Anti-colon cancer activity of Murraya koenigii leaves is due to constituent murrayazoline and O-methylmurrayamine A induced mTOR/AKT downregulation and mitochondrial apoptosis

Synthesis of novel carbazole hydrazine-carbothioamide scaffold as potent antioxidant, anticancer and antimicrobial agents

BACKGROUND

Carbazole-based molecules containing thiosemicarbazide functional groups are recognized for their diverse biological activities, particularly in enhancing therapeutic anticancer effects through inhibiting crucial pathways. These derivatives also exhibit noteworthy antioxidant properties.

OBJECTIVES

This study aims to synthesize, characterize, and evaluate the antioxidant and anticancer activities of 18 novel carbazole derivatives.

METHODS

The radical scavenging capabilities of the compounds were assessed using the 2,2-diphenyl-1-picrylhydrazyl assay. Antiproliferative activities were evaluated on MCF-7 cancer cell lines through viability assays. Additionally, the modulation of the PI3K/Akt/mTOR pathway, apoptosis/necrosis induction, and cell cycle analysis were conducted for the most promising anticancer agents.

RESULTS

nine compounds showed potent antioxidant activities with IC50 values lower than the positive control acarbose, with compounds 4 h and 4y exhibiting the highest potency (IC50 values of 0.73 and 0.38 µM, respectively). Furthermore, compounds 4o and 4r displayed significant anticancer effects, with IC50 values of 2.02 and 4.99 µM, respectively. Compound 4o, in particular, exhibited promising activity by targeting the PI3K/Akt/mTOR signaling pathway, inhibiting tumor survival, inducing apoptosis, and causing cell cycle arrest in MCF-7 cell lines. Furthermore, compound 4o was showed significant antimicrobial activities against S. aureus and E. coli, and antifungal effect against C. albicans. Its potential to overcome drug resistance through this pathway inhibition highlights its promise as an anticancer agent. Molecular docking simulations supported these findings, revealing favorable binding profiles and interactions within the active sites of the enzymes PI3K, AKT1, and mTOR. Moreover, assessing the druggability of the newly synthesized thiosemicarbazide derivatives demonstrated optimal physicochemical properties, further endorsing their potential as drug candidates.

Site-selective synthesis and pharmacological elucidation of novel semi-synthetic analogues of koenimbine as a potential anti-inflammatory agent

Koenimbine (1), a carbazole alkaloid isolated from Murraya koenigii, belongs to the Rutaceae family. Various pharmacological effects such as anti-diabetic, melanogenesis inhibition, anti-diarrheal, anti-cancer, and anti-inflammatory properties of koenimbine have already been reported. In the current study, we investigated the anti-inflammatory role of koenimbine (1) and its novel semi-synthetic derivative 8-methoxy-3,3,5-trimethylpyrano[3,2-a] carbazole-11(3H)-yl) (3-(trifluoromethyl) phenyl) methanone (1G) in both in vitro and in vivo biological systems. Our results demonstrated that the anti-inflammatory activity of 1G significantly lowered the production of NO, pro-inflammatory cytokines (IL-6, TNF-α & IL-1β), LTB4 following LPS stimulation in RAW 264.7 macrophages. Furthermore, 1G significantly attenuated the expression levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose dependent manner and also decreased the production of reactive oxygen species (ROS) in LPS-activated RAW 264.7 cells. In addition, the oral administration of 1G reduced the inflammatory response in carrageenan-induced paw edema in BALB/C mice. Moreover, it effectively reduced NO, IL-6, IL-1β & TNF-α levels, liver markers (AST, ALT), and kidney markers (BUN, CRE, and Urea). Also, 1G reverted the infiltration of inflammatory cells and tissue damage in lungs, liver and kidney enhanced the survival rate in LPS-challenged mice. 1G blocks NF-κB p65 from translocating into the nucleus and activating inflammatory gene transcription. These results illustrated that 1G suppresses the inflammatory effects both in-vitro and in-vivo studies via downregulating the nuclear factor kappa-B (NF-κB) signaling pathway. In conclusion, our results demonstrate that semi-synthetic derivative 1G can effectively attenuate the inflammatory response via NF-κB and MAPK signaling pathways; suggesting 1G is a potential novel anti-inflammatory drug candidate in treating inflammatory disorders.

