Exploring the Mechanisms of Traditional Chinese Herbal Therapy in Gastric Cancer: A Comprehensive Network Pharmacology Study of the Tiao-Yuan-Tong-Wei decoction

The use of herbal medicine as an adjuvant therapy in the management of gastric cancer has yielded encouraging outcomes, notably in enhancing overall survival rates and extending periods of disease remission. Additionally, herbal medicines have demonstrated potential anti-metastatic effects in gastric cancer. Despite these promising findings, there remains a significant gap in our understanding regarding the precise pharmacological mechanisms, the identification of specific herbal compounds, and their safety and efficacy profiles in the context of gastric cancer therapy. In addressing this knowledge deficit, the present study proposes a comprehensive exploratory analysis of the Tiao-Yuan-Tong-Wei decoction (TYTW), utilizing an integrative approach combining system pharmacology and molecular docking techniques. This investigation aims to elucidate the pharmacological actions of TYTW in gastric pathologies. It is hypothesized that the therapeutic efficacy of TYTW in counteracting gastric diseases stems from its ability to modulate key signaling pathways, thereby influencing PIK3CA activity and exerting anti-inflammatory effects. This modulation is observed predominantly in pathways such as PI3K/AKT, MAPK, and those directly associated with gastric cancer. Furthermore, the study explores how TYTW's metabolites (agrimoniin, baicalin, corosolic acid, and luteolin) interact with molecular targets like AKT1, CASP3, ESR1, IL6, PIK3CA, and PTGS2, and their subsequent impact on these critical pathways and biological processes. Therefore, this study represents preliminary research on the anticancer molecular mechanism of TYTW by performing network pharmacology and providing theoretical evidence for further experimental investigations.

Corosolic acid inhibits metastatic response of human renal cell carcinoma cells by modulating ERK/MMP2 signaling

Corosolic acid (CA), a plant-derived pentacyclic triterpenoid, has potent anti-inflammatory, anti-metabolic, and anti-neoplastic actions against a variety of human cancers. However, the specific mechanism by which CA inhibits the progression of renal cell carcinoma (RCC) is yet unclear. We found that CA (≤8 μM) had no influence on either the growth or viability of RCC cell lines (786-O, ACHN, and Caki-1) or normal HK2 cells. However, in a dose-dependent manner, CA prevented the invasion and migration of RCC cells. Human protease array analysis showed that CA reduced MMP2 expression. At increasing concentrations of CA, the expression of MMP2 was dose-dependently reduced, as shown by western blot and RT-PCR analyses as well as immunofluorescence staining. CA also stimulated ERK1/2 phosphorylation in 786-O and Caki-1 cells. Transfection of CA-treated RCC cells with siRNA-ERK restored MMP2 protein expression and the motility and invasion capabilities of RCC cells. Molecular docking study results showed that CA and MMP2 interact strongly. These findings elucidate the mechanism by which CA prevents RCC cells from migrating and invading, and these findings indicate that CA may be a potential anti-metastatic therapy for RCC.

Lagerstroemia speciosa Pers. (Lythraceae) Ethanolic Extract Attenuates Isoniazid-Induced Oxidative Stress and Hepatic Inflammation in Rats

Background Drug-induced liver injury is a common cause of acute liver failure. Isoniazid (INH) is used as a first-line treatment for tuberculosis. Clinical and experimental studies have reported abnormal liver function after INH therapy. Lagerstroemia speciosa Pers., commonly known as banaba, has been traditionally used to treat various ailments including diabetes and obesity due to its antioxidant and anti-inflammatory properties. Aim To investigate the hepatoprotective effect of ethanolic banaba leaf extract (EBLE) against INH-induced hepatotoxicity in rats. Materials and methods A total of 30 male Wistar albino rats (150 - 200 g) were divided into five groups (n = 6). Group I rats were served as a control and were administered dimethyl sulfoxide for the first 30 days and water for the next 30 consecutive days. Group II rats were administered INH (50 mg/kg, p.o.) once in the first 30 consecutive days and sacrificed at Day 30. Group III rats were administered INH for 30 consecutive days and left without treatment for the next 30 days. In Groups IV and V, rats were post-treated orally with EBLE 250 and 500 mg/kg, p.o. (0.3 ml/rat) for 30 days after INH administration. At the end of Day 60, the remaining group of animals were sacrificed. The blood and liver tissues were collected. The marker enzymes of hepatotoxicity, oxidative stress markers, inflammatory markers, and histopathology were analyzed. Results INH administration induced significant elevation of marker enzymes (aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, bilirubin, gamma-glutamyl transpeptidase) of hepatotoxicity in the serum. This treatment also increased lipid peroxidation and proinflammatory marker expression (tumor necrosis factor-alpha, transforming growth factor-beta, and nuclear factor kappa B (NF-κB) except inhibitor of NF-κB) and decreased antioxidants such superoxide dismutase, catalase, and glutathione in the liver tissue. All these abnormalities were significantly mitigated after treatment with EBLE. Conclusion The results of this study suggest that EBLE can be used for INH-induced hepatotoxicity.

Antibacterial activity of Lagerstreomia speciosa and its active compound, corosolic acid, enhances cefotaxime inhibitory activity against Staphylococcus aureus

AIMS

Various epidemiology studies have reported the emergence of Staphylococcus aureus and its methicillin resistance strain causing global health concerns, especially during and post-COVID-19 pandemic. This pathogen presents as a co-infection in patients with COVID-19. In addition, certain virulence factors and resistance to β-lactam antibiotics, including cefotaxime, have been identified. We aimed to investigate the antibacterial activity of Lagerstreomia speciosa, a medicinal plant with antidiabetic activity, against S. aureus, including the strain resistant to methicillin. Furthermore, we examined whether the extract and one of its bioactive compounds, corosolic acid, can enhance the therapeutic effect of cefotaxime on antibiotic-resistant S. aureus.

