• KSBB Journal
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• v.28 no.2
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• pp.74-79
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• 2013

There are a large number of bioactive sesquiterpene lactones from compositae plants including Hemistepita lyrata Bunge. In the present study, we purified two sesquiterpene lactones, Hemistepsin A and B, from H. lyrata and evaluated their antimicrobial activities against Malassezia obutusa. Chromatographic separation was used for the preparation of Hemistepsin A and B, and the identity of these compounds was confirmed by NMR. Strong inhibition of growth of M. obutusa was obtained with all doses of Hemistepsin A tested. Moreover, antifungal activity of Hemistepsin A occurred in a dose-dependent manner. Hemistepsin B also showed potent antifungal activity at the dose of $800{\mu}m/disc$. From these results, it was suggested that Hemistepsin A and B be beneficial for the preparation of the useful agent for treating scalp diseases occurred by dandruff-causing Malassezia species.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.176-179
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• 1999

In the bioactivity test of nine sesquiterpene lactons isolated from Hemisteptia lyrata, Chrysanthemum zawadskii and Chrysanthemum boreale, we investigated their antimicrobial activities against ten bacteria and six phytopathogenic fungi. Hemistepsin A and hemistepsin B isolated from H. lyrata and tulipinolide isolated from C. boreale exhibited strong antibacterial activity. In the antifungal test, hemistepsin B, angeloylcumambrin B, tigloylcumambrin B and costunolide showed broad activity. Both antibacterial and antifungal experiments exhibited quite clear specificity against microbial strains.

• BMB Reports
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• v.54 no.2
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• pp.106-111
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• 2021

Hemistepsin A (HsA) is a guaianolide sesquiterpene lactone that inhibits hepatitis and liver fibrosis. We evaluated the effects of HsA on liver X receptor (LXR)-mediated hepatic lipogenesis in vitro and in vivo. Up to 10 μM, HsA did not affect the viability of HepG2 and Huh7 cells. Pretreatment with 5-10 μM HsA significantly decreased the luciferase activity of the LXR response element, which was transactivated by T0901317, GW 3965, and LXRα/retinoid X receptor α overexpression. In addition, it significantly inhibited the mRNA expression of LXRα in HepG2 and Huh7 cells. It also suppressed the expression of sterol regulatory element-binding protein-1c and lipogenic genes and reduced the triglyceride accumulation triggered by T0901317. Intraperitoneal injection of HsA (5 and 10 mg/kg) in mice significantly alleviated the T0901317-mediated increases in hepatocyte diameter and the percentage of regions in hepatic parenchyma occupied by lipid droplets. Furthermore, HsA significantly attenuated hepatic triglyceride accumulation by restoring the impaired expression of LXRα-dependent lipogenic genes caused by T0901317. Therefore, based on its inhibition of the LXRα-dependent signaling pathway, HsA has prophylactic potential for steatosis.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.74-78
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• 1999

Nine sesquiterpene lactones, which were isolated from Hemisteptia lyrata Bunge, Chrysanthemum zawadskii Herbich var. latilobum Kitamura and Chrysanthemum boreale Makino were evaluated for the inhibition upon the nitric oxide release from the Raw cell and for the ACAT (acyl Co A: cholesterol acyltransferase) inhibitory assay. In the nitric oxide release inhibitory experiment, hemistepsin B $(IC_{50}\;=\;0.05\;{\mu}g/ml,\;0.15\;{\mu}M),$ cumambrin B, tulipinolide and costunolide exhibited strong inhibition with $IC_{50}$ values $0.05\;{\mu}g/ml\;(0.15\;{\mu}M),\;0.1\;{\mu}g/ml\;(0.38\;{\mu}M),\;0.2\;{\mu}g/ml\;(0.69\;{\mu}M)$ and $0.2\;{\mu}g/ml(0.86\;{\mu}M),$ respectively. In the ACAT inhibitory assay, angeloylcumambrin B, tigloylcumambrin B, tulipinolide and costunolide exhibited strong inhibition with $IC_{50}$ values $33\;{\mu}g/ml\;(95.4\;{\mu}M),\;22\;{\mu}g/ml\;(63.6\;{\mu}M),\;38\;{\mu}g/ml\;(151\;{\mu}M)$ and $17\;{\mu}g/ml(73.3\;{\mu}M),$ respectively, whereas other compounds did not exhibit significant activity against ACAT above $100\; {\mu}g/ml.$.

• Journal of Life Science
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• v.31 no.2
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• pp.126-136
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• 2021

Oxidative stress causes injury to and degeneration of retinal pigment epithelial (RPE) cells. It is involved in several retinal disorders and leads to vision loss. In the present study, we investigated the effect of 14 kinds of natural compounds and two kinds of synthetic compounds on oxidative stress-induced cellular damage in human PRE cell lines (ARPE-19). From among them, we selected five kinds of compounds, including auranofin, FK-509, hemistepsin A, honokiol, and spermidine, which have inhibitory effects against hydrogen peroxide (H2O2)-mediated cytotoxicity. In addition, we found that four kinds of compounds (excluding auranofin) have protective effects on H2O2-induced mitochondrial dysfunction. Furthermore, the expression of phosphorylation of histone H2AX, a sensitive marker of DNA damage, was markedly up-regulated by H2O2, whereas it was notably down-regulated by FK-506, honokiol, and spermidine treatment. Meanwhile, five kinds of candidate compounds had no effect on H2O2-induced intracellular reactive oxygen species (ROS) levels, suggesting that the five candidate compounds have protective effects on oxidative stress-induced cellular damage through the ROS-independent pathway. Taken together, according to the results of H2O2-mediated cellular damage―such as cytotoxicity, apoptosis, mitochondrial dysfunction, and DNA damage―spermidine and FK-506 are the natural and synthetic compounds with the most protective effects against oxidative stress in RPE. Although further studies on the identification of the mechanism responsible are required, the results of the present study suggest the possibility of using spermidine and FK-506 to suppress the risk of retinal disorders.