Differential cytotoxicity of MEX: a component of Neem oil whose action is exerted at the cell membrane level

A review of the anticancer activity of Azadirachta indica (Neem) in oral cancer

Background

Azadirachta indica (neem), belongs to the family of Meliaceae plants, is found in the Indian subcontinent. The neem tree is colloquially referred to as the village pharmacy due to its array of biological properties. Every part of the neem tree like its bark, leaves, sap, fruit, seeds, and twigs find a multitude of uses. It is customary to use them for management of skin diseases and various other infections.The anticancer properties of neem have been studied in the past and these include its ability to modulate the tumour environment, increase the cytotoxic ability of host monocytes and suppress the proliferation of tumour cells. The present review was conducted with the objective of scrutinizing and assimilating data about the usefulness Azadirachta indica in oral cancer from all the previously done work.

Material and methods

A planned review was conducted of all the studies that investigated the role of Azadirachta indica in oral cancer. Literature search was carried out using PubMed, Scopus and Google scholar databases. In addition to electronic searching, hand searching, cross referencing and various internet engines were also used to collect data. The articles were perused and articles not pertinent to our search were omitted.

Results and conclusion

The anticancer properties of neem were evaluated and the active constituents of neem have been demonstrated to unequivocally have preventive and therapeutic potential against oral cancer. Although, greater exploration of the anticancer properties of neem are required in order to effectively integrate it into the routine management of oral cancer.

Functional genomics screen with pooled shRNA library and gene expression profiling with extracts of Azadirachta indica identify potential pathways for therapeutic targets in head and neck squamous cell carcinoma

Tumor suppression by the extracts of Azadirachta indica (neem) works via anti-proliferation, cell cycle arrest, and apoptosis, demonstrated previously using cancer cell lines and live animal models. However, very little is known about the molecular targets and pathways that neem extracts and their associated compounds act through. Here, we address this using a genome-wide functional pooled shRNA screen on head and neck squamous cell carcinoma cell lines treated with crude neem leaf extracts, known for their anti-tumorigenic activity. We analyzed differences in global clonal sizes of the shRNA-infected cells cultured under no treatment and treatment with neem leaf extract conditions, assayed using next-generation sequencing. We found 225 genes affected the cancer cell growth in the shRNA-infected cells treated with neem extract. Pathway enrichment analyses of whole-genome gene expression data from cells temporally treated with neem extract revealed important roles played by the TGF-β pathway and HSF-1-related gene network. Our results indicate that neem extract affects various important molecular signaling pathways in head and neck cancer cells, some of which may be therapeutic targets for this devastating tumor.

An Overview on the Anticancer Activity of Azadirachta indica (Neem) in Gynecological Cancers

In recent years, a wide range of studies have pointed out the importance of nutraceuticals as reservoirs of therapeutic compounds for several diseases, including cancer. This study is centered on the role of some nutraceuticals as anticancer agents and on their efficiency in the oncological gynecological field. Gynecological cancers include cervical, ovarian, and breast neoplasia and these are the major causes of morbidity and mortality in the female population. Cervical neoplasia affects sexually active women aged between 30 and 40 years and is considered the second leading cause of death for women worldwide. Epidemiological studies have shown a strong association of this cancer with human papilloma virus (HPV) infection, independent of any others risk factors. Ovarian cancer represents about 4% of all women’s cancers and breast neoplasia registers 52.8 new cases per 100,000 women annually. Since ancient times, herbal therapies have shown a wide range of beneficial effects and a high potential for safeguarding human health. Azadirachta indica (Neem) is a medicinal plant of Indian origin, a tree with more of 140 isolated compounds and at least 35 biologically active principles that have shown an important influence as tumor suppressors by interfering with the carcinogenesis process. Used for centuries in Asia as a natural remedy for cancer, neem compounds present in bark, leaves, flowers, and seed oil have been shown to possess properties such as chemopreventive capacity, apoptotic activities, immunomodulatory effects, and induction of p53-independent apoptosis. The current study is a systematic literature review based on the anticarcinogenic potential of neem compounds in gynecological cancers.

