Pentacyclic triterpenes: New tools to fight metabolic syndrome

Antihypertensive Potential of Pistacia lentiscus var. Chia: Molecular Insights and Therapeutic Implications

Background: Hypertension poses a significant global health burden and is associated with cardiovascular morbidity. Chios mastic gum (CMG), derived from Pistacia lentiscus var. Chia, shows potential as a phytotherapeutic agent, due to its multifaceted beneficial effects. However, its anti-hypertensive effects and vascular, circulatory, and renal-related dysfunction, have not been thoroughly investigated. Herein, we aimed to explore the antihypertensive potential of CMG, focusing on vascular and renal endothelium, in vivo. Methods: Two models of hypertension in male rats, induced by Angiotensin II and Deoxycorticosterone acetate (DOCA)-high-salt administration, were utilized. CMG was administered at 220 mg/kg daily for four weeks after hypertension onset and blood pressure was measured non-invasively. Whole blood RNA sequencing, metabolomics, real-time PCR, and Western blot analyses of kidney and aorta tissues were additionally performed. Results: CMG significantly lowered systolic, diastolic, and mean blood pressure in both models. RNA sequencing revealed that CMG modulated immunity in the Angiotensin II model and metabolism in the DOCA-HS model. CMG downregulated genes related to oxidative stress and endothelial dysfunction and upregulated endothelial markers such as Vegfa. Metabolomic analysis indicated improved endothelial homeostasis via lysophosphatidylinositol upregulation. Conclusions: CMG emerges as a potent natural antihypertensive therapy, demonstrating beneficial effects on blood pressure and renal endothelial function.

Synthesis of Rhodamine-Conjugated Lupane Type Triterpenes of Enhanced Cytotoxicity

Various conjugates with rhodamines were prepared by starting with betulinic acid (BA) and platanic acid (PA). The molecules homopiperazine and piperazine, which were identified in earlier research, served as linkers between the rhodamine and the triterpene. The pentacyclic triterpene's ring A was modified with two acetyloxy groups in order to possibly boost its cytotoxic activity. The SRB assays' cytotoxicity data showed that conjugates 13-22, derived from betulinic acid, had a significantly higher cytotoxicity. Of these hybrids, derivatives 19 (containing rhodamine B) and 22 (containing rhodamine 101) showed the best values with EC50 = 0.016 and 0.019 μM for A2780 ovarian carcinoma cells. Additionally, based on the ratio of EC50 values, these two compounds demonstrated the strongest selectivity between malignant A2780 cells and non-malignant NIH 3T3 fibroblasts. A375 melanoma cells were used in cell cycle investigations, which showed that the cells were halted in the G1/G0 phase. Annexin V/FITC/PI staining demonstrated that the tumor cells were affected by both necrosis and apoptosis.

Wild and cultivated olive trees: Nutraceutical insights of extra virgin olive oils in cardiovascular and ocular diseases

Extra virgin olive oil (EVOO) from Olea europaea (cultivated olive tree) and the oil obtained from the wild olive variety or acebuche (ACE oil from Olea oleaster) contain an extraordinary number of bioactive molecules. These include oleic acid, sterols, tocopherols, triterpene compounds, and polyphenols. Both oils are known for their healthy properties and are considered to be a nutraceutical tool against cardiovascular diseases, including arterial hypertension, preeclampsia, and ocular diseases such as glaucoma or diabetic retinopathy. The benefits of EVOO and ACE oil stem from their anti-inflammatory, antioxidant, and anti-cancer properties. They also have potential as prebiotic compounds. In this update, we synthesise and illustrate the various characteristics and beneficial effects of olive oils from different varieties of olive trees, with special emphasis on Olea oleaster, also known as Olea europaea, L. var. sylvestris.

New Therapeutic Strategies for Obesity and Its Metabolic Sequelae: Brazilian Cerrado as a Unique Biome

Brazil has several important biomes holding impressive fauna and flora biodiversity. Cerrado being one of the richest ones and a significant area in the search for new plant-based products, such as foods, cosmetics, and medicines. The therapeutic potential of Cerrado plants has been described by several studies associating ethnopharmacological knowledge with phytochemical compounds and therapeutic effects. Based on this wide range of options, the Brazilian population has been using these medicinal plants (MP) for centuries for the treatment of various health conditions. Among these, we highlight metabolic diseases, namely obesity and its metabolic alterations from metabolic syndrome to later stages such as type 2 diabetes (T2D). Several studies have shown that adipose tissue (AT) dysfunction leads to proinflammatory cytokine secretion and impaired free fatty acid (FFA) oxidation and oxidative status, creating the basis for insulin resistance and glucose dysmetabolism. In this scenario, the great Brazilian biodiversity and a wide variety of phytochemical compounds make it an important candidate for the identification of pharmacological strategies for the treatment of these conditions. This review aimed to analyze and summarize the current literature on plants from the Brazilian Cerrado that have therapeutic activity against obesity and its metabolic conditions, reducing inflammation and oxidative stress.

3-Acetyl-11-keto-β-boswellic Acid-Based Hybrids Alleviate Acetaminophen-Induced Hepatotoxicity in HepG2 by the Regulation of Inflammatory and Oxidative Stress Pathways: An Integrated Approach

In an effort to develop new compounds for managing drug-induced liver injury, we prepared 23 novel hybrids based on 3-acetyl-11-keto-β-boswellic acid (AKBA) using various biocompatible linkers. A bioguided approach was employed to identify the most promising hybrid. Eight compounds exhibited superior anti-inflammatory activity compared to the parent compound. Two of these hybrids (5b and 18) were able to reduce gene expression of TNF-α in LPS-induced inflammation in RAW 264.7 cells, similar to dexamethasone. Subsequently, the hepatoprotective potential of these hybrids was evaluated against acetaminophen (APAP) toxicity in HepG2 cells at doses of 1 and 10 μM. Both hybrids effectively restored cytokine levels, which had been elevated by APAP, to normal levels. Furthermore, they normalized depleted superoxide dismutase and reduced glutathione levels while significantly reducing malondialdehyde (MDA) levels. Network pharmacology analysis suggested that AKBA-based hybrids exert their action by regulating PI3K and EGFR pathways, activating anti-inflammatory mechanisms, and initiating tissue repair and regeneration. Molecular docking studies provided insights into the interaction of the hybrids with PI3K. Additionally, the hybrids demonstrated good stability at different pH levels, following first-order kinetics, with relatively long half-lives, suggesting potential for absorption into circulation without significant degradation.

Triterpenoids from Meehania fargesii with Cytotoxic Activity1

In the investigation of Meehania fargesii, eighteen triterpenoids were isolated and identified, including a previously unknown compound with an 13,27-cycloursane skeleton, using techniques like 1D and 2D NMR, and HR-MS. Furthermore, the cytotoxicity of these compounds were evaluated against HCT116, MCF-7, and AGS cell lines using the CCK-8 method to examine their structure-activity relationship. Remarkably, compounds 13 and 16 exhibited higher cytotoxicity across all three cell lines compared to the positive drug. Western blot analysis revealed that these compounds activated apoptosis in HCT116 cells by promoting the Bax protein and inhibiting the Bcl-2 protein. This suggests that compounds 13 and 16 have potential as apoptosis-inducing agents in HCT116 cells.