Extract of Murraya koenigii selectively causes genomic instability by altering redox-status via targeting PI3K/AKT/Nrf2/caspase-3 signaling pathway in human non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Dietary bioactives have been used as alternative therapeutics to overcome various adverse effects caused by chemotherapeutics. Curry leaves are a widely used culinary spice and different parts of this plant have been used in traditional medicines. Curry leaves are a rich source of multiple bioactives, especially polyphenols and alkaloids. Therefore, extraction processes play a key role in obtaining the optimum yield of bioactives and their efficacy.

PURPOSE

We aim to select an extraction process that achieves the optimum yield of bioactives in curry leaves crude extract (CLCE) with minimum solvent usage and in a shorter time. Further, to investigate the anticancer properties of CLCE and its mechanism against lung cancer.

METHODS

Different extraction processes were performed and analyzed polyphenol content. The bioactives and essential oils present in curry leaves were identified through LC-MS/MS and GC-MS analysis. The cytotoxicity of microwave-assisted CLCE (MA-CLCE) was investigated through MTT and colony-forming assays. The DNA damage was observed by comet assay. The apoptotic mechanisms of MA-CLCE were investigated by estimating ROS production, depolarization of mitochondrial membrane potential (MMP), and apoptotic proteins. The glutathione assay estimated the antioxidant potential of MA-CLCE in normal cells.

RESULTS

Generally, conventional extraction methods require high temperatures, extra energy input, and time. Recently, green extraction processes are getting wider attention as alternative extraction methods. This study compared different extraction processes and found that the microwave-assisted extraction (MAE) method yields the highest polyphenols from curry leaves among other extraction processes with minimum processing. The MA-CLCE functions as an antioxidant under normal physiological conditions but pro-oxidant to cancer cells. MA-CLCE scavenges free radicals and enhances the intracellular GSH level in alveolar macrophages in situ. We found that MA-CLCE selectively inhibits cell proliferation and induces apoptosis in cancer cells by altering cellular redox status. MA-CLCE induces chromatin condensation and genotoxicity through ROS-induced depolarization of MMP. The depolarization of MMP causes the release of cytochrome c into the cytosol and activates the apoptotic pathway in lung cancer cells. However, pretreatment with ascorbic acid, an antioxidant, inhibits the MA-CLCE-induced apoptosis by reducing ROS production, which impedes mitochondrial membrane disruption, preventing BAX/BCL-2 expression alteration. Simultaneously, MA-CLCE downregulates the expression of survival signaling regulator PI3K/AKT, which modulates Nrf-2. MA-CLCE also diminishes intracellular antioxidant proficiency by suppressing Nrf-2 expression, followed by HO-1 expressions.

CONCLUSION

Among several extraction methods, MA-CLCE is rich in several bioactives, especially polyphenols, alkaloids, and essential oils. Here, we reported for the first time that MA-CLCE functions as a pro-oxidant to lung cancer cells and acts as an antioxidant to normal cells by regulating different cellular programs and signaling pathways. Therefore, it can be further developed as a promising phytomedicine against lung cancer.

Alkaloids and Colon Cancer: Molecular Mechanisms and Therapeutic Implications for Cell Cycle Arrest

Cancer is the second most fatal disease worldwide, with colon cancer being the third most prevalent and fatal form of cancer in several Western countries. The risk of acquisition of resistance to chemotherapy remains a significant hurdle in the management of various types of cancer, especially colon cancer. Therefore, it is essential to develop alternative treatment modalities. Naturally occurring alkaloids have been shown to regulate various mechanistic pathways linked to cell proliferation, cell cycle, and metastasis. This review aims to shed light on the potential of alkaloids as anti-colon-cancer chemotherapy agents that can modulate or arrest the cell cycle. Preclinical investigated alkaloids have shown anti-colon cancer activities and inhibition of cancer cell proliferation via cell cycle arrest at different stages, suggesting that alkaloids may have the potential to act as anticancer molecules.

