Alternaria alternata (SDHY01/02), a fungus associated with Lamellodysidea herbacea: its anticancer potential and responsible constituent(s).

One of the biggest global causes of death is cancer. The side effects of currently available therapies have triggered the search for new drugs. The marine environment, with its vast biodiversity, including sponges, is a rich source of natural products with immense pharmaceutical potential. The aim of the study was to analyze the microbes associated with the marine sponge, Lamellodysidea herbacea, and explore them as resources for anticancer ability. This study includes the isolation of fungi from L. herbacea, and their evaluation for cytotoxic potential against human cancer cell lines such as A-549 (lung), HCT-116 (colorectal carcinoma), HT-1080 (Fibrosarcoma), and PC-3 (prostate) using MTT assay. This revealed that fifteen extracts showed significant anticancer ability (IC50 ≤ 20 µg/mL), at least against one of the cell lines. Three extracts, SPG12, SPG19, and SDHY 01/02, were found significant in terms of anticancer activity, at least against three to four cell lines (IC50 values ≤ 20 µg/mL). The fungus SDHY01/02 was identified by sequencing the internal transcribed spacer (ITS) region as Alternaria alternata. Its extract showed IC50 values < 10 µg/mL against all the tested cell lines and was further analysed through light and fluorescence microscopy. The extract of SDHY01/02 was active (lowest IC50 4.27 µg/mL) against A549 cells in a dose-dependent manner and caused apoptotic cell death. Further, the extract was fractionated and analyzed the constituents by GC-MS (Gas Chromatography-Mass Spectrometry). Di-ethyl ether fraction revealed the constituents (having anticancer activity) such pyrrolo[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl); 4,5,6,7-tetrahydro-benzo[C]rhiophene-1-carboxylic acid cyclopropylamide; 17-pentatriacontene; 9,12-octadecadienoic acid (Z, Z)-, methyl ester; while DCM fraction contained Oleic acid, eicosyl ester. This is the first report of A. alternata with anticancer potential that has been isolated from the sponge L. herbacea, as far as we are aware.This A. alternata can be exploited to get anticancer molecule(s) in the future.

Antimicrobial and Cytotoxic Potential of Helminthosporin from Rumex abyssiniscus Jacq. Discovered as a Novel Source of Syringic Acid and Bis(2-ethyloctyl) Phthalate.

Rumex abyssinicus Jacq. is a perennial medicinal herb widely used in traditional medicine to treat many diseases. Phytochemicals of the plant were isolated using column chromatography and thin layer chromatography techniques. Extract, fractions and pure compounds were screened for antimicrobial activity against sensitive and multi-drug resistant microbes and their cytotoxicity was performed on different cancer cell lines. The mechanism of action of purified helminthosporin as well as the potent fraction containing a mixture of two compounds was assessed. Fraction R7C3 was the most potent antibacterial with the lowest MIC value of 0.12 µg/mL. Helminthosporin was the most potent compound with the lowest MIC value of 1.95 µg/mL. The compound was more potent than the antibiotic chloramphenicol against multi-drug resistant (MDR) bacteria with MIC equal to 16 µg/mL. The fraction and helminthosporin were shown to destroy the cell wall of the yeast and bacteria, and DNA fragmentation effect on the genome of Candida albicans and Bacillus cereus. Helminthosporin was the most cytotoxic compound with IC50 ˂ 10 µM. Fraction R7C3 showed the most potent cytotoxic effects on all cancer cell lines, with IC50 ranging from ˂1 to 4.35 ng/mL. Our study is the first report on the mechanism of action of helminthosporin, a potent candidate in the development of new drugs against multi-resistant bacteria and cancer cells. In addition, this study uncovered Rumex abyssinicus as a new source of syringic acid and bis(2-ethyloctyl) phthalate.

Synergistic combination of PMBA and 5-fluorouracil (5-FU) in targeting mutant KRAS in 2D and 3D colorectal cancer cells.

