Extraction and Purification of Ursolic Acid from the Apple Peel and in vitro Assessment of the Biochemical Antibacterial, Antioxidant and Wound Healing Characteristics

Background and Objective: Ursolic acid is a pentacyclic triterpenoid with various biological characteristics. The objective of this study was to investigate potentially biological activities of ursolic acid extracted from apple peels. Material and Methods: Ursolic acid was extracted from apple peels and purified using column chromatography. Then, the biochemical was analyzed using ultraviolet-visible spectroscopy, high-performance thin-layer chromatography, Fourier-transform infrared spectroscopy and nuclear magnetic resonance techniques. Antimicrobial effects of the purified ursolic acid on pathogenic bacterial species of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus subtilis were assessed using minimum inhibitory concentration and disc diffusion methods. Furthermore, the biochemical radical scavenging ability was assessed using 1,1-diphenyl-1-picrylhydrazyl method. Wound healing characteristics of the purified ursolic acid was studied using scratch assay method. Results and Conclusion: Minimum inhibitory concentration and disc diffusion results verified antibacterial effects of ursolic acid on Gram-positive bacterial species. Ursolic acid at concentra-tions higher than 625 µg ml-1 showed significant antioxidant activity, compared to that vitamin C did as reference antioxidant. It was shown that migration and proliferation of human umbilical vein endothelial cells can be promoted by the extracted ursolic acid, which was assessed via wound healing assays and 3(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide. Wound closure was 97%, revealed by the purified ursolic acid after 24 h. A low concentration of ursolic acid (< 20 µg ml-1) stimulated proliferation of human umbilical vein endothelial cells; however, 100 µg ml-1 of the extracted ursolic acid decreased the number of viable cells within 24 h (p < 0.05). Purified ursolic acid (10 µg ml-1) was able to upregulate (almost two times) FLT1 and VEGF-A gene expression in human umbilical vein endothelial cells. Results suggest that ursolic acid is an effective antioxidant and includes excellent antibiotic characteristics. In addition, it can affect endothelial cell proliferation, which is significant to enhance angiogenesis and improve wound healing processes

Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose Intolerance and Fatty Liver Disease

Skeletal muscle Akt activity stimulates muscle growth and imparts resistance to obesity, glucose intolerance and fatty liver disease. We recently found that ursolic acid increases skeletal muscle Akt activity and stimulates muscle growth in non-obese mice. Here, we tested the hypothesis that ursolic acid might increase skeletal muscle Akt activity in a mouse model of diet-induced obesity. We studied mice that consumed a high fat diet lacking or containing ursolic acid. In skeletal muscle, ursolic acid increased Akt activity, as well as downstream mRNAs that promote glucose utilization (hexokinase-II), blood vessel recruitment (Vegfa) and autocrine/paracrine IGF-I signaling (Igf1). As a result, ursolic acid increased skeletal muscle mass, fast and slow muscle fiber size, grip strength and exercise capacity. Interestingly, ursolic acid also increased brown fat, a tissue that shares developmental origins with skeletal muscle. Consistent with increased skeletal muscle and brown fat, ursolic acid increased energy expenditure, leading to reduced obesity, improved glucose tolerance and decreased hepatic steatosis. These data support a model in which ursolic acid reduces obesity, glucose intolerance and fatty liver disease by increasing skeletal muscle and brown fat, and suggest ursolic acid as a potential therapeutic approach for obesity and obesity-related illness

Ursolic acid inhibits colistin efflux and curtails colistin resistant Enterobacteriaceae