Neem (Azadirachta indica): An indian traditional panacea with modern molecular basis

BACKGROUND

For centuries, agents derived from natural sources (mother nature), especially plants have been the primary source of medicine. Neem, also referred to as Azadirachta indica is one such plant that has been so named because it provides freedom from all diseases, and used for thousands of years in Indian and African continents. Different parts of the plant including flowers, leaves, seeds and bark have been used to treat both acute and chronic human diseases; and used as insecticide; antimicrobial, larvicidal, antimalarial, antibacterial, antiviral, and spermicidal.

PURPOSE

What is there in neem and how it manifests its wide variety of effects is the focus of this review. How neem and its constituents modulate various cellular pathways is discussed. The animal and human studies carried out with neem and its constituents is also discussed.

CONCLUSION

Over 1000 research articles published on neem has uncovered over 300 structurally diverse constituents, one third of which are limonoids including nimbolide, azadarachtin, and gedunin. These agents manifest their effects by modulating multiple cell signaling pathways.

Neem Seed Oil Induces Apoptosis in MCF-7 and MDA MB-231 Human Breast Cancer Cells

Background:

In traditional Indian medicine, azadirachta indica (neem) is known for its wide range of medicinal properties. Various parts of neem tree including its fruit, seed, bark, leaves, and root have been shown to possess antiseptic, antiviral, antipyretic, anti-inflammatory, antiulcer, antimalarial, antifungal and anticancer activity.

Materials and Methods:

MCF-7 and MDA MB-231 cells were exposed to various concentrations of 2% ethanolic solution of NSO (1-30 µl/ml) and further processed for cell viability, cell cycle and apoptosis analysis. In addition, cells were analyzed for alteration in Mitochondrial Membrane Potential (MMP) and generation of Reactive Oxygen Species (ROS) using JC-1 and DCFDA staining respectively.

Results:

NSO give 50% inhibition at 10 µl/ml and 20 µl/ml concentration in MCF-7 and MDA MB-231 cells respectively and, arrests cells at G0/G1 phase in both the cell types. There was a significant alteration in mitochondrial membrane potential that leads to the generation of ROS and induction of apoptosis in NSO treated MCF-7 and MDA MB-231 cells.

Conclusion:

The results showed that NSO inhibits the growth of human breast cancer cells via induction of apoptosis and G1 phase arrest. Collectively these results suggest that NSO could potentially be used in the management of breast cancer.

Nanocapsules Containing Neem (Azadirachta Indica) Oil: Development, Characterization, And Toxicity Evaluation

In this study, we prepared, characterized, and performed toxicity analyses of poly(ε-caprolactone) nanocapsules loaded with neem oil. Three formulations were prepared by the emulsion/solvent evaporation method. The nanocapsules showed a mean size distribution around 400 nm, with polydispersity below 0.2 and were stable for 120 days. Cytotoxicity and genotoxicity results showed an increase in toxicity of the oleic acid + neem formulations according to the amount of oleic acid used. The minimum inhibitory concentrations demonstrated that all the formulations containing neem oil were active. The nanocapsules containing neem oil did not affect the soil microbiota during 300 days of exposure compared to the control. Phytotoxicity studies indicated that NC_20 (200 mg of neem oil) did not affect the net photosynthesis and stomatal conductance of maize plants, whereas use of NC_10 (100:100 of neem:oleic acid) and NC_15 (150:50 of neem:oleic acid) led to negative effects on these physiological parameters. Hence, the use of oleic acid as a complement in the nanocapsules was not a good strategy, since the nanocapsules that only contained neem oil showed lower toxicity. These results demonstrate that evaluation of the toxicity of nanopesticides is essential for the development of environmentally friendly formulations intended for applications in agriculture.

Ozonolysis of neem oil: preparation and characterization of potent antibacterial agents against multidrug resistant bacterial strains

Neem ozonated oils showed excellent broad-spectrum antimicrobial activity against standard E. faecalis, clinical vancomycin resistant E. faecium, clinical multiresistant K. pneumoniae (KPC), and S. aureus (MRSA and standard).