Current status of carbazole hybrids as anticancer agents

The drug resistance and low specificity of current available chemotherapeutics to cancer cells are the main reasons responsible for the failure of cancer chemotherapy and remain dramatic challenges for cancer therapy, creating an urgent need to develop novel anticancer agents. Carbazole nucleus, widely distributed in nature, is a predominant feature of a vast array of biologically active compounds. Carbazole derivatives exhibited potential antiproliferative activity against different cancer cell lines by diverse mechanisms, inclusive of arrest cell cycle and induce apoptosis, and several anticancer agents are carbazole-based compounds. Thus, carbazole derivatives represent a fertile source for discovery of novel anticancer therapeutic agents. Over the past several years, a variety of carbazole hybrids have been developed as potential anticancer agents. The present review focuses on the recent progress, from 2016 until now, in knowledge on anticancer properties, structure-activity relationships and mechanisms of action of carbazole hybrids to provide a basis for development of relevant therapeutic agents.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Natural substances derived from herbs or plants are promising sources of anticancer agents against colorectal cancer via triggering apoptosis

OBJECTIVES

Nowadays, one of the most common gastrointestinal cancers is colorectal cancer (CRC). Chemotherapy is still one of the main methods to treat cancer. However, the currently available synthetic chemotherapy drugs often cause serious adverse reactions. Apoptosis is generally considered as an ideal way for induction the death of tumour cells without the body's inflammatory response, and it is reported that lots of natural agents could trigger various cancer cells to apoptosis. The overarching aim of this project was to elucidate the specific mechanisms by which natural substances induce apoptosis in CRC cells and to be used as an alternative therapeutic option in the future.

KEY FINDINGS

The mechanisms for the pro-apoptotic effects of natural substances derived from herbs or plants include death receptor pathway, mitochondrial pathway, endoplasmic reticulum stress pathway, related signal transduction pathways (PI3K/Akt, MAPK, p53 signalling), and so on.

SUMMARY

This paper updated this information regarding the anti-tumour effects of natural agents via induction of apoptosis against CRC, which would be beneficial for future new drug research regarding natural products from herbs or plants.

The anticancer activity of carbazole alkaloids

Chemotherapy is the first choice for the majority of cancers, but severe side effects and drug resistance restrict the actual clinical efficacy. Carbazole alkaloids, mainly from the Rutaceae family, possess favorable donor ability, good planarity, rich photophysical properties, and excellent biocompatibility. Carbazole alkaloids could not only intercalate in DNA but could also inhibit telomerase and topoisomerase and regulate protein phosphorylation. Hence, carbazole alkaloids are useful in providing lead hits/candidates for the development of novel anticancer agents. This review summarizes the research progress made regarding the anticancer properties of carbazole alkaloids, covering articles published from January 2010 to June 2021.

Effects of ethanol extract of curry leaves (Murraya koenigii) on HER2 and caspase-3 expression in rat model mammary carcinoma

BACKGROUND AND AIM

Human epidermal growth factor receptor 2 (HER2/erbB2/neu) is a prognostic factor and biomarker for detecting mammary tumor malignancy. Leaves of curry (Murraya koenigii) contain alkaloid, flavonoid, and phenolic compounds that can be cytotoxic to tumor cells. Caspase-3 is an indicator of apoptosis in tumor cells. This study aimed to evaluate the effect of curry leaf extract on the expression of HER2 and caspase-3 in mammary tumor through immunohistochemical analyses.

