Echinocystic acid

Planta Med. 2013 Aug;79(12):1031-7

Echinocystic acid isolated from Eclipta prostrata suppresses lipopolysaccharide-induced iNOS, TNF-α, and IL-6 expressions via NF-κB inactivation in RAW 264.7 macrophages.[Pubmed: 23877917]

In this study, we aimed to identify the compounds in Eclipta prostrata responsible for its anti-inflammatory effects using an in vitro bioassay.
METHODS AND RESULTS:
Three triterpenoids, eclalbasaponin I, eclalbasaponin II, and Echinocystic acid, were isolated from an EtOAc fraction of the 70 % EtOH extract of E. prostrata by activity-guided fractionation based on the inhibition of nitric oxide release from lipopolysaccharide-induced RAW 264.7 macrophages. Of these three triterpenoids, Echinocystic acid inhibited lipopolysaccharide-induced production of nitric oxide and cytokines such as tumor necrosis factor-α and interleukin-6. Consistent with these observations, Echinocystic acid concentration-dependently inhibited lipopolysaccharide-induced inducible nitric oxide synthase expression at the protein level and inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6 expression at the mRNA level, and inhibited lipopolysaccharide-induced iNOS promoter binding activity. In addition, Echinocystic acid suppressed the lipopolysaccharide-induced transcriptional activity of nuclear factor-κB by blocking the nuclear translocation of p65.

Life Sci. 2014 Oct 2;114(2):62-9.

Echinocystic acid, isolated from Gleditsia sinensis fruit, protects endothelial progenitor cells from damage caused by oxLDL via the Akt/eNOS pathway.[Pubmed: 25086379 ]

Our previous studies revealed that Echinocystic acid (EA) showed obvious attenuation of atherosclerosis in rabbits fed a high-fat diet. However, the underlying mechanisms remain to be elucidated. Considering the importance of endothelial progenitor cells (EPCs) in atherosclerosis, we hypothesise that EPCs may be one of the targets for the anti-atherosclerotic potential of EA.
METHODS AND RESULTS:
After in vitro cultivation, EPCs were exposed to 100 μg/mL of oxidised low-density lipoprotein (oxLDL) and incubated with or without EA (5 and 20 μM) for 48 h. An additional two groups of EPCs (oxLDL+20 μM EA) were pre-treated with either wortmannin, an inhibitor of the phosphoinositide 3-kinase (PI3K) pathway, or nitro-l-arginine methyl ester (l-NAME), an endothelial nitric oxide synthase (eNOS)-specific inhibitor. Assessment of EPC apoptosis, adhesion, migration, and nitric oxide (NO) release was performed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) staining, cell counting, caspase-3 activity assay, transwell chamber assay, and Griess reagent, respectively. The protein expression of protein kinase B (Akt) and eNOS was detected using Western blot. Treatment of EPCs with oxLDL induced significant apoptosis and impaired adhesion, migration, and NO production. The deleterious effects of oxLDL on EPCs were attenuated by EA. However, when EPCs were pre-treated with wortmannin or l-NAME, the effects of EA were abrogated. Additionally, oxLDL significantly down-regulated eNOS protein expression as well as repression of eNOS and Akt phosphorylation.
CONCLUSIONS:
The inhibitory effect of oxLDL on Akt/eNOS phosphorylation was attenuated by EA. Taken together, the results indicate that EA protects EPCs from damage caused by oxLDL via the Akt/eNOS pathway.

Fitoterapia. 2010 Jan;81(1):8-10.

Protective effects of echinocystic acid isolated from Gleditsia sinensis Lam. against acute myocardial ischemia.[Pubmed: 19573579 ]

Echinocystic acid (EA), a pentacyclic triterpene, was isolated and identified from the fruits of Gleditsia sinensis Lam.
METHODS AND RESULTS:
The protective effects of EA were evaluated in rat models with acute myocardial ischemia induced by isoproterenol and vasopressin. In the electrocardiogram of anesthetized rats, EA prevented the ST-segment depression induced by isoproterenol or vasopressin in a dose-dependently manner. Furthermore, the mRNA expression of Bcl-2 was analyzed by RT-PCR. EA shows an elevation of Bcl-2 mRNA level in infarcted tissue induced by isoproterenol in rats.
CONCLUSIONS:
These results demonstrated for the first time EA has a cardioprotective effect and may be a natural drug.

Metab Brain Dis . 2016 Apr;31(2):455-63.