METHODS AND RESULTS

The minimum inhibitory concentration of each substance was determined using the standard broth microdilution test following the checkerboard dilution. The type of interactions, synergistic, additivity, indifference, or antagonism, were determined using isobolograms analysis and the dose reduction index (DRI). The evaluation of synergy and bactericidal activity of the natural products in combination with cefotaxime was performed using the time-kill kinetic assay. Corosolic acid, L. speciosa leaves extract, and bark extract alone showed antibacterial activity against all tested S. aureus ATCC 33591, S. aureus ATCC 29213, S. aureus ATCC 25923, and clinical isolated S. aureus. Corosolic acid enhanced the antibacterial activity of cefotaxime, showing a synergistic effect and greater DRI of cefotaxime against all tested S. aureus strains. Time-kill kinetic assay showed that corosolic acid has a more profound effect than L. speciosa extracts to potentiate the bactericidal activity of cefotaxime. Whereas L. speciosa leaves and bark extract showed some inhibitory effect on the growth of S. aureus after a single administration.

CONCLUSIONS

Lagerstreomia speciosa leaves and bark extract and its active compound, corosolic acid, could be used as a potential anti-Staphylococcus aureus treatment to enhance the therapeutic use of cefotaxime.

The Cardioprotective Effect of Corosolic Acid in the Diabetic Rats: A Possible Mechanism of the PPAR-γ Pathway

The study was conducted to determine whether corosolic acid could protect the myocardium of diabetic rats from damage caused by isoproterenol (ISO) and, if so, how peroxisome proliferator-activated receptor gamma (PPAR-γ) activation might contribute into this protection. Diabetes in the rats was induced by streptozotocin (STZ), and it was divided into four groups: the diabetic control group, diabetic rats treated with corosolic acid, diabetic rats treated with GW9662, and diabetic rats treated with corosolic acid plus GW9662. The study was carried out for 28 days. The diabetic control and ISO control groups showed a decrease in mean arterial pressure (MAP) and diastolic arterial pressure (DAP) and an increase in systolic arterial pressure (SAP). The rat myocardium was activated by corosolic acid treatment, which elevated PPAR-γ expression. A histopathological analysis showed a significant reduction in myocardial damage by reducing myonecrosis and edema. It was found that myocardial levels of CK-MB and LDH levels were significantly increased after treatment with corosolic acid. By decreasing lipid peroxidation and increasing endogenous antioxidant levels, corosolic acid therapy showed a significant improvement over the ISO diabetic group. In conclusion, our results prove that corosolic acid can ameliorate ISO-induced acute myocardial injury in rats. Based on these results, corosolic acid seems to be a viable new target for the treatment of cardiovascular diseases and other diseases of a similar nature.

Corosolic Acid Inhibits Secretory Phospholipase A2IIa as an Anti-Inflammatory Function and Exhibits Anti-Tumor Activity in Ehrlich Ascites Carcinoma Bearing Mice

Background

Inflammation is generally connected to tumour progression and development. The secretory phospholipase A2IIa (sPLA2IIa) is an important inflammatory enzyme that catalyse the hydrolysis of membrane phospholipids into arachidonic and lysophosphatidic acid, which are the precursors for production of a lot of pro-inflammatory mediators like prostaglandins, prostacyclins, thromboxanes, leukotrienes and platelet activating factors, which involved in the proliferation, migration, invasion, and metastasis. Therefore, investigating safe and effective sPLA2IIa inhibitors as a therapeutic agent to treat cancer is indeed in need.

Methods

Anti-inflammatory function of corosolic acid was evaluated by docking it with sPLA2IIa enzyme, sPLA2IIa inhibition, calcium and substrate concentration-dependent assays; intrinsic fluorescence and UV-CD analysis; neutralisation of sPLA2IIa induced indirect hemolytic and edema. Evaluated the anticancer activity of corosolic acid by MTT assays and caspase-3 expression; the anti-tumour activity by EAC-induced cell line and interleukin 6 expression.

Results

The corosolic acid inhibits sPLA2IIa activity to 82.21±2.82%. The inhibition was evaluated by increasing calcium from 2.5 to 15 µM and substrate from 20 to 120 nM, it did not affect the level of inhibition. Corosolic acid altered the intrinsic fluorescence and UV-CD spectra of sPLA2IIa enzyme, indicating the direct interaction. It neutralised sPLA2IIa induced hemolytic activity from 97±1.23% to 15.75±1.44% and edema from 171.51±2.39% to 119.3±2.6%. Further, as antiproliferative activity, corosolic acid reduced the PC3 cell viability from 99.66±0.57% to 23±2.64% and suppressed LPS-induced IL-6 level from 94.35±2.2% to 34.36±2.4%. It increased mean survivability time from 30 to 38 days and displayed the drug-like qualities.

Conclusion

All the experimental results have proven the corosolic acid as an anti-inflammatory and anticancer molecule that may further be used to develop it as a drug.

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.