LC-MS Fingerprinting Development for Standardized Precipitate from Agastache mexicana, Which Induces Antihypertensive Effect through NO Production and Calcium Channel Blockade

The aim of this work was to evaluate the vasorelaxant and antihypertensive effects of a standardized precipitate of the hydroalcoholic extract from Agastache mexicana (PPAm), comprising ursolic acid, oleanolic acid, acacetin, luteolin and tilianin, among others. In the ex vivo experiments, preincubation with L-NAME (nonspecific inhibitor of nitric oxide synthases) reduced the relaxation induced by PPAm; nevertheless, preincubation with indomethacin (nonspecific inhibitor of cyclooxygenases) did not generate any change in the vasorelaxation, and an opposed effect was observed to the contraction generated by CaCl2 addition. Oral administration of 100 mg/kg of PPAm induced a significant acute decrease in diastolic (DBP) and systolic (SBP) blood pressure in spontaneously hypertensive rats, without changes in heart rate. Additionally, PPAm showed a sustained antihypertensive subacute effect on both DBP and SBP for 10 days compared to the control group. On the other hand, human umbilical vein cells treated with 10 µg/mL of PPAm showed a significant reduction (p < 0.05) in intracellular adhesion molecule-1, compared to the control, but not on vascular cell adhesion molecule-1. In conclusion, PPAm induces a significant antihypertensive effect in acute- and subacute-period treatments, due to its direct vasorelaxant action on rat aortic rings through NO production and Ca2+ channel blockade.

Pentacyclic Triterpenes from Olive Leaves Formulated in Microemulsion: Characterization and Role in De Novo Lipogenesis in HepG2 Cells

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.

Biological Activities of Miracle Berry Supercritical Extracts as Metabolic Regulators in Chronic Diseases

Synsepalum dulcificum (Richardella dulcifica) is a berry fruit from West Africa with the ability to convert the sour taste into a sweet taste, and for this reason, the fruit is also known as the "miracle berry" (MB). The red and bright berry is rich in terpenoids. The fruit's pulp and skin contain mainly phenolic compounds and flavonoids, which correlate with their antioxidant activity. Different polar extracts have been described to inhibit cell proliferation and transformation of cancer cell lines in vitro. In addition, MB has been shown to ameliorate insulin resistance in a preclinical model of diabetes induced by a chow diet enriched in fructose. Herein, we have compared the biological activities of three supercritical extracts obtained from the seed-a subproduct of the fruit-and one supercritical extract obtained from the pulp and the skin of MB. The four extracts have been characterized in terms of total polyphenols content. Moreover, the antioxidant, anti-inflammatory, hypo-lipidemic, and inhibition of colorectal cancer cell bioenergetics have been compared. Non-polar supercritical extracts from the seed are the ones with the highest effects on the inhibition of bioenergetic of colorectal (CRC) cancer cells. At the molecular level, the effects on cell bioenergetics seems to be related to the inhibition of main drivers of the de novo lipogenesis, such as the sterol regulatory element binding transcription factor (SREBF1) and downstream molecular targets fatty acid synthase (FASN) and stearoyl coenzyme desaturase 1 (SCD1). As metabolic reprograming is considered as one of the hallmarks of cancer, natural extracts from plants may provide complementary approaches in the treatment of cancer. Herein, for the first time, supercritical extracts from MB have been obtained, where the seed, a by-product of the fruit, seems to be rich in antitumor bioactive compounds. Based on these results, supercritical extracts from the seed merit further research to be proposed as co-adjuvants in the treatment of cancer.

Modulation of Insulin Resistance by Silybum marianum Leaves, and its Synergistic Efficacy with Gymnema sylvestre, Momordica charantia, Trigonella-foenum graecum Against Protein Tyrosine Phosphatase 1B

Prolonged insulin resistance is considered one of the reasons for Type 2 Diabetes Mellitus. Upregulation of Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signalling, has been well studied as a key regulator in prognosis to insulin resistance. It has been widely studied as a desirable molecular therapeutic target. The study aimed to evaluate the efficacy of leaf extract of the medicinal plants Silybum marianum on the inhibition of PTP1B activity. It also explored the synergistic effect with extracts of Gymnema sylvestre (leaves), Momordica charantia (seeds), and Trigonella foenum graecum (seeds). The S. marianum leaves showed dose-dependent inhibition of PTP1B ranging from 9.48-47.95% (25-1000 μg mL-1). Assay with individual plant extracts showed comparatively lesser inhibition of PTP1B as compared to metformin as a control (38% inhibition). However, a synergistic effect showed nearly 45% PTP1B inhibition (higher than metformin) after the assay was done with selected four plant extracts in combination. The effect of leaf extracts of S. marianum was studied for glucose uptake efficiency in yeast cell lines which was found to be increased by 23% as compared to the control (without extract). Metformin improves glucose upake by yeast cells by ~15-31%. GC-MS analysis revealed 23 phytochemicals, some of which possessed anti-diabetic properties. A dose-dependent increase in antioxidant activity of S. marianum leaves extracts was observed (40-53%). The findings of the study highlighted the presence of various phytochemicals in leaves extracts that are effective against PTP1B inhibition and may help in reinvigorating drug development.

Corosolic acid inhibits tumour growth without compromising associating liver partition and portal vein ligation-induced liver regeneration in rats

BACKGROUND

Associating liver partition and portal vein ligation (ALPPS) technique is a promising strategy for unresectable primary liver tumours without sufficient future liver remnants (FLRs).

OBJECTIVE

Our study explored the effect of corosolic acid (CA) on inhibiting tumour growth without compromising ALPPS-induced liver regeneration.

METHODS

The ALPPS procedure was performed in Sprague-Dawley rats with orthotopic liver cancer. Blood, tumour, and FLR samples were collected, and the effect of CA on the inhibition of tumour progression and ALPPS-induced liver regeneration, and its possible mechanism, were investigated.

RESULTS

The tumour weight in the implantation/ALPPS group was higher than in the implantation without ALPPS group (p < .05), and the tumour weight in the implantation/ALPPS/CA group was lower than in the implantation/ALPPS group (p < .05). On postoperative day 15, the hepatic regeneration rate, and the expression of Ki67+ hepatocytes in the FLRs had increased significantly in the group that underwent ALPPS. The number of cluster of differentiation (CD) 86+ macrophages markedly increased in the FLRs and in the tumours of groups that underwent the ALPPS procedure. Additionally, the number of CD206+ macrophages was higher than the number of CD86+ macrophages in the tumours of the implantation and the implantation/ALPPS groups (p < .01, respectively); however, the opposite results were observed in the CA groups. The administration of CA downregulated the expression of transforming growth factor-beta (TGF-β), CD31, and programmed cell death protein 1 (PD-1) but increased the number of CD8+ lymphocytes in tumours.

CONCLUSION

Corosolic acid inhibits tumour growth without compromising ALPPS-induced liver regeneration. This result may be attributed to the CA-induced downregulation of PD-1 and TGF-β expression and the increased CD8+ lymphocyte infiltration in tumour tissue associated with the suppression of M2 macrophage polarisation. Key MessagesThis study aimed to investigate the effect of CA on ALPPS-induced liver regeneration and hepatic tumour progression after ALPPS-induced liver regeneration.Corosolic acid inhibits tumour growth without compromising ALPPS-induced liver regeneration. This result may be attributed to the CA-induced downregulation of PD-1 and TGF-β expression and the increased CD8+ lymphocyte infiltration in tumour tissue associated with the suppression of M2 macrophage polarisation.

