leaf extract induces cell cycle arrest and mitochondrial apoptosis in Dalton's Lymphoma: An in vitro and in vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

The present work is based on a wide spectrum of evidences available from scientific literature which reflects nutritional and medicinal values of natural products such as plants and their extracts. Moringa oleifera is one such popular plant species amidst indigenous tribal communities which is frequently used to treat ailments such as piles, sore throat, eye and ear infections and even poisonous bites of tropical fauna such as insects or snakes. Furthermore decoction of leaf and bark was used to cure fever and cough. Evidences further reveal that Moringa oleifera L. (Family Moringaceae), is widely distributed not only over the Indian sub-continent, but also over Philippines, Central America, Saudi Arabia and the Caribbean Islands and have been traditionally used to treat cancers since ancient times. However, therapeutic effects of Moringa oleifera on Non-Hodgkin Lymphoma (NHL) are yet to be established.

AIM OF THE STUDY

The study aims to investigate the anti-cancer effects of Moringa oleifera leaf extract against murine NHL Non-Hodgkin cells in vitro and in vivo.

MATERIAL AND METHODS

The pharmacologically active compounds of Moringa oleifera leaf extract were identified by GC-HRMS analysis. Tests of Moringa oleifera leaf extract's cytotoxicity against DL cells were carried out using the MTT assay. Chromatin condensation along with other morphological alterations were visualized through Fluorescence microscopy. Changes in the mitochondrial membrane potential (ΔΨm), the cell cycle, and apoptosis were analysed through flow cytometer. We tried to identify proteins involved in apoptosis and cell cycle through Western blotting using BALB/c mice as a model organism.

RESULTS

GC-HRMS study revealed that a methanol based leaf extract of Moringa oleifera (MOML) comprises of a variety of bioactive chemicals. Our results indicate that MOML successfully reduced the proliferation of DL cells by lowering ΔΨm, changing overall cell morphology. DL cells treated with MOML showed arrested cell cycle at the G2/M phase and substantially up-regulated the expression of p53 and p21. Elevated levels of Bax, Cyt-c, and Caspase-3 and lowered expression levels of Bcl-2 protein suggested induction of apoptosis. Mechanistically, the anticancer efficacy of MOML is attributed to MEK/ERK-mediated pathway inactivation in DL cells. It is also interesting to note that MOML-mediated inhibition of DL growth was accompanied by apoptosis induction and improvement in hematological parameters in DL-bearing mice.

CONCLUSION

Our finding suggested that MOML induces apoptosis and abrogates the growth of Dalton's lymphoma both in vitro and in vivo.

leaf extract induced anticancer effects on Dalton's Lymphoma via regulation of PKCα signaling pathway and mitochondrial apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Epidemiological studies promote the inclusion of natural-products in diet due to their inhibitory effects on various types of cancer. Among them, Achyranthes aspera L. (Family Amaranthaceae) is a medicinal plant in Ayurvedic pharmacopeia, found in India, Southeast Asia, America, and Sub-Saharan Africa. It is endowed with anti-inflammatory, anti-oxidant, and anti-cancer activities. However, its potential effect on Non-Hodgkin lymphomas (NHLs), has not yet been clarified.

AIM OF THE STUDY

In the present study, we aimed to investigate the effect of Achyranthes aspera L. leaf extracts on highly aggressive murine NHL called Dalton's Lymphoma (DL) in vitro and in vivo.

MATERIAL AND METHODS

GC-HRMS analysis was carried out for the identification of compounds present in A. aspera leaf extract. The cytotoxicity of various A. aspera leaf extracts was evaluated on DL cells by MTT assay. Chromatin condensation, nuclear fragmentation, and morphological changes were observed by microscopy technique. Flow cytometry was used to measure the changes in mitochondrial membrane potential (ΔΨm) and apoptosis. In addition, the expressions of apoptosis-related proteins were detected by western blotting. Meanwhile, the in vivo anti-tumor effect of leaf extract was tested in DL induced Balb/c mice.