Echinocystic acid reduces reserpine-induced pain/depression dyad in mice[Pubmed: 26729203]

Abstract Chronic pain has consistently been correlated with depression. Echinocystic acid (EA), a natural triterpone enriched in various herbs and used for medicinal purpose in many Asian countries, exhibits anti-inflammatory and analgesic activities. However, little is known the effects of EA on the depression. In present study, we investigated the anti-depression activities in the mouse model of reserpine-induced pain-depression dyad. Reserpine (1 mg/kg subcutaneously daily for 3 days) caused significant depression-like behaviors and pain sensation. Subsequent treatment of EA (5 mg/kg intragastrically daily for 5 days) attenuated the reserpine-induced pain/depression dyad as shown by the increase of pain threshold and the behaviors in forced swimming test, tail suspension test, and open field test. Furthermore, treatment of EA reversed the decrease of biogenic amines (norepinephrine, dopamine, and serotonin) in the brain region of hippocampus, a structure involved in the formation of emotional disorders. Levels of serotonin receptor 5-HT1A were decreased and levels of 5-HT2A were increased in the reserpine-injected mice. Treatment of EA could restore the alterations of serotonin receptors. At the same time, the increase in GluN2B-containing NMDA receptors, p-GluA1-Ser831, PSD-95 and CaMKII were integrated with the increase in caspase-3 and iNOS levels in the hippocampus of the reserpine-injected mice. EA significantly reversed the changes of above proteins. However, EA did not affect the levels of GluN2A-containing NMDA receptors and the total levels of GluA1 and p-GluA1-Ser845. Our study provides strong evidence that EA attenuates reserpine-induced pain/depression dyad partially through regulating the biogenic amines levels and GluN2B receptors in the hippocampus. Keywords: Depression; Echinocystic acid; Hippocampus; NMDA receptor; Pain; Serotonin.

Cancer Lett. 2004 Aug 20;212(1):21-32.

Echinocystic acid induces apoptosis in HL-60 cells through mitochondria-mediated death pathway.[Pubmed: 15246558 ]

Echinocystic acid (EA) is a natural triterpone enriched in various herbs and used for medicinal purpose in many Asian countries.
METHODS AND RESULTS:
In the present study, we reported that EA can induce apoptosis in human promyelocytic leukemia cells (HL-60), as characterized by DNA fragmentation, poly (ADP) ribose polymerase cleavage. The efficacious induction of apoptosis was observed at 100 microM for 6 h. Further molecular analysis showed that EA induced the cleavage of Bid protein, the loss of mitochondrial membrane potential (DeltaPsim) cytochrome c release from mitochondria into cytosol, and activation of caspase-3, -8 and -9. However, EA did not generate reactive oxygen species (ROS), and antioxidants including N-acetyl cysteine and catalase could not block EA-induced apoptosis in the HL-60 cells.
CONCLUSIONS:
These data suggest that EA induces apoptosis in HL-60 cells through ROS-independent mitochondrial dysfunction pathway.

Evid Based Complement Alternat Med. 2014;2014:823154.

Deciphering molecular mechanism underlying hypolipidemic activity of echinocystic Acid.[Pubmed: 24669228 ]

Our previous study showed that a triterpene mixture, consisting of Echinocystic acid (EA) and oleanolic acid (OA) at a ratio of 4 : 1, dose-dependently ameliorated the hyperlipidemia and atherosclerosis in rabbits fed with high fat/high cholesterol diets.
METHODS AND RESULTS:
This study was aimed at exploring the mechanisms underlying antihyperlipidemic effect of EA. Molecular docking simulation of EA was performed using Molegro Virtual Docker (version: 4.3.0) to investigate the potential targets related to lipid metabolism. Based on the molecular docking information, isotope labeling method or spectrophotometry was applied to examine the effect of EA on the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, acyl-CoA:cholesterol acyltransferase (ACAT), and diacylglycerol acyltransferase (DGAT) in rat liver microsomes. Our results revealed a strong affinity of EA towards ACAT and DGAT in molecular docking analysis, while low binding affinity existed between EA and HMG-CoA reductase as well as between EA and cholesteryl ester transfer protein. Consistent with the results of molecular docking, in vitro enzyme activity assays showed that EA inhibited ACAT and DGAT, with IC50 values of 103 and 139  μ M, respectively, and exhibited no significant effect on HMG-CoA reductase activity.
CONCLUSIONS:
The present findings suggest that EA may exert hypolipidemic effect by inhibiting the activity of ACAT and DGAT.