Semisynthetic Derivatives of Pentacyclic Triterpenes Bearing Heterocyclic Moieties with Therapeutic Potential

Medicinal plants have been used by humans since ancient times for the treatment of various diseases and currently represent the main source of a variety of phytocompounds, such as triterpenes. Pentacyclic triterpenes have been subjected to numerous studies that have revealed various biological activities, such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and hepatoprotective effects, which can be employed in therapy. However, due to their high lipophilicity, which is considered to exert a significant influence on their bioavailability, their current use is limited. A frequent approach employed to overcome this obstacle is the chemical derivatization of the core structure with different types of moieties including heterocycles, which are considered key elements in medicinal chemistry. The present review aims to summarize the literature published in the last 10 years regarding the derivatives of pentacyclic triterpenes bearing heterocyclic moieties and focuses on the biologically active derivatives as well as their structure-activity relationships. Predominantly, the targeted positions for the derivatization of the triterpene skeleton are C-3 (hydroxyl/oxo group), C-28 (hydroxyl/carboxyl group), and C-30 (allylic group) or the extension of the main scaffold by fusing various heterocycles with the A-ring of the phytocompound. In addition, numerous derivatives also contain linker moieties that connect the triterpenic scaffold with heterocycles; one such linker, the triazole moiety, stands out as a key pharmacophore for its biological effect. All these studies support the hypothesis that triterpenoid conjugates with heterocyclic moieties may represent promising candidates for future clinical trials.

Neuroprotective Effect of Corosolic Acid Against Cerebral Ischemia-Reperfusion Injury in Experimental Rats

Several therapeutic approaches were also urgently needed as ischaemic stroke was one of the most common brain disorders. Many phytochemicals have recently been discovered for the advancement of lead-like libraries that are concentrated on the peripheral and central nervous systems. Science does not yet understand how these drugs work, nor do they comprehend their in vivo characteristics. We investigated the potential benefits of corosolic acid (CA) in the treatment of brain injury caused by ischemia/reperfusion (I/R) in adult male Sprague-Dawley rats. Injury occurs after a 2-hour transient occlusion of the posterior cerebral artery and subsequent reperfusion (after 20 hours). Furthermore, the experiment assessed the size of the infarct, the amount of brain water present, as well as the neurofunctional conditions in rats. In the study, several markers of inflammation and cytokines associated with brain injury were measured. The Elisa kit was used in this study to measure the mRNA expression of interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin 1β, TNF-α (tumor necrosis factor), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and nitrous oxide (NO). The CA treatment significantly reduced brain water content, brain infarction volume, neurological scores, and Evans blue leakage (p < 0.001 and p < 0.001). Experimental rats were treated with CA after a significantly reduced level of anti-inflammatory, pro-inflammatory, and oxidative stress mediators was noted in their body tissues and serum (p < 0.001). By suppressing inflammatory responses in rats, CA demonstrated anti-inflammatory and neuroprotective properties.

Identification of Corosolic and Oleanolic Acids as Molecules Antagonizing the Human RORγT Nuclear Receptor Using the Calculated Fingerprints of the Molecular Similarity

RORγT is a protein product of the RORC gene belonging to the nuclear receptor subfamily of retinoic-acid-receptor-related orphan receptors (RORs). RORγT is preferentially expressed in Th17 lymphocytes and drives their differentiation from naive CD4+ cells and is involved in the regulation of the expression of numerous Th17-specific cytokines, such as IL-17. Because Th17 cells are implicated in the pathology of autoimmune diseases (e.g., psoriasis, inflammatory bowel disease, multiple sclerosis), RORγT, whose activity is regulated by ligands, has been recognized as a drug target in potential therapies against these diseases. The identification of such ligands is time-consuming and usually requires the screening of chemical libraries. Herein, using a Tanimoto similarity search, we found corosolic acid and other pentacyclic tritepenes in the library we previously screened as compounds highly similar to the RORγT inverse agonist ursolic acid. Furthermore, using gene reporter assays and Th17 lymphocytes, we distinguished compounds that exert stronger biological effects (ursolic, corosolic, and oleanolic acid) from those that are ineffective (asiatic and maslinic acids), providing evidence that such combinatorial methodology (in silico and experimental) might help wet screenings to achieve more accurate results, eliminating false negatives.

Corosolic Acid Attenuates the Invasiveness of Glioblastoma Cells by Promoting CHIP-Mediated AXL Degradation and Inhibiting GAS6/AXL/JAK Axis

Corosolic acid (CA), a bioactive compound obtained from Actinidia chinensis, has potential anti-cancer activities. Glioblastoma (GBM) is a malignant brain tumor and whether CA exerts anti-cancer activity on GBM remains unclear. This study was aimed to explore the anticancer activity and its underlying mechanism of CA in GBM cells. Our findings showed that CA ≤ 20 μM did not affect cell viability and cell proliferative rate of normal astrocyte and four GBM cells. Notably, 10 or 20 μM CA significantly inhibited cell migration and invasion of three GBM cells, decreased the protein level of F-actin and disrupted F-actin polymerization in these GBM cells. Further investigation revealed that CA decreased AXL level by promoting ubiquitin-mediated proteasome degradation and upregulating the carboxyl terminus of Hsc70-interacting protein (CHIP), an inducer of AXL polyubiquitination. CHIP knock-down restored the CA-reduced AXL and invasiveness of GBM cells. Additionally, we observed that CA-reduced Growth arrest-specific protein 6 (GAS6) and inhibited JAK2/MEK/ERK activation, and GAS6 pre-treatment restored attenuated JAK2/MEK/ERK activation and invasiveness of GBM cells. Furthermore, molecular docking analysis revealed that CA might bind to GAS6 and AXL. These findings collectively indicate that CA attenuates the invasiveness of GBM cells, attributing to CHIP upregulation and binding to GAS6 and AXL and subsequently promoting AXL degradation and downregulating GAS6-mediated JAK2/MEK/ERK cascade. Conclusively, this suggests that CA has potential anti-metastatic activity on GBM cells by targeting the CHIP/GAS6/AXL axis.

