Evaluation of Apoptosis and Autophagy Inducing Potential of Berberis aristata, Azadirachta indica, and Their Synergistic Combinations in Parental and Resistant Human Osteosarcoma Cells

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.

Artemisia argyi extract induces apoptosis in human gemcitabine-resistant lung cancer cells via the PI3K/MAPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia argyi H. Lév. & Vaniot (Asteraceae), also called "Chinese mugwort", is frequently used as a herbal medicine in China, Japan, Korea, and eastern parts of Russia. It is known as "ai ye" in China and "Gaiyou" in Japan. In ancient China, the buds and leaves of A. argyi were commonly consumed before and after Tomb-sweeping Day. It is used to treat malaria, hepatitis, cancer, inflammatory diseases, asthma, irregular menstrual cycle, sinusitis, and pathologic conditions of the kidney and liver. Although A. argyi extract (AAE) has shown anti-tumor activity against various cancers, the therapeutic effect and molecular mechanism of AAE remains to be further studied in lung cancer.

AIM OF THE STUDY

This study aimed to demonstrate the anti-tumor effect of AAE and its associated biological mechanisms in CL1-0 parent and gemcitabine-resistant (CL1-0-GR) lung cancer cells.

EXPERIMENTAL PROCEDURE

Human lung cancer cells CL1-0 and CL1-0-GR cells were treated with AAE. Cell viability was assessed using the MTT, colony, and spheroid formation assays. Migration, invasion, and immunofluorescence staining were used to determine the extent of epithelial- mesenchymal transition (EMT). JC-1 and MitoSOX fluorescent assays were performed to investigate the effect of AAE on mitochondria. Apoptosis was detected using the TUNEL assay and flow cytometry with Annexin V staining.

RESULT

We found that A. argyi significantly decreased cell viability and induced apoptosis, accompanied by mitochondrial membrane depolarization and increased ROS levels in both parent cells (CL1-0) and gemcitabine-resistant lung cancer cells (CL1-0-GR). AAE-induced apoptosis is regulated via the PI3K/AKT and MAPK signaling pathways. It also prevents CL1-0 and CL1-0-GR cancer cell invasion, migration, EMT, colony formation, and spheroid formation. In addition, AAE acts cooperative with commercial chemotherapy drugs to enhance tumor spheroid shrinkage.

CONCLUSION

Our study provides the first evidence that A. argyi treatment suppresses both parent and gemcitabine-resistant lung cancer cells by inducing ROS, mitochondrial membrane depolarization, and apoptosis, and reducing EMT. Our finding provides insights into the anti-cancer activity of A. argyi and suggests that A. argyi may serve as a chemotherapy adjuvant that potentiates the efficacy of chemotherapeutic agents.

Bioassay-guided isolation of anti-tumor polyprenylphloroglucinols from Calophyllum polyanthum and primary mechanism

Five compounds were isolated from Calophyllum polyanthum leaves (10.09 g) by bioassay-guided fractionation to evaluate their anti-tumor activity. Among these compounds, apetalic acid (1) demonstrated significant inhibitory activity against 8 types of tumor cells (MHCC97H, CNE1, CNE2, B16, LOVO, SW480, A549, 1299), especially against two colon cancer cells (LOVO, SW480). Apetalic acid could inhibit cell proliferation, migration, invasion and induce apoptosis. It could significantly up-regulate the expression levels of apoptosis-related genes (BAX, Caspase-9,) and proteins (BAX, Cleaved-caspase-9, Cleaved-caspase-3) and down-regulated the expression of inhibitor of apoptosis gene (Bcl-2) and proteins (Bcl-2, phosphorylated AKT). Possible mechanism of the antitumor activity of apetalic acid derived from Calophyllum polyanthum supports its use in the prevention and treatment of colorectal cancer.

Berberine and musculoskeletal disorders: The therapeutic potential and underlying molecular mechanisms

BACKGROUND

Musculoskeletal disorders are a group of disorders that affect the joints, bones, and muscles, causing long-term disability. Berberine, an isoquinoline alkaloid, has been previously established to exhibit beneficial properties in preventing various diseases, including musculoskeletal disorders.

PURPOSE

This review article aims to recapitulate the therapeutic potential of berberine and its mechanism of action in treating musculoskeletal disorders.

METHODS

A wide range of literature illustrating the effects of berberine in ameliorating musculoskeletal disorders was retrieved from online electronic databases (PubMed and Medline) and reviewed.

RESULTS

Berberine may potentially retard the progression of osteoporosis, osteoarthritis and rheumatoid arthritis. Limited studies reported the effects of berberine in suppressing the proliferation of osteosarcoma cells. These beneficial properties of berberine are mediated in part through its ability to target multiple signaling pathways, including PKA, p38 MAPK, Wnt/β-catenin, AMPK, RANK/RANKL/OPG, PI3K/Akt, NFAT, NF-κB, Hedgehog, and oxidative stress signaling. In addition, berberine exhibited anti-apoptotic, anti-inflammatory, and immunosuppressive properties.