MATERIALS AND METHODS

Thirty five Sprague-Dawley rats were divided into seven groups: negative control of tumor (P1), positive control of tumor (P2), tumor therapy with methotrexate (P3), and curry leaf extract doses of 300 and 400 mg/kg body weight/BW after tumor formation (P4, P5), and before tumor formation (P6, P7). Thirty rats of six groups were injected subcutaneously into the mammary glands with 7,12-dimethylbenz(α)-anthracene DMBA) twice within 2 weeks for mammary tumor formation. At the end of the treatments, the rats were euthanized, and their mammary glands were analyzed histopathologically and immunohistochemically using HER2 and caspase-3 antibodies.

RESULTS

Regarding the expression of HER2 detected in the epithelial cell membrane of the mammary gland, P2, P3, P4, and P5 revealed positive expression, P6 and P7 showed equivocal expression, while P1 showed negative expression. Regarding caspase-3 expression in the cytoplasm of epithelial cells, it was low in P1, moderate in P2, P5, P6, and P7, and high in P3 and P4. These findings suggest that DMBA injection produced mammary tumors with HER2 as a biomarker of mammary tumor, and high caspase-3 expression in P4 was the effect of curry leaves extract.

CONCLUSION

The extract of curry leaves at a dose of 300 mg/kg BW with preventive and curative effects can potentially be used as an anti-tumor agent, which effectively induces the apoptosis of tumor cells.

Phytochemicals from Ajwa dates pulp extract induce apoptosis in human triple-negative breast cancer by inhibiting AKT/mTOR pathway and modulating Bcl-2 family proteins

Ajwa dates (Phoenix dactylifera L.) have been described in traditional and alternative medicine to provide several health benefits, but their mechanism of apoptosis induction against human triple-negative breast cancer MDA-MB-231 cells remains to be investigated. In this study, we analyzed the phytoconstituents in ethanolic Ajwa Dates Pulp Extract (ADPE) by liquid chromatography-mass spectrometry (LC-MS) and investigated anticancer effects against MDA-MB-231 cells. LC-MS analysis revealed that ADPE contained phytocomponents belonging to classes such as carbohydrates, phenolics, flavonoids and terpenoids. MTT assay demonstrated statistically significant dose- and time-dependent inhibition of MDA-MB-231 cells with IC50 values of 17.45 and 16.67 mg/mL at 24 and 48 h, respectively. Hoechst 33342 dye and DNA fragmentation data showed apoptotic cell death while AO/PI and Annexin V-FITC data revealed cells in late apoptosis at higher doses of ADPE. More importantly, ADPE prompted reactive oxygen species (ROS) induced alterations in mitochondrial membrane potential (MMP) in ADPE treated MDA-MB-231 cells. Cell cycle analysis demonstrated that ADPE induced cell arrest in S and G2/M checkpoints. ADPE upregulated the p53, Bax and cleaved caspase-3, thereby leading to the downregulation of Bcl-2 and AKT/mTOR pathway. ADPE did not show any significant toxicity on normal human peripheral blood mononuclear cells which suggests its safe application to biological systems under study. Thus, ADPE has the potential to be used as an adjunct to the mainline of treatment against breast cancer.

A Review of the Anti-Cancer Potential of Murraya koenigii (Curry Tree) and Its Active Constituents

Murraya koenigii (MK) relates to the Rutaceae family and has many health benefits. To date, over eighty-eight carbazole alkaloids along with terpenoids, and other nutrients have been identified from different parts of this plant. This review presents accumulated information regarding the role of MK and its constituents in the prevention/treatment of cancer. Literature survey revealed that MK and its constituents target multiple deranged pathways associated with apoptosis, growth (JAK-STAT, mTOR), and cell cycle in a variety of cancerous cell lines (colon, lung, liver, skin, prostate, breast, etc.) and few animal models. Thus, the present review highlights the anticancer mechanism of MK and its phytoconstituents, and further future perspectives. The ameliorating effects of MK and its phytoconstituents against various cancers warrant its multi-institutional clinical trials as soon as possible. The prospects of relatively cheaper cancer drugs could then be brighter, particularly for the socio-economically feebler cancer patients of the world.

