Nimbolide inhibits androgen independent prostate cancer cells survival and proliferation by modulating multiple pro-survival signaling pathways

Nimbolide: promising agent for prevention and treatment of chronic diseases (recent update)

Background

Nimbolide, a bioactive compound derived from the neem tree, has garnered attention as a potential breakthrough in the prevention and treatment of chronic diseases. Recent updates in research highlight its multifaceted pharmacological properties, demonstrating anti-inflammatory, antioxidant, and anticancer effects. With a rich history in traditional medicine, nimbolide efficacy in addressing the molecular complexities of conditions such as cardiovascular diseases, diabetes, and cancer positions it as a promising candidate for further exploration. As studies progress, the recent update underscores the growing optimism surrounding nimbolide as a valuable tool in the ongoing pursuit of innovative therapeutic strategies for chronic diseases.

Methods

The comprehensive search of the literature was done until September 2020 on the MEDLINE, Embase, Scopus and Web of Knowledge databases.

Results

Most studies have shown the Nimbolide is one of the most potent limonoids derived from the flowers and leaves of neem (Azadirachta indica), which is widely used to treat a variety of human diseases. In chronic diseases, nimbolide reported to modulate the key signaling pathways, such as Mitogen-activated protein kinases (MAPKs), Wingless-related integration site-β (Wnt-β)/catenin, NF-κB, PI3K/AKT, and signaling molecules, such as transforming growth factor (TGF-β), Matrix metalloproteinases (MMPs), Vascular Endothelial Growth Factor (VEGF), inflammatory cytokines, and epithelial-mesenchymal transition (EMT) proteins. Nimbolide has anti-inflammatory, anti-microbial, and anti-cancer properties, which make it an intriguing compound for research. Nimbolide demonstrated therapeutic potential for osteoarthritis, rheumatoid arthritis, cardiovascular, inflammation and cancer.

Conclusion

The current review mainly focused on understanding the molecular mechanisms underlying the therapecutic effects of nimbolide in chronic diseases.

Limonoids from neem (Azadirachta indica A. Juss.) are potential anticancer drug candidates

Neem (Azadirachta indica A. Juss.), a versatile evergreen tree recognized for its ethnopharmacological value, is a rich source of limonoids of the triterpenoid class, endowed with potent medicinal properties. Extracts of neem have been documented to display anticancer effects in diverse malignant cell lines as well as in preclinical animal models that has largely been attributed to the constituent limonoids. Of late, neem limonoids have become the cynosure of research attention as potential candidate agents for cancer prevention and therapy. Among the various limonoids found in neem, azadirachtin, epoxyazadiradione, gedunin, and nimbolide, have been extensively investigated for anticancer activity. Azadirachtin, a potent biodegradable pesticide, exhibits profound antiproliferative effects by preventing mitotic spindle formation and cell division. The antiproliferative activity of gedunin has been demonstrated to be mediated primarily via inhibition of heat shock protein90 and its client proteins. Epoxyazadiradione inhibits pro-inflammatory and kinase-driven signaling pathways to block tumorigenesis. Nimbolide, the most potent cytotoxic neem limonoid, inhibits the growth of cancer cells by regulating the phosphorylation of keystone kinases that drive oncogenic signaling besides modulating the epigenome. There is overwhelming evidence to indicate that neem limonoids exert anticancer effects by preventing the acquisition of hallmark traits of cancer, such as cell proliferation, apoptosis evasion, inflammation, invasion, angiogenesis, and drug resistance. Neem limonoids are value additions to the armamentarium of natural compounds that target aberrant oncogenic signaling to inhibit cancer development and progression.

Nimbolide enhances the antitumor effect of docetaxel via abrogation of the NF-κB signaling pathway in prostate cancer preclinical models

Prostate cancer is the second most frequent type of cancer that affects men. Docetaxel (DTX) administration is the front-line therapy for patients with advanced prostate cancer and unfortunately, half of these patients develop resistance to DTX which could be due to its ability to activate the NF-κB pathway. The combinational effect of DTX and nimbolide on proliferation, apoptosis, activation of NF-κB, DNA binding ability of NF-κB, and expression of NF-κB-targeted gene products was investigated. The antitumor and antimetastatic effect of DTX or NL alone or in combination was also examined. The co-administration of NL and DTX resulted in a significant loss of cell viability with enhanced apoptosis in DTX-sensitive/resistant prostate cancer cells. NL abrogated DTX-triggered NF-κB activation and expression of its downstream antiapoptotic factors (survivin, Bcl-2, and XIAP). The combination of NL and DTX significantly reduced the DNA binding ability of NF-κB in both cell types. NL significantly enhanced the antitumor effect of DTX and reduced metastases in orthotopic models of prostate cancer. NL abolishes DTX-induced-NF-κB activation to counteract cell proliferation, tumor growth, and metastasis in the prostate cancer models.