Antibacterial activity of neem nanoemulsion and its toxicity assessment on human lymphocytes in vitro

Neem (Azadirachta indica) is recognized as a medicinal plant well known for its antibacterial, antimalarial, antiviral, and antifungal properties. Neem nanoemulsion (NE) (O/W) is formulated using neem oil, Tween 20, and water by high-energy ultrasonication. The formulated neem NE showed antibacterial activity against the bacterial pathogen Vibrio vulnificus by disrupting the integrity of the bacterial cell membrane. Despite the use of neem NE in various biomedical applications, the toxicity studies on human cells are still lacking. The neem NE showed a decrease in cellular viability in human lymphocytes after 24 hours of exposure. The neem NE at lower concentration (0.7-1 mg/mL) is found to be nontoxic while it is toxic at higher concentrations (1.2-2 mg/mL). The oxidative stress induced by the neem NE is evidenced by the depletion of catalase, SOD, and GSH levels in human lymphocytes. Neem NE showed a significant increase in DNA damage when compared to control in human lymphocytes (P<0.05). The NE is an effective antibacterial agent against the bacterial pathogen V. vulnificus, and it was found to be nontoxic at lower concentrations to human lymphocytes.

INSECTICIDAL AND OXIDATIVE EFFECTS OF AZADIRACHTIN ON THE MODEL ORGANISM Galleria mellonella L. (LEPIDOPTERA: PYRALIDAE)

The insecticidal effects, specifically, changes in hemolymph total protein and malondialdehyde (MDA) levels, and antioxidant enzyme activities of azadirachtin (AZA) given to the wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae) larvae via force feeding were investigated. Bioassays showed that the LD50 and LD99 (lethal dose) values of AZA were 2.1 and 4.6 μg/larva, respectively. Experimental analyses were performed with five doses of AZA (0.5, 1, 1.5, 2, and 3 μg/larva). Total protein level in larval hemolymph increased at all AZA doses at 24 h whereas a considerable decrease was observed at 2 and 3 μg/larva doses, and only an increase displayed at 1.5 μg/larva at 72 h. The level of MDA increased at 2 and 3 μg/larva doses at 24 h compared with controls. This trend was also observed at 1.5, 2, and 3 μg/larva doses at 72 h and MDA levels were lower when compared with those of 24 h at all doses except for 1.5 μg/larva dose. Catalase activity decreased at 1, 1.5, and 2 μg/larva doses at 24 h whereas increased at all doses except for 0.5 μg/larva at 72 h compared with controls. AZA led to a decline in superoxide dismutase activity at all experimental doses at 24 and 72 h except for 3 μg/larva doses at 72 h. An increase in glutathione-S-transferase (GST) activity was evident at all AZA doses at 24 h. AZA displayed 68% decline in GST activity at 72 h post treatments when compared to 24 h. Consequently, We infer that the toxicity of AZA extends beyond its known actions in molting processes to redox homeostasis.

In vitro anti-aging activities of extracts from leaves of Ma Kiang (Cleistocalyx nervosum var. paniala)

CONTEXT

Cleistocalyx nervosum (DC.) Kosterm. var. paniala (Roxb.) J. Parn. & Chantaran. (Myrtaceae) or Ma Kiang contains high amounts of phenolic compounds. Antioxidant activity of its fruit and seed has been investigated. However, limited available information concerning the biological activities of its leaves has been reported.

OBJECTIVE

To investigate the in vitro anti-aging potential of young and old leaves of Ma Kiang.

MATERIALS AND METHODS

Ma Kiang leaves were extracted using water, methanol, and chloroform as the solvents by cold (sonication) and hot (boiling) processes. The extracts were determined for total phenolic and flavonoid contents. The extracts (at 0.001-10 mg/ml) were tested for antioxidative and tyrosinase inhibition activities using a colorimetric method. The cytotoxicity of extracts (at 0.0001-1 mg/ml) was determined with human skin fibroblasts. Also, the extracts at 0.001, 0.01, and 0.1 mg/ml which showed no toxicity were tested for MMP-2 inhibition.

RESULTS

The cold methanol extract of the old leaves showed the highest total phenolic and flavonoid contents of 511.44 ± 18.23 μg GAE/mg and 262.96 ± 2.98 μg QE/mg, respectively. This extract also gave high free radical scavenging, lipid peroxidation inhibition, and tyrosinase inhibition activities with SC50, IPC50, and IC50 values of 0.02 ± 0.004, 0.23 ± 0.13, and 0.02 ± 0.006 mg/ml, respectively. The extract at 0.1 mg/ml exhibited the highest MMP-2 inhibition of 91.14 ± 1.67%.

DISCUSSION AND CONCLUSION

The anti-aging potential of the cold methanol extract from old leaves of Ma Kiang can be further developed as an anti-aging agent.