CONCLUSION

The current evidence indicates that berberine may be effective in preventing musculoskeletal disorders. However, findings from in vitro and in vivo investigations await further validation from human clinical trial.

In Vitro Evaluation of the Chemical Composition and Various Biological Activities of Ficus carica Leaf Extracts

Objectives

The present study aimed to investigate the inhibitory activities of enzymes related to diabetes mellitus and Alzheimer's disease of the methanol and water extracts of Ficus carica leaf extracts. The bioactive compounds and anticancer, antioxidant, and antimicrobial effects of the extracts were also investigated.

Materials and Methods

The bioactive compounds in the extracts were determined by gas chromatography-mass spectrometry. The antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6 sulphonic acid) (ABTS) radical scavenging, total phenol and flavonoid content, ferric reducing power, and iron chelating method. The anticancer, anticholinesterase, and antimicrobial effects were investigated using the XTT assay, Ellman method, and microdilution, respectively.

Results

Our results showed that between the water and methanol extracts there was a difference in terms of chemical composition. The antioxidant results suggested that both extracts have strong antioxidant activity. Similarly, both extracts showed strong α-glucosidase and α-amylase inhibition activity, while the water extract had higher inhibition activity than the methanol extract against acetylcholinesterase and butyrylcholinesterase. The methanol extract of F. carica exhibited significant anticancer activity on MDA-MB-231 cells and showed moderate antimicrobial activities against Escherichia coli and Staphylococcus aureus.

Conclusion

Our results suggest that F. carica leaves could be a valuable source for developing a promising therapeutic agent in cancer, diabetes, and Alzheimer's disease.

Berberine represses human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt signaling pathways

Berberine, an isoquinoline alkaloid from Coptidis Rhizoma, has been characterized as a potential anticancer drug due to its good anti-tumor effects. However, the molecular mechanisms involved in anti-gastric cancer remain poorly understood. Herein, the role of berberine in gastric cancer suppression by inducing cytostatic autophagy in vitro and in vivo was first investigated. Results showed that berberine induced an obvious growth inhibitory effect on gastric cancer BGC-823 cells without toxicity to human peripheral blood mononuclear cells. Treatment with berberine triggered cell autophagy, as demonstrated by the punctuate distribution of monodansylcadaverine staining and GFP-LC3, as well as the LC3-II, Beclin-1 and p-ULK1 promotion, and p62 degradation. Inhibition of autophagy by 3-MA, CQ, Baf-A1 and BECN1 siRNA obviously increased cell viability of berberine-exposed gastric cancer cells, which confirmed the anti-cancer role of autophagy induced by berberine. Mechanistic studies showed that berberine inhibited mTOR, Akt and MAPK (ERK, JNK and p38) pathways thereby inducing autophagy. Inhibition of above pathways increases berberine induced autophagy and cytotoxicity. Interestingly, mTOR/p70S6K was inhibited by the MAPK but not Akt. Furthermore, inhibition of autophagy reversed berberine down-regulated mTOR, Akt and MAPK. In xenografts, the berberine induced autophagy leads to suppression of tumor proliferation with no side-effect, and western blotting displayed an apparent attenuation of p-mTOR, p-p70S6K, p-Akt, p-ERK, p-JNK and p-p38 in tumors from berberine treated mice. Briefly, these results indicated that berberine repressed human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt, and provided a molecular basis for the treatment of gastric cancer.

Berberis Plants-Drifting from Farm to Food Applications, Phytotherapy, and Phytopharmacology

The genus Berberis includes about 500 different species and commonly grown in Europe, the United States, South Asia, and some northern areas of Iran and Pakistan. Leaves and fruits can be prepared as food flavorings, juices, and teas. Phytochemical analysis of these species has reported alkaloids, tannins, phenolic compounds and oleanolic acid, among others. Moreover, p-cymene, limonene and ocimene as major compounds in essential oils were found by gas chromatography. Berberis is an important group of the plants having enormous potential in the food and pharmaceutical industry, since they possess several properties, including antioxidant, antimicrobial, anticancer activities. Here we would like to review the biological properties of the phytoconstituents of this genus. We emphasize the cultivation control in order to obtain the main bioactive compounds, the antioxidant and antimicrobial properties in order to apply them for food preservation and for treating several diseases, such as cancer, diabetes or Alzheimer. However, further study is needed to confirm the biological efficacy as well as, the toxicity.