In vitro activity of celastrol in combination with thymol against carbapenem-resistant Klebsiella pneumoniae isolates

Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial and community-acquired infections. Klebsiella has developed resistance against antimicrobials including the last resort class; carbapenem. Currently, treatment options for carbapenem-resistant-Klebsiella (CRK) are very limited. This study aims to restore carbapenem effectiveness against CRK using celastrol and thymol. Clinical Klebsiella isolates were identified using biochemical and molecular methods. Antimicrobial susceptibility was determined using disk-diffusion method. Carbapenemase-production was tested phenotypically and genotypically. Celastrol and thymol-MICs were determined and the carbapenemase-inhibitory effect of sub-MICs was investigated. Among 85 clinical Klebsiella isolates, 72 were multi-drug-resistant and 43 were meropenem-resistant. Phenotypically, 39 isolates were carbapenemase-producer. Genotypically, bla_NDM1 was detected in 35 isolates, bla_VIM in 17 isolates, bla_OXA in 18 isolates, and bla_KPC was detected only in 6 isolates. Celastrol showed significant inhibitory effect against carbapenemase-hydrolytic activity. Meropenem-MIC did not decrease in presence of celastrol, only 2-fold decrease was observed with thymol, while 4-64 fold decrease was observed when meropenem was combined with both celastrol and thymol. Furthermore, thymol increased CRK cell wall-permeability. Molecular docking revealed that celastrol is superior to thymol for binding to KPC and VIM-carbapenemase. Our study showed that celastrol is a promising inhibitor of multiple carbapenemases. While meropenem-MIC were not affected by celastrol alone and decreased by only 2-folds with thymol, it decreased by 4-64 folds in presence of both celastrol and thymol. Thymol increases the permeability of CRK-envelope to celastrol. The triple combination (meropenem/celastrol/thymol) could be useful for developing more safe and effective analogues to restore the activity of meropenem and other β-lactams.

Traditional processing increases biological activities of Dendrobium offificinale Kimura et. Migo in Southeast Yunnan, China

The orchid Dendrobium officinale grows throughout southeast China and southeast Asian countries and is used to treat inflammation and diabetes in traditional Chinese medicine. Tie pi feng dou is a well-known traditional Chinese medicine made from the dried D. officinale stems. Processing alters the physicochemical properties of TPFD; however, it is unclear how processing affects the quality and medicinal value of this plant. Here, we analyzed and compared the chemical composition of fresh stems of D. officinale and TPFD and explored possible explanations for the enhanced medicinal efficacy of processed D. officinale stems using qualitative and quantitative methods. To identify the components of FSD and TPFD, we used ultra-high-performance liquid chromatography combined with mass spectrometry in negative and positive ion modes and interpreted the data using the Human Metabolome Database and multivariate statistical analysis. We detected 23,709 peaks and identified 2352 metabolites; 370 of these metabolites were differentially abundant between FSD and TPFD (245 more abundant in TPFD than in FSD, and 125 less abundant), including organooxygen compounds, prenol lipids, flavonoids, carboxylic acids and their derivatives, and fatty acyls. Of these, 43 chemical markers clearly distinguished between FSD and TPFD samples, as confirmed using orthogonal partial least squares discriminant analysis. A pharmacological activity analysis showed that, compared with FSD, TPFD had significantly higher levels of some metabolites with anti-inflammatory activity, consistent with its use to treat inflammation. In addition to revealing the basis of the medicinal efficacy of TPFD, this study supports the benefits of the traditional usage of D. officinale.

State-of-the-Art and Opportunities for Bioactive Pentacyclic Triterpenes from Native Mexican Plants

Native Mexican plants are a wide source of bioactive compounds such as pentacyclic triterpenes. Pentacyclic triterpenes biosynthesized through the mevalonate (MVA) and the 2-C-methyl-D-erythritol-phosphate (MEP) metabolic pathways are highlighted by their diverse biological activity. Compounds belonging to the oleanane, ursane, and lupane groups have been identified in about 33 Mexican plants, located geographically in the southwest of Mexico. The works addressing these findings have reported 45 compounds that mainly show antimicrobial activity, followed by anti-inflammatory, cytotoxic, anxiolytic, hypoglycemic, and growth-stimulating or allelopathic activities. Extraction by maceration and Soxhlet with organic solvents and consecutive chromatography of silica gel have been used for their whole or partial purification. Nanoparticles and nanoemulsions are the vehicles used in Mexican formulations for drug delivery of the pentacyclic triterpenes until now. Sustainable extraction, formulation, regulation, isolation, characterization, and bioassay facilities are areas of opportunity in pentacyclic triterpenes research in Mexico while the presence of plant and human resources and traditional knowledge are strengths. The present review discusses the generalities of the pentacyclic triterpene (definition, biogenic classification, and biosynthesis), a summary of the last two decades of research on the compounds identified and their evaluated bioactivity, the generalities about the extraction and purification methods used, drug delivery aspects, and a critical analysis of the advantages and limitations of research carried out in this way.

Effects of two triterpenoids from Nigella sativa seeds on insulin resistance of 3T3-L1 adipocytes

Insulin resistance (IR) is a physiological abnormality that occurs when insulin fails to activate the signal transduction pathway in target organs. It was found that supplementation of Nigella sativa seeds with oral antidiabetic medicines helps improve blood glucose control by enhanced β cells activity and alleviation of IR. However, the activities and related mechanisms of phytochemicals from N. sativa seeds have not been thoroughly explored. In this study, the effects of two triterpenoids, 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1→4)-β-D-glucopyranose-L-(1→6)-β-D-glucopyranose]-hederagenin (Hxrarg) and 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-hederagenin (Hxra), on IR were studied by 3T3-L1 adipocytes model. The results demonstrated that Hxrarg and Hxra inhibited maturation of 3T3-L1 preadipocytes, dramatically stimulated glucose uptake of IR-3T3-L1 adipocytes, promoted transcription of IRS, AKT, PI-3K, and GLUT4 mRNA. Western Blot results suggested that Hxrarg and Hxra were able to markedly up-regulate expression of p-IRS, p-AKT, PI-3K, and GLUT4 proteins. These findings could provide a basic foundation for the continued development and application of N. sativa in medicine and functional foods.

Asiatic acid alleviates liver fibrosis via multiple signaling pathways based on integrated network pharmacology and lipidomics

Liver fibrosis is characterized by the abnormal deposition of the extracellular matrix with a severe inflammatory response and/or metabolic disorder. Asiatic acid (AA), a natural compound derived from Centella asiatica, exhibited potent anti-fibrosis effects. This investigation first confirmed the anti-fibrosis effects of AA in TGF-β-LX-2 cells and CCl₄-induced liver fibrosis mice, and then sought to elucidate a novel mechanism of action by integrating network pharmacology and lipidomics. Network pharmacology was used to find potential targets of AA, while lipidomics was used to identify differential metabolites between fibrosis and recovered cohorts. AA could suppress hepatic stellate cell activation in vitro and improve liver fibrosis in vivo. Network pharmacology unveiled the genes involved in pathways in cancer, peroxisome proliferators-activated receptors signaling pathway, and arachidonic acid metabolism pathway. Furthermore, five key genes were found in the both human and mouse databases, indicating that arachidonic acid metabolism was important. Changes in lyso-phosphocholine (22:5), prostaglandin F2α, and other related lipid metabolites also suggested the involvement of arachidonic acid metabolism the anti-fibrotic effect. In summary, our integrated strategies demonstrated that AA targeted multiple targets and impeded the progression of liver fibrosis by ameliorating arachidonic acid metabolism.