Modulating the ERK1/2-MMP1 Axis through Corosolic Acid Inhibits Metastasis of Human Oral Squamous Cell Carcinoma Cells

Corosolic acid (CA; 2α-hydroxyursolic acid) is a natural pentacyclic triterpenoid with antioxidant, antitumour and antimetastatic activities against various tumour cells during tumourigenesis. However, CA’s antitumour effect and functional roles on human oral squamous cell carcinoma (OSCC) cells are utterly unknown. In this study, our results demonstrated that CA significantly exerted an inhibitory effect on matrix metalloproteinase (MMP)1 expression, cell migration and invasion without influencing cell growth or the cell cycle of human OSCC cells. The critical role of MMP1 was confirmed using the GEPIA database and showed that patients have a high expression of MMP1 and have a shorter overall survival rate, confirmed on the Kaplan–Meier curve assay. In the synergistic inhibitory analysis, CA and siMMP1 co-treatment showed a synergically inhibitory influence on MMP1 expression and invasion of human OSCC cells. The ERK1/2 pathway plays an essential role in mediating tumour progression. We found that CA significantly inhibits the phosphorylation of ERK1/2 dose-dependently. The ERK1/2 pathway played an essential role in the CA-mediated downregulation of MMP1 expression and in invasive motility in human OSCC cells. These findings first demonstrated the inhibitory effects of CA on OSCC cells’ progression through inhibition of the ERK1/2–MMP1 axis. Therefore, CA might represent a novel strategy for treating OSCC.

Lagerstroemia speciosa (L.) Pers., ethanolic leaves extract attenuates dapsone-induced liver inflammation in rats

Drug-induced liver injury is a common cause of acute liver failure. Dapsone is increasingly used in combination with rifampicin for the treatment of leprosy and also for several dermatological disorders. Clinically, abnormal liver function and focal bile duct destruction were reported after dapsone therapy. Lagerstroemia speciosa Pers., commonly known as Banaba has been traditionally used to treat various ailments including diabetes and obesity due to its antioxidant and anti-inflammatory efficacies. This study investigated the hepatoprotective effect of ethanolic banaba leaves extract (EBLE) against dapsone-induced hepatotoxicity in rats. Dapsone (30 mg/kg, i.p.) was administered twice daily for 30 days. In separate groups, rats were post-treated orally with EBLE (250 and 500 mg/kg) and silymarin (100 mg/kg) once daily for 30 days after dapsone administration. The marker enzymes of hepatotoxicity, oxidative stress markers, inflammatory markers and histopathology of liver were done. HPTLC analysis confirmed the presence of 12.87 µg of corosolic acid per mg of EBLE. Dapsone administration-induced significant (p < 0.001) elevation of marker enzymes of hepatotoxicity in serum. This treatment also increased lipid peroxidation (p < 0.001) and pro-inflammatory markers (tumor necrosis factor-alpha, transforming growth factor-beta, and nuclear factor kappa-B) expressions (p < 0.001) and decreased antioxidants (p < 0.001) such superoxide dismutase, catalase and glutathione in the liver tissue. All these abnormalities were significantly (p < 0.001) mitigated after EBLE (500 mg/kg) and silymarin post-treatments. The results of this study suggest that silymarin and EBLE can be used for dapsone-induced hepatotoxicity.

Corosolic acid ameliorates non-alcoholic steatohepatitis induced by high-fat diet and carbon tetrachloride by regulating TGF-β1/Smad2, NF-κB, and AMPK signaling pathways

Hawthorn (Crataegus pinnatifida Bunge. var. major) is an edible and medicinal fruit that is very common in food and traditional Chinese medicine. Corosolic acid (CA), a pentacyclic triterpenoid, which is an active component of hawthorn (Crataegus pinnatifida Bunge. var. major), has been exhibiting various pharmacological activities such as antidiabetic, antibacterial, anticancer, antiinflammatory, and antioxidant effects. The study aimed to evaluate the effect of CA on non-alcoholic steatohepatitis (NASH) in mice induced by 60 kcal% high-fat diet (HFD) and carbon tetrachloride (CCl₄ ). CA lowered liver index and serum AST, ALT, TG, and TC levels compared to those in the model group. Histological analyses of the liver tissues of mice treated with CA revealed significantly decreased number of lipid droplets and alleviated inflammation and fibrosis. CA inhibited the transcripts of pro-fibrogenic markers (including α-SMA, collagen I, and TIMP-1) and the levels of pro-inflammatory cytokines (including TNF-α, IL-1β, caspase-1, and IL-6) associated with hepatic fibrosis, and NF-κB translocation and TGF-β1/Smad2 and AMPK pathways. In addition, CA reduced lipid accumulation via the regulation of AMPK and NF-κB activation in FFA-induced steatotic HepG2 cells. CA also decreased α-SMA, collagen I expressions, and Smad2 phosphorylation, which were reduced by TGF-β1 treatment in LX2 cells. Our results suggested that CA ameliorated NASH through regulating TGF-β1/Smad2, NF-κB, and AMPK signaling pathways, and CA could be developed as a potential health functional food or therapeutic agent for NASH patients.