Synthesis and biological evaluation of pyranocarbazole derivatives as Anti-tumor agents

A series of pyrano[3,2-a]carbazole alkaloids were designed and synthesized as derivatives of Girinimbine. The anticancer activities of these derivatives (3, 4a-j, 5a, 5c, 5f, 5i, 6c, 7a, 7c, 7f, 7i) against 10 cancer cell lines were studied. Among them, compounds 3 and 7i with N-methyl piperazine showed significant anticancer activity against MCF-7 cell lines with the IC50 values of 1.77 and 4.32 μM, respectively. Furthermore, their effects on altering cell morphology, inducing cell cycle arrest and apoptosis in MCF-7 cells were studied in vitro. In addition, the molecular docking study was carried out by using Discovery Studio software to predict the interactions between these derivatives and tubulin. All in all, these consequences reveal that pyranocarbazole derivatives with N-methyl piperazine can be used as potential anticancer lead compounds and provide useful points for the further optimization of pyranocarbazole alkaloids.

Antimalarial application of quinones: A recent update

Atovaquone belongs to a naphthoquinone class of drugs and is used in combination with proguanil (Malarone) for the treatment of acute, uncomplicated malaria caused by Plasmodium falciparum (including chloroquine-resistant P. falciparum/P. vivax). Numerous quinone-derived compounds have attracted considerable attention in the last few decades due to their potential in antimalarial drug discovery. Several semi-synthetic derivatives of natural quinones, synthetic quinones (naphtho-/benzo-quinone, anthraquinones, thiazinoquinones), and quinone-based hybrids were explored for their in vitro and in vivo antimalarial activities. A careful literature survey revealed that this topic has not been compiled as a review article so far. Therefore, we herein summarise the recent discovery (the year 2009-2020) of quinone based antimalarial compounds in chronological order. This compilation would be very useful towards the exploration of novel quinone-derived compounds against malarial parasites with promising efficacy and lesser side effects.

Metronidazole-conjugates: A comprehensive review of recent developments towards synthesis and medicinal perspective

Nitroimidazoles based compounds remain a hot topic of research in medicinal chemistry due to their numerous biological activities. Moreover, many clinical candidates based on this chemical core have been reported to be valuable in the treatment of human diseases. Metronidazole (MTZ) derived conjugates demonstrated a potential application in medicinal chemistry research over the last decade. In this review, we summarize the synthesis, key structure-activity-relationship (SAR) and associated biological activities such as antimicrobial, anticancer, antidiabetic, anti-inflammatory, anti-HIV and anti-parasitic (Anti-trichomonas, antileishmanial, antiamoebic and anti-giardial) of explored MTZ-conjugates. The molecular docking analysis is also presented simultaneously, which will assist in developing an understanding towards designing of new MTZ-conjugates for target-based drug discovery against multiple disease areas.

Anti-cancer effects of Porphyra haitanensis polysaccharides on human colon cancer cells via cell cycle arrest and apoptosis without causing adverse effects in vitro

In this study, the anticancer effects of Porphyra haitanensis polysaccharides (PHPs) on human colon cancer cells and non-cancerous cells were evaluated. PHP was extracted by an ultrasonic/microwave-assisted method, and three fractions of polysaccharides (PHP-F1, PHP-F2 and PHP-F3) were obtained through a DEAE-52 cellulose ion-exchange column. The results of the cytotoxicity test showed that all of the PHP fractions had inhibitory effects on the growth of colon cancer cells HT-29, LoVo and SW-480, but no toxic effects on the normal human cells HaCaT. The fractions PHP-F2 and PHP-F3 had the most significant cytotoxicity on HT-29 cells. Studies on intracellular reactive oxygen species (ROS) levels, cell apoptosis, the apoptosis index (using Hoechst 33342 staining) and analysis of cell cycle arrest using flow cytometry revealed that the fractions PHP-F2 and PHP-F3 could apparently induce oxidative stress and apoptosis in HT-29 cells and cause cell G0-G1 phase arrest. These findings suggest that polysaccharides from P. haitanensis have anticancer effects on human colon cancer cells and therefore might be regarded as new candidates for the prevention and treatment of colon cancers.