Recent Advances Regarding the Molecular Mechanisms of Triterpenic Acids: A Review (Part I)

Triterpenic acids are phytocompounds with a widespread range of biological activities that have been the subject of numerous in vitro and in vivo studies. However, their underlying mechanisms of action in various pathologies are not completely elucidated. The current review aims to summarize the most recent literature, published in the last five years, regarding the mechanism of action of three triterpenic acids (asiatic acid, oleanolic acid, and ursolic acid), corelated with different biological activities such as anticancer, anti-inflammatory, antidiabetic, cardioprotective, neuroprotective, hepatoprotective, and antimicrobial. All three discussed compounds share several mechanisms of action, such as the targeted modulation of the PI3K/AKT, Nrf2, NF-kB, EMT, and JAK/STAT3 signaling pathways, while other mechanisms that proved to only be specific for a part of the triterpenic acids discussed, such as the modulation of Notch, Hippo, and MALAT1/miR-206/PTGS1 signaling pathway, were highlighted as well. This paper stands as the first part in our literature study on the topic, which will be followed by a second part focusing on other triterpenic acids of therapeutic value.

Molecular Mechanisms Underlying the Effects of Olive Oil Triterpenic Acids in Obesity and Related Diseases

Dietary components exert protective effects against obesity and related metabolic and cardiovascular disturbances by interfering with the molecular pathways leading to these pathologies. Dietary biomolecules are currently promising strategies to help in the management of obesity and metabolic syndrome, which are still unmet medical issues. Olive oil, a key component of the Mediterranean diet, provides an exceptional lipid matrix highly rich in bioactive molecules. Among them, the pentacyclic triterpenic acids (i.e., oleanolic acid) have gained clinical relevance in the last decade due to their wide range of biological actions, particularly in terms of vascular function, obesity and insulin resistance. Considering the promising effects of these triterpenic compounds as nutraceuticals and components of functional foods against obesity and associated complications, the aim of our review is to decipher and discuss the main molecular mechanisms underlying these effects driven by olive oil triterpenes, in particular by oleanolic acid. Special attention is paid to their signaling and targets related to glucose and insulin homeostasis, lipid metabolism, adiposity and cardiovascular dysfunction in obesity. Our study is aimed at providing a better understanding of the impact of dietary components of olive oil in the long-term management of obesity and metabolic syndrome in humans.

The Optimized Delivery of Triterpenes by Liposomal Nanoformulations: Overcoming the Challenges

The last decade has witnessed a sustained increase in the research development of modern-day chemo-therapeutics, especially for those used for high mortality rate pathologies. However, the therapeutic landscape is continuously changing as a result of the currently existing toxic side effects induced by a substantial range of drug classes. One growing research direction driven to mitigate such inconveniences has converged towards the study of natural molecules for their promising therapeutic potential. Triterpenes are one such class of compounds, intensively investigated for their therapeutic versatility. Although the pharmacological effects reported for several representatives of this class has come as a well-deserved encouragement, the pharmacokinetic profile of these molecules has turned out to be an unwelcomed disappointment. Nevertheless, the light at the end of the tunnel arrived with the development of nanotechnology, more specifically, the use of liposomes as drug delivery systems. Liposomes are easily synthesizable phospholipid-based vesicles, with highly tunable surfaces, that have the ability to transport both hydrophilic and lipophilic structures ensuring superior drug bioavailability at the action site as well as an increased selectivity. This study aims to report the results related to the development of different types of liposomes, used as targeted vectors for the delivery of various triterpenes of high pharmacological interest.

Advances in Anti-inflammatory Activity, Mechanism and Therapeutic Application of Ursolic Acid

In vivo and in vitro studies reveal that Ursolic Acid (UA) is able to counteract endogenous and exogenous inflammatory stimuli and has favorable anti-inflammatory effects. The antiinflammatory mechanisms mainly include decreasing the release of histamine in mast cells, suppressing the activities of lipoxygenase, cyclooxygenase and phospholipase, and reducing the production of nitric oxide and reactive oxygen species, blocking the activation of the signal pathway, downregulating the expression of inflammatory factors, and inhibiting the activities of elastase and complement. These mechanisms can open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle inflammatory diseases, such as arthritis, atherosclerosis, neuroinflammation, liver diseases, kidney diseases, diabetes, dermatitis, bowel diseases, cancer. The anti-inflammatory activity, the anti-inflammatory mechanism of ursolic acid and its therapeutic applications are reviewed in this paper.

Relationship between Maturity Stage, Triterpenoid Content and Cytotoxicity of Sorbus intermedia (EHRH.) PERS. Fruits - A Chemometric Approach

In this study, two ursane-type triterpenes, i. e., ursolic acid (UA) and 3-O-β-acetoxyursolic acid (AUA), were isolated and quantified in Sorbus intermedia (EHRH.) PERS. fruits. UA and AUA levels differed slightly throughout fruit maturation, and both triterpenes showed similar dynamics of accumulation with the highest levels found in ripe fruits (up to 6.33±0.56 and 1.17±0.18 mg/g dw. of UA and AUA, respectively). The extracts derived from unripe fruits displayed significant cytotoxic effects against WM793, DU-145, PC3, 8505C, Caco2 and A549 cells, but no correlation between UA and AUA levels and cytotoxicity was found. On the other hand, extracts from mature fruits were not active towards almost all of the tested cell lines. The chemometric approach showed that the extracts derived from fruits harvested earlier clustered to form a clearly distanced group from extracts prepared from more-mature fruits. The extracts at higher concentrations formed separate groups, which indicated the concentration-dependent effect of these extracts on the cells.

Corosolic acid inhibits cancer progression by decreasing the level of CDK19-mediated O-GlcNAcylation in liver cancer cells

Diabetes is an important risk factor for liver cancer, but its mechanism is unknown. Corosolic acid (CA) has been proven to have both hypoglycemic and antitumor effects, so revealing the function of CA can help us understand the relationship between diabetes and liver cancer. In previous studies, we confirmed that CA can effectively inhibit the expression of YAP, an important oncoprotein in HCC cells, and the proliferation of HCC cells. In addition, we also found that O-GlcNAcylation plays an indispensable role in HCC tumorigenesis. However, it is not clear whether CA can inhibit the effect of O-GlcNAcylation on HCC cells. In this study, the antitumor ability of CA was investigated by inhibiting the O-GlcNAcylation level and its corresponding mechanism. The results showed that HG (high glucose) could promote the proliferation of liver cancer cells, while CA could inhibit cell growth under HG conditions and tumor growth in a xenotransplantation model. CA can inhibit the activation of the HBP pathway and reduce the expression of YAP and OGT under HG conditions. Importantly, we found that CA can reduce YAP expression and O-GlcNAcylation by inhibiting the activity of CDK19. Overexpression of CDK19 partially reversed the CA-induced decrease in YAP and O-GlcNAcylation. This is the first evidence that CA can reduce the proliferative capacity of cells with high glucose levels and further inhibit tumor growth by inactivating the CDK19/YAP/O-GlcNAcylation pathway, suggesting that CA is a candidate drug for the development of treatments against diabetes-associated liver cancer.

