Betulinic acid isolated from Bacopa monniera (L.) Wettst suppresses lipopolysaccharide stimulated interleukin-6 production through modulation of nuclear factor-kappaB in peripheral blood mononuclear cells

Plant In Vitro Culture Factories for Pentacyclic Triterpenoid Production

Pentacyclic triterpenoids are a diverse subclass of naturally occurring terpenes with various biological activities and applications. These compounds are broadly distributed in natural plant resources, but their low abundance and the slow growth cycle of plants pose challenges to their extraction and production. The biosynthesis of pentacyclic triterpenoids occurs through two main pathways, the mevalonic acid (MVA) pathway and the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, which involve several enzymes and modifications. Plant in vitro cultures, including elicited and hairy root cultures, have emerged as an effective and sustainable system for pentacyclic triterpenoid production, circumventing the limitations associated with natural plant resources. Bioreactor systems and controlling key parameters, such as media composition, temperature, light quality, and elicitor treatments, have been optimized to enhance the production and characterization of specific pentacyclic triterpenoids. These systems offer a promising bioprocessing tool for producing pentacyclic triterpenoids characterized by a low carbon footprint and a sustainable source of these compounds for various industrial applications.

Bioactive Constituents of Verbena officinalis Alleviate Inflammation and Enhance Killing Efficiency of Natural Killer Cells

Natural killer (NK) cells play key roles in eliminating pathogen-infected cells. Verbena officinalis (V. officinalis) has been used as a medical plant in traditional and modern medicine for its anti-tumor and anti-inflammatory activities, but its effects on immune responses remain largely elusive. This study aimed to investigate the potential of V. officinalis extract (VO extract) to regulate inflammation and NK cell functions. We examined the effects of VO extract on lung injury in a mouse model of influenza virus infection. We also investigated the impact of five bioactive components of VO extract on NK killing functions using primary human NK cells. Our results showed that oral administration of VO extract reduced lung injury, promoted the maturation and activation of NK cells in the lung, and decreased the levels of inflammatory cytokines (IL-6, TNF-α and IL-1β) in the serum. Among five bioactive components of VO extract, Verbenalin significantly enhanced NK killing efficiency in vitro, as determined by real-time killing assays based on plate-reader or high-content live-cell imaging in 3D using primary human NK cells. Further investigation showed that treatment of Verbenalin accelerated the killing process by reducing the contact time of NK cells with their target cells without affecting NK cell proliferation, expression of cytotoxic proteins, or lytic granule degranulation. Together, our findings suggest that VO extract has a satisfactory anti-inflammatory effect against viral infection in vivo, and regulates the activation, maturation, and killing functions of NK cells. Verbenalin from V. officinalis enhances NK killing efficiency, suggesting its potential as a promising therapeutic to fight viral infection.

Betulinic Acid Inhibits the Stemness of Gastric Cancer Cells by Regulating the GRP78-TGF-β1 Signaling Pathway and Macrophage Polarization

Cancer stemness is the process by which cancer cells acquire chemoresistance and self-renewal in the tumor microenvironment. Glucose-regulated protein 78 (GRP78) is a biomarker for gastric cancer and is involved in cancer stemness. By inducing cancer stemness in various types of cancer, the polarization of macrophages into tumor-associated macrophages (TAMs) controls tumor progression. Betulinic acid (BA) is a bioactive natural compound with anticancer properties. However, whether GRP78 regulates TAM-mediated cancer stemness in the tumor microenvironment and whether BA inhibits GRP78-mediated cancer stemness in gastric cancer remain unknown. In this study, we investigated the role of GRP78 in gastric cancer stemness in a tumor microenvironment regulated by BA. The results indicated that BA inhibited not only GRP78-mediated stemness-related protein expression and GRP78-TGF-β-mediated macrophage polarization into TAMs, but also TAM-mediated cancer stemness. Therefore, BA is a promising candidate for clinical application in combination-chemotherapy targeting cancer stemness.

Neurotransmitters and molecular chaperones interactions in cerebral malaria: Is there a missing link?

Plasmodium falciparum is responsible for the most severe and deadliest human malaria infection. The most serious complication of this infection is cerebral malaria. Among the proposed hypotheses that seek to explain the manifestation of the neurological syndrome in cerebral malaria is the vascular occlusion/sequestration/mechanic hypothesis, the cytokine storm or inflammatory theory, or a combination of both. Unfortunately, despite the increasing volume of scientific information on cerebral malaria, our understanding of its pathophysiologic mechanism(s) is still very limited. In a bid to maintain its survival and development, P. falciparum exports a large number of proteins into the cytosol of the infected host red blood cell. Prominent among these are the P. falciparum erythrocytes membrane protein 1 (PfEMP1), P. falciparum histidine-rich protein II (PfHRP2), and P. falciparum heat shock proteins 70-x (PfHsp70-x). Functional activities and interaction of these proteins with one another and with recruited host resident proteins are critical factors in the pathology of malaria in general and cerebral malaria in particular. Furthermore, several neurological impairments, including cognitive, behavioral, and motor dysfunctions, are known to be associated with cerebral malaria. Also, the available evidence has implicated glutamate and glutamatergic pathways, coupled with a resultant alteration in serotonin, dopamine, norepinephrine, and histamine production. While seeking to improve our understanding of the pathophysiology of cerebral malaria, this article seeks to explore the possible links between host/parasite chaperones, and neurotransmitters, in relation to other molecular players in the pathology of cerebral malaria, to explore such links in antimalarial drug discovery.

