Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 20, Issue 2, 2020

Nature is a rich source of natural drug-like compounds with minimal side effects. Phytochemicals better known as “Natural Products” are found abundantly in a number of plants. Since time immemorial, spices have been widely used in Indian cuisine as flavoring and coloring agents. Most of these spices and condiments are derived from various biodiversity hotspots in India (which contribute 75% of global spice production) and form the crux of India’s multidiverse and multicultural cuisine. Apart from their aroma, flavor and taste, these spices and condiments are known to possess several medicinal properties also. Most of these spices are mentioned in the Ayurveda, the indigenous system of medicine. The antimicrobial, antioxidant, antiproliferative, antihypertensive and antidiabetic properties of several of these natural products are well documented in Ayurveda. These phytoconstituemts are known to act as functional immunoboosters, immunomodulators as well as anti-inflammatory agents. As anticancer agents, their mechanistic action involves cancer cell death via induction of apoptosis, necrosis and autophagy. The present review provides a comprehensive and collective update on the potential of 66 commonly used spices as well as their bioactive constituents as anticancer agents. The review also provides an in-depth update of all major in vitro, in vivo, clinical and pharmacological studies done on these spices with special emphasis on the potential of these spices and their bioactive constituents as potential functional foods for prevention, treatment and management of cancer.

Background: Ganoderma lucidum (Leyss. ex Fr.) Karst. (G. lucidum, GL) belongs to the family of Ganodermataceae (Basidiomycetes), and possesses activities including antitumor, antimicrobial, antiviral, and antiaging activities. Triterpenoids are typical chemical constituents in G. lucidum, and play an important role in the anti-cancer effects. According to the substituent group at the carbon 26 position, GL total triterpenes fraction can be divided into two types, Neutral Triterpene Fraction (NTF) and an Acidic Triterpene Fraction (ATF). The anti-cancer effects of total triterpenes fraction and total acidic triterpene fraction extracted from G. lucidum have been widely known in vivo and in vitro, whereas few have focused on total neutral triterpene fraction. Objective: The aim of this study was to evaluate the anti-cancer effects of NTF extracted from G. lucidum in vitro and in vivo and explore its anti-cancer active constituents on SW620 human colorectal cancer cells. Methods: NTF and ATF were extracted from the dry fruiting body of G. lucidum by impregnation method with 90% ethanol, and further isolated by using alkaline extraction and acid precipitation method. The total triterpenoid content of NTF and ATF was determined by using ultraviolet-visible spectrophotometry. The cytotoxic effects on human colon cancer cells SW480, SW620, SW1116, and mouse embryonic fibroblast cell line NIH3T3 were evaluated by using the MTT method. The anti-cancer activity of NTF in vivo was evaluated in Athymic nude mice against SW620 cells. An activity-guided separation and purification process were used to identify the anti-cancer active constituents of NTF by column and preparative high-performance liquid chromatography. Structures of the constituents were confirmed by 1H-NMR, 13C-NMR and MS. Protein expression was performed by Western blotting. Results: The percentage of total triterpenoids was 46.7% and 57.6% in ATF and NTF, respectively. Both fractions could reduce the viability of SW480, SW620, and SW1116 cells in vitro, whereby NTF exhibited a stronger effect than ATF. NTF markedly inhibited the growth of SW620 cell xenografts in mice at doses (250, 500mg/kg) during the treatment. Furthermore, a new garnoderic alcohol, named as ethyl ganoderate A and eight known ganoderic alcohols were isolated and identified from NTF by a bioassay-guided separation process. All of these compounds possessed anti-cancer activities against SW620 cells in vitro. As a representative ganoderma alcohol, ganodermanondiol significantly reduced the viability of SW620 cells through the induction of apoptosis, which was associated with the upregulated the levels of cleaved-poly (ADP-ribose) polymerase (PARP), cleaved-caspase-3, and -9. In addition, ganodermanondiol showed low cytotoxic activity against normal NIH3T3 cells. Conclusion: NTF are potential anti-cancer agents against colon cancer and the active constituents may be ganoderic alcohols whose inhibitory mechanism of anti-cancer action may be related to the activation of a mitochondrial- dependent pathway.