Major triterpenoids from Eucalyptus tereticornis have enhanced beneficial effects in cellular models when mixed with minor compounds present in raw extract

Obesity is a major risk factor for type 2 diabetes mellitus development and is characterized by an abnormal expansion of adipose tissue and low-grade chronic inflammation that contribute to insulin resistance. Although there are multiple treatments, most therapies can produce undesirable side effects and therefore, new and effective treatments with fewer side effects are necessary. Previously, we demonstrated that a natural extract from the leaves of Eucalyptus tereticornis (OBE100) has anti-inflammatory, hypoglycemic and hypolipidemic activities. The major compounds identified in OBE100 were three pentacyclic triterpenoids, ursolic acid, oleanolic acid, and ursolic acid lactone. Triterpenoids have shown multiples biological activities. This current study compared the biological effect produced by OBE100 with five different reconstituted mixtures of these triterpenoids. Different cell lines were used to evaluate cytotoxicity, reactive oxygen species production, inflammatory cytokine expression, glucose uptake induction, leptin and adiponectin expression, and lipid accumulation. OBE100 treatment was the most efficacious and none of the formulated triterpenoid mixtures significantly improved on this. Moreover, OBE100 was less toxic and reduced reactive oxygen species production. Our study showed that the proven beneficial properties of triterpenoids may be enhanced due to the interaction with minor secondary metabolites present in the natural extract improving their anti-inflammatory properties.

The in vitro and in vivo study of oleanolic acid indole derivatives as novel anti-inflammatory agents: Synthesis, biological evaluation, and mechanistic analysis

Oleanolic acid (OA) is a well-known natural product possessing many important pharmacological activities; however, its weak bioactivities significantly restrict the potential application in drug development. The structural modification of oleanolic acid is an effective mean to enhance its bioactivity with lower toxicity but it is challenging. In the present study, we systematically synthesized a series of new 11-oxooleanolic acid derivatives and evaluated their anti-inflammatory activities with a LPS induced BV2 cells inflammation model and a 12-O-tetradecanoyl phorbol-13-acetate (TPA) induced ear inflammation mice model. It was found that compounds 8 and 9 show more potent anti-inflammatory effects than OA and exhibit a low cytotoxicity. The possible mechanism of action was also investigated. The in vitro and in vivo results revealed that these two new 11-oxooleanolic acid derivatives may exert anti-inflammatory activities through the inhibition of NO, pro-inflammatory cytokines and chemokines (IL-1β, IL-6, IL-12, TNF-α, MCP-1 and MIP-1α) and upregulation of anti-inflammatory cytokines (IL-10), which may be caused by inhibiting the activation of NF-κB, MAPKs and PI3K/Akt related inflammatory signaling pathways and the activation of Nrf2/HO-1 signaling pathway. The results suggest that these two 11-oxooleanolic acid derivatives may be potential candidates for further anti-inflammatory drug development and our study demonstrated an important and practical strategy for drug discovery through the rational modification of natural products.

Pentacyclic triterpene carboxylic acids derivatives integrated piperazine-amino acid complexes for α-glucosidase inhibition in vitro

Eighteen derivatives of pentacyclic triterpene carboxylic acids (Maslinic acid, Corosolic acid and Asiatic acid) have been prepared by coupling the piperazine complex of l-amino acids at the C-28 site of the parent compounds. The α-glucosidase inhibitory activities of the pristine derivatives were evaluated in vitro. The results indicated that the inhibitory activity of some compounds (15e IC₅₀ = 591 μM, 16e IC₅₀ = 423 μM) was closed to that of the reference acarbose (IC₅₀ = 347 μM) in ethanol-water system. In addition, compound 16e (IC₅₀ = 380 μM) showed superior inhibitory activity than acarbose (IC₅₀ = 493 μM) in the measurement system with DMSO as solvent. The comparison of two different solvent systems showed that the derivatives had better α-glucosidase inhibitory activity in the DMSO system than that of in ethanol-water system. Regrettably, all of the as-synthesized derivatives exhibited inferior α-glucosidase inhibitory activities than those of the parent compounds in both test solvent systems. Furthermore, the result of enzyme kinetics demonstrated that the inhibition mechanism of compound 16e was noncompetitive inhibition with the inhibition constant K_i = 552 μM.

Indole- and Pyrazole-Glycyrrhetinic Acid Derivatives as PTP1B Inhibitors: Synthesis, In Vitro and In Silico Studies

Regulating insulin and leptin levels using a protein tyrosine phosphatase 1B (PTP1B) inhibitor is an attractive strategy to treat diabetes and obesity. Glycyrrhetinic acid (GA), a triterpenoid, may weakly inhibit this enzyme. Nonetheless, semisynthetic derivatives of GA have not been developed as PTP1B inhibitors to date. Herein we describe the synthesis and evaluation of two series of indole- and N-phenylpyrazole-GA derivatives (4a-f and 5a-f). We measured their inhibitory activity and enzyme kinetics against PTP1B using p-nitrophenylphosphate (pNPP) assay. GA derivatives bearing substituted indoles or N-phenylpyrazoles fused to their A-ring showed a 50% inhibitory concentration for PTP1B in a range from 2.5 to 10.1 µM. The trifluoromethyl derivative of indole-GA (4f) exhibited non-competitive inhibition of PTP1B as well as higher potency (IC₅₀ = 2.5 µM) than that of positive controls ursolic acid (IC₅₀ = 5.6 µM), claramine (IC₅₀ = 13.7 µM) and suramin (IC₅₀ = 4.1 µM). Finally, docking and molecular dynamics simulations provided the theoretical basis for the favorable activity of the designed compounds.

Interaction of selected terpenoids with two SARS-CoV-2 key therapeutic targets: An in silico study through molecular docking and dynamics simulations

The outbreak of COVID-19 disease caused by SARS-CoV-2, along with the lack of targeted medicaments, forced the scientific world to search for new antiviral formulations. In the current emergent situation, drug repurposing of well-known traditional and/or approved drugs could be the most effective strategy. Herein, through computational approaches, we aimed to screen 14 natural compounds from limonoids and terpenoids class for their ability to inhibit the key therapeutic target proteins of SARS-CoV-2. Among these, some limonoids, namely deacetylnomilin, ichangin and nomilin, and the terpenoid β-amyrin provided good interaction energies with SARS-CoV-2 3CL hydrolase (Mpro) in molecular dynamic simulation. Interestingly, deacetylnomilin and ichangin showed direct interaction with the catalytic dyad of the enzyme so supporting their potential role in preventing SARS-CoV-2 replication and growth. On the contrary, despite the good affinity with the spike protein RBD site, all the selected phytochemicals lose contact with the amino acid residues over the course of 120ns-long molecular dynamics simulations therefore suggesting they scarcely can interfere in SARS-CoV-2 binding to the ACE2 receptor. The in silico analyses of docking score and binding energies, along with predicted pharmacokinetic profiles, indicate that these triterpenoids might have potential as inhibitors of SARS-CoV-2 Mpro, recommending further in vitro and in vivo investigations for a complete understanding and confirmation of their inhibitory potential.