A Comprehensive Review on Preclinical Evidence Based Neuroprotective Potential of Bacopa Monnieri Against Parkinson's Disease

Parkinson's diseaseis a chronic and gradually progressive neurodegenerative disorder triggered due to the loss of dopamine-releasing neurons in the region of substantianigra pars compacta characterized by the motor symptoms such as tremor, bradykinesia, akinesia, and postural instability. Proteinopathies, mitochondrial dysfunction induced dopaminergic neuronal deterioration, and gene mutations arethe hallmarks of Parkinson's disease. The bioactive components of Brahmi such as Bacoside A, Bacoside B, and Bacosaponins, belong to various chemical families. Brahmi's neuroprotective role includes reducing neuronal oxidative stress, dopaminergic neuronal degeneration, mitochondrial dysfunction, inflammation, aggregation inhibition of α-synuclein, and improvement of cognitive and learning behaviour. Researchers found that Bacopa monnieri significantly increased brain levels of glutathione, vitamin C, vitamin E, and vitamin A in rats exposed to cigarette smoke. Brahmi has a potent antioxidant property and neuroprotective effects against PD that help reduce oxidative stress, neuroinflammation and enhance the dopamine level. The review collates all the preclinical studies that prove the beneficial neuroprotective effect of Brahmi for treating PD.

Betulinic Acid-Doxorubicin-Drug Combination Induced Apoptotic Death via ROS Stimulation in a Relapsed AML MOLM-13 Cell Model

In this study, cell death regulation and induction in AML cell line from a relapsed MLL-rearranged cell model (MOLM-13) was investigated with doxorubin (Dox) and betulinic acid (BetA), singly and in combination. CyQUANT Direct^® and Annexin V/propidium iodide double staining were used to measure the cytotoxic and cell death induction effects of the compounds, respectively. Reactive oxygen species (ROS) generation was measured using 2′,7′-dichlorofluorescin diacetate staining. Expressions of proteins and genes were examined by Western blot and reverse transcription polymerase chain reaction analysis, respectively. BetA (20 μM) and Dox (1 μM) indicated a synergistic growth inhibitory effect on MOLM-13 cells. The combined drug caused more cells to reside in irreversible late apoptotic stage compared to the single treatments (p < 0.05). Elevation in ROS may be the synergistic mechanism involved in MOLM-13 cell death since ROS can directly disrupt mitochondrial activity. In contrast, in leukaemic U-937 cells, the combination treatments attenuated Dox-induced cell death. Dox and the drug combination selectively reduced (p < 0.05) a recently reported anti-apoptotic Bcl-2 protein isoform p15-20-Bcl-2 in MOLM-13 by our group, without affecting the usually reported p26-Bcl-2-α. Further studies using known inhibitors of apoptosis are required to confirm the potential of Dox-BetA combination to modulate these pathways.

A randomized phase II remote study to assess Bacopa for Gulf War Illness associated cognitive dysfunction: Design and methods of a national study

AIMS

Gulf War Illness (GWI) is a chronic, debilitating, multi-symptom condition affecting as many as one-third of the nearly 700,000 U.S. troops deployed to the Middle East during the 1990-1991 Gulf War (GW). The treatment of GWI relies on symptom management. A common challenge in studying the efficacy of interventions for symptom management is participant recruitment related to factors such as the burden of travelling to study sites and the widespread dispersion of Veterans with GWI. The goal of this study is to assess the efficacy of a novel low-risk therapeutic agent, Bacopa monnieri, for cognitive function in Veterans with GWI and to evaluate the utility of a remote patient-centric study design developed to promote recruitment and minimize participant burden.

MAIN METHODS

To promote effective participant recruitment, we developed a remote patient-centric study design. Participants will be recruited online through social media and through a web-based research volunteer list of GW Veterans. An online assessment platform will be used, and laboratory blood draws will be performed at clinical laboratory sites that are local to participants. Furthermore, the assigned intervention will be mailed to each participant.

SIGNIFICANCE

These study design adaptations will open participation to Veterans nearly nationwide and reduce administrative costs while maintaining methodologic rigor and participant safety in a randomized, placebo-controlled phase II clinical trial.

Synergistic effect of Betulinic acid, Apigenin and Skimmianine (BASk) in high cholesterol diet rabbit: Involvement of CD36-TLR2 signaling pathway

BACKGROUND

Progression of chronic inflammatory disease, atherosclerosis is a multifactorial process. Cluster of differentiation 36 (CD36) mediated downstream activation of Toll like receptor 2 (TLR2) and NLRP3 (Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3) inflammasome signaling pathway actively participates during chronic inflammation. Nowadays, synergistic combinations of bioactive compounds attained priority in the field of drug discovery and development as therapeutic agents. An investigation regarding the anti-inflammatory potential of a novel drug formulation, BASk which is a combination of three bioactive compounds Betulinic acid (B):Apigenin (A):Skimmianine (Sk) remains the focus area of this research study. We also elucidate the molecular mechanism behind the therapeutic potential of BASk through CD36 mediated activation TLR2-NLRP3 signaling pathway.