Lagerstroemia speciosa (L.) Pers., ethanolic extract attenuates simultaneously administered isoniazid- and dapsone-induced hepatotoxicity in rats

Herbal tea of Lagerstroemia speciosa Pers., commonly known as banaba, has been traditionally used to treat various ailments including diabetes and obesity due to its antioxidant and anti-inflammatory efficacies. Drug-induced liver injury is a common cause of acute liver failure. Isoniazid (INH) is used as the first-line treatment for tuberculosis; clinical and experimental studies have reported an abnormal liver function after INH therapy. Dapsone (DDS) is used for leprosy and other infections. This study investigates the hepatoprotective effect of ethanolic banaba leaves extract (EBLE) against simultaneously administered INH- and DDS-induced hepatotoxicity in rats. DDS (30 mg/kg, i.p.) and INH (50 mg/kg. p.o.) were administered simultaneously for 30 days. In separate groups, rats were posttreated orally with EBLE (500 mg/kg) and silymarin (100 mg/kg) for 30 days after INH + DDS administration. The marker enzymes of hepatotoxicity, oxidative stress markers, inflammatory markers, and histopathology were done. Simultaneous administration of INH- and DDS-induced significant elevation of marker enzymes of hepatotoxicity in the serum. This treatment also increased lipid peroxidation and pro-inflammatory markers (tumor necrosis factor alpha, transforming growth factor beta, and nuclear factor kappa B) expressions and decreased intracellular antioxidants such as superoxide dismutase, catalase, and glutathione in the liver tissue. All these abnormalities were significantly mitigated after EBLE and SIL posttreatments. The results of this study suggest that EBLE and silymarin can be protective against INH + DDS-induced hepatotoxicity. PRACTICAL APPLICATIONS: Herbal tea contain Lagerstroemia speciosa leaves are used in several Southeast Asian countries due to its rich antioxidant and inflammatory properties. This study showed the hepatoprotective efficacy of L. speciosa ethanolic extract against simultaneously administered dapsone- and isoniazid-induced hepatotoxicity in rats. L. speciosa administration was found to decrease dapsone- and isoniazid-induced oxidative stress and hepatic inflammation. L. speciosa herbal tea can reduce drug-induced hepatic complications as it contains phytochemicals such as corosolic acid, gallic acid, ellagic acid and berberine and are implicated for its hepatoprotective effect. Therefore, L. speciosa extract can be used for drug-induced liver injury.

Corosolic acid inhibits colorectal cancer cells growth as a novel HER2/HER3 heterodimerization inhibitor

BACKGROUND AND PURPOSE

Colorectal cancer is the third most common cancer worldwide. HER2 and HER3 are two members of human epidermal receptor family of tyrosine kinase receptors (RTKs) and associated with poor survival in colorectal cancer. They have been observed as important therapeutic targets in various types of cancer. Corosolic acid, a natural pentacyclic triterpene, has been demonstrated to have a significant anti-cancer activity. However, the target of corosolic acid has not yet been explored. This study aimed to reveal the direct targets of corosolic acid underlying its anti-cancer activities.

EXPERIMENTAL APPROACH

The targets of corosolic acid were revealed by the phospho-RTK array, bio-layer interferometry, co-immunoprecipitation, and proximity ligation assay. The inhibitory action of corosolic acid on HER2/HER3 heterodimerization and related downstream signalling were investigated in HCT116 and SW480 cells. In addition, the chemo-preventive effects of corosolic acid were validated in both HCT116 xenograft model and AOM/DSS model.

KEY RESULTS

Our results demonstrated that corosolic acid could prevent NRG1-induced HER2/HER3 heterodimerization and suppress the phosphorylation of both HER2 and HER3. Furthermore, HER2 and HER3 could regulate the downstream signalling pathways of RalA/RalBP1/CDK1 and PI3K/Akt/PKA, respectively, resulting in the changes in phosphorylation of Drp1 and mitochondrial dynamics. corosolic acid exhibited anti-cancer activity in both HCT116 xenograft model and AOM/DSS model.

CONCLUSIONS AND IMPLICATIONS

Collectively, our results demonstrated corosolic acid directly targeted HER2 and HER3 heterodimerization and inhibited mitochondrial fission via regulating RalA/RalBP1/CDK1 and PI3K/Akt/PKA pathways, revealing a novel mechanism underlying the beneficial effects of corosolic acid on colorectal cancer.

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.

Corosolic acid ameliorates cardiac hypertrophy via regulating autophagy

Aim: In this work, we explored the role of corosolic acid (CRA) during pressure overload-induced cardiac hypertrophy. Methods and results: Cardiac hypertrophy was induced in mice by aortic banding. Four weeks post-surgery, CRA-treated mice developed blunted cardiac hypertrophy, fibrosis, and dysfunction, and showed increased LC3 II and p-AMPK expression. In line with the in vivo studies, CRA also inhibited the hypertrophic response induced by PE stimulation accompanying with increased LC3 II and p-AMPK expression. It was also found that CRA blunted cardiomyocyte hypertrophy and promoted autophagy in Angiotensin II (Ang II)-treated H9c2 cells. Moreover, to further verify whether CRA inhibits cardiac hypertrophy by the activation of autophagy, blockade of autophagy was achieved by CQ (an inhibitor of the fusion between autophagosomes and lysosomes) or 3-MA (an inhibitor of autophagosome formation). It was found that autophagy inhibition counteracts the protective effect of CRA on cardiac hypertrophy. Interestingly, AMPK knockdown with AMPKα2 siRNA-counteracted LC3 II expression increase and the hypertrophic response inhibition caused by CRA in PE-treated H9c2 cells. Conclusion: These results suggest that CRA may protect against cardiac hypertrophy through regulating AMPK-dependent autophagy.

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.