Repeatedly heated mix vegetable oils-induced atherosclerosis and effects of Murraya koenigii

Background

Statins are considered as standard drugs to control cholesterol levels, but their use is also associated with renal hypertrophy, hemorrhagic stroke, hepatomegaly, and myopathy. Murraya koenigii is an herb that is used in traditional cuisine and as a medicine in South Asia. Here we assessed the antidyslipidemic and antiatherosclerotic effects of this spice in repeated heated mix vegetable oils (RHMVO)-induced atherosclerotic models.

Methods

Aqueous extract of M. koenigii leaves (Mk LE) was prepared and its phytoconstituents were determined. Rabbits were divided into 5 groups (n = 10). Except for the control group, all the other four groups were treated with RHMVO for 16 weeks (dose = 2 ml/kg/day) to induce dyslipidemia and atherosclerosis. These groups were further treated for 10 weeks either with 300 and 500 mg/kg/day Mk LE, lovastatin, RHMVO, or left untreated. Body and organ weights were measured along with oxidative stress and tissue damage parameters. Lipid profile and hepatic function markers were studied. Atheroma measurement and histopathological examination were also performed in control and treated groups.

Results

Mk LE significantly (p < 0.05) attenuated RHMVO-induced dyslipidemia and atheroma formation. Furthermore, fat accumulation and lipid peroxidation in hepatic tissues were reduced by Mk LE in a dose-dependent manner. Our results indicated that the antidyslipidemic effects of Mk LE in 500 mg/kg/day dose were comparable to lovastatin. Additionally, oxidative stress markers were reduced much more significantly in Mk LE-500 than in the statin group (p < 0.05).

Conclusions

This study recommends Mk LE as a potent antioxidant and lipid-lowering natural medicine that can attenuate the RHMVO-induced atherosclerotic in optimal doses and duration. Therefore, Mk LE can be accessible, cheap, and free of adverse effects alternate to statins.

Chemopreventive activity of hydroethanolic Murraya koenigii leaves extract (HEMKLE) against chemically induced skin carcinogenesis in mice

The present study aimed to examine the chemoprotective effect of Hydroethanolic Murraya koenigii leaves extract (HEMKLE) on murine skin carcinogenesis model. For the study, male LACA mice divided into four groups (n = 15 per group). Group I (Control), Group II (DMBA/TPA), Group III (HEMKLE), and Group IV (HEMKLE + DMBA/TPA). Skin tumors were induced in Group II (DMBA/TPA) and Group IV (HEMKLE + DMBA/TPA) by topical application of 7, 12 dimethylbenz[a]anthracene (DMBA) [500 nmol/100 μL of acetone, twice a week for two weeks] and 12-O-tetradecanoyl phorbol-13-acetate (TPA) [1.7 nmol/100 μL of acetone, twice a week for eighteen weeks] and HEMKLE (200 mg/kg b. w.) was administered orally (instilled by oral gavage). The chemoprotective response of HEMKLE was evident by inhibition in tumor incidence, mean tumor volume, mean tumor burden, total number of tumors, and tumor size in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA). HEMKLE administration also decreased the reactive oxygen species (ROS) and lipid peroxidation (LPO) levels and increased the antioxidants enzyme activities in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA) that suggests its antioxidant potential. HEMKLE administration also increased the mRNA and protein expression of caspase-9 and caspase-3 and decreased the mRNA and protein expression of Bcl-2 in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA) that suggest its apoptosis-inducing effect on DMBA/TPA induced skin carcinogenesis.