METHODS

OxLDL induced hPBMCs used to screen out a suitable combination of BASk via MTT, COX, LOX, NOS and MPO assays. Hypercholesterolemia is induced in rabbits by supplementing with 1% cholesterol + 0.5% cholic acid and treated with BASk (2:2:1) (5 mg/Kg) and atorvastatin (10 mg/Kg) for 60 days. CD36, TLR2, NLRP3, NFκB, cytokines, endothelial damage were quantified by reverse transcription, real time PCR, ELISA, flow cytometry and histopathology.

RESULTS

hPBMCs pretreated with BASk at 2:2:1 ratio significantly decreased the activities of COX, 15-LOX, NOS and MPO on OxLDL induction than quercetin. Down regulation of CD36, TLR2, MyD88, TRAF6 by BASk further buttressed NLRP3 inflammasome activation mediated by the transcription factor NFκB. This is in correlation with the effect of BASk by balancing pro (IL-1β, IL-18) and anti-inflammatory (TGF-β) mediators in the aortic endothelial cells.

CONCLUSION

BASk exerted its anti-inflammatory potential by reducing pro-inflammatory mediators during cholesterol supplementation via down regulating CD36 mediated TLR2 - NLRP3 inflammasome cascade. This deciphers a synergistic combination named BASk (2:2:1) as a novel drug formulation against chronic inflammatory disease, atherosclerosis.

Plant triterpenoid saponins: biosynthesis, in vitro production, and pharmacological relevance

The saponins are a diverse class of natural products, with a broad scale distribution across different plant species. Chemically characterized as triterpenoid glycosides, they posses a 30C oxidosqualene precursor-based aglycone moiety (sapogenin), to which glycosyl residues are subsequently attached to yield the corresponding saponin. Based on the chemically distinct aglycone moieties, broadly, they are divided into triterpenoid saponins (dammaranes, ursanes, oleananes, lupanes, hopanes, etc.) and the sterol glycosides. This review aims to present in detail the biosynthesis patterns of the different aglycones from a common precursor and their glycosylation patterns to yield the functionally active glycoside. The review also presents recent advances in the pharmacological activities of these saponins, particularly as potent anti-neoplastic pharmacophores, antioxidants, or anti-viral/antibacterial agents. Since alternate production pedestals for these pharmacologically important triterpenes via cell and tissue cultures are an attractive option for their sustainable production, recent trends in the variety and scale of in vitro production of plant triterpenoids have also been discussed.

Combinatorial Action of Triterpenoid, Flavonoid, and Alkaloid on Inflammation

In the present study, the synergistic effects of BASk, a combination of betulinic acid (B), apigenin (A), and skimmianine (Sk) in the ratio of 1:1:1, were studied to construct a novel drug mixture against inflammation via the TLR4-nuclear factor Kappa light chain enhancer of activated B cells (NFκB) signaling pathway. In silico drug likeness and docking studies recommended 3 bioactive compounds as suitable ligands for drug development. BASk inhibited TLR4 from its dimerization with MD2 and blocked the TLR4 signaling cascade. Reduced nuclear translocation of NFκB inhibited the release of pro-inflammatory mediators (IL-1β and TNF-α), COX-2 expression, and PGE2. Similarly, BASk exerted its protective role by reducing pro-inflammatory mediators and elevating anti-inflammatory cytokine, IL-10. This confirms the inhibiting potential of BASk in the activation of the TLR4-NFκB signaling cascade. Thus, BASk was superior in its anti-inflammatory effect on oxidized low density lipoprotein (ox-LDL) induced human peripheral blood mononuclear cells than its individual components synergistically. Since BASk inhibited COX-2 expression and further release of PGE2, it is a potent therapeutic agent with better efficacy against inflammation because COX-2 is the target site for treating inflammatory diseases. Thus, it can be clearly stated that this innovation will be a breakthrough in the treatment of inflammatory diseases.

Arbutus species (Ericaceae) as source of valuable bioactive products

In addition to nutrients, plant foods contain compounds that may provide additional health benefits improving the quality of life. Species from Arbutus genus (Ericaceae) represent a promising source of healthy phytochemicals. Bioactive compounds including such as anthocyanins, iridoids, phenols, triterpenes, sterols, and fatty acids are reported from Arbutus species. Some Arbutus species revealed promising biological activities including antioxidant, anti-inflammatory, anti-proliferative, anti-diabetic, and antimicrobial activities, and deserve for that reason further consideration for new drug discovery. However, only few species are investigated scientifically for their chemical profile and biological activities. The aim of this article is to summarize the current knowledge of the components and biological properties of Arbutus species common in Mediterranean area, as well as the future prospects on their applications as potentially valuable products.

An Integrative Approach to Neuroinflammation in Psychiatric disorders and Neuropathic Pain

Neuroinflammation is a complex process involving both the peripheral circulation and the Central Nervous System (CNS) and is considered to underlie many CNS disorders including depression, anxiety, schizophrenia, and pain. Stressors including early-life adversity, psychosocial stress, and infection appear to prime microglia toward a pro-inflammatory phenotype. Subsequent inflammatory challenges then drive an exaggerated neuroinflammatory response involving the upregulation of pro-inflammatory mediators that is associated with CNS dysfunction. Several pharmacologic inhibitors of pro-inflammatory cytokines including TNF-α and IL-1β show good clinical efficacy in terms of ameliorating neuroinflammatory processes. Mind/body and plant-based interventions such as yoga, breathing exercises, meditation, and herbs/spices have also been demonstrated to reduce pro-inflammatory cytokines and have a positive impact on depression, anxiety, cognition, and pain. As the intricate connections between the immune system and the nervous system continue to be elucidated, successful therapies for reducing neuroinflammation will likely involve an integrated approach combining drug therapy with nonpharmacologic interventions.

