title: In vitro evaluation of antioxidant and cytotoxic activities of lignin fractions extracted from Acacia nilotica.
abstract: Lignin is one of the most important phytomacromolecule with diverse therapeutic properties such as anticancer, antimicrobial, anti-inflammatory and immune-stimulatory. The present study was carried out to evaluate the in vitro antioxidant, free radical scavenging and anti-proliferative/cytotoxic activities of eleven different lignin fractions, extracted from the wood of Acacia nilotica by pressurized solvent extraction (PSE) and successive solvent extraction (SSE) methods. Results indicate that the PSE fractions have high polyphenolic content and reducing power. However, the antioxidant efficiency examined by DPPH and ABTS radical scavenging assay was higher in SSE fractions. All lignin fractions revealed a significant ability to scavenge nitric oxide, hydroxyl and superoxide radicals. The extracted lignin fractions display high ferric ion reducing capacity and also possess excellent antioxidant potential in the hydrophobic (linoleic acid) system. Fractions extracted by polar solvent has the highest iron (Fe(2+)) chelating activity as compared to other factions, indicating their effect on the redox cycling of iron. Four lignin fractions depicted higher cytotoxic potential (IC50: 2-15 μg/mL) towards breast cancer cell line (MCF-7) but were ineffective (IC50: ≥ 100 μg/mL) against normal primary human hepatic stellate cells (HHSteCs). These findings suggest that the lignin extracts of A. nilotica wood has a remarkable potential to prevent disease caused by the overproduction of radicals and also seem to be a promising candidate as natural antioxidant and anti-cancer agents.
authors.affiliation: Department of Biotechnology, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh 495009, India.
authors.forename: Anand
authors.initials: A
authors.lastname: Barapatre
authors.affiliation: Tumor Biology Laboratory, National Institute of Pathology, New Delhi 110029, India.
authors.forename: Avtar Singh
authors.initials: AS
authors.lastname: Meena
authors.affiliation: Centre for Chemical Biology, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad, TS 500 007, India.
authors.forename: Sowmya
authors.initials: S
authors.lastname: Mekala
authors.affiliation: Centre for Chemical Biology, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad, TS 500 007, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Das
authors.affiliation: Department of Biotechnology, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh 495009, India. Electronic address: harit74@yahoo.co.in.
authors.forename: Harit
authors.initials: H
authors.lastname: Jha
mesh_terms: D000045:Acacia / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005609:Free Radicals / Q000737:chemistry; D006801:Humans; D007501:Iron / Q000737:chemistry; D007502:Iron Chelating Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008031:Lignin / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019787:Linoleic Acid / Q000737:chemistry; D061986:MCF-7 Cells; D009569:Nitric Oxide / Q000737:chemistry; D059808:Polyphenols / Q000032:analysis; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D005609:Free Radicals; D007502:Iron Chelating Agents; D059808:Polyphenols; D009569:Nitric Oxide; D008031:Lignin; D019787:Linoleic Acid; D007501:Iron
keywords: Acacia; Cytotoxicity; Fractionation; Free radical scavenging; Lignin; Reactive oxygen species scavenging