Chaga mushroom triterpenoids as adjuncts to minimally invasive cancer therapies: A review

Cancer has become the second leading cause of death in the world. Integrative cancer therapy management is continuously evolving to enhance treatment outcomes. Chaga mushroom (Inonotus obliquus) is a parasitic fungus acclaimed to contain pharmaceutical and nutraceutical value in the fight against cancer. In particular, triterpenoid constituents derived from Chaga mushrooms have been recognized for their anti-cancer activity after distinguished cytotoxicity was repeatedly observed in cancer cells treated in vitro with lipophilic fractions of extract compared to aqueous ones. Studies that investigate the anti-cancer activity of Chaga mushroom triterpenoids are reviewed in this article to determine which cancer cell lines demonstrate the greatest susceptibility to them while highlighting the structure-activity relationships that are involved. Triterpenoid supplementation as an adjunct to cancer treatment may be a viable option as inotodiol and 3-β-22 α-dihydroxylanosta-8, 25-diene-24-one have been shown to exhibit anti-cancer activity similar to that of conventional drugs. Advances in addressing bioavailability challenges are also included in this review as studies include in vivo components.

Vitamin-Containing Antioxidant Formulation Reduces Carcinogen-Induced DNA Damage through ATR/Chk1 Signaling in Bronchial Epithelial Cells In Vitro

Lung cancer has the highest mortality rate worldwide and is often diagnosed at late stages, requiring genotoxic chemotherapy with significant side effects. Cancer prevention has become a major focus, including the use of dietary and supplemental antioxidants. Thus, we investigated the ability of an antioxidant formulation (AOX1) to reduce DNA damage in human bronchial epithelial cells (BEAS-2B) with and without the combination of apple peel flavonoid fraction (AF4), or its major constituent quercetin (Q), or Q-3-O-d-glucoside (Q3G) in vitro. To model smoke-related genotoxicity, we used cigarette-smoke hydrocarbon 4-[(acetoxymethyl)nitrosamino]-1-(3-pyridyl)-1-butanone (NNKOAc) as well as methotrexate (MTX) to induce DNA damage in BEAS-2B cells. DNA fragmentation, γ-H2AX immunofluorescence, and comet assays were used as indicators of DNA damage. Pre-exposure to AOX1 alone or in combination with AF4, Q, or Q3G before challenging with NNKOAc and MTX significantly reduced intracellular reactive oxygen species (ROS) levels and DNA damage in BEAS-2B cells. Although NNKOAc-induced DNA damage activated ATM-Rad3-related (ATR) and Chk1 kinase in BEAS-2B cells, pre-exposure of the cells with tested antioxidants prior to carcinogen challenge significantly reduced their activation and levels of γ-H2AX (p ≤ 0.05). Therefore, AOX1 alone or combined with flavonoids holds promise as a chemoprotectant by reducing ROS and DNA damage to attenuate activation of ATR kinase following carcinogen exposure.

Abstract 1779: Dietary supplementation of haskap berry anthocyanin and probiotics attenuate the severity of DSS-induced acute colitis in Balb/c mice

Introduction: Colitis-associated colorectal cancer is a specific type of colorectal cancer that develops from long-standing chronic inflammatory conditions in colorectal epithelium. Genotoxic compounds produced by inflammatory cells can damage DNA and thereby can initiate malignant transformation. Haskap (Lonicera caerulea L.) berry, is a rich source of dietary anthocyanins, specifically cyanidin-3-O-glucoside (C3G). C3G has been shown to possess anti-inflammatory and anti-cancer properties. This study aimed at investigating the oral supplementation of free- or microencapsulated-haskap anthocyanin (310 mg/kg of body weight/mouse) alone or with probiotics (1×109 CFU/day) on the severity reduction of dextran sulphate sodium (DSS)- induced acute colitis in Balb/c mice.

Methodology: The study was carried out in two main phases: 1) optimization of microencapsulation of haskap anthocyanin using novel coating materials; and 2) Investigating the combined effect of anthocyanin and probiotics on DSS-induced acute colitis in vivo. Maltodextrin and inulin (3:1 w/w) were used as coating materials and four different core to shell ratios (1:1, 1:1.5, 1:2 and 1:3) were tested. The best ratio (1:1.5) was selected based on the physical characteristics, encapsulation yield, efficiency, recovery, and anthocyanin retention in the particles and was then used in DSS induced acute colitis model. Thirty-five Balb/C male mice of seven weeks old were divided into seven dietary supplementation groups (n=5) to receive either free anthocyanin, microencapsulated anthocyanin, or probiotics alone or as combinations of anthocyanin and probiotics. The colonic inflammation of mice was induced by oral administration of DSS at 3% for 7 days. Attenuation of acute colitis was investigated through clinical data, western blot, histopathology, and ELISA.