Simultaneous Determination of α-Glucosidase Inhibitory Triterpenoids in Psidium guajava Using HPLC-DAD-ELSD and Pressurized Liquid Extraction

Psidium guajava, a popular food and medicine dual purposes plant cultivated in tropical and subtropical regions, has been widely used as food crop and folk medicine, such as anti-diabetes agent, around the world. Triterpenoids have been considered as the major active ingredients of P. guajava. In the present study, a high-performance liquid chromatography coupled with diode array and evaporative light scattering detectors (HPLC–DAD–ELSD) method was developed for simultaneous determination of nine triterpenoids in P. guajava. Pressurized liquid extraction (PLE) was performed for sample preparation, and the analysis was achieved on a Cosmosil 5C18-MS-II (Nacalai Tesque, Kyoto, Japan) column eluted with gradient 0.1% aqueous formic acid-methanol system. The drift tube temperature of ELSD was set at 40 °C, and nitrogen flow-rate was at 1.6 L/min. All calibration curves for the analytes showed good linear regression (R² > 0.9992) within test ranges. The established method was validated for intra-day and inter-day precisions (RSDs < 5%) and accuracy (recovery 94.23–106.87%). The validated method was successfully applied to determinate nine triterpenoids in 15 samples from the leave or fruit of P. guajava. In addition, the α-glucosidase inhibition assay showed good α-glucosidase inhibition activity in almost all the determined triterpenoids. The present study suggested that triterpenoids should be the quality control markers for P. guajava and HPLC–DAD–ELSD was an effective tool for the quality control of P. guajava.

Antileishmanial Compounds Isolated from Psidium Guajava L. Using a Metabolomic Approach

With an estimated annual incidence of one million cases, leishmaniasis is one of the top five vector-borne diseases. Currently available medical treatments involve side effects, including toxicity, non-specific targeting, and resistance development. Thus, new antileishmanial chemical entities are of the utmost interest to fight against this disease. The aim of this study was to obtain potential antileishmanial natural products from Psidium guajava leaves using a metabolomic workflow. Several crude extracts from P. guajava leaves harvested from different locations in the Lao People's Democratic Republic (Lao PDR) were profiled by liquid chromatography coupled to high-resolution mass spectrometry, and subsequently evaluated for their antileishmanial activities. The putative active compounds were highlighted by multivariate correlation analysis between the antileishmanial response and chromatographic profiles of P. guajava mixtures. The results showed that the pooled apolar fractions from P. guajava were the most active (IC₅₀ = 1.96 ± 0.47 µg/mL). Multivariate data analysis of the apolar fractions highlighted a family of triterpenoid compounds, including jacoumaric acid (IC₅₀ = 1.318 ± 0.59 µg/mL) and corosolic acid (IC₅₀ = 1.01 ± 0.06 µg/mL). Our approach allowed the identification of antileishmanial compounds from the crude extracts in only a small number of steps and can be easily adapted for use in the discovery workflows of several other natural products.

Inhibitory effect of corosolic acid on α-glucosidase: kinetics, interaction mechanism, and molecular simulation

BACKGROUND

The suppression of α-glucosidase activity to retard glucose absorption is an important therapy for type-2 diabetes. Corosolic acid (CRA) is a potential antidiabetic component in many plant-based foods and herbs. In this study, the interplay mechanism between α-glucosidase and corosolic acid was investigated by several methods, including three-dimensional fluorescence spectra, circular dichroism spectra, and molecular simulation.

RESULTS

Corosolic acid significantly inhibited α-glucosidase reversibly in an uncompetitive manner and its IC₅₀ value was 1.35 × 10^-5 mol L^-1 . A combination of CRA with myricetin exerted a weak synergy against α-glucosidase. The intrinsic fluorescence of α-glucosidase was quenched via a static quenching course and the binding constant was 3.47 × 10³  L mol^-1 at 298 K. The binding of CRA to α-glucosidase was mainly driven by hydrophobic forces and resulted in a partial extension of the protein polypeptide chain with a loss of α-helix content. The molecular simulation illustrated that CRA bound to the entrance part of the active center of α-glucosidase and interacted with the amino acid residues Ser157, Arg442, Phe303, Arg315, Tyr158, and Gln353, which could hinder the release of substrate and catalytic reaction product, eventually suppressing the catalytic activity of α-glucosidase.

CONCLUSIONS

These results may suggest new insights into corosolic acid from food sources as a potential α-glucosidase inhibitor that could better control diabetes. © 2019 Society of Chemical Industry.

Corosolic acid impairs human lung adenocarcinoma A549 cells proliferation by inhibiting cell migration

The present study aimed to investigate the anticancer effects of corosolic acid (CA) in the human lung adenocarcinoma A549 cell line. A549 cells were treated with increasing concentrations of CA, prior to assessing cell viability, migration rate, vascular endothelial growth factor receptor 2 (VEGFR2) kinase activity and cytoskeleton structure. In addition, in vivo imaging system was used to analyze the anticancer effects of CA in vivo. Results demonstrated that CA exhibited a low cytotoxicity with a half maximal inhibitory concentration of 65 µM. In addition, 4 µM CA efficiently inhibited A549 cell migration. Furthermore, CA inhibited VEGFR2 kinase activity and disrupted tubulin structure. Data also revealed that CA inhibited A549 cell proliferation in a xenograft mouse model. In conclusion, results from the present study suggested that CA may be used as a novel potential therapy for lung cancer.

