ANTICANCER, ANTIOXIDANT AND ANTIVIRAL ACTIVITY OF NOVEL NANO-PARABIOTIC WEISSELLA PARAMESENTEROIDES MN2C2

Abstract

Probiotics, or beneficial bacteria, rely on their viability to offer health benefits. The concept of "paraprobiotics," suggesting that non-viable bacteria may offer health benefits similar to live probiotics, has challenged this notion. In some cases, administering live probiotics to individuals with weakened immune systems can be risky. Paraprobiotics could be a viable alternative in such scenarios. Paraprobiotics refer to the use of inactivated microbial cells or cell fractions to promote health benefits. Due to their extended shelf life, safety profile, and various beneficial effects such as cholesterol reduction, immune modulation, anti-inflammatory properties, and anti-cancer potential, paraprobiotics have gained significant attention. The main objective of this study was to develop parabiotics and nano-parabiotics using a cost-effective waste medium and asseass their in vitro biological activities, including antioxidant, anticancer, and antiviral properties, for potential functional food applications. The probiotic strain Weissella paramesenteroides MN2C2 was cultured in a low-cost sweet whey medium (LCSWM), and the resulting culture was separated into supernatant and heat-killed cells (HK), which were then sonicated to produce sonicated heat-killed (SHK) nano-parabiotics. The biological activities of HK and SHK were evaluated in vitro, including their antioxidant, anticancer, and antiviral activities. Furthermore, the safe and biologically active concentrations were determined for incorporation into functional dairy products such as yogurt, along with sensory evaluation. The HK and SHK parabiotics were successfully prepared using LCSWM and characterized as nano-formulations with sizes of 618.7 nm for HK and 456.4 nm for SHK, as determined by dynamic light scattering (DLS) and Transmission Electron Microscopy (TEM). The IC50 values for the antioxidant activities of HK and SHK were determined to be 38.36 µg/mL and 37.61 µg/mL, respectively. Both HK and SHK demonstrated a safe concentration of 1.1 mg/mL with a selectivity index (SI) of 2.2 against colorectal adenocarcinoma (Caco-2) cells, and SHK exhibited a 99.99% reduction in virus titers against Coxsackie virus B3 (CVB3). Finally, a safe dose of SHK was incorporated into yogurt as a functional food with acceptable sensory attributes.