Results: None of the dietary supplements showed hepatotoxicity in experimental mice hence the tested amounts were in safe limits. Compared with the DSS alone group, anthocyanin + probiotics supplemented group significantly inhibited the severity of colitis as measured by colon shortening, and disease activity index score. All the supplementary diets reduced the expression of occludin but had no effect on claudin-3 and claudin-4 expressions. Histological assessments, measures of inflammatory mediators and characterization of the gut microbiome will be presented.

Conclusions: Dietary supplementation of haskap berry anthocyanin + probiotics protects against DSS-induced colitis possibly through attenuating the epithelial inflammation.

Citation Format: K.V. Surangi Dharmawansa, Andrew Stadnyk, H.P. Vasantha Rupasinghe. Dietary supplementation of haskap berry anthocyanin and probiotics attenuate the severity of DSS-induced acute colitis in Balb/c mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1779.

Special Issue "Flavonoids and Their Disease Prevention and Treatment Potential": Recent Advances and Future Perspectives

In recent years, the interest in flavonoids as dietary bioactives to prevent human diseases, as well as their candidacy as pharmaceutical leads, has exponentially expanded [...].

Dietary Flavonoids in p53-Mediated Immune Dysfunctions Linking to Cancer Prevention

The p53 protein plays a central role in mediating immune functioning and determines the fate of the cells. Its role as a tumor suppressor, and in transcriptional regulation and cytokine activity under stress conditions, is well defined. The wild type (WT) p53 functions as a guardian for the genome, while the mutant p53 has oncogenic roles. One of the ways that p53 combats carcinogenesis is by reducing inflammation. WT p53 functions as an anti-inflammatory molecule via cross-talk activity with multiple immunological pathways, such as the major histocompatibility complex I (MHCI) associated pathway, toll-like receptors (TLRs), and immune checkpoints. Due to the multifarious roles of p53 in cancer, it is a potent target for cancer immunotherapy. Plant flavonoids have been gaining recognition over the last two decades to use as a potential therapeutic regimen in ameliorating diseases. Recent studies have shown the ability of flavonoids to suppress chronic inflammation, specifically by modulating p53 responses. Further, the anti-oxidant Keap1/Nrf2/ARE pathway could play a crucial role in mitigating oxidative stress, leading to a reduction of chronic inflammation linked to the prevention of cancer. This review aims to discuss the pharmacological properties of plant flavonoids in response to various oxidative stresses and immune dysfunctions and analyzes the cross-talk between flavonoid-rich dietary intake for potential disease prevention.

Impact of Citral and Phloretin, Alone and in Combination, on Major Virulence Traits of Streptococcus pyogenes

Streptococcus pyogenes is well documented as a multi-virulent and exclusively human pathogen. The LuxS-based signaling in these bacteria has a crucial role in causing several infections through pathways that are pathogenic. This study evaluated the individual and synergistic effects of citral and phloretin against S. pyogenes in relation to major virulence traits. The in vitro synergy of citral and phloretin was evaluated by the checkerboard method. The fractional inhibitory concentration (FIC) values were calculated to determine the interactions between the inhibitors. The bacteria’s virulence properties were tested in the presence of the molecules, individually as well as in combination. Molecules’ cytotoxicity was tested using human tonsil epithelial cells. The synergistic effects of the molecules on the expression of biofilm and quorum sensing genes were tested using quantitative real-time polymerase chain reaction (qRT-PCR). The molecules were also tested for their impact on LuxS protein by molecular docking, modeling, and free-energy calculations. When the two molecules were assessed in combination (synergistic effect, FIC Index of 0.5), a stronger growth inhibitory activity was exhibited than the individual molecules. The cell surface hydrophobicity, as well as genes involved in quorum sensing and biofilm formation, showed greater suppression when the molecules were tested in combination. The in silico findings also suggest the inhibitory potential of the two molecules against LuxS protein. The binding orientation and the binding affinity of citral and phloretin well support the notion that there is a synergistic effect of citral and phloretin. The data reveal the combination of citral and phloretin as a potent antibacterial agent to combat the virulence of S. pyogenes.