Betulinic acid derivative BA5, a dual NF-kB/calcineurin inhibitor, alleviates experimental shock and delayed hypersensitivity

Betulinic acid (BA) is a naturally occurring triterpenoid with several biological properties already described, including immunomodulatory activity. Here we investigated the immunomodulatory activity of eight semi-synthetic amide derivatives of betulinic acid. Screening of derivatives BA1-BA8 led to the identification of compounds with superior immunomodulatory activity than BA on activated macrophages and lymphocytes. BA5, the most potent derivative, inhibited nitric oxide and TNFα production in a concentration-dependent manner, and decreased NF-κB activation in Raw 264.7 cells. Additionally, BA5 inhibited the proliferation of activated lymphocytes and the secretion of IL-2, IL-4 IL-6, IL-10, IL-17A and IFNɣ, in a concentration-dependent manner. Flow cytometry analysis in lymphocyte cultures showed that treatment with BA5 induces cell cycle arrest in pre-G1 phase followed by cell death by apoptosis. Moreover, BA5 also inhibited the activity of calcineurin, an enzyme that plays a critical role in the progression of cell cycle and T lymphocyte activation. BA5 has a synergistic inhibitory effect with dexamethasone on lymphoproliferation, showing a promising profile for drug combination. Finally, we observed immunosuppressive effects of BA5 in vivo in mouse models of lethal endotoxemia and delayed type hypersensitivity. Our results reinforce the potential use of betulinic acid and its derivatives in the search for potent immunomodulatory drugs.

Betulinic acid is a PPARγ antagonist that improves glucose uptake, promotes osteogenesis and inhibits adipogenesis

PPAR antagonists are ligands that bind their receptor with high affinity without transactivation activity. Recently, they have been demonstrated to maintain insulin-sensitizing and antidiabetic properties, and they serve as an alternative treatment for metabolic diseases. In this work, an affinity-based bioassay was found to be effective for selecting PPAR ligands from the dried extract of an African plant (Diospyros bipindensis). Among the ligands, we identified betulinic acid (BA), a compound already known for its anti-inflammatory, anti-tumour and antidiabetic properties, as a PPARγ and PPARα antagonist. Cell differentiation assays showed that BA inhibits adipogenesis and promotes osteogenesis; either down-regulates or does not affect the expression of a series of adipogenic markers; and up-regulates the expression of osteogenic markers. Moreover, BA increases basal glucose uptake in 3T3-L1 adipocytes. The crystal structure of the complex of BA with PPARγ sheds light, at the molecular level, on the mechanism by which BA antagonizes PPARγ, and indicates a unique binding mode of this antagonist type. The results of this study show that the natural compound BA could be an interesting and safe candidate for the treatment of type 2 diabetes and bone diseases.

Bacopa monnieri extract increases rat coronary flow and protects against myocardial ischemia/reperfusion injury

Background

This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points.

Methods

In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 μg/ml B. monnieri ethanolic extract (30 min), or (ii) with normal solution or extract for 10 min preceding no-perfusion ischemia (30 min) followed by reperfusion (30 min) with normal solution. Infarct volumes were measured by triphenyltetrazolium staining. L-type Ca²⁺-currents (I_{Ca, L}) were measured by whole-cell patching in HL-1 cells, a mouse atrial cardiomyocyte cell line. Cytotoxicity of B. monnieri was assessed in rat isolated ventricular myocytes by trypan blue exclusion.

Results

In normally perfused hearts, B. monnieri increased coronary flow by 63 ± 13% (30 μg/ml) and 216 ± 21% (100 μg/ml), compared to control (5 ± 3%) (n = 8–10, p < 0.001). B. monnieri treatment preceding ischemia/reperfusion improved left ventricular developed pressure by 84 ± 10% (30 μg/ml), 82 ± 10% (100 μg/ml) and 52 ± 6% (control) compared to pre- ischemia/reperfusion. Similarly, functional recovery showed a sustained increase. Moreover, B. monnieri (100 μg/ml) reduced the percentage of infarct size from 51 ± 2% (control) to 25 ± 2% (n = 6-8, p < 0.0001). B. monnieri (100 μg/ml) reduced I_{Ca, L} by 63 ± 4% in HL-1 cells. Ventricular myocyte survival decreased at higher concentrations (50–1000 μg/ml) B. monnieri.

Conclusions

B. monnieri improves myocardial function following ischemia/reperfusion injury through recovery of coronary blood flow, contractile force and decrease in infarct size. Thus this may lead to a novel cardioprotectant strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1637-z) contains supplementary material, which is available to authorized users.

The Ayurvedic plant Bacopa monnieri inhibits inflammatory pathways in the brain

ETHNOPHARMACOLOGICAL RELEVANCE

Bacopa monnieri (L) Wettst (common name, bacopa) is a medicinal plant used in Ayurveda, the traditional system of medicine of India, as a nootropic. It is considered to be a "medhya rasayana", an herb that sharpens the mind and the intellect. Bacopa is an important ingredient in many Ayurvedic herbal formulations designed to treat conditions such as memory loss, anxiety, poor cognition and loss of concentration. It has also been used in Ayurveda to treat inflammatory conditions such as arthritis. In modern biomedical studies, bacopa has been shown in animal models to inhibit the release of the pro-inflammatory cytokines TNF-α and IL-6. However, less is known regarding the anti-inflammatory activity of Bacopa in the brain.