Pentacyclic Triterpenoids with Nitrogen-Containing Heterocyclic Moiety, Privileged Hybrids in Anticancer Drug Discovery

Pentacyclic triterpenoids are well-known phytochemicals with various biological activities commonly found in plants as secondary metabolites. The wide range of biological activities exhibited by triterpenoids has made them the most valuable sources of pharmacological agents. A number of novel triterpenoid derivatives with many skeletal modifications have been developed. The most important modifications are the formation of analogues or derivatives with nitrogen-containing heterocyclic scaffolds. The derivatives with nitrogen-containing heterocyclic compounds are among the most promising candidate for the development of novel therapeutic drugs. About 75% of FDA-approved drugs are nitrogen-containing heterocyclic moieties. The unique properties of heterocyclic compounds have encouraged many researchers to develop new triterpenoid analogous with pharmacological activities. In this review, we discuss recent advances of nitrogen-containing heterocyclic triterpenoids as potential therapeutic agents. This comprehensive review will assist medicinal chemists to understand new strategies that can result in the development of compounds with potential therapeutic efficacy.

Ursolic Acid Lactone Obtained from Eucalyptus tereticornis Increases Glucose Uptake and Reduces Inflammatory Activity and Intracellular Neutral Fat: An In Vitro Study

Obesity has a strong relationship to insulin resistance and diabetes mellitus, a chronic metabolic disease that alters many physiological functions. Naturally derived drugs have aroused great interest in treating obesity, and triterpenoids are natural compounds with multiple biological activities and antidiabetic mechanisms. Here, we evaluated the bioactivity of ursolic acid lactone (UAL), a lesser-known triterpenoid, obtained from Eucalyptus tereticornis. We used different cell lines to show for the first time that this molecule exhibits anti-inflammatory properties in a macrophage model, increases glucose uptake in insulin-resistant muscle cells, and reduces triglyceride content in hepatocytes and adipocytes. In 3T3-L1 adipocytes, UAL inhibited the expression of genes involved in adipogenesis and lipogenesis, enhanced the expression of genes involved in fat oxidation, and increased AMP-activated protein kinase phosphorylation. The range of biological activities demonstrated in vitro indicates that UAL is a promising molecule for fighting diabetes.

Anticancer Potential of Betulonic Acid Derivatives

Clinical trials have evidenced that several natural compounds, belonging to the phytochemical classes of alkaloids, terpenes, phenols and flavonoids, are effective for the management of various types of cancer. Latest research has proven that natural products and their semisynthetic variants may serve as a starting point for new drug candidates with a diversity of biological and pharmacological activities, designed to improve bioavailability, overcome cellular resistance, and enhance therapeutic efficacy. This review was designed to bring an update regarding the anticancer potential of betulonic acid and its semisynthetic derivatives. Chemical derivative structures of betulonic acid including amide, thiol, and piperidine groups, exert an amplification of the in vitro anticancer potential of betulonic acid. With the need for more mechanistic and in vivo data, some derivatives of betulonic acids may represent promising anticancer agents.

Targeting Mitochondrial Metabolism in Prostate Cancer with Triterpenoids

Metabolic reprogramming is a hallmark of malignancy. It implements profound metabolic changes to sustain cancer cell survival and proliferation. Although the Warburg effect is a common feature of metabolic reprogramming, recent studies have revealed that tumor cells also depend on mitochondrial metabolism. Due to the essential role of mitochondria in metabolism and cell survival, targeting mitochondria in cancer cells is an attractive therapeutic strategy. However, the metabolic flexibility of cancer cells may enable the upregulation of compensatory pathways, such as glycolysis, to support cancer cell survival when mitochondrial metabolism is inhibited. Thus, compounds capable of targeting both mitochondrial metabolism and glycolysis may help overcome such resistance mechanisms. Normal prostate epithelial cells have a distinct metabolism as they use glucose to sustain physiological citrate secretion. During the transformation process, prostate cancer cells consume citrate to mainly power oxidative phosphorylation and fuel lipogenesis. A growing number of studies have assessed the impact of triterpenoids on prostate cancer metabolism, underlining their ability to hit different metabolic targets. In this review, we critically assess the metabolic transformations occurring in prostate cancer cells. We will then address the opportunities and challenges in using triterpenoids as modulators of prostate cancer cell metabolism.

Pentacyclic Triterpene Profile and Its Biosynthetic Pathway in Cecropia telenitida as a Prospective Dietary Supplement

Promising research over the past decades has shown that some types of pentacyclic triterpenes (PTs) are associated with the prevention of type 2 diabetes (T2D), especially those found in foods. The most abundant edible sources of PTs are those belonging to the ursane and oleanane scaffold. The principal finding is that Cecropia telenitida contains abundant oleanane and ursane PT types with similar oxygenation patterns to those found in food matrices. We studied the compositional profile of a rich PT fraction (DE16-R) and carried out a viability test over different cell lines. The biosynthetic pathway connected to the isolated PTs in C. telenitida offers a specific medicinal benefit related to the modulation of T2D. This current study suggests that this plant can assemble isobaric, positional isomers or epimeric PT. Ursane or oleanane scaffolds with the same oxygenation pattern are always shared by the PTs in C. telenitida, as demonstrated by its biosynthetic pathway. Local communities have long used this plant in traditional medicine, and humans have consumed ursane and oleanane PTs in fruits since ancient times, two key points we believe useful in considering the medicinal benefits of C. telenitida and explaining how a group of molecules sharing a closely related scaffold can express effectiveness.

Asiatic Acid, a Natural Compound that Exerts Beneficial Effects on the Cystometric and Biochemical Parameters in the Retinyl Acetate-Induced Model of Detrusor Overactivity

Scientists have been constantly looking for new synthetic and natural compounds that could have beneficial effects in bladder overactivity. Our attention was drawn by asiatic acid that influences a number of molecules and signaling pathways relevant for the proper functioning of the urinary tracts in humans. In the present project we wanted to check whether asiatic acid would have positive effects in the confirmed animal model of detrusor overactivity (DO) and whether it would affect the bladder blood flow, urothelium thickness, inflammatory and oxidative stress markers, neurotrophic and growth factors, and other parameters important for the activity of the urinary bladder. The outcomes of our study showed that a 14-day administration of asiatic acid (30 mg/kg/day) by oral gavage normalizes the cystometric parameters corresponding to DO and reduces the accompanying oxidative stress (measured by the levels of malondialdehyde–61,344 ± 24,908 pg/ml vs. 33,668 ± 5,071 pg/ml, 3-nitrotyrosine–64,615 ± 25,433 pg/ml vs. 6,563 ± 1,736 pg/ml, and NOS2–2,506 ± 411.7 vs. 3,824 ± 470.1 pg/ml). Moreover, it decreases the urinary secretion of neurotrophins (BDNF–304.4 ± 33.21 pg/ml vs. 119.3 ± 11.49 pg/ml and NGF–205.5 ± 18.50 vs. 109.7 ± 15.94 pg/ml) and prevents the changes in a range of biomarkers indicating the dysfunction of the urinary bladder, CGRP (421.1 ± 56.64 vs. 108.1 ± 11.73 pg/ml), E-Cadherin (773.5 ± 177.5 pg/ml vs. 1,560 ± 154.5 pg/ml), OCT3 (3,943 ± 814.6 vs. 1,018 ± 97.07 pg/ml), SNAP-23 (6,763 ± 808.9 pg/ml vs. 3,455 ± 554.5 pg/ml), SNAP-25 (2,038 ± 162.7 pg/ml vs. 833.3 ± 65.48), substance P (171.7 ± 16.86 pg/ml vs. 65.07 ± 8.250 pg/ml), SV2A (1,927 ± 175.3 pg/ml vs. 1,154 ± 254.9 pg/ml), tight junction protein 1 (360.1 ± 95.05 pg/ml vs. 563.4 ± 65.43 pg/ml), VAChT (16,470 ± 2,419 pg/ml vs. 7,072 ± 1,339 pg/ml), VEGFA (318.3 ± 37.89 pg/ml vs. 201.5 ± 22.91 pg/ml). The mentioned parameters are associated with smooth muscle contractions, urothelial barrier, transportation and release of transmitters, or bladder compensation. Thus, the presented findings allow to suggest a possible future role of asiatic acid in the prevention of conditions accompanied by DO, such as overactive bladder.

