Asiatic acid

Asiatic acid ameliorates dextran sulfate sodium-induced murine experimental colitis via suppressing mitochondria-mediated NLRP3 inflammasome activation.[Pubmed: 25523461]

Int Immunopharmacol. 2015 Feb;24(2):232-8.

In the present study, the effect of Asiatic acid, a natural triterpenoid compound, on murine experimental colitis induced by dextran sulfate sodium (DSS) and its possible mechanism were examined in vivo and vitro.
METHODS AND RESULTS:
Oral administration of Asiatic acid dose-dependently attenuated the loss of body weight and shortening of colon length induced by DSS. The disease activity index, histopathologic scores of musco and myeloperoxidase activity were also significantly reduced by Asiatic acid treatment. Protein and mRNA levels of DSS-induced pro-inflammatory cytokines in colon, including TNF-α, IL-1β, IL-6 and IFN-γ, were markedly suppressed by Asiatic acid. At the same time, decreased activation of caspase-1 in peritoneal macrophages was detected in Asiatic acid-treated mice, which suggested that the NLRP3 inflammasome activation was suppressed. In addition, we also found that Asiatic acid dose-dependently inhibited IL-1β secretion, caspase-1 activation as well as inflammasome assembling in vitro. Furthermore, the mechanism of Asiatic acid was related to the inhibition of mitochondrial reactive oxygen species generation and prevention of mitochondrial membrane potential collapse.
CONCLUSIONS:
Taken together, our results demonstrate the ability of Asiatic acid to inhibit NLRP3 inflammasome activation and its potential usage in the treatment of inflammatory bowel diseases.

Asiatic acid alleviates hemodynamic and metabolic alterations via restoring eNOS/iNOS expression, oxidative stress, and inflammation in diet-induced metabolic syndrome rats.[Pubmed: 24441717 ]

Nutrients. 2014 Jan 16;6(1):355-70.

Asiatic acid is a triterpenoid isolated from Centella asiatica. The present study aimed to investigate whether Asiatic acid could lessen the metabolic, cardiovascular complications in rats with metabolic syndrome (MS) induced by a high-carbohydrate, high-fat (HCHF) diet.
METHODS AND RESULTS:
Male Sprague-Dawley rats were fed with HCHF diet with 15% fructose in drinking water for 12 weeks to induce MS. MS rats were treated with Asiatic acid (10 or 20 mg/kg/day) or vehicle for a further three weeks. Plasma nitrate and nitrite (NOx) were markedly high with upregulation of inducible nitric oxide synthase (iNOS) expression, but dowregulation of endothelial nitric oxide synthase (eNOS) expression (p<0.05). Asiatic acid significantly improved insulin sensitivity, lipid profiles, hemodynamic parameters, oxidative stress markers, plasma TNF-α, NOx, and recovered abnormality of eNOS/iNOS expressions in MS rats (p<0.05).
CONCLUSIONS:
In conclusion, Asiatic acid improved metabolic, hemodynamic abnormalities in MS rats that could be associated with its antioxidant, anti-inflammatory effects and recovering regulation of eNOS/iNOS expression.

Antidiabetic and antihyperlipidemic activity of asiatic acid in diabetic rats, role of HMG CoA: in vivo and in silico approaches.[Pubmed: 24075211]

Phytomedicine. 2014 Feb 15;21(3):225-32.

Hyperlipidemia is an associated complication of diabetes and also a major risk factor for cardiovascular diseases.
METHODS AND RESULTS:
The present study was designed to examine the antihyperlipidemic effect of Asiatic acid (AA) in streptozotocin (STZ) induced diabetic rats. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of STZ (40 mg/kg b.w.). Diabetic rats show increased plasma glucose, total cholesterol, triglycerides, free fatty acids, phospholipids, low density lipoprotein, very low density liprotein, atherogenic index and decreased insulin and high density lipoprotein in diabetic rats. The activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG CoA) reductase increased significantly in contrast to the activities of lipoprotein lipase and lecithin cholesterol acyltransferase. In addition, the molecular docking of AA against HMG CoA reductase involved in cholesterol biosynthesis using Argus software. Diabetic rats were treated with AA shifted all these parameters towards normalcy. AA has shown best ligand binding energy 11.8122 kcal/mol. The antihyperlipidemic effect of AA was compared with glibenclamide; a well-known antihyperglycemic drug.
CONCLUSIONS:
In conclusion, this study indicates that AA showed an antihyperlipidemic effect in addition to its antidiabetic effect in experimental diabetes.

