previous study included the semisynthetic reactions on oleanolic acid, a common wood-derived oleanane-type triterpene. Ten rationally designed derivatives of oleanolic acid were synthesized based on docking studies and tested for their topoisomerase I and IIα inhibitory activity. Semisynthetic reactions targeted C-3, C-12, C-13 and C-17. Some of these compounds act as dual inhibitors for both topoisomerase I and IIα giving new anticancer agents. The cytotoxic activity of these compounds on B16 melanoma cancer cells was evaluated. Results showed that most of these compounds have a higher cytotoxic activity on B16 melanoma cells.

2016 ◽  
Vol 32 (4) ◽  
pp. 1899-1907
Author(s):  
Min-Jin Kim ◽  
Sang Kim ◽  
Suk Yun ◽  
Seung-Young Kim ◽  
Kwang Hyun ◽  
...  

2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Enos Tangke Arung ◽  
Kuniyoshi Shimizu ◽  
Ryuichiro Kondo

Artocarpus plants have been a focus of constant attention due to the potential for skin whitening agents. In the in vitro experiment, compounds from the Artocarpus plants, such as artocarpanone, norartocarpetin, artocarpesin, artogomezianol, andalasin, artocarbene, and chlorophorin showed tyrosinase inhibitory activity. Structure-activity investigations revealed that the 4-substituted resorcinol moiety in these compounds was responsible for their potent inhibitory activities on tyrosinase. In the in vitro assay, using B16 melanoma cells, the prenylated polyphenols isolated from Artocarpus plants, such as artocarpin, cudraflavone C, 6-prenylapigenin, kuwanon C, norartocarpin, albanin A, cudraflavone B, and brosimone I showed potent inhibitory activity on melanin formation. Structure-activity investigations revealed that the introduction of an isoprenoid moiety to a non-isoprenoid-substituted polyphenol enhanced the inhibitory activity of melanin production in B16 melanoma cells. In the in vivo investigation, the extract of the wood of Artocarpus incisus and a representative isolated compound from it, artocarpin had a lightening effect on the skin of guinea pigs’ backs. Other in vivo experiments using human volunteers have shown that water extract of Artocarpus lakoocha reduced the melanin formation in the skin of volunteers. These results indicate that the extracts of Artocarpus plants are potential sources for skin whitening agents.


Holzforschung ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 514-518 ◽  
Author(s):  
Enos Tangke Arung ◽  
Keisuke Yoshikawa ◽  
Kuniyoshi Shimizu ◽  
Ryuichiro Kondo

Abstract By means of bioassay-guided fractionation using mushroom tyrosinase, a geranylated stilbene, chlorophorin, was characterized as the principal tyrosinase inhibitor in the heartwood of Chlorophora excelsa (Moraceae). It inhibited the oxidation of L-tyrosine and DL-3,4-dihydroxyphenylalanine (DL-DOPA) due to mushroom tyrosinase and melanin biosynthesis on B16 melanoma cells. Chlorophorin, which is a slight yellowish compound, has previously been reported as an unstable compound in light. On the basis of this finding, a chlorophorin derivative [4-(3″,7″-dimethyloctyl)-2′,3,4′,5-tetrahydroxydihydrostilbene; hexahydrochlorophorin] which is colorless, obtained by the hydrogenation of chlorophorin with Pd/C, was also tested to develop a superior material for practical use. Hexahydrochlorophorin showed more potent inhibitory activity on tyrosinase and melanin biosynthesis, and lower cytotoxicity towards B16 melanoma cells than chlorophorin.


2012 ◽  
Vol 9 (8) ◽  
pp. 1500-1507 ◽  
Author(s):  
Takashi Kikuchi ◽  
Kensuke Watanabe ◽  
Yuichi Tochigi ◽  
Ayako Yamamoto ◽  
Makoto Fukatsu ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2697
Author(s):  
Thouria Bourhim ◽  
Myra O. Villareal ◽  
Chemseddoha Gadhi ◽  
Hiroko Isoda

The beneficial effect on health of argan oil is recognized worldwide. We have previously reported that the cake that remains after argan oil extraction (argan press-cake or APC) inhibits melanogenesis in B16 melanoma cells in a time-dependent manner without cytotoxicity. In this study, the global gene expression profile of B16 melanoma cells treated with APC extract was determined in order to gain an understanding of the possible mechanisms of action of APC. The results suggest that APC extract inhibits melanin biosynthesis by down-regulating microphthalmia-associated transcription factor (Mitf) and its downstream signaling pathway through JNK signaling activation, and the inhibition of Wnt/β-catenin and cAMP/PKA signaling pathways. APC extract also prevented the transport of melanosomes by down-regulating Rab27a expression. These results suggest that APC may be an important natural skin whitening product and pharmacological agent used for clinical treatment of pigmentary disorders.


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