Corosolic Acid Research Articles

Simultaneous determination of corosolic acid and euscaphic acid in the plasma of normal and diabetic rat after oral administration of extract of Potentilla discolor Bunge by high‐performance liquid chromatography/electrospray ionization mass spectrometry

Potentilla discolor Bunge has been used for diabetes in China for a long time. Corosolic acid (CA) and euscaphic acid (EA), with significant anti-diabetic activity, are two major triterpenoids in P. discolor. In this study, a specific, sensitive and convenient LC-MS method has been developed for simultaneous determination of CA and EA in the plasma of normal and diabetic rats after oral administration of the extract of P. discolor. The chromatographic separation was achieved using an Alltima C18 column (53 × 7.0 mm, i.d., 3 µm) with a mobile phase composed of 0.1% formic acid water and 0.1% formic acid acetonitrile at a flow rate of 1.0 mL/min. The detection was performed by MS with electrospray ionization interface in negative selected ion monitoring mode. All the validation data, such as specificity, linearity (r(2) > 0.9991 within 0.025-10.0 µg/mL), lower limit of quantitation (2.5 ng/mL), precision (intra- and inter-day <14.7%), accuracy (<15.0%), recovery (85.7-110.8%) and stability were determined and all of them were within the required limits. This method was successfully applied for the evaluation of the pharmacokinetic behaviors of these two compounds in the plasma of normal and diabetic rats.

RAPID LC-MS/MS METHOD FOR SIMULTANEOUS DETERMINATION OF COROSLIC ACID AND ASIATIC ACID FROM A MARKET FORMULATION OF LAGERSTROEMIA SPECIOSA LEAF EXTRACT SPIKED IN HUMAN PLASMA

Asiatic acid (AA) and Corosolic acid (CA) are two naturally occurring pentacyclic triterpenes that has shown numerous therapeutic activities and are active biomarkers of the commercially important plant Lagerstroemia speciosa (L). Lagerstroemia speciosa Linn., a Southeast Asian tree has shown wide range of therapeutic activities and is therefore used in numerous dietary supplements and herbal formulations. A research article has been published previously by the same authors for simultaneous quantitative determination of AA and CA from human plasma. The present research work involves an extension of this previous work wherein a sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method has been developed and validated for simultaneous analysis of AA and CA from a market formulation containing L. speciosa leaf extract spiked in human plasma. The analytes were extracted from the matrix using a simple solid-phase extraction procedure. Glycyrrhetinic acid (GA) was used as the internal standard for both analytes. A Kromasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves simple isocratic chromatography conditions and mass spectrometric detection in the negative ionization mode using a Waters Xevo TQS MS/MS system. The proposed method has been validated with a linear range of 1.00 – 1000ng/mL and 5 – 10000ng/mL for AA and CA respectively. The intra-day and inter-day precision and accuracy of the quality control samples were within the acceptance criteria of ±15% for both the triterpenoids. The total elution time was about 5 min which allows higher throughput. The assay values were found to be 0.88 % and 0.31% for Corosolic acid and Asiatic acid respectively in the market formulation containing L. speciosa leaf extract. This validated method can be applied for analysis of real samples from a bioequivalence study involving administration of formulations containing asiatic acid and corosolic acid as their active therapeutic components.

Purification of Two Triterpenoids from Schisandra chinensis by Macroporous Resin Combined with High-Speed Counter-Current Chromatography

A method for preparative purification of corosolic acid and nigranoic acid from Schisandra chinensis (SC) was established using a combination of macroporous absorption resin column separation and high-speed counter-current chromatography (HSCCC). The crude extracts obtained from SC using 70% ethanol were separated on a macroporous resin column and then eluted with a graded ethanol series. The 70% ethanol fraction was used as the sample for separation of the two triterpenoids by HSCCC. The two-phase solvent system used for HSCCC separation was chloroform-n-butanol-methanol-water (10:0.5:7:4, v/v/v/v). The upper phase was used as the stationary phase of HSCCC. Corosolic acid (16.4 mg) of 96.3% purity and nigranoic acid (9.5 mg) of 98.9% purity were obtained in a one-step HSCCC separation from 100 mg of the sample. The structures of corosolic acid and nigranoic acid were identified by (1)H-nuclear magnetic resonance (NMR) and (13)C-NMR.

Chemical Constituents and Cytotoxic Effect of the Main Compounds of Lythrum salicaria L.

