• Natural Product Sciences
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• v.23 no.4
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• pp.265-269
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• 2017

Pseudolaric acids of Pseudolarix kaempferi (Pinaceae) have been known as diterpenoids with potent anti-fungal-, anti-microbial, and cytotoxic activities. In the present study, the five MeOH extracts were prepared from the five plant part (root bark, stem bark, leaf, the inner part of root, and cone) to find the relation between the concentration of pseudolaric acids and cytotoxicity. Pseudolaric acids B and C were isolated from the root bark of P. kaempferi to use them as standard compounds. The five extracts were tested on cytotoxicity against six cancer cell lines, A549 (lung), HCT116 (colon), MDA-MB-231 (breast), SNU638 (stomach), and SK-hep-1 (liver) by SRB assay, but against K562 (leukemia) by SRB- or MTT assay. HPLC quantification were performed on a Shisheido Capcell PAK C18 column ($5{\mu}m$, $4.6mm{\times}250mm$) using 254 nm wavelength. The cytotoxicity ($IC_{50}$, $0.36{\mu}g/ml$ on K562 cell lines) of the root bark extract was potent and the content (101.1 mg/g extract) of pseudolaric acid B was very high in the root bark. These results suggest that the MeOH extract obtained from the root bark could be developed as the anti-cancer agent with a high quantity of pseudolaric acid B.

• Archives of Pharmacal Research
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• v.28 no.1
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• pp.68-72
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• 2005

Pseudolaric acid B is a major compound found in the bark of Pseudolarix kaempferi Gordon. In our study, pseudolaric acid B inhibited growth of human melanoma cells, A375-S2 in a time and dose-dependent manner. A375-S2 cells treated with pseudolaric acid B showed typical characteristics of apoptosis including morphologic changes, DNA fragmentation, sub-diploid peak in flow cytometry, cleavage of poly-ADP ribose polymerase (PARP) and degradation of inhibitor of caspase-activated DNase (ICAD). P53 protein expression was upregulated while cells were arrested at the $G_2/M$ phase of the cell cycle. There was a decrease in the expression of anti-apoptotic Bcl-2 and Bcl-xL proteins, whereas pro-apoptotic Bax was increased. The two classical caspase substrates, PARP and ICAD, were both decreased in a time-dependent manner, indicating the activation of downstream caspases.