Vochysia tucanorum Mart. butanol fraction presents antitumoral activity in vivo and prevents the installation of cachexia in solid Ehrlich tumor model

Background

Cancer is a multifactorial disease caused by uncontrolled proliferation of cells. About 50–80% of cancer patients develop cachexia, a complex metabolic syndrome associated with an increase of mortality and morbidity. However, there are no effective therapies in medical clinic for cancer cachexia. Vochysia tucanorum Mart. is a common three of the Brazilian “Cerrado”. The butanolic fraction of V. tucanorum (Fr-BuVt), very rich in triterpenes with various biological activities, might be interesting in being tested in cancer cachexia syndrome. Hence, the present study was undertaken to investigate the antitumoral activity of Fr-BuVt and its potential against cachexia development.

Methods

Ehrlich tumor was used as model of cancer cachexia. Ascitic Ehrlich tumor cells were collected, processed and inoculated subcutaneously in saline solution (1 × 10⁷/100 μl; ≥95% viability) for the obtention of solid Ehrlich carcinoma. After inoculation, solid Ehrlich carcinoma-bearing mice were treated by 14 consecutive days by gavage with Fr-BuVt (200 mg/kg). Body weight and tumor volume were measure during the treatment period. Tumors were removed, weighed and properly processed to measure the content and phosphorylation levels of key-proteins involved to apoptotic and proliferation process by Western Blot. Muscles and adipose tissues were removed for weighed. Serum was collected to cytokines levels and energetic blood markers measurements.

Results

The treatment with the Fr-BuVt (200 mg/kg, 14 days) decreased the solid Ehrlich tumor volume and weight besides increased the expression of the pro-apoptotic proteins caspase-3 and BAX, but also decreased the expression of the proteins involved in proliferation NFκB, mTOR and ERK. In addition, our data shows that the administration of Fr-BuVt was able to prevent the installation of cancer cachexia in Ehrlich carcinoma-bearing mice, since prevented the loss of body weight, as well as the loss of muscle and adipose tissue. Moreover, an improvement in some blood parameters such as decrease in cytokines TNF-α and IL-6 levels is observed.

Conclusions

The study revealed that Fr-BuVt has antitumoral activity and prevent installation of cancer cachexia in Ehrlich model. Therefore, Fr-BuVt may represent an alternative treatment for cancer cachexia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03190-1.

Biogenic Synthesis of Silver Nanoparticles with High Antimicrobial and Catalytic Activities using Sheng Di Huang (Rehmannia glutinosa)

Silver nanoparticles (AgNPs) are widely sought after for a variety of biomedical and environmental applications due to their antimicrobial and catalytic properties. We present here a green and simple synthesis of AgNPs utilizing traditional Chinese medicinal herbs. The screening of 20 aqueous herb extracts shows that Sheng Di Huang (Rehmannia glutinosa) had the most promising potential in producing AgNPs of 30±6 nm, with narrow size distribution and high crystallinity. The antimicrobial activities of these AgNPs conducted on E. coli cells were found to be superior in comparison to poly(vinylpyrrolidone)-capped AgNPs synthesized using common chemical method. Additionally, the AgNPs obtained possess excellent catalytic performance in the reduction of 4-nitrophenol to 4-aminophenol. We compared the phytochemical and FTIR spectral analyses of the herb extract before and after synthesis, in order to elucidate the phytochemicals responsible for the reduction of Ag⁺ ions and the capping of the AgNPs produced.

Triterpenic Acid Amides as a Promising Agent for Treatment of Metabolic Syndrome

A series of triterpenic acid amides were synthesized incorporating a 2-ethoxy-3-phenylpropanoic acid pharmacophore fragment. The synthesized compounds were tested for their ability to improve glycemic control and to counter lipid abnormalities in C57BL/6 mice placed on a high-fat/high-cholesterol diet. Of all tested compounds, the dihydrobetulonic derivative (16b) had the most pronounced effect in decreasing blood glucose levels, total cholesterol (TC), and high-density lipoproteins (HDL). All the synthesized compounds displayed a relatively safe profile in the animal studies carried out in this work.

Development and Evaluation of Oleanolic Acid Dosage Forms and Its Derivatives

Oleanolic acid is a pentacyclic triterpenoid compound that exists widely in medicinal herbs and other plants. Because of the extensive pharmacological activity, oleanolic acid has attracted more and more attention. However, the structural characteristics of oleanolic acid prevent it from being directly made into new drugs, which limits the application of oleanolic acid. Through the application of modern preparation techniques and methods, different oleanolic acid dosage forms and derivatives have been designed and synthesized. These techniques can improve the water solubility and bioavailability of oleanolic acid and lay a foundation for the new drug development. In this review, the recent progress in understanding the oleanolic acid dosage forms and its derivatives are discussed. Furthermore, these products were evaluated comprehensively from the perspective of characterization and pharmacokinetics, and this work may provide ideas and references for the development of oleanolic acid preparations.

Biological effects of corosolic acid as an anti-inflammatory, anti-metabolic syndrome and anti-neoplasic natural compound

Accumulating evidence has indicated that corosolic acid exerts anti-diabetic, anti-obesity, anti-inflammatory, anti-hyperlipidemic and anti-viral effects. More importantly, corosolic acid has recently attracted much attention due to its anticancer properties and innocuous effects on normal cells. Furthermore, the increasing proportion of obese and/or diabetic populations has led to an epidemic of non-alcoholic fatty liver disease (NAFLD), which frequently progresses to hepatocellular carcinoma (HCC). Evidence has indicated that NAFLD is closely associated with the development of HCC and comprises a high risk factor. The present review summarizes the anticancer effects of corosolic acid in vitro and in vivo, and its related molecular mechanisms. It also describes the inhibitory effects of corosolic acid on the progression of NAFLD and its associated molecular mechanisms, providing guidance for future research on corosolic acid in NAFLD-related HCC prevention and treatment. To the best of our knowledge, a review of corosolic acid as an anticancer agent has not yet been reported. Due to its multitargeted activity in cancer cells, corosolic acid exerts anticancer effects when administered alone, and acts synergistically when administered with chemotherapeutic drugs, even in drug-resistant cells. In addition, as a novel tool to treat metabolic syndromes, corosolic acid uses the same mechanism in its action against cancer as that used in the progression of NAFLD-related HCC. Therefore, corosolic acid has been suggested as an agent for the prevention and treatment of NAFLD-related HCC.