Inhibitory effects of asiatic acid on 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol 13-acetate-induced tumor promotion in mice.[Pubmed: 17202682]

Biol Pharm Bull. 2007 Jan;30(1):176-9.

Asiatic acid, a pentacyclic triterpene, has been reported to induce apoptosis of various human cancer cells.
METHODS AND RESULTS:
In the present study, we assessed the anti-tumor promoting effect of Asiatic acid against 12-O-tetradecanoylphorbol 13-acetate (TPA)-mediated skin tumorigenesis in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated ICR mice. Topical application of Asiatic acid prior to each application of TPA resulted in a significant reduction in skin tumor formation. We also found that pre-application of Asiatic acid alleviated TPA-induced [3H]thymidine incorporation, which is a conventional marker for skin tumor promotion. In addition, Asiatic acid inhibited the TPA-induced generation of nitric oxide (NO) and expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), which are known to play important roles in tumor growth, especially in the promotion stage. In addition, topical application of aminoguanidine (AG), a selective iNOS inhibitor, and N(G)-nitro-L-arginine-methyl ester (NAME), another iNOS inhibitor, 30 min prior to TPA treatment significantly inhibited the TPA-induced COX-2 expression.
CONCLUSIONS:
These results suggest that Asiatic acid may exert anti-tumorigenesis through inhibitory actions in NO and COX-2 signals.

Asiatic acid reduces blood pressure by enhancing nitric oxide bioavailability with modulation of eNOS and p47phox expression in L-NAME-induced hypertensive rats.[Pubmed: 24723332]

Asiatic acid promotes p21(WAF1/CIP1) protein stability through attenuation of NDR1/2 dependent phosphorylation of p21(WAF1/ CIP1) in HepG2 human hepatoma cells.[Pubmed: 24568526 ]

Asian Pac J Cancer Prev. 2014;15(2):963-7.

Asiatic acid is a triterpenoid isolated from Centella asiatica.
METHODS AND RESULTS:
The present study aimed to investigate whether Asiatic acid could lessen the metabolic, cardiovascular complications in rats with metabolic syndrome (MS) induced by a high-carbohydrate, high-fat (HCHF) diet. Male Sprague-Dawley rats were fed with HCHF diet with 15% fructose in drinking water for 12 weeks to induce MS. MS rats were treated with Asiatic acid (10 or 20 mg/kg/day) or vehicle for a further three weeks. MS rats had an impairment of oral glucose tolerance, increases in fasting blood glucose, serum insulin, total cholesterol, triglycerides, mean arterial blood pressure, heart rate, and hindlimb vascular resistance; these were related to the augmentation of vascular superoxide anion production, plasma malondialdehyde and tumor necrosis factor-alpha (TNF-α) levels (p<0.05). Plasma nitrate and nitrite (NOx) were markedly high with upregulation of inducible nitric oxide synthase (iNOS) expression, but dowregulation of endothelial nitric oxide synthase (eNOS) expression (p<0.05). Asiatic acid significantly improved insulin sensitivity, lipid profiles, hemodynamic parameters, oxidative stress markers, plasma TNF-α, NOx, and recovered abnormality of eNOS/iNOS expressions in MS rats (p<0.05).
CONCLUSIONS:
In conclusion, Asiatic acid improved metabolic, hemodynamic abnormalities in MS rats that could be associated with its antioxidant, anti-inflammatory effects and recovering regulation of eNOS/iNOS expression.

Phytother Res. 2014 Oct;28(10):1506-12.

We investigated the effect of Asiatic acid (AA) on hemodynamic status, vascular function, oxidative stress markers, endothelial nitric oxide synthase (eNOS), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit expression in Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats.
METHODS AND RESULTS:
Male Sprague-Dawley rats treated with L-NAME (40 mg/kg/day) in drinking water for 5 weeks showed significant increases in mean arterial pressure, heart rate, hindlimb vascular resistance, vascular dysfunction, superoxide anion (O2(•-)) production, and plasma malondialdehyde. Moreover, NO metabolite (NOx) levels were reduced, aortic eNOS expression was downregulated, and NADPH oxidase subunit p47(phox) was upregulated in hypertensive rats (p < 0.05). Hypertensive rats that were administered AA (10 or 20 mg/kg/day) for the last 2 weeks of the study showed significant improvement in hemodynamic status and vascular function. The antihypertensive effects of AA were associated with elevated plasma NOx levels, together with upregulation of eNOS expression. Decreased vascular O2(•-) production, consistent with downregulation of p47(phox) expression, was also observed after AA treatment.
CONCLUSIONS:
Our results are therefore consistent with a model whereby AA reduces blood pressure by enhancing NO bioavailability.