ß-Boswellic acid (ß-BA), a potent NF-kB signaling pathway inhibitor, has shown synergistic anti-cancerous activity (NCT03149081, NCT00243022 and NCT02977936) in various clinical trials as complementary therapies. The study has been conducted to investigate the effect and efficacy of 2-pyridin-4-yl methylene ß-boswellic acid (PMBA) and 5-Flourouracil (5-FU) in combination therapy for the treatment of KRAS mutant colon cancer. Analysis of isobologram showed synergistic combination index (CI > 1) of PMBA and 5-FU against the HCT-116 G13D and SW-620 G12V cell lines. The growth-inhibiting PMBA also caused apoptosis mediating effects with dose-dependent increase in caspase-3 activity, while inhibiting the formation of colonies in combination with 5-FU. As evident, PMBA affected colorectal 3D CSC properties including the ability to self-renew along with the expression of multi-drug resistance genes, viz., ABCB1, ABCC1 and ALDH1A1, ALDH1A2, ALDH1A3, ALDH3A1, and CSC markers like CD44, CD166, EPCAM, OCT-4, SOX-2, and NANOG compared with those in 2D model explaining the expression pattern of oncogenic KRAS G13D, G12V mutation. When examined for plasma level of PMBA (20 mg) and PMBA+5-FU (20 + 40 mg), a time-dependent increase in the level of the drug (5-FU) was detected, indicating its absorption and bioavailability with excellent half-life of the PMBA for both routes of administration (IV and Oral), thereby indicating a new adjuvant therapy for KRAS mutant colon cancer.

Carbohydrate Modifications of Neoandrographolide for Improved Reactive Oxygen Species-Mediated Apoptosis through Mitochondrial Pathway in Colon Cancer.

Modifications at the carbohydrate moiety of neoandrographolide, isolated from the medicinal plant Andrographis paniculata, result in more potent and less toxic derivatives, namely, 4',6'-benzylidene neoandrographolide (2b) and 4'6'-p-methoxybenzylidene neoandrographolide (2c). These showed improved cytotoxicity against SW-620, PC-3, and A549 cancer cell lines. Nuclear morphology studies were conducted on compound 2b by 4',6-diamidino-2-phenylidole staining and detection of intracellular reactive oxygen species (ROS) accumulation. It showed an increase in the generation of cellular and mitochondrial ROS level. The probable relation of B-cell lymphoma-2 (Bcl-2, an apoptosis inhibitor) to B-cell lymphoma-2-associated X protein (Bax, an apoptosis promoter) ratio with caspase-3 (apoptosis coordination enzyme) in the colon cancer cell line SW-620 was investigated, and it was discovered that upon 2b treatment, the expression of caspase-3 Bax increased remarkably. However, in 2b-treated cells, the expression of Bcl-2 was downregulated as compared to untreated cells.

A new clerodane furano diterpene glycoside from Tinospora cordifolia triggers autophagy and apoptosis in HCT-116 colon cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Tinospora cordifolia is a miraculous ayurvedic herb used in the treatment of innumerable diseases such as diabetes, gonorrhea, secondary syphilis, anaemia, rheumatoid arthritis, dermatological diseases, cancer, gout, jaundice, asthma, leprosy, in the treatment of bone fractures, liver & intestinal disorders, purifies the blood, gives new life to the whole body; (rejuvenating herb) and many more. Recent studies have revealed the anticancer potential of this plant but not much work has been done on the anticancer chemical constituents actually responsible for its amazing anticancer effects. This prompted us to investigate this plant further for new potent anticancer molecules. AIM OF THE STUDY: The present study was designed to isolate and identify new promising anticancer candidates from the aqueous alcoholic extract of T. cordifolia using bioassay-guided fractionation. MATERIALS AND METHODS: The structures of the isolated compounds were determined on the basis of spectroscopic data interpretation and that of new potent anticancer molecule, TC-2 was confirmed by a single-crystal X-ray crystallographic analysis of its corresponding acetate. The in vitro anti-cancer activity of TC-2 was evaluated by SRB assay and the autophagic activity was investigated by immunofluorescence microscopy. Annexin-V FITC and PI dual staining was applied for the detection of apoptosis. The studies on Mitochondrial Membrane potential and ROS (Reactive oxygen species) production were also done. RESULTS: Bioassay guided fractionation and purification of the aqueous alcoholic stem extract of Tinospora cordifolia led to the isolation of a new clerodane furano diterpene glycoside (TC-2) along with five known compounds i.e. cordifolioside A (ß-D-Glucopyranoside,4-(3-hydroxy-1-propenyl)- 2,6-dimethoxyphenyl 3-O-D-apio-ß-D-furanosyl) (TC-1), ß-Sitosterol(TC-3), 2ß,3ß:15,16-Diepoxy- 4α, 6ß-dihydroxy-13(16),14-clerodadiene-17,12:18,1-diolide (TC-4), ecdysterone(TC-5) and tinosporoside(TC-6). TC-2 emerged as a potential candidate for the treatment of colon cancer. CONCLUSION: The overall study on the bioassay guided isolation of T.cordifolia identified and isolated a new clerodane furano diterpenoid that exhibited anticancer activity via induction of mitochondria mediated apoptosis and autophagy in HCT116 cells. We have reported a promising future candidate for treating colon cancer.