Objective: To assess the differential cytotoxic activity of PPIs on different human cancer cell lines; namely A549 lung cancer, CACO-2 colorectal cancer, MCF-7 breast cancer, and PANC-1 pancreatic cancer, A375 skin melanoma. Methods: In this study, the five human cancer cell lines and human non-cancerous fibroblasts were treated with increasing concentration of PPIs Omeprazole (OMP), Esomeprazole (ESOM), and Lansoprazole (LANSO) (50-300μM), over 24h, 48h, and 72h. Cell viability was determined using 3-(4,5- Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and the IC50 values of PPIs were measured. The most sensitive cell line A375 was used for further investigation. The cytotoxic effects of LANSO on these cells were assessed using Annexin-V Propidium Iodide (AV-PI) flow cytometry. As of action mechanism; anti-inflammatory effects of each PPIs and PPIs-DOXO combination therapy on LPS-stimulated RAW 264.7 mouse macrophages were assessed. Results: Dose and time dependence cytotoxic activity of PPIs on human cancer cell lines was founded. Unlike DOXO; All PPIs had a selective cytotoxic effect in the normal fibroblasts. Unlike the equipotent OMP and ESOM; LANSO was the most potent drug with IC50 values at 72h of 99, 217, 272, 208, 181μM against A375, A549, CACO-2, MCF-7, and PANC-1, respectively. AV-PI flow cytometry revealed dose-dependent apoptotic effects of LANSO alone and substantially enhanced in DOXO-co-treatments. Interestingly unlike ESOM and OMP, LANSO proved more effective than indomethacin in LPS-stimulated RAW 264.7 macrophages. None of the tested compounds, as well as indomethacin, exerted any cytotoxicity against RAW 264.7 macrophages. PPIs-DOXO lacked potential synergistic combination antiinflammation therapies. Conclusion: This study provides the evidence that PPIs induce a direct and differential cytotoxic activity against human cancer cell line by the induction of the apoptosis. Moreover, PPIs increase cancer cell lines sensitivity to doxorubicin via apoptosis augmentation. Nevertheless, PPIs-DOXO lacked potential synergistic combination therapies in either antiproliferation or anti-inflammation.

Background and Purpose: Colorectal cancer is one of the leading causes of cancer-related death in elderly people. The natural product muricatacin is an important member of the γ-lactone family, and it has exhibited antitumour activity in multiple cancer cell lines; however, the antitumour activities of muricatacin stereoisomers and their derivatives in colorectal cancer cells have not yet been systematically explored. Methods: The colorectal carcinoma cell line HCT116 was investigated in this study. Cell proliferation was assessed by MTT assay or crystal violet staining. Cell cycle arrest and cell apoptosis were evaluated by flow cytometry assay. The expression levels of p53, p21, cyclin E, cyclin D1, caspase-3, cleaved caspase-3, caspase-9, cleaved caspase-9 and LC3B were measured using western blot analysis. Autophagy induced by M2 was monitored by immunofluorescence assay with an antibody against LC3B. Results: Cell proliferation assays showed that both naturally occurring muricatacin (M4) and its synthetic stereoisomer (M2) are potent cell growth inhibitors in HCT116 cells, with IC50 values of 79.43 and 83.17μM, respectively; these values are much lower than those of the other two isomers, M1 and M3, and those of the sixmembered lactone analogues. The flow cytometry analysis revealed that M2 and M4 induced significant cell cycle arrest during G0/G1 phase and caused relatively low apoptosis rates in HCT116 cells. Further analysis indicated that M2 caused p53-independent p21 induction and cyclin E/cyclin D1 downregulation. In addition, M2 also markedly induced autophagy in the early stage of administration. Conclusion: Our results suggested that muricatacins possess potent antitumour activity against the colorectal carcinoma cell line HCT116 through inducing G0/G1 phase cell cycle arrest and autophagy in the early stage of administration.

Background: Colorectal cancer is the third most commonly diagnosed cancer in the world, causing many deaths every year. Combined chemotherapy has opened a new horizon in treating colorectal cancer. The objective of the present study is to investigate the activity of oxaliplatin in combination with emetine and patulin against colorectal cancer models. Methods: IC50 values of oxaliplatin, emetine and patulin were determined against human colorectal cancer cell lines (HT-29 and Caco-2) using MTT reduction assay. Synergistic, antagonistic and additive effects from the selected binary combinations were determined as a factor of sequence of administration and added concentrations. Proteomics was carried out to identify the proteins which were accountable for combined drug action applying to the selected drug combination. Results: Oxaliplatin in combination with patulin produced synergism against human colorectal cancer models depending on dose and sequence of drug administration. Bolus administration of oxaliplatin with patulin proved to be the best in terms of synergistic outcome. Altered expressions of nine proteins (ACTG, PROF1, PPIA, PDIA3, COF1, GSTP1, ALDOA, TBA1C and TBB5) were considered for combined drug actions of oxaliplatin with patulin. Conclusion: Bolus administration of oxaliplatin with patulin has the potential to be used in the treatment of colorectal cancer, and would warrant further evaluation using suitable animal model.