AIM OF THE STUDY

The current study examines the ability of Bacopa to inhibit the release of pro-inflammatory cytokines from microglial cells, the immune cells of the brain that participate in inflammation in the CNS. The effect of Bacopa on signaling enzymes associated with CNS inflammatory pathways was also studied.

MATERIALS AND METHODS

Various extracts of Bacopa were prepared and examined in the N9 microglial cell line in order to determine if they inhibited the release of the proinflammatory cytokines TNF-α and IL-6. Extracts were also tested in cell free assays as inhibitors of caspase-1 and matrix metalloproteinase-3 (enzymes associated with inflammation) and caspase-3, which has been shown to cleave protein Tau, an early event in the development of Alzheimer's disease.

RESULTS

The tea, infusion, and alkaloid extracts of bacopa, as well as Bacoside A significantly inhibited the release of TNF-α and IL-6 from activated N9 microglial cells in vitro. In addition, the tea, infusion, and alkaloid extracts of Bacopa effectively inhibited caspase 1 and 3, and matrix metalloproteinase-3 in the cell free assay.

CONCLUSIONS

Bacopa inhibits the release of inflammatory cytokines from microglial cells and inhibits enzymes associated with inflammation in the brain. Thus, Bacopa can limit inflammation in the CNS, and offers a promising source of novel therapeutics for the treatment of many CNS disorders.

Optimization of Betulinic Acid Extraction from Tecomella undulata Bark Using a Box-Behnken Design and Its Densitometric Validation

Betulinic acid (BA) is a pentacyclic triterpenoid acid obtained from the stem bark of Tecomella undulata Seem. (Bignoniaceae). Development of an efficient extraction method for the isolation of BA is important as it has a wide range of pharmacological activity. A Box-Behnken design (BBD) was used to investigate the effect of extraction variables such as temperature (30-60 °C), time (4-8 h) and solvent to drug ratio (300-500 mL/100 g) on the maximization of BA yield and its quantification using validated densitometric high performance thin layer chromatography coupled with ultraviolet detection (HPTLC-VIS). A quadratic polynomial model was found to best fit the model with R² = 0.99. The optimized Soxhlet extraction yielded 2.449% w/w of BA at a temperature 53.86 °C, time 6.38 h and solvent to drug ratio 371 mL/100 g. BA in Tecomella undulata bark was detected at Rf value of 0.65 at 510 nm using the solvent system toluene-ethyl acetate-glacial acetic acid (8.5:1.5:0.02 v/v/v). The analytical method was validated and the linear regression analysis reflects good linear relationship (R² = 0.9902). Lower %RSD and SEM suggested that the developed HPTLC-VIS method was precise, accurate and robust. Therefore, these economical techniques are very efficient and promising for the extraction and quantification of pharmaceutically important BA.

Evaluation of anticancer potential of Bacopa monnieri L. against MCF-7 and MDA-MB 231 cell line

Background:

The ethanolic extract of Bacopa monnieri contains bacoside A and B, brahmin, cucurbitacins, and betulinic acid. Currently, cucurbitacins have also been reported for their strong anti-tumorigenic and anti-proliferative activity by inducing cell cycle arrest at the G₂/M phase and formation of multiplied cells. The present study was carried out to evaluate the in vitro cytotoxic activity of ethanolic extract of dichloromethane (DCM) fraction of B. monnieri on two different cell lines.

Materials and Methods:

The ethanolic extract of B. monnieri was prepared using soxhlet extraction method and different fractions (hexane, DCM, methanol, acetone, and water) of ethanolic extracts were prepared. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay of ethanolic extract and of all fractions was carried out on MCF-7 and MDA-MB 231 cell lines. The presence of cucurbitacins and betulinic acid in these fractions was confirmed by high-performance thin layer chromatography.

Results:

The IC₅₀ values of ethanolic extract of B. monnieri in MCF-7 and MDA-MB 231 cell lines were 72.0 μg/mL and 75.0 μg/mL, respectively. The DCM fraction of B. monnieri showed maximum cytotoxic activity among all fraction upto 72 h and was found to be 57.0 μg/mL and 42.0 μg/mL, respectively.

Conclusion:

The results showed good cytotoxic activity in DCM fraction in both the cell lines may be due to the presence of cucurbitacins and betulinic acid in DCM fraction.

RETRACTED:Betulinic acid downregulates expression of oxidative stress-induced lipoprotein lipase via the PKC/ERK/c-Fos pathway in RAW264.7 macrophages

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Concerns raised by Dr. Sander Kersten in PubPeer pointed out that Figures 6.1B and 6.2B of this paper were different figures but the legends and Western blots were identical; the quantification was also seen to be different between the two figures. Shortly afterwards, the authors asked to publish a corrigendum for part B of Figure 6.1, including images of western blots and associated bar plots. Subsequently, the journal conducted an investigation and found evidence that there had been improper manipulation and duplication of images in Figures 2 E, 6.2 B, 5 A and and 6.2 D, as shown by the reuse of several western blot bands with approximately 180° rotation in each case. After raising the complaint with the authors, the corresponding author agreed that the paper should be retracted. The authors apologise to the readers of the journal.