Lythrum salicaria L. (Lythraceae), a herbaceous plant growing widely in Iran, has been well known for many centuries for its astringent and styptic properties. A phytochemical investigation of this plant, based on spectroscopic analysis, identified fourteen compounds: 5-hydroxypyrrolidin-2-one (1), umbelliferone-6-carboxylic acid (2), 3,3',4'-tri-O-methylellagic acid-4-O-beta-D-(2"-acetyl)-glucopyranoside (3), 3,3',4'-tri-O-methylellagic acid-4-O-beta-D-glucopyranoside (4), daucosterol (5), phytol (6), dodecanoic acid (7), oleanolic acid (8), 3,3',4'-tri-O-methylellagic acid (9), corosolic acid (10), beta-sitosterol (11), peucedanin (12), buntansin (13), and erythrodiol (14). All compounds, except for 8 and 11, have been isolated from L. salicaria for the first time. Cytotoxic activities of the compounds were examined against three cancerous cell lines, colon carcinoma (HT-29), leukemia (K-562), and breast ductal carcinoma (T47D), and Swiss mouse embryo fibroblast (NIH-3T3) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and methotrexate as positive control. Compounds 5, 10, 11, and 14 were the most active against the HT-29 cell line with IC50 values of 192.7, 36.8, 38.2, and 12.8 microg/mL, respectively. Compounds 14, 11, 5, and 10 were 6.4, 2.8, 2.6, and 1.4 times, respectively, more selective than methotrexate. Compound 5 was the most active against the K-562 cell line (IC50 = 50.2 microg/mL), with a selectivity exceeding that of methotrexate 13.3 times. The results of the cytotoxic assay confirmed that growth and proliferation of the cancer cell lines are predominantly influenced by triterpene derivatives and sterols of this plant.

Two new stereoisomeric antioxidant triterpenes from Potentilla fulgens

The roots of Potentilla fulgens have been used for a long time as a folk remedy for many ailments without having information on its pharmacological action. Of the various extracts prepared by partitioning of the methanol extract, the ethyl acetate fraction was found to possess better antioxidant and cytotoxic activities. The degree of reduction in cloning efficiencies of MCF-7 cell lines was more with ethyl acetate than with hexane fraction of the root-extract. Hence, this fraction was further purified and nine compounds, including two new ursane type triterpenoids Fulgic acid A (4) and Fulgic acid B (5), were identified and characterized. Other compounds were identified as ursolic acid, euscaphic acid, corosolic acid, epicatechin, catechin, p-hydroxybenzaldehyde and gallic acid. Chemical structures were elucidated by spectroscopic methods, especially ESIHRMS and 2D NMR techniques. The new compounds showed good antioxidant activity and therefore this plant can be a source of natural antioxidants.

Corosolic acid enhances the antitumor effects of chemotherapy on epithelial ovarian cancer by inhibiting signal transducer and activator of transcription 3 signaling

Resistance to chemotherapy poses a serious problem for the treatment of advanced epithelial ovarian cancer patients. The mechanisms of chemoresistance are complex and studies have implicated signal transducer and activator of transcription 3 (STAT3) signaling in the chemoresistance of cancer cells. The present study investigated whether corosolic acid (CA), which has been previously reported to be a STAT3 inhibitor, was able to increase the sensitivity to chemotherapeutic drugs in epithelial ovarian cancer cells. CA also markedly enhanced the anticancer effect of paclitaxel, cisplatin and doxorubicin. In addition, CA abrogated the cell-cell interactions between macrophages and epithelial ovarian cancer cells and inhibited the macrophage-induced activation of epithelial ovarian cancer cells. These data indicated that CA was able to reverse the chemoresistance of epithelial ovarian cancer cells and suppress the cell-cell interaction with tumorigenic macrophages. Thus, CA may be useful as an adjuvant treatment to patients with advanced ovarian and other types of cancer due to the multiple anticancer effects.

Cytotoxic Activity of Ursolic Acid Derivatives Obtained by Isolation and Oxidative Derivatization

Structure-activity relationships of ursane-type pentacyclic triterpenes obtained from natural sources and by chemical derivatization are reviewed. Ursolic acid, corosolic acid, and a new ursane-type pentacyclic triterpene, 7,24-dihydroxyursolic acid, were isolated from the methanolic extract of the leaves of the Bangladeshi medicinal plant, Saurauja roxburghii. Derivatization of ursolic acid by oxidation with dioxoruthenium (VI) tetraphenylporphyrins was investigated. Oxidation selectivity on the terpene structure was modulated by the auxiliaries introduced on the tetraphenylporphyrin. The natural triterpenes and oxidized derivatives were tested for cytotoxicity against the C6 rat glioma and A431 human skin carcinoma cell lines. Although they have the same ursane-type pentacyclic triterpene cores, the position and numbers of hydroxyls on the terpene structures significantly affected the activity and the selectivity towards the tested cell lines.

