First report on a novel Nigrospora sphaerica isolated from Catharanthus roseus plant with anticarcinogenic properties

Abstract

SummaryThis paper reports on the vinca alkaloid produced by a novel Nigrospora sphaerica isolated from Catharanthus roseus. Through liquid chromatography–mass spectrometry (LCMS), only the crude mycelia extract of this fungus was positive for determination of vinblastine. This vinca alkaloid was then purified by using high‐performance liquid chromatography (HPLC) and tested for cytotoxicity activity using MTT assays. The breast cell line cancer (MDA‐MB 231) was treated with a purified vinblastine which was intracellulary produced by N. sphaerica. The purified vinblastine from extracted leaf of C. roseus was used as a standard comparison. A positive result with a value of half maximal inhibitory concentration (IC 50) of > 32 μg ml−1 was observed compared with standard (IC 50) of 350 μg ml−1 only. It showed that a vinblastine produced by N. sphaerica has a high cytotoxicity activity even though the concentration of vinblastine produced by this endophytic fungus was only 0.868 μg ml−1.

Nigrospora sphaerica products from the flowering dogwood exhibit antitumorigenic effects via the translational regulator, pS6 ribosomal protein

“…In addition, treatment with 10 µg/ml of N. sphaerica induced a cytostatic cellular response in lung cancer cells and a cytotoxic cellular response in glioblastoma cells over the 6-day time period [ Figure 4]. These data are consistent with the antiproliferative effects of N. sphaerica products observed in leukemia and breast cancer cells [11,21] . Figure 4 shows an experiment representative of three independent experiments performed in duplicate (means ± SE) that displayed similar results.…”

“…The endophyte N. sphaerica has been previously reported in a number of plant species [11,[18][19][20] . To the best of our knowledge, this study is the first report to show the association of N. sphaerica with C. florida as confirmed using ITS rDNA sequence and phylogenetic analysis [ Figure 1].…”

“…To this end, the current study examined the antitumor activity of crude extracts prepared from the endophytic fungus Nigrospora sphaerica isolated from C. florida, which has previously been described as an endophyte resource for several biomedical applicable compounds such as antibiotics [7,8] , antiviral anthraquinones, azaphilones [9] , and the antifungal griseofulvin [10] . Of specific significance, the alkaloid chemotherapeutic drug, vinblastine, is also a product of the endophytic fungus N. sphaerica although isolated from Catharanthus roseus (Madagascar periwinkle) [11] . However, the clinical caveat with the utility of the microtubule poison vinblastine for the treatment of human cancers has been its associated toxicities, making it imperative to identify sources for chemotherapeutic agents with improved toxicity profiles.…”

Antioxidants and Phytochemical Analysis of Endophytic Fungi Isolated from a Medicinal Plant Catharanthus roseus

“…All fungi strains used in this project were previously isolated and identified by Ayob and Simarani [9]. The crude fungal extract has been prepared [10] and divided into crude mycelia extract (CME) and crude supernatant extract (CSE). Briefly, the cell free filtrate was extracted with a dichloromethane (3x200 ml) and evaporated to dryness using rotary evaporator.…”

Cytotoxicity and antimicrobial activity of alkaloids extracted from Catharanthus roseus associated endophytic fungi

“…Similarly, mycelial extract of the fungus Nigrospora sphaerica isolated from C. roseus produced vinblastine with a concentration higher than produced by the plant leaf extract. Vinblastine produced by N. sphaerica had a higher cytotoxic activity when using MTT assay against breast cell line cancer MDA-MB 231 (Ayob et al, 2017). Different extracts (methanol, ethanol, chloroform, ethyl acetate and acetone) of aerial parts of C. roseus showed in vitro cytotoxicity against MCF (breast cancer) cell lines by using MTT assay method (Ruskin and Aruna, 2014).…”