RESULT

GC-HRMS analysis of A. aspera methanolic leaf extract (AAML) revealed the presence of ten pharmacologically active compounds. The results showed that AAML suppressed cell proliferation, decreased mitochondrial membrane potential, changed the morphological structure, and induced apoptosis. Moreover, AAML could promote the release of cytochrome c by regulating Bcl-2 family proteins and then activated caspase-9/ -3 to triggered cell apoptosis. At the same time in DL cells treated with AAML, the protein kinase Cα (PKCα) pathway was inhibited in a concentration-dependent manner. Remarkably, in vivo, AAML mediated suppression of DL growth in Balb/c mice was accompanied by attenuation of the PKCα pathway and induction of apoptosis. Our result suggested that AAML promotes mitochondrial apoptotic cascade in DL cells by suppressing the PKCα signaling pathway.

CONCLUSION

The study suggests that AAML could potently suppress DL progression by promoting apoptosis via mitochondrial-cascade and attenuation of the PKCα signaling pathway.

Biochemical changes associated with ascorbic acid-cisplatin combination therapeutic efficacy and protective effect on cisplatin-induced toxicity in tumor-bearing mice

Cisplatin is one of the well-established anticancer drugs being used against a wide spectrum of cancers. However, full therapeutic efficacy of the drug is limited due to development of various toxicities in the host. This study examines the comparative therapeutic effectiveness and toxicities of cisplatin alone and in combination of dietary ascorbic acid (AA) in ascites Dalton's lymphoma-bearing mice. The findings show that the combination treatment of mice with ascorbic acid plus cisplatin has much better therapeutic efficacy against murine ascites Dalton's lymphoma (DL) in comparison to cisplatin alone and this may involve a decrease in reduced glutathione (GSH), catalase activity and increased lipid peroxidation (LPO) in Dalton's lymphoma tumor cells. At the same time, combination treatment indicates a protective role of ascorbic acid against cisplatin-induced tissue toxicities (side effects) in the hosts. Cisplatin-induced histopathological changes in liver, kidney and testes were decreased after combination treatment. The analysis of renal function test (RFT), liver function test (LFT) and sperm abnormalities also suggest an improvement in these parameters after combination treatment. Therefore, it may be concluded that the increased GSH level, catalase activity and decreased LPO in the tissues, i.e., liver, kidney and testes after combination treatment may be involved in its protective ability against cisplatin-induced tissue toxicities in the host.

Carboxylic group-induced synthesis and characterization of selenium nanoparticles and its anti-tumor potential on Dalton's lymphoma cells

Carboxylic group-induced synthesis of selenium nanoparticles (SeNPs) was achieved using sodium selenosulphate as a precursor. The particles were stabilized and capped with 0.01% polyvinyl alcohol under ambient conditions. This is a simple and easy method of producing SeNPs in a size range from 35 to 105 nm. The synthesized SeNPs were purified by centrifugation at 11,500 × g for 20 min and characterized by UV-visible spectroscopy, FTIR spectroscopy, XRD, DSC and TEM. It was observed that the synthesized SeNPs showed differences in their absorption spectra, phase composition and crystal structure, thermodynamic behaviour, size and shape. Further, to confirm anti-tumour potential of the synthesized SeNPs induced by the carboxylic group of acetic acid, pyruvic acid and benzoic acid, cell viability assay, nuclear morphology testing and DNA fragmentation assay were carried out using Dalton's lymphoma (DL) cells. DL cells treated with the SeNPs showed reduced cell viability, altered nuclear morphology, typical apoptotic DNA ladder and apoptosis. Therefore, these SeNPs may have therapeutic relevance to treat this type of cancer.

Antitumor effect of soybean lectin mediated through reactive oxygen species-dependent pathway

AIMS

The present study evaluated the potential role of soybean lectin's (SBL) anticancer effect in vitro in different cancer cell lines and the therapeutic effectiveness in vivo in Dalton's lymphoma (DL) bearing mice model.

MAIN METHODS

The effect of SBL on cell growth and viability was measured using MTT assay in different cancer cells in vitro. Apoptosis, autophagic cell death, DNA-damaging potential and reactive oxygen species (ROS) were analyzed in HeLa cells. The in vivo efficacy of SBL was demonstrated in Dalton's lymphoma (DL) bearing mice.