Preventive Effect of Corosolic Acid on Lipid Profile Against Carbon Tetrachloride-Induced Hepatotoxic Rats

Preventive Effect of Corosolic Acid on Lipid Profile Against Carbon Tetrachloride-Induced Hepatotoxic Rats

A convenient synthesis of 2β,3α-dihydroxyurs-12-en-28-oic acid as a natural diastereoisomer of corosolic acid

Abstract 2 β ,3 α -Dihydroxyurs-12-en-28-oic acid ( 6 ) is a naturally occurring diastereoisomer of corosolic acid with glycogen phosphorylase inhibitory activity. A new strategy for the semi-synthesis of 6 was developed. Using the commercially available ursolic acid ( 1 ) as the starting materials, 6 was synthesized through five facile reactions with a high stereoselectivity and an overall yield of 47.3%. The structure of 6 was confirmed by optical rotation, ESI-MS, 1 H NMR and 13 C NMR data.

Chemopreventive effect of corosolic acid in human hepatocellular carcinoma cells

Anticancer effects of corosolic acid have been demonstrated earlier in human cervix adenocarcinoma and osteosarcoma cells, but the exact underlying molecular mechanisms have not been studied. Hence, an attempt was made to identify the anticancer mechanism of corosolic acid in human hepatocellular carcinoma cells [HepG2]. The anticancer activity of corosolic acid through cell growth inhibition by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, mitochondrial membrane potential and apoptotic fragmentations by fluorescence microscope was evaluated. In addition, the cleavage of PARP, NF-κB, cytochrome c (cyt. C) release, and Bax and Bcl2 expression was analyzed by Western blot. The results clearly indicate that corosolic acid was involved in the alteration of mitochondrial membrane potential resulting in the release of cyt. C from mitochondria and increased ROS generation. The corosolic acid treatment causes the induction of apoptosis in a dose dependent manner (IC 50 , 40 μM). In conclusion, corosolic acid had chemopreventive effect on HepG2 cells by apoptosis. Keywords : Corosolic acid, hepatocellular carcinoma, reactive oxygen species (ROS), apoptosis, lipid peroxidation African Journal of Biotechnology Vol. 12(19), pp. 2733-2742

English

The present study was designed to investigate the hepatoprotective and antioxidant properties of corosolic acid (CRA) on carbon tetrachloride (CCl4)-induced liver damage in rats. Liver damage was induced by giving a single oral dose of CCl4&nbsp;(1:1 in liquid paraffin) at 1.25 ml/kg body weight (BW). Rats were pretreated with CRA dose of 10, 20 and 40 mg/kg BW (once daily for 7 days before CCl4&nbsp;intoxication). Pretreatment with CRA showed significant hepatoprotection by reducing the aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) enzymatic activities which had been raised by CCl4administration. The levels of lipid peroxidation markers such as thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were significantly increased by CCl4administration and pretreatment with CRA; the levels of lipid peroxidative markers were reduced. The activities of enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) and the levels of non enzymic antioxidants (Vitamins C, Vitamins E and reduced glutathione (GSH)) were decreased by CCl4&nbsp;administration and those pretreated with CRA above enzymic and non enzymic antioxidants were increased. The present study concluded that CRA possesses hepatoprotective and antioxidant properties against CCl4-induced hepatotoxicity in rats. &nbsp; Key words:&nbsp;Hepatotoxicity, carbon tetrachloride (CCl4), corosolic acid, lipids peroxidations, antioxidant.

Retracted: Management of Diabetes and Its Complications with Banaba (Lagerstroemia speciosa L.) and Corosolic Acid

Retracted: Management of Diabetes and Its Complications with Banaba (<i>Lagerstroemia speciosa</i> L.) and Corosolic Acid

Corosolic acid induces apoptotic cell death in human lung adenocarcinoma A549 cells in vitro

Corosolic acid (CRA), a triterpenoid from medicinal herbs, has been shown to induce apoptosis in several cell lines, with the exception of A549 cells. In this report, we investigated the apoptotic effect and mechanism of CRA in A549 cells. The present study shows that CRA significantly inhibits cell viability in a concentration- and time-dependent manner. Exposure to CRA induces sub-G1 cell cycle arrest and causes apoptotic death in A549 cells. CRA also triggers the activation of caspases and poly(ADP-ribose) polymerase, an effect antagonized by z-vad-fmk. In addition, exposure to CRA leads to a significant increase in the levels of reactive oxygen species (ROS) in A549 cells. Furthermore, exposure to the ROS scavenger N acetylcysteine (NAC)prevents CRA-induced apoptosis, suggesting a role for ROS in CRA-induced apoptosis. ROS are critical regulators of caspase-mediated apoptosis in A549 cells. These results indicate that CRA induces mitochondria-mediated and caspase-dependent apoptosis in A549 cells by altering anti-apoptotic proteins in a ROS-dependent manner.