Medicinal Profile, Phytochemistry, and Pharmacological Activities of Murraya koenigii and its Primary Bioactive Compounds

The discovery of several revitalizing molecules that can stop or reduce the pathology of a wide range of diseases will be considered a major breakthrough of the present time. Available synthetic compounds may provoke side effects and health issues, which heightens the need for molecules from plants and other natural resources under discovery as potential methods of replacing synthetic compounds. In traditional medicinal therapies, several plant extracts and phytochemicals have been reported to impart remedial effects as better alternatives. Murraya koenigii (M. koenigii) belongs to the Rutaceae family, which is commonly used as a medicinally important herb of Indian origin in the Ayurvedic system of medicine. Previous reports have demonstrated that the leaves, roots, and bark of this plant are rich sources of carbazole alkaloids, which produce potent biological activities and pharmacological effects. These include antioxidant, antidiabetic, anti-inflammatory, antitumor, and neuroprotective activities. The present review provides insight into the major components of M. koenigii and their pharmacological activities against different pathological conditions. The review also emphasizes the need for more research on the molecular basis of such activity in various cellular and animal models to validate the efficacy of M. koenigii and its derivatives as potent therapeutic agents.

PI3K/ Akt/ mTOR Pathway as a Therapeutic Target for Colorectal Cancer: A Review of Preclinical and Clinical Evidence

Background:

Phosphoinositide 3-kinase (PI3Ks) is a member of intracellular lipid kinases and involved in the regulation of cellular proliferation, differentiation and survival. Overexpression of the PI3K/Akt/mTOR signalling has been reported in various forms of cancers, especially in colorectal cancers (CRC). Due to their significant roles in the initiation and progression events of colorectal cancer, they are recognized as a striking therapeutic target.

Objective:

The present review is aimed to provide a detailed outline on the role of PI3K/Akt/mTOR pathway in the initiation and progression events of colorectal cancers as well as its function in drug resistance. Further, the role of PI3K/Akt/mTOR inhibitors alone and in combination with other chemotherapeutic drugs, in alleviating colorectal cancer is also discussed. The review contains preclinical and clinical evidence as well as patent literature of the pathway inhibitors which are natural and synthetic in origin.

Methods:

The data were obtained from PubMed/Medline databases, Scopus and Google patent literature.

Results:

PI3K/Akt/mTOR signalling is an important event in colorectal carcinogenesis. In addition, it plays significant roles in acquiring drug resistance as well as metastatic initiation events of CRCs. Several small molecules of natural and synthetic origin have been found to be potent inhibitors of CRCs by effectively downregulating the pathway. Data from various clinical studies also support these pathway inhibitors and several among them are patented.

Conclusion:

Inhibitors of the PI3K/mTOR pathway have been successful for the treatment of primary and metastatic colorectal cancers, rendering the pathway as a promising clinical cancer therapeutic target.

Mahanimbine Exerts Anticancer Effects on Human Pancreatic Cancer Cells by Triggering Cell Cycle Arrest, Apoptosis, and Modulation of AKT/Mammalian Target of Rapamycin (mTOR) and Signal Transducer and Activator of Transcription 3 (STAT3) Signalling Pathways

Background

Pancreatic cancer causes tremendous mortality across the globe mainly due to late diagnosis and unavailability of efficient chemotheruptic agents. In the current study the anticancer potential of a plant derived alkaloid, Mahanimbine, was examined against a panel of pancreatic cancer cells.

Material/Methods

The cell proliferation was determined by MTT assay. Annexin V/PI and DAPI staining were performed to detect apoptosis. Cell cycle distribution was investigated by flow cytometery. Cell migration was detected by wound healing assay and protein expression was checked by western blotting.

