Cephalotaxus griffithii Hook.f. needle extract induces cell cycle arrest, apoptosis and suppression of hTERT and hTR expression on human breast cancer cells

Regulation of Interferon-β-Modified Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes in Proliferation and Apoptosis of Prostate Cancer Cells

Prostate cancer (PCa) poses a serious burden to men. Interferon-β (IFN-β) is implicated in cancer cell growth. This study hence explored the regulation of IFN-β-modified human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) in PCa cells. In vitro-cultured hUCMSCs were transfected with pcDNA3.1-IFN-β plasmid or IFN-β siRNA. hUCMSC-Exos were extracted by ultracentrifugation and identified. PCa cells (PC3 and LNCap) were treated with Exos. Cellular internalization of Exos by cells was detected by uptake assay. Cell proliferation, cycle, and apoptosis were evaluated by CCK-8, EdU staining, and flow cytometry. Levels of cell cycle-related proteins (cyclin D/cyclin E) were determined by Western blot. The effect of IFN-β-modified hUCMSC-Exos in vivo was analyzed. IFN-β-modified hUCMSC-Exos (Exooe-IFN-β or Exosi-IFN-β) were successfully isolated. IFN-β was encapsulated in Exos, and PCa cells could uptake Exos. After treating with Exooe-IFN-β, PCa cell proliferation was impeded, the percentage of cells in the G0/G1 phase, cyclin D/cyclin E levels, and cell apoptotic rate were elevated, while cells treated with Exooe-IFN-β exhibited contrary trends. IFN-β-modified hUCMSC-Exos reduced PCa tumor size and weight in vivo. Conjointly, IFN-β-modified hUCMSC-Exos suppress PCa cell proliferation and facilitate apoptosis.

Progress in structure, synthesis and biological activity of natural cephalotane diterpenoids

The Cephalotaxus genus is well-known owing to the numerous complex, biologically relevant natural products that can be obtained from its constituent species. The successful identification of various Cephalotaxus alkaloids and natural, structurally diverse cephalotane diterpenoids that exhibit antitumor activities and excellent pharmacological properties has encouraged the discovery of previously undescribed compounds from this genus. The present review summarizes the different strategies for the total synthesis of cephalotane diterpenoids as well as their diverse chemical structures, antitumor activities, structure-activity relationships (SARs), and biosynthetic pathways.

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.

Ethnopharmacology, chemodiversity, and bioactivity of Cephalotaxus medicinal plants

Cephalotaxus is the only genus of Cephalotaxaceae family, and its natural resources are declining due to habitat fragmentation, excessive exploitation and destruction. In many areas of China, folk herbal doctors traditionally use Cephalotaxus plants to treat innominate swollen poison, many of which are cancer. Not only among Han people, but also among minority ethnic groups, Cephalotaxus is used to treat various diseases, e.g., cough, internal bleeding and cancer in Miao medicine, bruises, rheumatism and pain in Yao medicine, and ascariasis, hookworm disease, scrofula in She medicine, etc. Medicinal values of some Cephalotaxus species and compounds are acknowledged officially. However, there is a lack of comprehensive review summarizing the ethnomedicinal knowledge of Cephalotaxus, relevant medicinal phytometabolites and their bioactivities. The research progresses in ethnopharmacology, chemodiversity, and bioactivities of Cephalotaxus medicinal plants are reviewed and commented here. Knowledge gaps are pinpointed and future research directions are suggested. Classic medicinal books, folk medicine books, herbal manuals and ethnomedicinal publications were reviewed for the genus Cephalotaxus (Sanjianshan in Chinese). The relevant data about ethnobotany, phytochemistry, and pharmacology were collected as comprehensively as possible from online databases including Scopus, NCBI PubMed, Bing Scholar, and China National Knowledge Infrastructure (CNKI). "Cephalotaxus", and the respective species name were used as keywords in database search. The obtained articles of the past six decades were collated and analyzed. Four Cephalotaxus species are listed in the official medicinal book in China. They are used as ethnomedicines by many ethnic groups such as Miao, Yao, Dong, She and Han. Inspirations are obtained from traditional applications, and Cephalotaxus phytometabolites are developed into anticancer reagents. Cephalotaxine-type alkaloids, homoerythrina-type alkaloids and homoharringtonine (HHT) are abundant in Cephalotaxus, e.g., C. lanceolata, C. fortunei var. alpina, C. griffithii, and C. hainanensis, etc. New methods of alkaloid analysis and purification are continuously developed and applied. Diterpenoids, sesquiterpenoids, flavonoids, lignans, phenolics, and other components are also identified and isolated in various Cephalotaxus species. Alkaloids such as HHT, terpenoids and other compounds have anticancer activities against multiple types of human cancer. Cephalotaxus extracts and compounds showed anti-inflammatory and antioxidant activities, immunomodulatory activity, antimicrobial activity and nematotoxicity, antihyperglycemic effect, and bone effect, etc. Drug metabolism and pharmacokinetic studies of Cephalotaxus are increasing. We should continue to collect and sort out folk medicinal knowledge of Cephalotaxus and associated organisms, so as to obtain new enlightenment to translate traditional tips into great therapeutic drugs. Transcriptomics, genomics, metabolomics and proteomics studies can contribute massive information for bioactivity and phytochemistry of Cephalotaxus medicinal plants. We should continue to strengthen the application of state-of-the-art technologies in more Cephalotaxus species and for more useful compounds and pharmacological activities.