Transcriptome sequencing and identification of cytochrome P450 monooxygenases involved in the biosynthesis of maslinic acid and corosolic acid in Avicennia marina

Grey mangrove (Avicennia marina) is a traditional medicine used for the treatment of various diseases, including rheumatism and ulcers; however, the compounds responsible for its curative effects remain largely unknown. Triterpenoids are a diverse group of plant-specialized metabolites derived from a common precursor, 2,3-oxidosqualene. Triterpenoids are potentially responsible for the beneficial effects of A. marina; however, the chemical profiles of triterpenoids in A. marina and their biosynthetic genes have not been identified. Cytochrome P450 monooxygenases (P450s) have key roles in the structural diversification of plant triterpenoids by catalyzing site-specific oxidation of triterpene scaffolds. Recent studies have revealed that the CYP716 family represents the most common clade of P450s involved in triterpenoid biosynthesis. In this study, we performed triterpenoid profiling and RNA sequencing of A. marina leaves. Mining of CYP716 family genes and enzymatic activity assays of encoded proteins revealed that CYP716A259 catalyzed oxidation at the C-28 position of the pentacyclic triterpene skeletons of β-amyrin, α-amyrin, and lupeol to produce oleanolic acid, ursolic acid, and betulinic acid, respectively. The other functionally defined P450, CYP716C53, catalyzed the C-2α hydroxylation of oleanolic acid and ursolic acid to produce maslinic acid and corosolic acid, respectively. The possible involvement of CYP716A259 and CYP716C53 in the biosynthesis of these health-benefiting compounds in A. marina leaves, and the possible contribution of the resulting compounds to the reported bioactivities of A. marina leaf extract, are discussed.

Vasodilator Activity of Compounds Isolated from Plants Used in Mexican Traditional Medicine

Arterial hypertension is one of the main risk factors in the development of cardiovascular diseases. Therefore, it is important to look for new drugs to treat hypertension. In this study, we carried out the screening of 19 compounds (triterpenes, diterpenes, sesquiterpenes, lignans, and flavonoids) isolated from 10 plants used in Mexican traditional medicine to determine whether they elicited vascular smooth muscle relaxation and, therefore, could represent novel anti-hypertension drug candidates. The vasorelaxant activity of these compounds was evaluated on the isolated rat aorta assay and the results obtained from this evaluation showed that three compounds induced a significant vasodilatory effect: meso-dihydroguaiaretic acid [half maximal effective concentration (EC₅₀), 49.9 ± 11.2 µM; maximum effect (Emax), 99.8 ± 2.7%]; corosolic acid (EC₅₀, 108.9 ± 6.7 µM; Emax, 96.4 ± 4.2%); and 5,8,4′-trihydroxy-3,7-dimethoxyflavone (EC₅₀, 122.3 ± 7.6 µM; Emax, 99.5 ± 5.4%). Subsequently, involvement of the NO/cyclic guanosine monophosphate (cGMP) and H₂S/ATP-sensitive potassium channel (K_ATP) pathways on the vasodilator activity of these compounds was assessed. The results derived from this analysis showed that the activation of both pathways contributes to the vasorelaxant effect of corosolic acid. On the other hand, the vasodilator effect of meso-dihydroguaiaretic acid and 5,8,4′-trihydroxy-3,7-dimethoxyflavone, partly involves stimulation of the NO/cGMP pathway. However, these compounds also showed an important endothelium-independent vasorelaxant effect, whose mechanism of action remains to be clarified. This study indicates that meso-dihydroguaiaretic acid, corosolic acid, and 5,8,4′-trihydroxy-3,7-dimethoxyflavone could be used as lead compounds for the synthesis of new derivatives with a higher potency to be developed as drugs for the prevention and treatment of cardiovascular diseases.

Corosolic Acid Induces Non-Apoptotic Cell Death through Generation of Lipid Reactive Oxygen Species Production in Human Renal Carcinoma Caki Cells

Corosolic acid is one of the pentacyclic triterpenoids isolated from Lagerstroemia speciose and has been reported to exhibit anti-cancer and anti-proliferative activities in various cancer cells. In the present study, we investigated the molecular mechanisms of corosolic acid in cancer cell death. Corosolic acid induces a decrease of cell viability and an increase of cell cytotoxicity in human renal carcinoma Caki cells. Corosolic acid-induced cell death is not inhibited by apoptosis inhibitor (z-VAD-fmk, a pan-caspase inhibitor), necroptosis inhibitor (necrostatin-1), or ferroptosis inhibitors (ferrostatin-1 and deferoxamine (DFO)). Furthermore, corosolic acid significantly induces reactive oxygen species (ROS) levels, but antioxidants (N-acetyl-l-cysteine (NAC) and trolox) do not inhibit corosolic acid-induced cell death. Interestingly, corosolic acid induces lipid oxidation, and α-tocopherol markedly prevents corosolic acid-induced lipid peroxidation and cell death. Anti-chemotherapeutic effects of α-tocopherol are dependent on inhibition of lipid oxidation rather than inhibition of ROS production. In addition, corosolic acid induces non-apoptotic cell death in other renal cancer (ACHN and A498), breast cancer (MDA-MB231), and hepatocellular carcinoma (SK-Hep1 and Huh7) cells, and α-tocopherol markedly inhibits corosolic acid-induced cell death. Therefore, our results suggest that corosolic acid induces non-apoptotic cell death in cancer cells through the increase of lipid peroxidation.