Adaptation to Hypoxia May Promote Therapeutic Resistance to Androgen Receptor Inhibition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) surpasses other BC subtypes as the most challenging to treat due to its lack of traditional BC biomarkers. Nearly 30% of TNBC patients express the androgen receptor (AR), and the blockade of androgen production and AR signaling have been the cornerstones of therapies for AR-positive TNBC. However, the majority of women are resistant to AR-targeted therapy, which is a major impediment to improving outcomes for the AR-positive TNBC subpopulation. The hypoxia signaling cascade is frequently activated in the tumor microenvironment in response to low oxygen levels; activation of the hypoxia signaling cascade allows tumors to survive despite hypoxia-mediated interference with cellular metabolism. The activation of hypoxia signaling networks in TNBC promotes resistance to most anticancer drugs including AR inhibitors. The activation of hypoxia network signaling occurs more frequently in TNBC compared to other BC subtypes. Herein, we examine the (1) interplay between hypoxia signaling networks and AR and (2) whether hypoxia and hypoxic stress adaptive pathways promote the emergence of resistance to therapies that target AR. We also pose the well-supported question, “Can the efficacy of androgen-/AR-targeted treatments be enhanced by co-targeting hypoxia?” By critically examining the evidence and the complex entwinement of these two oncogenic pathways, we argue that the simultaneous targeting of androgen biosynthesis/AR signaling and hypoxia may enhance the sensitivity of AR-positive TNBCs to AR-targeted treatments, derail the emergence of therapy resistance, and improve patient outcomes.

Huangjia Ruangan Granule Inhibits Inflammation in a Rat Model with Liver Fibrosis by Regulating TNF/MAPK and NF-κB Signaling Pathways

The Huangjia Ruangan granule (HJRG) is a clinically effective Kampo formula, which has a significant effect on liver fibrosis and early liver cirrhosis. However, the mechanism underlying HJRG in treating liver fibrosis remains unclear. In this study, carbon tetrachloride (CCl₄) was used to induce liver fibrosis in rats to clarify the effect of HJRG on liver fibrosis and its mechanism. Using network pharmacology, the potential mechanism of HJRG was initially explored, and a variety of analyses were performed to verify this mechanism. In the liver fibrosis model, treatment with HJRG can maintain the liver morphology, lower the levels of AST and ALT in the serum, and ameliorate pathological damage. Histopathological examinations revealed that the liver structure was significantly improved and fibrotic changes were alleviated. It can effectively inhibit collagen deposition and the expression of α-SMA, reduce the levels of the rat serum (HA, LN, PC III, and Col IV), and inhibit the expression of desmin, vimentin, and HYP content in the liver. Analyzing the results of network pharmacology, the oxidative stress, inflammation, and the related pathways (primarily the TNF signaling pathway) were identified as the potential mechanism of HJRG against liver fibrosis. Experiments confirmed that HJRG can significantly increase the content of superoxide dismutase and glutathione and reduce the levels of malondialdehyde and myeloperoxidase in the rat liver; in addition, HJRG significantly inhibited the content of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and reduced the expression of inflammatory regulators (Cox2 and iNOS). Meanwhile, treatment with HJRG inhibited the phosphorylation of NF-κB P65, IκBα, ERK, JNK, and MAPK P38. Moreover, HJRG treatment reversed the increased expression of TNFR1. The Huangjia Ruangan granule can effectively inhibit liver fibrosis through antioxidation, suppressing liver inflammation by regulating the TNF/MAPK and NF-κB signaling pathways, thereby preventing the effect of liver fibrosis.

Modulation of Long Non-Coding RNAs by Different Classes of Secondary Metabolites from Plants: A Mini-Review on Antitumor Effects

The broad pharmacological spectrum of plants is related to their secondary metabolism, which is responsible for the synthesis of different compounds that have multiple effects on cellular physiology. Among the biological effects presented by phytochemicals, their use for the prevention and treatment of cancer can be highlighted. This occurs due to several mechanisms of antitumor action demonstrated by these compounds, including regulation of the cell signaling pathways and inhibition of tumor growth. In this way, long non-coding RNAs (lncRNAs) appear to be promising targets for the treatment of cancer. Their deregulation has already been related to a variety of clinical-pathological parameters. However, the effects of secondary metabolites on lncRNAs are still restricted. For this reason, the present review aimed to gather data on phytochemicals with action on lncRNAs in order to confirm their possible antitumor potential. According to the literature, terpenoid and flavonoid are the main examples of secondary metabolites involved with lncRNAs activity. In addition, the lncRNAs H19, CASC2, HOTAIR, NKILA, CCAT1, MALAT1, AFAP1-AS1, MEG3, and CDKN2B-AS1 can be highlighted as important targets in the search for new anti-tumor agents since they act as modulating pathways related to cell proliferation, cell cycle, apoptosis, cell migration and invasion. Finally, challenges for the use of natural products as a commercial drug were also discussed. The low yield, selectivity index and undesirable pharmacokinetic parameters were emphasized as a difficulty for obtaining these compounds on a large scale and for improving the potency of its biological effect. However, the synthesis and/or development of formulations were suggested as a possible approach to solve these problems. All of these data together confirm the potential of secondary metabolites as a source of new anti-tumor agents acting on lncRNAs.