A review of saponin intervention in metabolic syndrome suggests further study on intestinal microbiota

Metabolic syndrome (MetS) is a series of symptoms including insulin resistance, obesity, dyslipidemia, elevated fasting blood glucose levels, and hepatic steatosis. As a key criterion in MetS, the onset of insulin resistance is related to abnormal levels of circulating free fatty acids and adipokines. It has been discovered in recent years that metabolites and pathogen-associated molecular patterns of intestinal/gut microbiota are also important factors that cause insulin resistance and MetS. Saponins are the main components of many botanicals and traditional Chinese medicines (TCMs), such as ginseng, platycodon, licorice, and alfalfa. They have poor bioavailability, but can be transformed into secondary glycosides and aglycones by intestinal microbiota, further being absorbed. Based on in vivo and in vitro data, we found that saponins and their secondary metabolites have a preventive effect on MetS, and the effective targets are distributed in the intestine and other organs in human body. Intestinal targets involve pancreatic lipase, dietary cholesterol, and intestinal microbiota. Other targets include central appetite, nuclear receptors such as PPAR and LXR, AMPK signaling pathway and adipokines levels, etc. In view of the poor bioavailability of saponins, it is inferred that targets for prototype-saponins to interfere with MetS is mainly located in the intestine, and the activation of other targets may be related to secondary glycosides and aglycones transformed from saponins by intestinal flora. We suggest that the role of intestinal microbiota in saponin intervention in MetS should be further investigated.

Characterization of Corosolic Acid as a KPC-2 Inhibitor That Increases the Susceptibility of KPC-2-Positive Bacteria to Carbapenems

The emergence of KPC-producing Gram-negative bacteria in clinical practice highlights the need to search for novel antimicrobials and new anti-infection strategies. In this study, we constructed a laboratory KPC-2-positive strain, E. coli BL21(DE3) (pET28a-KPC-2) and identified the activity of KPC-2 in this strain. Using enzyme inhibition assays, checkerboard MIC assays, growth curves, time-killing assays and combined disk test, we found that the natural compound corosolic acid (CA) significantly inhibited the activity of the class A β-lactamase KPC-2, which is common among clinical isolates. CA treatment increased the antibacterial or bactericidal activity of imipenem and meropenem against E. coli BL21(DE3) (pET28a-KPC-2) in vitro (FIC index = 0.17 ± 0.03 for both carbapenems). In addition, the mouse intraperitoneal infection model confirmed that the combination therapy significantly reduced the bacterial load in the livers and spleens following subcutaneous administration. Our results showed that CA can be used to extend the life of carbapenems, providing a viable strategy for severe infections caused by KPC-2-positive bacteria.

Terpenoids as Potential Geroprotectors

Terpenes and terpenoids are the largest groups of plant secondary metabolites. However, unlike polyphenols, they are rarely associated with geroprotective properties. Here we evaluated the conformity of the biological effects of terpenoids with the criteria of geroprotectors, including primary criteria (lifespan-extending effects in model organisms, improvement of aging biomarkers, low toxicity, minimal adverse effects, improvement of the quality of life) and secondary criteria (evolutionarily conserved mechanisms of action, reproducibility of the effects on different models, prevention of age-associated diseases, increasing of stress-resistance). The number of substances that demonstrate the greatest compliance with both primary and secondary criteria of geroprotectors were found among different classes of terpenoids. Thus, terpenoids are an underestimated source of potential geroprotectors that can effectively influence the mechanisms of aging and age-related diseases.

Soyasapogenol-A targets CARF and results in suppression of tumor growth and metastasis in p53 compromised cancer cells

We screened some phytochemicals for cytotoxic activity to human cancer cells and identified Soyasapogenol-A (Snol-A) as a potent candidate anti-cancer compound. Interestingly, Soyasapogenin-I (Snin-I) was ineffective. Viability assays endorsed toxicity of Snol-A to a wide variety of cancer cells. Of note, wild type p53 deficient cancer cells (SKOV-3 and Saos-2) also showed potent growth inhibitory effect. Molecular analyses demonstrated that it targets CARF yielding transcriptional upregulation of p21^WAF1 (an inhibitor of cyclin-dependent kinases) and downregulation of its effector proteins, CDK2, CDK-4, Cyclin A and Cyclin D1. Targeting of CARF by Snol-A also caused (i) downregulation of pATR-Chk1 signaling leading to caspase-mediated apoptosis and (ii) inactivation of β-catenin/Vimentin/hnRNPK-mediated EMT signaling resulting in decrease in migration and invasion of cancer cells. In in vivo assays, Snol-A caused suppression of tumor growth in subcutaneous xenograft model and inhibited lung metastasis in tail vein injection model. Taken together, we demonstrate that Snol-A is a natural inhibitor of CARF and may be recruited as a potent anti-tumor and anti-metastasis compound for treatment of p53-deficient aggressive malignancies.

Chemistry, Biological Activities and In Silico Bioprospection of Sterols and Triterpenes from Mexican Columnar Cactaceae

The Cactaceae family is an important source of triterpenes and sterols. The wide uses of those plants include food, gathering, medicinal, and live fences. Several studies have led to the isolation and characterization of many bioactive compounds. This review is focused on the chemistry and biological properties of sterols and triterpenes isolated mainly from some species with columnar and arborescent growth forms of Mexican Cactaceae. Regarding the biological properties of those compounds, apart from a few cases, their molecular mechanisms displayed are not still fully understand. To contribute to the above, computational chemistry tools have given a boost to traditional methods used in natural products research, allowing a more comprehensive exploration of chemistry and biological activities of isolated compounds and extracts. From this information an in silico bioprospection was carried out. The results suggest that sterols and triterpenoids present in Cactaceae have interesting substitution patterns that allow them to interact with some bio targets related to inflammation, metabolic diseases, and neurodegenerative processes. Thus, they should be considered as attractive leads for the development of drugs for the management of chronic degenerative diseases.

Optimized Extraction of Total Triterpenoids from Jujube (Ziziphus jujuba Mill.) and Comprehensive Analysis of Triterpenic Acids in Different Cultivars

Triterpenoid compounds are one of the main functional components in jujube fruit. In this study, the optimal process for ultrasound-assisted extraction (UAE) of total triterpenoids from jujube fruit was determined using response surface methodology (RSM). The optimal conditions were as follows: temperature of 55.14 °C, ethanol concentration of 86.57%, time of 34.41 min, and liquid-to-solid ratio of 39.33 mL/g. The triterpenoid yield was 19.21 ± 0.25 mg/g under optimal conditions. The triterpenoid profiles and antioxidant activity were further analyzed. Betulinic acid, alphitolic acid, maslinic acid, oleanolic acid, and ursolic acid were the dominant triterpenoid acids in jujube fruits. Correlation analysis revealed a significant positive correlation between the major triterpenic acids and antioxidant activities. The variations of triterpenoid profiles and antioxidant activity within the jujube fruits and the degree of variation were evaluated by hierarchical cluster analysis (HCA) and principal component analysis (PCA), respectively. The results provide important guidance for the quality evaluation and industrial application of jujube fruit.