Endothall

Endothall (Endothal) is a protein phosphatase 2A (PP2A) inhibitor with IC50s of 90 nM and 5 µM for PP2A and PP1, respectively. Endothall can be used as an herbicide. Endothall also is useful in cancer chemotherapy[1].

Signaling Pathways >> Metabolic Enzyme/Protease >> Phosphatase

Endothall, an organic acid, is the least toxic structural analogue of Cantharidin that still inhibits PP2A[2]. Endothall inhibits preferentially hepatocellular carcinoma (HCC) growth and these new rat hepatocellular carcinoma lines may be useful for further biochemical and pharmacological studies on PP2A inhibitors, and for testing new forms of treatment of hepatic cell carcinomas. The HR-2, HR-3, HR-4, and Zajdela hepatocellular carcinomas are most sensitive to Endothall (IC50 of 1.7, 1.2, 0.9, and 1.7 µg/mL), whereas newborn rat hepatocytes growing exponentially in primary culture (IC50=6.2 µg/mL), rat DHD/K12 colon carcinoma cells (IC50=3.6 µg/mL), or human HT-29 colon carcinoma cells (IC50=4.9 µg/mL) were less sensitive[2]. Endothall inhibits the growth of HCC lines in culture more than that of normal hepatocytes or colon carcinomas, inducing mitotic arrest, followed by cell death. Endothall causes dose- and time-dependent cytostasis specifically in G2/M[2]. Endothall (3 µg/mL) inhibits the cell cycle at G2/M and subsequent apoptotic cell death[2].

Endothall exhibits acute LD50 of 14 mg/kg in mice[2].

[1]. Janetti R Signorelli, et al. Protein phosphatases decrease their activity during capacitation: a new requirement for this event. PLoS One. 2013 Dec 2;8(12):e81286.

[2]. J P Thièry, et al. Hepatocellular carcinoma cell lines from diethylnitrosamine phenobarbital-treated rats. Characterization and sensitivity to endothall, a protein serine/threonine phosphatase-2A inhibitor. Hepatology. 1999 May;29(5):1406-17.

MOLECULAR FORMULA :

C8-H10-O5

MOLECULAR WEIGHT :

186.18

WISWESSER LINE NOTATION :

T55 A AOTJ CVQ DVQ

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - man

DOSE/DURATION :

571 uL/kg

TOXIC EFFECTS :

Cardiac - other changes Kidney, Ureter, Bladder - urine volume decreased Nutritional and Gross Metabolic - metabolic acidosis

REFERENCE :

AJEMEN American Journal of Emergency Medicine. (WB Saunders, Philadelphia, PA) V.1- 1983- Volume(issue)/page/year: 6,509,1988

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

38 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

PCOC** Pesticide Chemicals Official Compendium, Association of the American Pesticide Control Officials, Inc., 1966. (Topeka, KS) Volume(issue)/page/year: -,471,1966

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Administration onto the skin

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

>1 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

FAATDF Fundamental and Applied Toxicology. (Academic Press, Inc., 1 E. First St., Duluth, MN 55802) V.1- 1981- Volume(issue)/page/year: 7,299,1986

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

14 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JAFCAU Journal of Agricultural and Food Chemistry. (American Chemical Soc., Distribution Office Dept. 223, POB 57136, West End Stn., Washington, DC 20037) V.1- 1953- Volume(issue)/page/year: 35,823,1987 *** U.S. STANDARDS AND REGULATIONS *** EPA FIFRA 1988 PESTICIDE SUBJECT TO REGISTRATION OR RE-REGISTRATION FEREAC Federal Register. (U.S. Government Printing Office, Supt. of Documents, Washington, DC 20402) V.1- 1936- Volume(issue)/page/year: 54,7740,1989