Nimbolide, a Neem Limonoid, Is a Promising Candidate for the Anticancer Drug Arsenal

Nimbolide, a major limonoid constituent of Azadirachta indica, commonly known as neem, has attracted increasing research attention owing to its wide spectrum of pharmacological properties, predominantly anticancer activity. Nimbolide is reported to exert potent antiproliferative effects on a myriad cancer cell lines and chemotherapeutic efficacy in preclinical animal tumor models. The potentiality of nimbolide to circumvent multidrug resistance and aid in targeted protein degradation broaden its utility in enhancing therapeutic modalities and outcome. Accumulating evidence indicates that nimbolide prevents the acquisition of cancer hallmarks such as sustained proliferation, apoptosis evasion, invasion, angiogenesis, metastasis, and inflammation by modulating kinase-driven oncogenic signaling networks. Nimbolide has been demonstrated to abrogate aberrant activation of cellular signaling by influencing the subcellular localization of transcription factors and phosphorylation of kinases in addition to influencing the epigenome. Nimbolide, with its ever-expanding repertoire of molecular targets, is a valuable addition to the anticancer drug arsenal.

Nanodelivery and anticancer effect of a limonoid, nimbolide, in breast and pancreatic cancer cells

Introduction

Nimbolide (Nim), a limonoid obtained from the neem tree, Azadirachta indica, has several pharmacological properties, including anticancer effects in different type of cancers. No drug-delivery system has been reported for enhancing the therapeutic application of this novel hydrophobic molecule.

Methods

In the present research, poly(lactic-co-glycolic acid) (PLGA) nanoparticles of Nim (Nim-nano) were formulated by nanoprecipitation, characterized for physicochemical properties, and screened for anticancer potential in breast (MCF-7 and MDA-MB-231) and pancreatic (AsPC-1) cancer cell lines.

Results

The Nim-nano had a particle size of 183.73±2.22 nm and 221.20±11.03 nm before and after lyophilization, respectively. Cryoprotectants (mannitol and sucrose) significantly inhibited growth in particle size due to lyophilization. The ζ-potential of the Nim-nano was −22.40±4.40 mV. Drug loading and encapsulation efficiency of Nim-nano were 5.25%±1.12% and 55.67%±12.42%, respectively. The Nim-nano exhibited sustained release of Nim for more than 6 days in PBS (pH 7.4) and showed two- to three-fold enhanced cytotoxicity in breast and pancreatic cancer cell lines compared with free Nim.

Conclusion

The Nim-nano formulation has great potential for treatment of cancers, such as pancreatic and breast cancer. Further, the PLGA-polymer surface can be modified by conjugation with polyethylene glycol, receptor-binding ligands (eg, folic acid), and other that which may lead to targeted delivery of Nim in the treatment of cancer.

Nimbolide suppresses non-small cell lung cancer cell invasion and migration via manipulation of DUSP4 expression and ERK1/2 signaling

Nimbolide plays an important role in treating human diseases. In these years, the anticancer property of nimbolide has been paid more and more attention. However, the role of nimbolide in non-small cell lung cancer (NSCLC) remains unclear. In this study, we found that nimbolide treatment suppressed the invasion and migration of NSCLC cells, in a dose-dependent manner. Moreover, nimbolide treatment dose-dependently inhibited ERK1/2 activation, decreased Snail and MMP-3 expression, and increased E-cadherin expression. Further, we found that nimbolide treatment upregulated DUSP4 expression. DUSP4 knockdown attenuated nimbolide-mediated inhibition of cell invasion, migration and ERK1/2 activation. We also found that DUSP4 knockdown suppressed the effect of nimbolide on MMP-3, Snail and E-cadherin expression. Taken together, our study demonstrates that nimbolide treatment can upregulate the expression of DUSP4, thus inhibiting ERK1/2 activation. Inhibition of ERK1/2 pathway by nimbolide decreases MMP-3 and Snail expression, and increases E-cadherin expression, which finally inhibits NSCLC cell invasion and migration. Therefore, nimbolide may act as a novel drug to inhibit NSCLC invasion and metastasis through manipulation of ERK1/2 signaling and DUSP4 expression.