||Alantolactone is sesquiterpene lactone, significantly reduces feeding and survival of Tribolium confusum.
1.Inhibition of thioredoxin reductase by alantolactone prompts oxidative stress-mediated apoptosis of HeLa cells.
Zhang J1, Li Y1, Duan D1, Yao J1, Gao K2, Fang J3. Biochem Pharmacol. 2016 Feb 15;102:34-44. doi: 10.1016/j.bcp.2015.12.004. Epub 2015 Dec 11.
The mammalian thioredoxin reductase (TrxR) isoenzymes, TrxR1 in cytosol or nucleus, TrxR2 in mitochondria, and TrxR3 in testis, are essential seleno-flavoenzymes with a conserved penultimate selenocysteine (Sec) residue at the C-terminus, and have attracted increasing interests as potential targets for development of cancer chemotherapeutic agents. The sesquiterpene lactone alantolactone (ATL), an active component from the traditional folk medicine Inula helenium, has been documented possessing multiple pharmacological functions, especially the anticancer activity. However, the underlying mechanism has not been well defined. We reported that ATL inhibits both the recombinant TrxR and the enzyme in the cellular environment. The alpha-methylene-gamma-lactone moiety in ATL and the Sec residue in TrxR are critical for targeting TrxR by ATL. By employing our newly developed pull down assay, we demonstrated the remarkable elevation of the oxidized thioredoxin in HeLa cells after ATL treatment.
2.Induction of ROS Overload by Alantolactone Prompts Oxidative DNA Damage and Apoptosis in Colorectal Cancer Cells.
Ding Y1, Wang H2, Niu J3, Luo M4, Gou Y5, Miao L6, Zou Z7, Cheng Y8,9. Int J Mol Sci. 2016 Apr 14;17(4). pii: E558. doi: 10.3390/ijms17040558.
Cancer cells typically display higher than normal levels of reactive oxygen species (ROS), which may promote cancer development and progression but may also render the cancer cells more vulnerable to further ROS insult. Indeed, many of the current anticancer therapeutics kill cancer cells via induction of oxidative stress, though they target both cancer and normal cells. Recently, alantolactone (ATL), a natural sesquiterpene lactone, has been shown to induce apoptosis by increasing ROS levels specifically in cancer cells; however, the molecular mechanisms linking ROS overproduction to apoptosis remain unclear. Here we show that the ATL-induced ROS overload in human SW480 and SW1116 colorectal cancer cells was followed by a prominent accumulation of cellular oxidized guanine (8-oxoG) and immediate increase in the number of DNA strand breaks, indicating that increased ROS resulted in extensive oxidative DNA damage. Consequently, the G₁/S-CDK suppresser CDKN1B (p21) and pro-apoptotic proteins Bax and activated caspase-3 were upregulated, while anti-apoptotic Bcl-2 was downregulated, which were followed by cell cycle arrest at G₁ and marked apoptosis in ATL-treated cancer but not non-cancer cells.
3.High body clearance and low oral bioavailability of alantolactone, isolated from Inula helenium, in rats: extensive hepatic metabolism and low stability in gastrointestinal fluids.
Lee JY1, Kim SB1, Chun J2, Song KH2, Kim YS2, Chung SJ1, Cho HJ3, Yoon IS4, Kim DD1. Biopharm Drug Dispos. 2016 Apr;37(3):156-67. doi: 10.1002/bdd.2005.
Alantolactone (ALA) is a major bioactive sesquiterpene lactone present in the roots of Inula helenium L. (Asteraceae) which has been used widely in traditional medicine against various diseases such as asthma, cancer and tuberculosis. The pharmacologic activities of alantolactone have been well characterized, yet information on the physicochemical and pharmacokinetic properties of alantolactone and their mechanistic elucidation are still limited. Thus, this study aims to investigate the oral absorption and disposition of alantolactone and their relevant mechanisms. Log P values of alantolactone ranged from 1.52 to 1.84, and alantolactone was unstable in biological samples such as plasma, urine, bile, rat liver microsomes (RLM) and simulated gastrointestinal fluids. The metabolic rate of alantolactone was markedly higher in rat liver homogenates than in the other tissue homogenates. A saturable and concentration-dependent metabolic rate profile of alantolactone was observed in RLM, and rat cytochrome P450 (CYP) 1 A, 2C, 2D and 3 A subfamilies were significantly involved in its hepatic metabolism.
4.Alantolactone exhibited anti-herpes simplex virus 1 (HSV-1) action in vitro.
Rezeng C1, Yuan D, Long J, Suonan D, Yang F, Li W, Tong L, Jiumei P. Biosci Trends. 2015 Dec;9(6):420-2. doi: 10.5582/bst.2015.01171.
The aim of this study was to determine the inhibitory action of alantolactone, a gradient of traditional Chinese medicine Inulae Radix (Tu-Mu-Xiang), on herpes simplex virus 1 (HSV-1). African green monkey kidney cells (Vero cells) were infected with HSV-1 and the protective effects of alantolactone on Vero cells were examined. At concentrations of 10(-6), 10(-7), and 10(-8) g/mL, alantolactone did not have a marked harmful effect on the viability of Vero cells according to an MTT assay. Based on the cytopathic effect (CPE) and MTT assays, alantolactone at these concentrations exhibited antiviral action and protected cells from being damaged by HSV-1. Results indicated that alantolactone had potent anti-HSV-1 action and provided evidence for use of Inulae Radix in the treatment of HSV-1 infection.