Abstract Colistin resistance in Enterobacteriaceae especially Klebsiella pneumoniae and Escherichia coli is driving the evolution of pan drug resistant strains. Screening a library of 13 plant nutraceuticals led to the identification of acetyl shikonin and ursolic acid, which exhibited synergy with colistin against extremely drug resistant (XDR) clinical strains of E. coli (U3790) and K. pneumoniae (BC936). Ursolic acid caused a significant colistin MIC reversal of 16-fold in U3790 and 4-fold in BC936 strains. Ursolic acid also potentiated the bactericidal effect of colistin against both U3790 and BC936 by causing ~ 4 to 4.5 log fold decline in CFU of both clinical isolates in a time kill assay. At 2× minimum effective concentration, ursolic acid was non-toxic to zebrafish as evidenced by brain and liver enzyme profiles and by histopathology studies. In combination with colistin, ursolic acid reduced bacterial bioburden of U3790/BC936 by 1–1.58 log fold from the infected muscle tissue of zebrafish. Mechanistic explorations via studies on real time efflux, membrane potential and intracellular accumulation of dansyl chloride tagged colistin revealed that colistin efflux is inhibited by ursolic acid. In addition, ursolic acid also enhanced outer membrane permeability which probably facilitates colistin’s attack on outer and inner membranes. Our study shows that ursolic acid synergizes with colistin by inhibiting colistin efflux in Enterobacteriaceae that helps to curtail colistin resistant Enterobacteriaceae.https://deepblue.lib.umich.edu/bitstream/2027.42/148135/1/13568_2019_Article_750.pd

Microwave-Assisted Extraction of Oleanolic Acid and Ursolic Acid from Ligustrum lucidum Ait

Oleanolic acid and ursolic acid are the main active components in fruit of Ligustrum lucidum Ait, and possess anticancer, antimutagenic, anti-inflammatory, antioxidative and antiprotozoal activities. In this study, microwave-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, microwave power, extraction temperature and microwave time, on the extraction efficiencies of oleanolic acid and ursolic acid from Ligustrum lucidum were evaluated. The influence of experimental parameters on the extraction efficiency of ursolic acid was more significant than that of oleanolic acid (p < 0.05). The optimal extraction conditions were 80% ethanol aqueous solution, the ratio of material to liquid was 1:15, and extraction for 30 min at 70 °C under microwave irradiation of 500 W. Under optimal conditions, the yields of oleanolic acid and ursolic acid were 4.4 ± 0.20 mg/g and 5.8 ± 0.15 mg/g, respectively. The results obtained are helpful for the full utilization of Ligustrum lucidum, which also indicated that microwave-assisted extraction is a very useful method for extraction of oleanolic acid and ursolic acid from plant materials

Effects of Ursolic Acid and its Analogues on Soybean 15-Lipoxygenase Activity and the Proliferation Rate of A human Gastric Tumour Cell Line

The authors have previously isolated and purified ursolic acid from heather flowers (Calluna vulgarts). This terpene was found to inhibit HL-60 leukaemic cell proliferation and arachidonic acid oxidative metabolism in various cell species. The effects of ursolic acid and its analogues on soybean 15-lipoxygenase activity and on the proliferation of a human gastric tumour cell line (HGT), have been assessed. These triterpenes inhibited soybean 15-lipoxygenase at its optimal activity (pH 9). The proliferation ofHGT was decreased in a dose-dependent manner. At 20 μM the rank order is: ursolic acid > uvaol > oleanolic acid > methyl ursolate. The carboxylic group at the C28 position of ursolic acid appears to be implicated in the inhibition of both lipoxygenase activity and cell proliferation. Thus methylation of this group decreases these two inhibitory properties. Oleanolic acid, which differs by the position of one methyl group (C20 instead of C19) is less inhibitory than ursolic acid. The lipophilicity of the terpene is also implicated since uvaol appears to be more inhibitory than methyl ursolate

The Ursolic Acid Content of Rumput Mutiara (Hedyotis corimbosa L.) Grown in Various Locations