Targeting telomerase for its advent in cancer therapeutics

Telomerase has emerged as an important primary target in anticancer therapy. It is a distinctive reverse transcriptase enzyme, which extends the length of telomere at the 3' chromosomal end, and uses telomerase reverse transcriptase (TERT) and telomerase RNA template-containing domains. Telomerase has a vital role and is a contributing factor in human health, mainly affecting cell aging and cell proliferation. Due to its unique feature, it ensures unrestricted cell proliferation in malignancy and plays a major role in cancer disease. The development of telomerase inhibitors with increased specificity and better pharmacokinetics is being considered to design and develop newer potent anticancer agents. Use of natural and synthetic compounds for the inhibition of telomerase activity can lead to an opening of new vistas in cancer treatment. This review details about the telomerase biochemistry, use of natural and synthetic compounds; vaccines and oncolytic virus in therapy that suppress the telomerase activity. We have discussed structure-activity relationships of various natural and synthetic telomerase inhibitors to help medicinal chemists and chemical biology researchers with a ready reference and updated status of their clinical trials. Suppression of human TERT (hTERT) activity through inhibition of hTERT promoter is an important approach for telomerase inhibition.

Reverse Screening Bioinformatics Approach to Identify Potential Anti Breast Cancer Targets Using Thymoquinone from Neutraceuticals Black Cumin Oil

BACKGROUND

Functional foods, neutraceuticals and natural antioxidants have established their potential roles in the protection of human health and diseases. Thymoquinone (TQ), the main bioactive component of Nigella sativa seeds (black cumin seeds), a plant derived neutraceutical was used by ancient Egyptians because of their ability to cure a variety of health conditions and used as a dietary food supplement. Owing to its multi targeting nature, TQ interferes with a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Additionally, TQ can specifically sensitize tumor cells towards conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells besides being cost effective and safe. TQ was found to play a protective role when given along with chemotherapeutic agents to normal cells.

METHODS

In the present study, reverse in silico docking approach was used to search for potential molecular targets for cancer therapy. Various metastatic and apoptotic targets were docked with the target ligand. TQ was also tested for its anticancer activities for its ability to cause cell death, arrest cell cycle and ability to inhibit PARP gene expression.

RESULTS

In silico docking studies showed that TQ effectively docked metastatic targets MMPs and other apoptotic and cell proliferation targets EGFR. They were able to bring about cell death mediated by apoptosis, cell cycle arrest in the late apoptotic stage and induce DNA damage too. TQ effectively down regulated PARP gene expression which can lead to enhanced cancer cell death.

CONCLUSION

Thymoquinone a neutraceutical can be employed as a new therapeutic agent to target triple negative breast cancer which is otherwise difficult to treat as there are no receptors on them. Can be employed along with standard chemotherapeutic drugs to treat breast cancer as a combinatorial therapy.

Telomerase Inhibitors from Natural Products and Their Anticancer Potential

Telomeres and telomerase are nowadays exploring traits on targets for anticancer therapy. Telomerase is a unique reverse transcriptase enzyme, considered as a primary factor in almost all cancer cells, which is mainly responsible to regulate the telomere length. Hence, telomerase ensures the indefinite cell proliferation during malignancy—a hallmark of cancer—and this distinctive feature has provided telomerase as the preferred target for drug development in cancer therapy. Deactivation of telomerase and telomere destabilization by natural products provides an opening to succeed new targets for cancer therapy. This review aims to provide a fundamental knowledge for research on telomere, working regulation of telomerase and its various binding proteins to inhibit the telomere/telomerase complex. In addition, the review summarizes the inhibitors of the enzyme catalytic subunit and RNA component, natural products that target telomeres, and suppression of transcriptional and post-transcriptional levels. This extensive understanding of telomerase biology will provide indispensable information for enhancing the efficiency of rational anti-cancer drug design.

Cephalotaxus Alkaloids

Cephalotaxus alkaloids represent a family of plant secondary metabolites known for 60 years. Significant activity against leukemia in mice was demonstrated for extracts of Cephalotaxus. Cephalotaxine (CET) (1), the major alkaloid of this series was isolated from Cephalotaxus drupacea species by Paudler in 1963. The subsequent discovery of promising antitumor activity among new Cephalotaxus derivatives reported by Chinese, Japanese, and American teams triggered extensive structure elucidation and biological studies in this family. The structural feature of this cephalotaxane family relies mainly on its tetracyclic alkaloid backbone, which comprises an azaspiranic 1-azaspiro[4.4]nonane unit (rings C and D) and a benzazepine ring system (rings A and B), which is linked by its C3 alcohol function to a chiral oxygenated side chain by a carboxylic function alpha to a tetrasubstituted carbon center. The botanical distribution of these alkaloids is limited to the Cephalotaxus genus (Cephalotaxaceae). The scope of biological activities of the Cephalotaxus alkaloids is mainly centered on the antileukemic activity of homoharringtonine (HHT) (2), which in particular demonstrated marked benefits in the treatment of orphan myeloid leukemia and was approved as soon as 2009 by European Medicine Agency and by US Food and Drug Administration in 2012. Its exact mechanism of action was partly elucidated and it was early recognized that HHT (2) inhibited protein synthesis at the level of the ribosome machinery. Interestingly, after a latency period of two decades, the topic of Cephalotaxus alkaloids reemerged as a prolific source of new natural structures. To date, more than 70 compounds have been identified and characterized. Synthetic studies also regained attention during the past two decades, and numerous methodologies were developed to access the first semisynthetic HHT (2) of high purity suitable for clinical studies, and then high grade enantiomerically pure CET (1), HHT (2), and analogs.