Results

The results revealed that Mahanimbine could inhibit the proliferation of the all the pancreatic cancer cells with lower cytoxicity against the normal cells. The IC₅₀ ranged from 3.5 to 64 μM against the pancreatic cancer cell lines. The lowest IC₅₀ of 3.5 μM was observed tor the Capan-2 and SW119 pancreatic cancer cell lines. The anticancer activity of Mahanimbine against the Capan-2 and SW119 cells was found to be due to G₀/G₁ cell cycle arrest and induction of apoptosis. Mahanimbine prompted apoptosis was also associated with decline in Bcl-2 and enhancement of the Bax expression. Further, it was observed that Mahanimbine could inhibit the AKT/mTOR and STAT3 signalling pathways in the Capan-2 and SW119 pancreatic cancer cells. The effects of the Mahanimbine were also examined on the migration of the Capan-2 and SW119 pancreatic cancer cells. It was found that Mahanimbine could inhibit the motility and migration of both the pancreatic cancer cell lines.

Conclusions

We found that Mahanimbine inhibits the proliferation of pancreatic cancer cells and as such Mahanimbine may prove beneficial in the management of pancreatic cancer.

New piperidine derivative DTPEP acts as dual-acting anti-breast cancer agent by targeting ERα and downregulating PI3K/Akt-PKCα leading to caspase-dependent apoptosis

OBJECTIVES

In our ongoing studies to develop ER targeting agents, we screened for dual-acting molecules with a hypothesis that a single molecule can also target both ER positive and negative groups of breast cancer.

MATERIALS AND METHODS

1-(2-(4-(Dibenzo[b,f]thiepin-10-yl)phenoxy)ethyl)piperidine (DTPEP) was synthesized and screened in both MCF-7 (ER+ve) and MDA-MB-231 (ER-ve) cells. Assays for analysis of cell cycle, ROS, apoptosis and MMP loss were carried out using flow cytometry. Its target was investigated using western blot, transactivation assay and RT-PCR. In vivo efficacy of DTPEP was validated in LA-7 syngeneic rat mammary tumour model.

RESULTS

Here, we report identification of dual-acting molecule DTPEP that downregualtes PI3K/Akt and PKCα expression, induces ROS and ROS-dependent apoptosis, loss of mitochondrial membrane potential, induces expression of caspase indicative of both intrinsic and extrinsic apoptosis in MCF-7 and MDA-MB-231 cells. In MCF-7 cells, DTPEP downregulates ERα expression and activation. In MDA-MB-231 cells, primary cellular target of DTPEP is not clearly known, but it downregualtes PI3K/Akt and PKCα expression. In vivo study showed regression of LA-7 syngeneic mammary tumour in SD rat.

CONCLUSIONS

We identified a new dual-acting anti-breast cancer molecules as a proof of concept which is capable of targeting both ER-positive and ER-negative breast cancer.

Carnosic acid induces apoptosis of hepatocellular carcinoma cells via ROS-mediated mitochondrial pathway

Carnosic acid (CA), an important bioactive phenolic diterpene mainly found in labiate plants, exerts various biological functions, including antioxidant, anti-inflammatory, antitumor, and neuroprotective activities. In the present study, we proved the deleterious effects of CA against hepatocellular carcinoma (HCC) in both in vitro and in vivo models. In vitro, CA significantly decreased cell viability, inhibited cell proliferation and migration, enhanced apoptosis, and increased caspase-3, -8, and -9 activities in HepG2 and SMMC-7721 cells. Specifically, CA led to a decreased mitochondrial membrane potential (MMP) and increases in intracellular reactive oxygen species (ROS) levels and apoptosis-related protein expression. Pre-incubation of HCC cells with N-Acetyl-l-cysteine (NAC), a ROS inhibitor, strongly suppressed CA-induced apoptotic phenomena, including reduced cell viability, excessive ROS levels, MMP decreases, and abnormal protein expression, suggesting an association of CA-induced apoptosis with oxidative stress-mediated mitochondrial pathways. In HepG2-and SMMC-7721-xenograft tumor mouse models, treatment with CA inhibited tumor growth and modulated apoptosis-related protein expression, confirming the anti-HCC effects of this chemical. Moreover, the CA-mediated anti-HCC effects associated with oxidative stress provide experimental evidence to support the potential use of CA as a drug therapy for HCC.