Phytomedicine. 2012 Dec 15;20(1):84-8.

Lancemaside A isolated from Codonopsis lanceolata and its metabolite echinocystic acid ameliorate scopolamine-induced memory and learning deficits in mice.[Pubmed: 23079229 ]

The rhizome of Codonopsis lanceolata (family Campanulaceae), which contains lancemaside A as a main constituent, has been used as herbal medicine to treat inflammation, insomnia, and hypomnesia.
METHODS AND RESULTS:
Lancemaside A and Echinocystic acid, which is its metabolite by intestinal microflora, potently inhibited acetylcholinesterase activity in a dose-dependent manner, with IC₅₀ value 13.6 μM and 12.2 μM, respectively. Its inhibitory potency is comparable with that of donepezil (IC₅₀=10.9 μM). Lancemaside A and Echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on passive avoidance task. Lancemaside A orally administered 5h before treatment with scopolamine reversed scopolamine-induced memory and learning deficits more potently than one orally administered 1h before. Echinocystic acid more potently reversed it than lancemaside A. Lancemaside A and Echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on the Y-maze and Morris water maze tasks. Lancemaside A and Echinocystic acid also increased the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (p-CREB).
CONCLUSIONS:
Based on these findings, orally administered lancemaside A may be metabolized to Echinocystic acid, which may be absorbed into the blood and ameliorate memory and learning deficits by inhibiting AChE activity and inducing BDNF and p-CREB expressions.

PLoS One. 2015 Aug 28;10(8):e0136572.

Osteoprotective Effect of Echinocystic Acid, a Triterpone Component from Eclipta prostrata, in Ovariectomy-Induced Osteoporotic Rats.[Pubmed: 26317835 ]

Echinocystic acid (EA) is a natural triterpone enriched in various herbs and has been used for medicinal purposes in China.
METHODS AND RESULTS:
In the present study, we systematically examined the effects of EA on ovariectomy-induced osteoporosis in rats for the first time. Three-month-old female ovariectomy (OVX) Sprague-Dawley rats were used to evaluate the osteoprotective effect of EA. Results showed that administration of EA (5 or 15 mg/kg/day) for 12 weeks prevented lower levels of maximum stress and Young's modulus of femur induced by OVX. EA also recovered bone metabolic biomarkers levels in OVX rats, including osteocalcin, alkaline phosphatese, deoxypyridinoline, and urinary calcium and phosphorus. EA (5 and 15 mg/kg/day) could prevent the alteration of total bone mineral density in the femur caused by OVX. However, only high dose (15 mg/kg/day) of EA significantly improved trabecular architecture, as evidenced by higher levels of bone volume/tissue volume, trabecula number, and trabecula thickness, and lower levels of trabecula separation and structure model index compared with OVX rats. In addition, EA treatment decresed the serum levels of IL-1β and TNF-α in OVX rats.
CONCLUSIONS:
In conclusion, EA could prevent reduction of bone mass and strength and improve the cancellous bone structure and biochemical properties in OVX rats. Hence, EA may serve as a new candidate or a leading compound for anti-osteoporosis.

Eur J Med Chem. 2013 Jun;64:160-8.

Elucidation of the pharmacophore of echinocystic acid, a new lead for blocking HCV entry.[Pubmed: 23644199 ]

METHODS AND RESULTS:
To elucidate the pharmacophore of Echinocystic acid (EA), an oleanane-type triterpene displaying substantial inhibitory activity on HCV entry, two microbial strains, Rhizopus chinensis CICC 3043 and Alternaria alternata AS 3.4578, were utilized to modify the chemical structure of EA. Eight new metabolites with regio- and stereo-selective introduction of hydroxyl and lactone groups at various inert carbon positions were obtained. The anti-HCV entry activity of the metabolites 2-13, along with their parental compound EA and other analogs 14-15, were evaluated. Most of the metabolites showed no improvement but detrimental effect on potency except compound 5 and 6, which showed similar and even a litter higher anti-HCV entry activity than that of EA.
CONCLUSIONS:
The results demonstrated that ring A, B, C and the left side of ring E of EA are highly conserved, while ring D and the right side of ring E of EA are flexible. Introduction of a hydroxyl group at C-16 enhanced the triterpene potency. Further analysis indicated that the hemolytic effect of EA disappeared upon such modifications.