Anti-Proliferative Activities and Apoptosis Induction by Triterpenes Derived from Eriobotrya japonica in Human Leukemia Cell Lines

Eriobotrya japonica leaf is a traditional herbal medicine that contains numerous triterpenes, which have various pharmacological properties. In this study, we investigated the anti-proliferative activity of four triterpenes derived from E. japonica, including corosolic acid (CA), ursolic acid (UA), maslinic acid (MA) and oleanolic acid (OA), in human leukemia cell lines. CA showed the strongest anti-proliferative activity in all of the leukemia cell lines tested, but not in normal human skin fibroblast cell lines. To determine the mechanism underlying the anti-proliferative effect of CA, we examined the effect of CA on molecular events known as apoptosis induction. CA induced chromatin condensation, DNA fragmentation, sub-G1 phase DNA, activation of caspase-3, -8 and -9 and the cleavage of PARP in HL-60. CA also activated Bid and Bax, leading to the loss of mitochondrial membrane potential (Δψm) and cytochrome c release into the cytosol, whereas Bcl-2 and Bcl-xL were unaffected by CA. These results suggest that CA has an anti-proliferative effect on leukemia cells via the induction of apoptosis mediated by mitochondrial dysfunction and caspase activation. CA may be a potential chemotherapeutic agent for the treatment of human leukemia.

Corosolic acid impairs tumor development and lung metastasis by inhibiting the immunosuppressive activity of myeloid‐derived suppressor cells

Recent studies demonstrated that myeloid cells are associated with systemic immunosuppression in tumor-bearing hosts. In particular, myeloid cells positive for Gr-1 and CD11b in tumor-bearing mice are called myeloid-derived suppressor cells (MDSC) because of their suppression of T-cell activation. In this study, we investigated the antitumor effects of corosolic acid (CA) in murine sarcoma model. The results from the in vivo study showed that CA administration did not suppress the tumor proliferation index, but significantly impaired subcutaneous tumor development and lung metastasis. Furthermore, CA administration inhibited signal transducer and activator of transcription-3 (Stat3) activation and increased in the number of infiltrating lymphocytes in tumor tissues. Ex vivo analysis demonstrated that a significant immunosuppressive effect of MDSC in tumor-bearing mice was abrogated and the mRNA expressions of cyclooxygenase-2 and CCL2 in MDSC were significantly decreased by CA administration. Furthermore, CA enhanced the antitumor effects of adriamycin and cisplatin in in vitro. Since Stat3 is associated with tumor progression not only in osteosarcoma, but also in other malignant tumors, our findings indicate that CA might be widely useful in anticancer therapy by targeting the immunosuppressive activity of MDSC and through its synergistic effects with anticancer agents.

Chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity

To study the chemical constituents of Rabdosia japonica var. glaucocalyx and their anti-complementary activity on the basis of preliminary studies. Target isolation guided by anti-complementary activity test, compounds in the chloroform and n-butanol fractions were isolated and purified by silica gel and Sephadex LH-20 column chromatographies, and preparative HPLC. The structures were identified by various spectroscopic data including ESI-MS, 1H-NMR and 13C-NMR data. The compounds were evaluated for anti-complementary activity in vitro. Eleven compounds were isolated from the chloroform and n-butanol soluble fractions and identified as stigmasterol (1), stigmas-9 (11) -en-3-ol (2), glaucocalyxin D (3), kamebakaurin (4), maslinic acid (5), corosolic acid (6), minheryins I (7), diosmetin (8), caffeic acid ethylene ester (9), caffeic acid (10) and vitexin (11). Isoquercetrin, rutin, quercetin, 3-methylquercetin, luteolin, 7-methylluteolin, and apigenin which were isolated from the preliminary studies together with compounds 9 and 10 showed inhibition of the complement system by the classical pathway. Compounds 2, 4, 6-9 and 11 were obtained from this plant for the first time. Caffeic acid (10) showed the strongest activity in vitro with a CH50 value of 0.041 g x L(-1).

A new ursane-type nor-triterpenoid from the leaves of Eucommia ulmoides Oliv.

