Diospyros malabarica fruit preparation mediates immunotherapeutic modulation and epigenetic regulation to evoke protection against non-small cell lung cancer (NSCLC)

Abstract

Ethnopharmacological relevance: Diospyros malabarica is an ethnomedicinal plant with hypoglycaemic, anti-bacterial, and anti-cancer properties and it belongs to the Ebenaceae family which is well known for its medicinal uses since ancient times and application of its bark and unripened fruit has been significantly mentioned in Ayurvedic texts. The Diospyros malabarica species which is known as the Gaub in Hindi and Indian Persimmon in English is native to India, however, it is distributed throughout the tropics.

Aim of the study: As Diospyros malabarica fruit preparation (DFP) possesses medicinal values, the study aims to evaluate its role as natural, non-toxic, and cost-effective dendritic cells (DCs) maturing immunomodulatory agent and also as an epigenetic regulator to combat Non-small cell lung cancer (NSCLC) which is a type of lung cancer whose treatment options such as chemotherapy, radiation therapy, etc. are accompanied with some adverse side effects. Thus, immunotherapeutic strategies are in high demand to evoke tumor protective immunity against NSCLC without causing such side effects.

Materials and methods: Peripheral Mononuclear Cells (PBMCs) derived monocytes of normal subjects and NSCLC patients were utilized to generate DCs matured with either LPS (LPSDC) or DFP (DFPDC). Mixed Lymphocyte Reaction (MLR) was carried out with the differentially matured DCs co-culturing T cells and cytotoxicity of lung cancer cells (A549) was measured through LDH release assay and cytokine profiling was carried out via ELISA respectively. PBMCs of normal subjects and NSCLC patients have transfected separately in vitrowith CRISPR-activation plasmid of p53 and CRISPR-Cas9 knockout plasmid of c-Myc to analyze epigenetic mechanism(s) in the presence and absence of DFP.

Results: Diospyros malabarica fruit preparation (DFP) treated DC upregulates the secretion of T helper (T_H)1 cell specific cytokines (IFN-γ and IL-12) and signal transducer and activator of transcription molecules (STAT1 and STAT4). Furthermore, it also downregulates the secretion of T_H2-specific cytokines (IL-4 and IL-10). Diospyros malabarica fruit preparation (DFP) enhances p53 expression by reducing methylation levels at the CpG island of the promoter region. Upon c-Myc knockout, epigenetic markers such as H3K4Me3, p53, H3K14Ac, BRCA1, and WASp were enhanced whereas H3K27Me3, JMJD3, and NOTCH1 were downregulated.

Conclusion: Diospyros malabarica fruit preparation (DFP) not only increases the expression of type 1 specific cytokines but also augments tumor suppression modulating various epigenetic markers to evoke tumor protective immunity without any toxic activities.

Keywords: Dendritic cell (DC); Diospyros malabarica fruit Preparation (DFP); Epigenetics; Immunomodulation; Non–small cell lung cancer (NSCLC); T helper (T(H)) cells.