KEY FINDINGS

SBL demonstrated clear, strong antiproliferative activity without affecting normal cells; however, heat denaturation of SBL diminished the antiproliferative efficacy of molecule as demonstrated by MTT assay. A sharp 74.51 ± 3.5% and 82.95 ± 5.8% inhibition of tumor cell proliferation in DL mice occurred when SBL was administered at a dosage of 1 and 2mg/kg body weight (i.p.), respectively, for ten days with the induction of autophagic and apoptotic cell death. An in vitro investigation revealed that SBL-mediated autophagy, apoptosis and DNA damage in HeLa cells were inflicted through the generation of ROS in a dose-dependent manner. Interestingly, pre-treating HeLa cells with N-acetylcysteine (NAC), a typical ROS scavenger, led to a noticeable reduction in SBL-induced autophagy, apoptosis and DNA-damaging activities, suggesting that SBL's antitumor potential was governed by ROS activation.

SIGNIFICANCE

In this study, we evaluated the apoptotic, autophagic death, and DNA-damaging effects of SBL in cancer cells, which may have the potential to be used as a phyto-derived protein for cancer therapy.

Tumor growth retardation and chemosensitizing action of fatty acid synthase inhibitor orlistat on T cell lymphoma: implication of reconstituted tumor microenvironment and multidrug resistance phenotype

BACKGROUND

Orlistat, a fatty acid synthase (FASN) inhibitor, has been demonstrated to inhibit tumor cell survival. However, the mechanism(s) of its tumor growth retarding action against malignancies of hematological origin remains unclear. It is also not understood if the antitumor action of orlistat implicates modulated susceptibility of tumor cell to anticancer drugs. Therefore, the present investigation focuses to study the antitumor and chemosensitizing action of orlistat in a murine host bearing a progressively growing T cell lymphoma.

METHODS

Tumor-bearing mice were administered with vehicle alone or containing orlistat followed by administration of PBS with or without cisplatin. Tumor progression and survival of tumor-bearing host were monitored along with analysis of tumor cell survival and apoptosis. Tumor ascitic fluid was examined for pH, NO and cytokines. Expression of genes and proteins was investigated by RT-PCR and western blot respectively. ROS was analyzed by DCFDA staining and FASN activity by spectrophotometry.

RESULTS

Orlistat administration to tumor-bearing mice resulted in tumor growth retardation, prolonged life span, declined tumor cell survival and chemosensitization to cisplatin. It was accompanied by increased osmotic fragility, modulated acidosis, expression of ROS, NO, cytokines, MCT-1 and VH(+) ATPase, Bcl2, Caspase-3, P53, inhibited FASN activity and declined expression of MDR and MRP-1 proteins.

CONCLUSION

Orlistat manifests antitumor and chemosensitizing action implicating modulated regulation of cell survival, reconstituted-tumor microenvironment and altered MDR phenotype.

GENERAL SIGNIFICANCE

These observations indicate that orlistat could be utilized as an adjunct regimen for improving antitumor efficacy of cisplatin.

Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: a role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications.

A low dose of doxorubicin improves antioxidant defence system and modulates anaerobic metabolism during the development of lymphoma

Objective:

The objective of the present study is to find low dose of doxorubicin (DOX) with cancer preventive activity and to check the implication of this low dose of DOX on antioxidant defence system during lymphoma growth in mice, as the clinical utility of anthracycline anticancer drugs, especially DOX is limited by a progressive cardiotoxicity linked to mitochondrial damage.

Materials and Methods:

We selected a dose of DOX (0.90 mg/kg body weight of mouse), which is about 20 folds lower than clinically used dose for cancer treatment. The cancer preventive action is monitored by modulation of anaerobic metabolism. The effect of this dose on antioxidant defence system is analyzed by testing the activities of antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST). The activities of these enzymes were monitored at different intervals during the growth of lymphoma in mice.

Results:

The activities of antioxidant enzymes, such as CAT, SOD, and GST, were found to decrease gradually during the growth of lymphoma in mice. The anaerobic metabolism was increasing with lymphoma growth. We report that about 20 folds lower dose of DOX enhances the activities of antioxidant enzymes and decreases anaerobic metabolism during the development of lymphoma. These enzymes of antioxidant defence system suppress oxidative stress and mitochondrial damage, whereas a decrease in anaerobic metabolism checks cancer growth.

Conclusions:

The result suggests that dose cumulative cellular toxicity of DOX may be avoided by treating cancer in animals with lower doses of DOX in combination with other drugs.