A new ursane-type nortriterpenoid, (11S,12S)-4-methyl-11,12-epoxy-2-hydroxy-3-oxoursa-1,4-dine-28-oic acid γ-lactone (1), named ulmoidol A, together with ten known compounds: ulmoidol (2), corosolic acid (3), 2α,3α-dihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (4), oleanolic acid (5), ursolic acid (6), cycloart-3β, 25-diol (7), foliasalacioside B1 (8), (6R,7E,9R)-9-hydroxy-4,7-megastigmadien-3-one-9-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (9), (6R,7E,9R)-9-hydroxy-4,7-megastigma-dien-3-one-9-O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (10), and quercetin 3-O-sambubioside (11) were isolated from the leaves of Eucommia ulmoides Oliv. The structure of compound 1 was determined by extensive spectroscopic analysis, and its absolute configuration was determined by CD experiments and a computational method. Compounds 3, 4, 7–10 were isolated from this plant for the first time. Compounds 3 and 4 showed inhibition to PTPIB activities, with IC50 values of 0.69 and 3.98 μM, respectively.

One new pyrroline compound from Callistemon viminalis (Sol. Ex Gaertner) G.Don Ex Loudon

One new compound: 3,4-dihydro-2-(hydroxymethyl)-4-methyl-2H-pyrrol-2-ol (5) was isolated from the fruits and bark of Callistemon viminalis along with the known compounds lupeol (1), octacosanol (2), β-sitosterol (3), betulin (4), betulinic acid (6), ursolic acid (7), corosolic acid (8), β-sitosterol-3-O-β-D-glucoside (9), methyl gallate (10), gallic acid (11), catechin (12), ellagic acid (13) and 3-O-acetylursolic acid (14) (compound 14 was isolated from the bark and not detected in the fruits). Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, MS, IR spectra and COSY and HR-MS for 5a). The antioxidant activity of the total extracts, petroleum ether, CH2Cl2 and EtOAc fractions together with the compounds 6, 7, 9, 10, 11, 12 and 13 was comparable with that of the standard antioxidant, ascorbic acid.

A simple GC–MS method for the screening of betulinic, corosolic, maslinic, oleanolic and ursolic acid contents in commercial botanicals used as food supplement ingredients

The occurrence of triterpene pentacyclic acids in plants is extensive, but little is known about their availability in commercial extracts. A simple GC–MS method for the simultaneous determination of betulinic, corosolic, maslinic, oleanolic and ursolic acids was developed and applied to 38 different commercial plant extracts sold as ingredients for dietary supplements. A suitable protocol was set up to perform routine control of a diverse array of samples with different botanical, chemical and physical characteristics. Remarkable quantities of corosolic acid were found in dried extracts from aerial parts of Lagerstroemia speciosa and Ortosiphon stamineus (14233 and 1132mg/kg, respectively), while oleanolic acid was abundant in O. stamineus and Crataegus monogyna flowers (2774 and 2339mg/kg); ursolic was identified in O. stamineus, C. monogyna, L. speciosa and Arctostaphylos uva-ursi leaves (7773, 4165, 2108 and 1034mg/kg). Only L. speciosa was rich in maslinic acid (4958mg/kg), while minor amounts of betulinic acid (257 and 80mg/kg) were detected in L. speciosa and C. monogyna extracts. Lower quantities of triterpenic acids were identified in dried extracts of Harpagophyton procumbens root, propolis, Punica granatum root, Styrax benzoin, Vaccinium myrtillus fruits and Vitis vinifera seeds. Decoctions and fluid extracts lacked or contained very low amounts of triterpenic acids. Results are discussed in terms of quality and safety of these ingredients.

Bioavailability, Distribution, and Antioxidative Effects of Selected Triterpenes in Mice

This study analyzed the content of eight triterpenes (oleanolic acid, ursolic acid, arjunolic acid, asiatic acid, boswellic acid, corosolic acid, madecassic acid, and maslinic acid) in ten vegetables and eight fruits. These compounds at 0.5% were supplied to mice for 4 or 8 weeks. The bioavailability, tissue distribution, and antioxidative protection of these triterpenes were examined. Results showed that triterpenes were detected in eight vegetables and six fruits. Basil and brown mustard contained seven test triterpenes, in the range of 14-102 mg/100 g dry weight. The level of each triterpene in plasma, brain, heart, liver, kidney, colon, and bladder increased as the feeding period was increased from 4 weeks to 8 weeks (P < 0.05). Renal homogenates from mice with triterpene intake had greater antioxidative effects against glucose-induced glutathione loss and malondialdehyde and oxidized glutathione production when compared with those from control groups (P < 0.05). These data support that these triterpenes were absorbed and deposited in their intact forms, which in turn exerted in vivo antioxidative protection.