In vivo protective effect of betulinic acid on dexamethasone induced thymocyte apoptosis by reducing oxidative stress

BACKGROUND

Dexamethasone (Dex), a synthetic glucocorticoid, is strictly controlled for use due to its serious side effects, including immune suppression. Betulinic acid (BA), an antioxidant prepared from the white birch, exhibits immunomodulation properties. To assess the implications and investigate the mechanisms of BA-elicited immunomodulation, we hypothesized that Dex induced thymocyte apoptosis via oxidative stress could be lessened by BA.

METHODS

Mice were given oral doses of BA (0.25, 0.5, and 1.0mg/kg) daily for 14 days, and induced oxidative stress by giving a single dose of Dex intraperitoneal at the dosage of 25mg/kg body weight 8h after the last administration of BA.

RESULTS

Dex administration alone significantly decreased antioxidant enzyme activities, while significantly increased reactive oxygen species (ROS) production, lipid peroxidation, mitochondrial dysfunctions, caspase-3 activation and cellular apoptosis. However, pretreatment with BA dose-dependently mitigated Dex-induced oxidative damage after 14 days of feeding. In addition to ROS scavenging activity in Dex-induced thymocyte, BA administration decreased lipid peroxidation, up-regulated antioxidant enzymes, restored mitochondrial function, increased Bcl-2 expression but reduced Bax expression, inhibited caspase-3 activation, and improved cell survival.

CONCLUSIONS

These findings reveal a protective capability of BA against Dex-induced cell death by reducing oxidative stress via mitochondrial mediated signal pathway which could be the potential mechanism underlying BA-elicited immunomodulation.

Betulinic Acid and its Derivatives as Potential Antitumor Agents

Betulinic acid (BA) is a lupane-type pentacyclic triterpene, distributed ubiquitously throughout the plant kingdom. BA and its derivatives demonstrate multiple bioactivities, particularly an antitumor effect. This review critically describes the recent research on isolation, synthesis, and derivatization of BA and its natural analogs betulin and 23-hydroxybetulinic acid. The subsequent part of the review focuses on the current knowledge of antitumor properties, combination treatments, and pharmacological mechanisms of these compounds. A 3D-QSAR analysis of 62 BA derivatives against human ovarian cancer A2780 is also included to provide information concerning the structure-cytotoxicity relationships of these compounds.

Ameliorative effect of betulinic acid on oxidative damage and apoptosis in the splenocytes of dexamethasone treated mice

Betulinic acid (BA) is a bioactive pentacyclic triterpene that exhibits a variety of biological activities including antioxidative and immunomodulative properties. The objective of this study was to investigate the potential splenocytes protective effect and underlying mechanism of BA using dexamethasone (Dex)-induced mice as a model system. Pretreatment with BA (0.25, 0.5, and 1.0 mg/kg) dose-dependently ameliorated Dex-induced oxidative damage and apoptosis after 14 days of feeding. In addition to reactive oxygen species scavenging activity in Dex-induced splenocytes, BA administration up-regulated antioxidant enzymes, decreased lipid peroxidation, restored mitochondrial function, decreased the expression of pro-apoptotic protein Bax, prevented the decline of anti-apoptotic protein Bcl-2, inhibited caspase-9 and caspase-3 activation, and improved cell survival. These findings reveal that BA was able to mitigate Dex-induced oxidative stress and might play an important role in repairs of oxidative damage in immunological system.

Enhanced bacoside production in shoot cultures of Bacopa monnieri under the influence of abiotic elicitors

The effect of different abiotic elicitors [jasmonic acid, copper sulphate (CuSO4) and salicyclic acid] at varying concentrations on the stimulation of biomass and bacoside production in in vitro Bacopa monnieri shoot culture was studied. A systematic study conducted over a period of 35 days indicated that the maximum bacoside production (6.74 mg g(-1) dry weight (DW)) was obtained after a lag of 7 days and thereafter, the content decreased gradually to again increase at 28 days (5.91 mg g(-1) DW). Therefore, elicitation experiments were carried out over a period of 3, 6 and 9 days. The shoot cultures treated with 45 mg L(-1) of CuSO4 exhibited the highest bacoside content of 8.73 mg g(-1) DW (∼1.42-fold higher) than in control cultures (6.14 mg g(-1) DW). This study indicates the effectiveness of abiotic elicitation on bacoside production in in vitro shoot cultures of this medicinally important herb known for its memory-enhancing properties.

Bacopa monnieri (L.) exerts anti-inflammatory effects on cells of the innate immune system in vitro

Bacopa monnieri (L., BM) is a traditional Ayurvedic medicinal herb recognised for its efficacy in relieving acute pain and inflammation, as related to selective inhibition of cyclo-oxygenase-2 (COX-2) enzyme and consequent reduction in COX-2-mediated prostanoid mediators. BM is also associated with cognitive enhancing (nootropic) activity including improving memory free recall, observed after prolonged intake (>3 months). It is likely that the time frame required to exert an effect in the brain reflects regulation by BM of chronic inflammation and oxidative stress associated with aging and chronic diseases, and other polypharmacological effects. We report down-regulation by BM of NO and TNF-α in stimulated RAW 246.7 macrophages and of IFN-γ in stimulated human blood cells. Furthermore, in human blood cells, IL-10 was slightly elevated indicating polarisation towards a regulatory T cell phenotype. These results provide further supportive evidence to justify the clinical evaluation of BM for managing diseases involving chronic systemic and brain inflammation driven by the innate immune system.