Autophagy Regulated by Gain of Function Mutant p53 Enhances Proteasomal Inhibitor-Mediated Cell Death through Induction of ROS and ERK in Lung Cancer Cells

Mutations in p53, especially gain of function (GOF) mutations, are highly frequent in lung cancers and are known to facilitate tumor aggressiveness. Yet, the links between mutant GOF-p53 and lung cancers are not well established. In the present study, we set to examine how we can better sensitize resistant GOF-p53 lung cancer cells through modulation of cellular protein degradation machineries, proteasome and autophagy. H1299 p53 null lung cancer cells were stably transfected with R273H mutant GOF-p53 or wild-type (wt) p53 or empty vectors. The presence of R273H-P53 conferred the cancer cells with drug resistance not only against the widely used chemotherapeutic agents like cisplatin (CDDP) or 5-flurouracil (5-FU) but also against potent alternative modes of therapy like proteasomal inhibition. Therefore, there is an urgent need for new strategies that can overcome GOF-p53 induced drug resistance and prolong patient survival following failure of standard therapies. We observed that the proteasomal inhibitor, peptide aldehyde N-acetyl-leu-leu-norleucinal (commonly termed as ALLN), caused an activation of cellular homeostatic machinery, autophagy in R273H-P53 cells. Interestingly, inhibition of autophagy by chloroquine (CQ) alone or in combination with ALLN failed to induce enhanced cell death in the R273H-P53 cells; however, in contrast, an activation of autophagy by serum starvation or rapamycin increased sensitivity of cells to ALLN-induced cytotoxicity. An activated autophagy was associated with increased ROS and ERK signaling and an inhibition of either ROS or ERK signaling resulted in reduced cytotoxicity. Furthermore, inhibition of GOF-p53 was found to enhance autophagy resulting in increased cell death. Our findings provide novel insights pertaining to mechanisms by which a GOF-p53 harboring lung cancer cell is better sensitized, which can lead to the development of advanced therapy against resistant lung cancer cells.

Nimbolide, a neem limonoid inhibits cytoprotective autophagy to activate apoptosis via modulation of the PI3K/Akt/GSK-3β signalling pathway in oral cancer

Of late, nimbolide, a limonoid from the neem tree (Azadirachta indica) has gained increasing research attention owing to its potent antiproliferative and apoptosis-inducing effects. The present study was designed to investigate the effect of nimbolide on autophagy and the time point at which the phosphorylation status of GSK-3β and PI3K dictate the choice between autophagy and apoptosis in SCC131 and SCC4 oral cancer cells. Additionally, we analysed changes in the expression of proteins involved in autophagy and apoptosis after therapeutic intervention with nimbolide in a hamster model of oral oncogenesis. Furthermore, we also demonstrate changes in the expression of key genes involved in apoptosis and autophagy during the stepwise evolution of hamster and human OSCCs. Nimbolide-induced stereotypical changes in oral cancer cells characteristic of both apoptosis and autophagy. Time-course experiments revealed that nimbolide induces autophagy as an early event and then switches over to apoptosis. Nimbolide negatively regulates PI3K/Akt signalling with consequent increase in p-GSK-3βTyr216, the active form of GSK-3β that inhibits autophagy. Downregulation of HOTAIR, a competing endogenous RNA that sponges miR-126 may be a major contributor to the inactivation of PI3K/Akt/GSK3 signalling by nimbolide. Analysis of key markers of apoptosis and autophagy as well as p-AktSer473 during sequential progression of hamster and human OSCC revealed a gradual evolution to a pro-autophagic and antiapoptotic phenotype that could confer a survival advantage to tumors. In summary, the results of the present study provide insights into the molecular mechanisms by which nimbolide augments apoptosis by overcoming the shielding effects of cytoprotective autophagy through modulation of the phosphorylation status of Akt and GSK-3β as well as the ncRNAs miR-126 and HOTAIR. Development of phytochemicals such as nimbolide that target the complex interaction between proteins and ncRNAs that regulate the autophagy/apoptosis flux is of paramount importance in cancer prevention and therapeutics.

Nimbolide induced apoptosis by activating ERK-mediated inhibition of c-IAP1 expression in human hepatocellular carcinoma cells

Nimbolide is one of the major compounds from the leaves and flowers of the neem tree and exhibits antitumor properties on various cancer cells. However, no report has shown that nimbolide induces apoptosis in vitro and in vivo in human hepatocellular carcinoma cells. Our results indicated that it inhibited cell growth in Huh-7 and PLC/PRF/5 cells. We also found that nimbolide induced cell death through the induction of G2/M phase arrest and mitochondrial dysfunction, accompanied by the increased expression of cleaved caspase-7, caspase-9, caspase-3, caspase-PARP, and Bax and decreased expression of Mcl-1 and Bcl-2. A human apoptosis antibody array analysis demonstrated that inhibition of the apoptosis family proteins (XIAP, c-IAP1, and c-IAP2) was one of the major targets of nimbolide. Additionally, nimbolide sustained activation of ERK expression. Moreover, pretreatment with U0126 (MEK inhibitor) markedly abolished nimbolide-inhibited cell viability, induced cell apoptosis, ERK phosphorylation, cleaved caspase-9, caspase-3, cleaved-PARP activation, and increased c-IAP1 expression in Huh-7 cells. An in vivo study showed that nimbolide significantly reduced Huh-7 tumor growth and weight in a xenograft mouse model. This study indicated the antitumor potential of nimbolide in human hepatocellular carcinoma cells.