The triterpenoid corosolic acid blocks transformation and epigenetically reactivates Nrf2 in TRAMP-C1 prostate cells

Corosolic acid (CRA) is found in various plants and has been used as a health food supplement worldwide. Although it has been reported that CRA exhibits significant anticancer activity, the effect of this compound on prostate cancer remains unknown. In this study, we investigated the effect of CRA on cellular transformation and the reactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) through epigenetic regulation in TRAMP-C1 prostate cells. Specifically, we found that CRA inhibited anchorage-independent growth of prostate cancer TRAMP-C1 cells but not Nrf2 knockout prostate cancer TRAMP-C1 cells. Moreover, CRA induced mRNA and protein expression of Nrf2, heme oxygenase-1 (HO-1) and NAD(P)H Quinone Oxidoreductase 1 (NQO1). Bisulfite genomic sequencing and methylated DNA immunoprecipitation results revealed that CRA treatment decreased the level of methylation of the first five CpG sites of the Nrf2 promoter. Histone modification was analyzed using a chromatin immunoprecipitation (ChIP) assay, which revealed that CRA treatment increased the acetylation of histone H3 lysine 27 (H3K27ac) while decreasing the trimethylation of histone H3 lysine 27 (H3K27me3) in the promoter region of Nrf2. Furthermore, CRA treatment attenuated the protein expression of DNA methyltransferases (DNMTs) and histone deacetylases (HDACs). These findings indicate that CRA has a significant anticancer effect in TRAMP-C1 cells, which could be partly attributed to epigenetics including its ability to epigenetically restore the expression of Nrf2.

Microbial transformation of the anti-diabetic agent corosolic acid by Cunninghamella echinulata

The pentacyclic triterpenoid corosolic acid was metabolized by Cunninghamella echinulata CGMCC 3.2000 to its C-24 aldehyde group metabolite and five other hydroxylated metabolites: madasiatic acid (2), 2α, 3β, 7β-trihydroxyurs-12-en-28-oic acid (3), 2α, 3β, 15α-trihydroxyurs-12-en-28-oic acid (4), 2α, 3β, 6β, 7β-tetrahydroxyurs-12-en-28-oic acid (5), 2α, 3β, 7β, 15α-tetrahydroxyurs-12-en-28-oic acid (6), and 2α, 3β,7β-trihydroxy-24-al-urs-12-en-28-oic acid (7); compounds 3, 5, and 7 were new compounds. The α-glucosidase inhibitory effects of the metabolites were also evaluated.

Corosolic Acid Exhibits Anti-angiogenic and Anti-lymphangiogenic Effects on In Vitro Endothelial Cells and on an In Vivo CT-26 Colon Carcinoma Animal Model

We describe the anti-angiogenic and anti-lymphangiogenic effects of corosolic acid, a pentacyclic triterpenoid isolated from Cornus kousa Burg. A mouse colon carcinoma CT-26 animal model was employed to determine the in vivo anti-angiogenic and anti-lymphangiogenic effects of corosolic acid. Corosolic acid induced apoptosis in CT-26 cells, mediated by the activation of caspase-3. In addition, it reduced the final tumor volume and the blood and lymphatic vessel densities of tumors, indicating that it suppresses in vivo angiogenesis and lymphangiogenesis. Corosolic acid inhibited the proliferation and tube formation of human umbilical vein endothelial cells and human dermal lymphatic microvascular endothelial cells. In addition, corosolic acid decreased the proliferation and migration of human umbilical vein endothelial cells stimulated by angiopoietin-1. Pretreatment with corosolic acid decreased the phosphorylation of focal adhesion kinase (FAK) and ERK1/2, suggesting that corosolic acid contains anti-angiogenic activity that can suppress FAK signaling induced by angiopoietin-1.

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.

Corosolic acid triggers mitochondria and caspase-dependent apoptotic cell death in osteosarcoma MG-63 cells

The response of osteosarcoma MG-63 cells to corosolic acid treatment has been investigated. The results showed that corosolic acid significantly inhibited cell viability in both a dose and a time dependent manner. It was found that corosolic acid increased the Bax/Bcl-2 ratio by up-regulating Bax expression, disrupted mitochondrial membrane potential and triggered the release of cytochrome c from mitochondria into the cytoplasm. Corosolic acid treatment triggered the activation of caspase-8, 9 and 3. The apoptosis was obviously inhibited by pretreatment with a general caspase inhibitor, z-VAD-FMK. Moreover, pretreatment of CsA, a cyclophilin D ligand that inhibits mitochondria potential uncoupling, prevented the activation of caspase-9 and caspase-3, but not caspase-8, and the apoptosis of MG-63 cells, triggered by corosolic acid. All these results indicated that corosolic acid-induced apoptosis was associated with the activation of caspases via a mitochondrial pathway.

Isolation and identification of intestinal CYP3A inhibitors from cranberry (Vaccinium macrocarpon) using human intestinal microsomes

Cranberry juice is used routinely, especially among women and the elderly, to prevent and treat urinary tract infections. These individuals are likely to be taking medications concomitantly with cranberry juice, leading to concern about potential drug-dietary substance interactions, particularly in the intestine, which, along with the liver, is rich in expression of the prominent drug metabolizing enzyme, cytochrome P450 3A (CYP3A). Using a systematic in vitro-in vivo approach, a cranberry juice product was identified recently that elicited a pharmacokinetic interaction with the CYP3A probe substrate midazolam in 16 healthy volunteers. Relative to water, cranberry juice inhibited intestinal first-pass midazolam metabolism. In vitro studies were initiated to identify potential enteric CYP3A inhibitors from cranberry via a bioactivity-directed fractionation approach involving dried whole cranberry [Vaccinium macrocarpon Ait. (Ericaceae)], midazolam, and human intestinal microsomes (HIM). Three triterpenes (maslinic acid, corosolic acid, and ursolic acid) were isolated. The inhibitory potency (IC(50)) of maslinic acid, corosolic acid, and ursolic acid was 7.4, 8.8, and < 10 µM, respectively, using HIM as the enzyme source and 2.8, 4.3, and < 10 µM, respectively, using recombinant CYP3A4 as the enzyme source. These in vitro inhibitory potencies, which are within the range of those reported for two CYP3A inhibitory components in grapefruit juice, suggest that these triterpenes may have contributed to the midazolam-cranberry juice interaction observed in the clinical study.