Neem components as potential agents for cancer prevention and treatment

Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment.

Structure and electronic properties of azadirachtin

We performed a combined DFT and Monte Carlo (13)C NMR chemical-shift study of azadirachtin A, a triterpenoid that acts as a natural insect antifeedant. A conformational search using a Monte Carlo technique based on the RM1 semiempirical method was carried out in order to establish its preferred structure. The B3LYP/6-311++G(d,p), wB97XD/6-311++G(d,p), M06/6-311++G(d,p), M06-2X/6-311++G(d,p), and CAM-B3LYP/6-311++G(d,p) levels of theory were used to predict NMR chemical shifts. A Monte Carlo population-weighted average spectrum was produced based on the predicted Boltzmann contributions. In general, good agreement between experimental and theoretical data was obtained using both methods, and the (13)C NMR chemical shifts were predicted highly accurately. The geometry was optimized at the semiempirical level and used to calculate the NMR chemical shifts at the DFT level, and these shifts showed only minor deviations from those obtained following structural optimization at the DFT level, and incurred a much lower computational cost. The theoretical ultraviolet spectrum showed a maximum absorption peak that was mainly contributed by the tiglate group.

Resveratrol exhibits a strong cytotoxic activity in cultured cells and has an antiviral action against polyomavirus: potential clinical use

Background

Resveratrol is a non flavonoid polyphenol compound present in many plants and fruits and, at especially high concentrations, in the grape berries of Vitis vinifera. This compound has a strong bioactivity and its cytoprotective action has been demonstrated, however at high concentrations the drug exhibits also an effective anti-proliferative action. We recently showed its ability to abolish the effects of oxidative stress in cultured cells. In this work we assayed the bioactivity of resveratrol as antiproliferative and antiviral drug in cultured fibroblasts. Studies by other Authors showed that this natural compound inhibits the proliferation of different viruses such as herpes simplex, varicella-zoster and influenza A. The results presented here show an evident toxic activity of the drug at high concentrations, on the other hand at sub-cytotoxic concentrations, resveratrol can effectively inhibit the synthesis of polyomavirus DNA. A possible interpretation is that, due to the damage caused by resveratrol to the plasma membrane, the transfer of the virus from the endoplasmic reticulum to the nucleus, may be hindered thus inhibiting the production of viral DNA.

Methods

The mouse fibroblast line 3T6 and the human tumor line HL60 were used throughout the work. Cell viability and vital cell count were assessed respectively, by the MTT assay and Trypan Blue staining. Cytotoxic properties and evaluation of viral DNA production by agarose gel electrophoresis were performed according to standard protocols.

Results

Our results show a clear dose dependent both cytotoxic and antiviral effect of resveratrol respectively at high and low concentrations. The cytotoxic action is exerted towards a stabilized cell-line (3T6) as well as a tumor-line (HL60). Furthermore the antiviral action is evident after the phase of virion entry, therefore data suggest that the drug acts during the synthesis of the viral progeny DNA.

Conclusion

Resveratrol is cytotoxic and inhibits, in a dose dependent fashion, the synthesis of polyomavirus DNA in the infected cell. Furthermore, this inhibition is observed at non cytotoxic concentrations of the drug. Our data imply that cyto-toxicity may be attributed to the membrane damage caused by the drug and that the transfer of polyomavirus from the endoplasmic reticulum to the cytoplasm may be hindered. In conclusion, the cytotoxic and antiviral properties of resveratrol make it a potential candidate for the clinical control of proliferative as well as viral pathologies.

Alterations of the plasma membrane caused by murine polyomavirus proliferation: an electrorotation study

In this report we investigate the alterations of the dielectric properties of the plasma membrane caused by the infection of cultured fibroblasts with murine polyomavirus. The approach consists in a well-established dielectric spectroscopy technique, electrorotation, which has been successfully used in our laboratory to study the alterations of the plasma membrane of cells exposed to various forms of stress. The response to viral proliferation was time dependent as shown by evaluation of the de novo synthesis of viral DNA. This response was paralleled by gradual damage of the membrane evidenced by alteration of the dielectric parameters, specific capacitance and conductance. The electrorotation results show a reduced effect on the dielectric properties of the membrane when infection is carried out in the presence of a natural oil (MEX). In this case a drastic reduction in viral DNA synthesis was also monitored, thus indicating an antiviral action of this product.