Antioxidant and anticancer activities of Lactobacillus Hilgardii strain AG12a

Abstract

Background: It has been proven that probiotic Lactobacillus bacteria have inhibitory effects on human cancer cell lines. The aim of this study is to isolate and characterize the antioxidant probiotic Lactobacillus and determine the possible anticancer activities of the selected strain. Methods: One of the Lactobacillus strain isolated from camel doogh sample showed the high antioxidant activity by using of different methods such as resistance to hydrogen peroxide, hydroxyl radical and superoxide anions. The antioxidant strain was characterized by sequencing of 16S rRNA V2-V3 regions and the 16S-23S intergenic spacer (ITS). The methanol extract of this strain supernatant was fractionated using thin layer chromatography (TLC) and antioxidant activity of fractions was detected by 0.1% of DPPH through TLC-DPPH bioautography. In vitro anticancer activity of each fraction was investigated by using MTT and flow cytometry methods. Results: According to the phylogenetic results, the antioxidant Lactobacillus strain was closely related to Lactobacillus hilgardii strain E91 (Accession No. EF536365). After fractionation and anti-proliferation assessments of Lactobacillus hilgardii strain AG12a extracellular materials, one of the antioxidant fraction (F4) showed maximum DPPH radical scavenging activity (IC 50 of 535.27 μg/mL). MTT assay of the F4 fraction demonstrated cytotoxic activity against Caco-2 with the IC50 value of 299.05 μg/mL. The cell death activity of the fraction was confirmed by flow cytometry with 30.925. Conclusions: In this study, the anticancer and apoptotic properties of Lactobacillus hilgardii against Caco-2 cell line was reported for the first time. The isolated bioactive fraction from the extracellular methanol extract needs to be further investigated in human studies of cancer therapy.

An In Vivo Study of Lactobacillus rhamnosus (PTCC 1637) as a New Therapeutic Candidate in Esophageal Cancer

“…Finally, 100 μl dimethyl sulfoxide (DMSO) was added, and the optical density of each well was read at 570 nm using ELISA plate reader (STAT Fax-USA, Model: Z100). To assess the cell viability, the absorption of drug-treated cells was divided by the absorption of control (non-drug) cells and multiplied by 100 [24][25][26][27]. Analyses were done using GraphPad prism version 5 software.…”

An Evolving Technology That Integrates Classical Methods with Continuous Technological Developments: Thin-Layer Chromatography Bioautography

“…LJ Hanka et al developed a quantitative microbiological assay and a bioautography system with Penicillium avellaneum UC-4376 for the antitumor drug maytansine and its homologues maytanprine and maytanbutine [ 67 ]. However, this method uses micro-dilution over separation, tracking and selecting; therefore, investigators cannot determine whether there are active antitumor components in crude extract samples in one step [ 68 ].…”

Lactobacillus plantarum Metabolites Elicit Anticancer Effects by Inhibiting Autophagy-Related Responses

“…The anticancer effects and its underlying mechanisms of L. plantarum and other Lactobacillus species have been previously reported [ 22 , 23 , 24 , 25 ]. L. salivarin REN suppressed the upregulation of COX-2 expression and therefore, decreased the rate of oral carcinogenesis [ 26 , 27 ].…”

“…L. salivarin REN suppressed the upregulation of COX-2 expression and therefore, decreased the rate of oral carcinogenesis [ 26 , 27 ]. L. hilgardii also showed an anticancer effect via inducing apoptosis pathways [ 22 ]. Moreover, Lactobacillus species are known to regulate autophagy.…”

“…Most of the mechanisms that explain the anticancer effect of L. plantarum have been with a focus on apoptosis. However, other Lactobacillus species have shown to regulate autophagy [ 22 , 33 , 34 ]. Therefore, we hypothesized the anticancer effect of L. plantarum is related to autophagy regulation.…”