Bacopa monniera selectively attenuates suppressed Superoxide dismutase activity in Diazepam induced amnesic mice

BACKGROUND

Amnesia is characterized by loss of memory that could result from abnormal neuro-chemical homeostasis, genetic predisposition or drug abuse. We earlier reported that B. monniera attenuates diazepam, scopolamine and L-NNA induced amnesia and wanted to test if SOD levels were affected by its administration.

PURPOSE

B. monniera is earlier reported to augment the defense system for oxidative stress by increasing the activities of superoxide dismutase, therefore, we investigated its levels after B. monniera administration in combination with different amnesic agents.

METHODS

We treated mice with amnesic agents such as scopolamine, diazepam, L-NNA and MK 801 either with or without B. monniera.

RESULTS

Diazepam (1.75 mg/kg ip) significantly reduced SOD activity while it was unaltered when Scopolamine (0.1 mg/kg ip), MK 801 (0.17 mg/kg ip) and L-NNA (30 mg/kg ip) were administered. B. monniera significantly attenuated diazepam induced suppression of SOD activity.

CONCLUSION

It is suggested that the mechanism of B. monniera's antiamnesic effect may vary depending on the type of amnesic agent used. However, antioxidant mechanism may be central to evoking the memory enhancing effects of B. monniera against diazepam induced amnesia.

Cardioprotective effect of betulinic Acid on myocardial ischemia reperfusion injury in rats

Objectives. This study aims to investigate the effect of betulinic acid (BA) on myocardial ischemia reperfusion/injury in an open-chest anesthetized rat model. Methods. The model was induced by 30 minutes left anterior descending occlusion followed by 2 hours reperfusion. There are six groups in our present study: sham operation group, ischemia/reperfusion group, low-dosage BA group, medium-dosage BA group, high-dosage BA group, and fosinopril sodium group. Rats in the latter four groups were administrated with BA (50, 100, and 200 mg/kg, i.g.) or fosinopril sodium (10 mg/kg, i.g.) once a day for 7 days before operation, respectively. Rats in the former two groups were given the same volume of vehicle (0.5% CMC-Na, i.g.). During the operation, cardiac function was continuously monitored. Serum LDH and CK were measured with colorimetric assays. The expression of Bcl-2 and Bax and the apoptosis of cardiomyocytes were investigated with western blot and TUNEL assay, respectively. Results. Pretreatment with BA improved cardiac function and attenuated LDH and CK activities compared with IR group. Further investigation demonstrated that the expression of Bcl-2 and Bax and TUNEL assay was in line with the above results. Conclusion. BA may reduce the release of LDH and CK, prevent cardiomyocytes apoptosis, and eventually alleviate the extent of the myocardial ischemia/reperfusion injury.

Betulinic acid, a bioactive pentacyclic triterpenoid, inhibits skeletal-related events induced by breast cancer bone metastases and treatment

Many breast cancer patients experience bone metastases and suffer skeletal complications. The present study provides evidence on the protective and therapeutic potential of betulinic acid on cancer-associated bone diseases. Betulinic acid is a naturally occurring triterpenoid with the beneficial activity to limit the progression and severity of cancer, diabetes, cardiovascular diseases, atherosclerosis, and obesity. We first investigated its effect on breast cancer cells, osteoblastic cells, and osteoclasts in the vicious cycle of osteolytic bone metastasis. Betulinic acid reduced cell viability and the production of parathyroid hormone-related protein (PTHrP), a major osteolytic factor, in MDA-MB-231 human metastatic breast cancer cells stimulated with or without tumor growth factor-β. Betulinic acid blocked an increase in the receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin ratio by downregulating RANKL protein expression in PTHrP-treated human osteoblastic cells. In addition, betulinic acid inhibited RANKL-induced osteoclastogenesis in murine bone marrow macrophages and decreased the production of resorbed area in plates with a bone biomimetic synthetic surface by suppressing the secretion of matrix metalloproteinase (MMP)-2, MMP-9, and cathepsin K in RANKL-induced osteoclasts. Furthermore, oral administration of betulinic acid inhibited bone loss in mice intra-tibially inoculated with breast cancer cells and in ovariectomized mice causing estrogen deprivation, as supported by the restored bone morphometric parameters and serum bone turnover markers. Taken together, these findings suggest that betulinic acid may have the potential to prevent bone loss in patients with bone metastases and cancer treatment-induced estrogen deficiency.

Antagonism of betulinic acid on LPS-mediated inhibition of ABCA1 and cholesterol efflux through inhibiting nuclear factor-kappaB signaling pathway and miR-33 expression

ATP-binding cassette transporter A1 (ABCA1) is critical in exporting cholesterol from macrophages and plays a protective role in the development of atherosclerosis. The purpose of this study was to investigate the effects of betulinic acid (BA), a pentacyclic triterpenoid, on ABCA1 expression and cholesterol efflux, and to further determine the underlying mechanism. BA promoted ABCA1 expression and cholesterol efflux, decreased cellular cholesterol and cholesterol ester content in LPS-treated macrophages. Furthermore, we found that BA promoted ABCA1 expression via down-regulation of miR-33s. The inhibition of LPS-induced NF-κB activation further decreased miR-33s expression and enhanced ABCA1 expression and cholesterol efflux when compared with BA only treatment. In addition, BA suppressed IκB phosphorylation, p65 phosphorylation and nuclear translocation, and the transcription of NF-κB-dependent related gene. Moreover, BA reduced atherosclerotic lesion size, miR-33s levels and NF-κB activation, and promoted ABCA1 expression in apoE^−/− mice. Taken together, these results reveal a novel mechanism for the BA-mediated ABCA1 expression, which may provide new insights for developing strategies for modulating vascular inflammation and atherosclerosis.

