In Vitro Murine Lymphoma L5178y-R Cells Growth Inhibition By Endophytic Fungi Isolated From Lophocereus Marginatus

Background: Chemotherapy is one of the main treatments to fight cancer. However, about 90% of failures in this procedure are due to the invasion and metastasis of drug-resistant cancer cells. Therefore, the search for new drugs has become critical in oncology. Endophytic fungi, as important sources of bioactive compounds, represent an alternative for the isolation, characterization, and development of new pharmacological treatments for cancer control. The aim of the present study was to evaluate the cytotoxic activity of liquid culture extracts of endophytic fungi isolated from Lophocereus marginatus against murine lymphoma L5178Y-R cells. Methods: Endophytic fungi obtained from L. marginatus stems were isolated and morphologically characterized. Aqueous, methanolic, and ethyl acetate extracts were obtained from fungal liquid cultures. To evaluate the anticancer activity, we used tumor L5178Y-R cells and control peripheral blood mononuclear cells (PBMCs). Extracts were evaluated at 250 and 25 µg/mL and 250 µg/mL, using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) colorimetric reduction assay to determine cytotoxicity. Vincristine and 1% DMSO were used as positive and negative controls, respectively. The IC50 value and selectivity index (SI) were determined only for the extracts that presented the highest antitumor activity. These isolates were molecularly identified from sequencing of the spacer region of the ribosomal DNA internal transcript (ITS). A metabolite production curve was performed with selected isolates to determine the time of the highest antitumor activity. Results: Ten endophytic fungi from L. marginatus were isolated and morphologically characterized. Results showed that aqueous extracts presented lower lymphoma cells growth inhibition (\u3c 50%) at the highest concentration evaluated (250 µg/mL), as compared with ethyl acetate and methanolic extracts, which showed up to 93.4% and 94.3% cells growth inhibition, respectively. Ten extracts with \u3e 80% tumor cells growth inhibition were selected and evaluated at 250 µg/mL on PBMCs viability. Extracts showing less than 50% cytotoxicity to PBMCs were selected and IC50 and IS were determined. Strain PME-H005 presented the highest toxicity against L5178Y-R cells and the highest SI with IC50 of 39.7 µg/mL and IS \u3e 6.2, as compared with PBMCs. Four isolates that showed the highest antitumor activity were molecularly identified, corresponding to the species Penicillium citrinum, Aspergillus versicolor, Metarhizium anisopliae, and Cladosporium sp. When performing the metabolite production curve, it was observed that only A. versicolor PME-H005 and M. anisopliae PME-H007 strains retained antitumor activity, where the ethyl acetate extracts showed the highest activity with IC50 values of 23.2 µg/ mL (28 d) for the PME-H005 strain and 2.7 µg/mL (21 d) for PME-H007. Conclusions: A. versicolor PME-H005 and M. anisopliae PME-H007 strains extracts showed significant antitumor activity against L5178Y-R lymphoma cells. Further research is required to characterize bioactive compounds responsible for this activity

Detection of Israeli Acute Paralysis Virus (IAPV) and Apis mellifera Filamentous Virus (AmFV) in Honey Bees in Mexico

The recent alarming loss of honey bee colonies around the world is believed to be related to the presence of viruses. The aim of this study was to detect two major viral diseases, Apis mellifera Filamentous virus (AmFV) and Israeli Acute Paralysis Virus (IAPV) using Reverse Transcription - Polymerase Chain Reaction RT-PCR, in honey bees in Mexico. Adult and larvae honey bee samples were collected from asymptomatic colonies of six major beekeeping regions in the state of Chihuahua, Mexico. Both viruses were detected in both developmental stages of honey bees, IAPV at a higher prevalence (23.5%) as compared to AmFV, only in 0.9% of samples. However, this is the first report on AmFV infection in Mexican apiaries. Further studies are required to understand the AmFV and IAPV impact on colony loss in Mexico and to develop strategies for enhancing the control of viral diseases