Hedyotis corimbosa L. or Rumput Mutiara (Indonesian Local name) is one of the plants that is getting more famous as an herbal medicine and is consumed by the public to cure diseases or to maintain health. All parts of Hedyotis corimbosa L. can be used as an efficacious drug, which is an anti-inflammatory, anticancer, antipyretic, diuresis, blood circulation, antitoxin, etc. As an herbal ingredient, Hedyotis corimbosa L. is currently known as a wild plant that has not been popularly cultivated, thus the quality of Hedyotis corimbosa L. is varied. Therefore, it is necessary to map which areas produce Hedyotis corimbosa L. with highest ursolic acid. This study aimed to determine the content of ursolic acid in Hedyotis corimbosa L. from its various different growth locations. This research applied thin layer chromatography techniques and the analysis of variance with a level of α = 5% using Unbalanced Incomplete Block Design. The results showed that site altitude treatment did not show any significant difference in the number of leaves, root length, plant height, node length, stem diameter, number of branches, leaf width, leaf length, flower stem length, total extract Yield, and ursolic acid levels. Still, it showed significantly different effects on water content, dry rendement, and productivity. The correlation analysis showed that there is no significant correlation at α = 5% between ursolic acid content and root length, plant height, leaf width, leaf length, and total extract Yield while node length, stem diameter, number of branches, flower stem length, number of leaves, dry rendement and productivity showed a significantly positive correlation with ursolic acid content. Water content showed significantly negative correlation with ursolic acid content. The conclusion is that there is no significant difference in ursolic acid content from plants grown at low altitudes and medium altitude. However, the content of ursolic acid from medium altitude is relatively higher compared to ursolic acid content from low altitude. This implies that there is a tendency for ursolic acid content in Hedyotis corimbosa L. to be influenced by the conditions of its growth location so that cultivation treatment with different conditions will affect the ursolic acid content

SYNTHESIS AND CHARACTERIZATION OF NEW IMINE AND PTHALIC ACID DERIVATIVES OF URSOLIC ACID

Objective: The current work envisages synthesis of novel ursolic acid derivatives and characterization by spectral methods that can be possible candidates for anti-inflammatory and anticancer activity. Methods: A series of imine and phthalic acid derivatives of ursolic acid (3β-hydroxyurs-12-en-28-oic acid), have been synthesized. 3-hydroxyimino-urs-12-en-28-olic acid was treated with alkyl halide in the presence of sodium hydride in ethanol to yield 3-alkyloxyimino-urs-12-en-28-oic acid and further converted to its ester derivatives. Ursolic acid was reacted with phthalic anhydride in pyridine to get mono and di-substituted ester derivatives. Results: Novel substituted imino and pthalic derivatives were synthesized. The compounds synthesized were characterized by MS, IR, 1H and [13]C-NMR spectroscopy. Conclusion: The derivatives prepared may facilitate designing of similar newer analogues which may be useful for generating possible candidates from ursolic acid for anti-imflammatory and anti-cancer potential. Ursolic acid oximes and its anhydrides exhibit valuable biological properties and are important starting materials for further transformations

Detection and Quantification of Glucuronidation of Ursolic Acid (UA) in Human Liver Microsomes (HLMs).

https://scholarscompass.vcu.edu/uresposters/1270/thumbnail.jp

Ursolic acid enhances macrophage autophagy and attenuates atherogenesis

Macrophage autophagy has been shown to be protective against atherosclerosis. We previously discovered that ursolic acid (UA) promoted cancer cell autophagy. In the present study, we aimed to examine whether UA enhances macrophage autophagy in the context of atherogenesis. Cell culture study showed that UA enhanced autophagy of macrophages by increasing the expression of Atg5 and Atg16l1, which led to altered macrophage function. UA reduced pro-interleukin (IL)-1β protein levels and mature IL-1β secretion in macrophages in response to lipopolysaccharide (LPS), without reducing IL-1β mRNA expression. Confocal microscopy showed that in LPS-treated macrophages, UA increased LC3 protein levels and LC3 appeared to colocalize with IL-1β. In cholesterol-loaded macrophages, UA increased cholesterol efflux to apoAI, although it did not alter mRNA or protein levels of ABCA1 and ABCG1. Electron microscopy showed that UA induced lipophagy in acetylated LDL-loaded macrophages, which may result in increased cholesterol ester hydrolysis in autophagolysosomes and presentation of free cholesterol to the cell membrane. In LDLR(−/−) mice fed a Western diet to induce atherogenesis, UA treatment significantly reduced atherosclerotic lesion size, accompanied by increased macrophage autophagy. In conclusion, the data suggest that UA promotes macrophage autophagy and, thereby, suppresses IL-1β secretion, promotes cholesterol efflux, and attenuates atherosclerosis in mice