Bacopa monnieri Phytochemicals Mediated Synthesis of Platinum Nanoparticles and Its Neurorescue Effect on 1-Methyl 4-Phenyl 1,2,3,6 Tetrahydropyridine-Induced Experimental Parkinsonism in Zebrafish

Current discovery demonstrates the rapid formation of platinum nanoparticles using leaf extract of a neurobeneficial plant, Bacopa monnieri (BmE). The nanoparticles (BmE-PtNPs) were stabilized and then coated with varied phytochemicals present within the leaf extract. These nanoparticles demonstrated the same activity of Complex I, as that of oxidizing NADH to NAD⁺ using a spectrophotometric method. This suggests that BmE-PtNPs are a potential medicinal substance for oxidative stress mediated disease with suppressed mitochondrial complex I, namely, Parkinson's disease (PD). Hence, the neuroprotective potentials of the phytochemical coated nanoparticle were explored in 1-methyl 4-phenyl 1,2,3,6 tetrahydropyridine- (MPTP-)induced experimental Parkinsonism in zebrafish model. BmE-PtNPs pretreatment significantly reversed toxic effects of MPTP by increasing the levels of dopamine, its metabolites, GSH and activities of GPx, catalase, SOD and complex I, and reducing levels of MDA along with enhanced locomotor activity. Taken together, these findings suggest that BmE-PtNPs have protective effect in MPTP-induced neurotoxicity in this model of Parkinson's disease via their dual functions as mitochondrial complex I and antioxidant activity.

Betulinic acid inhibits endotoxin-stimulated phosphorylation cascade and pro-inflammatory prostaglandin E(2) production in human peripheral blood mononuclear cells

BACKGROUND AND PURPOSE

Betulinic acid (BA) is a naturally occurring triterpenoid widely distributed throughout the plant kingdom. We previously reported that BA inhibits lipopolysaccharide (LPS)-induced interleukin-6 production through modulation of nuclear factor κB (NF-κB) in human peripheral blood mononuclear cells (hPBMCs). This study attempted to identify other mechanisms through which BA modulates LPS signalling in mononuclear cells. The effects of BA on signalling pathways downstream were focused on in this study.

EXPERIMENTAL APPROACH

We determined the ability of BA to interfere with p38 and extracellular regulated kinase (ERK) phosphorylation as well as Akt phosphorylation and nuclear factor-κB activation using LPS-activated hPBMCs as an in vitro model. LPS-induced endotoxin shock in mice was the in vivo model employed.

KEY RESULTS

BA inhibited LPS-induced COX-2 protein expression and prostaglandin E(2) production and also attenuated LPS-induced ERK and Akt phosphorylation, but not p38 in hPBMCs. BA abolished LPS-induced IκBα phosphorylation and thus normalized the levels of IκBα in cytosol. BA also inhibited LPS-induced reactive oxygen species formation and lactate dehydrogenase release. Interestingly, BA improved the life span of mice in endotoxin shock and also inhibited PGE(2) production and myeloperoxidase activity in vivo.

CONCLUSIONS AND IMPLICATIONS

BA modulates LPS-induced COX-2 expression in hPBMCs by inhibiting ERK and Akt pathways as well as by modulating IκBα phosphorylation. At the same time, no cell toxicity was observed. The effect of the drug was confirmed through in vivo experiments. The study gives an insight into the molecular mechanisms of BA.

Inflammatory signaling in skeletal muscle insulin resistance: green signal for nutritional intervention?

PURPOSE OF REVIEW

To review the evidence implying a role of inflammatory signaling pathways, specifically nuclear factor-κB and c-Jun NH2-terminal kinase, in fatty acid-induced skeletal muscle insulin resistance and to discuss the potential of dietary interventions to interfere with these processes.

RECENT FINDINGS

Fatty acids can induce skeletal muscle insulin resistance via inflammatory signaling after binding Toll-like receptors at the cell membrane of muscle cells or after accumulating as intramyocellular lipid metabolites. In both processes, activation of intracellular inflammatory signaling is involved. The majority of literature addressing the causality of muscle nuclear factor-κB activation in skeletal muscle insulin resistance suggests that insulin resistance does not require muscle nuclear factor-κB activation. Recently, strong evidence was given that c-Jun NH2-terminal kinase signaling is an important inflammatory pathway involved in skeletal muscle insulin resistance. Furthermore, it is well established that proinflammatory cytokines originating from the enlarged adipose tissue or from activated adipose tissue macrophages can cause muscle insulin resistance. Recently, also macrophages resided in the muscle have been proposed to play an important role in muscle insulin resistance. Because of their anti-inflammatory characteristics, several dietary components like polyphenols may be interesting candidates for manipulating skeletal muscle insulin resistance.

SUMMARY

Several dietary components, like polyphenols, have been reported to interfere with inflammatory signaling. To test whether these compounds can be used to prevent or reverse insulin resistance, well controlled human intervention studies have to be designed.