Abstract
Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) is a well-known epiphytic lichen commonly used in Indian spice mixtures and food preparations such as curries. This study is an attempt to find the best extraction methodology with respect to extractive yield, total polyphenolic content (TPC), total flavonoid content and antioxidant activities of lichen P. furfuracea. Two phenolic compounds, atraric acid and olivetoric acid were isolated and quantified in their respective extracts with the aid of reverse phase high performance liquid chromatography (RP-HPLC). The highest concentration of both the compounds, atraric acid (4.89 mg/g DW) and olivetoric acid (11.46 mg/g DW) were found in 70% methanol extract. A direct correlation was also observed between the concentrations of these compounds with the free radical scavenging potential of the extracts which might contribute towards the antioxidant potential of the extract. Moreover, scanning electron microscopy and HPLC analysis which was used to study the effect of pre-processing on extraction process highlighted the capacity of a mixer grinder technique for improved separation of surface localized metabolites and enrichment of the fraction. An investigation of the chemical profile of the bioactive extract 70% methanol extract using UHPLC-DAD-MS lead to tentative identification of forty nine compounds. This extract was also assessed towards HEK 293 T cell line for cytotoxicity analysis. Concentration range of 0.156 to 100 µg/ml of PF70M extract exhibited no significant cell death as compared to control. Further, the active extract showed protective effect against hydroxyl radical’s destructive effects on DNA when assessed using DNA nicking assay. Based upon this, it can be concluded that optimization of extraction solvent, sample pre-proceesing and extraction techniques can be useful in extraction of specific antioxidant metabolites.
Highlights
Bioactive secondary metabolites of natural origin are extremely useful in food, pharmaceutical, agrochemical, nutraceutical and cosmeceutical industries due to their multifaceted biological activities such as antioxidant, antimicrobial, anticancer and antifungal (Goel et al, 2011; Sisodia et al, 2013; Goel et al, 2014; Newman and Cragg, 2016; Goel et al, 2020)
The maximum extractive yield was obtained in 70% methanol followed by water and methanol and the key driver behind the increased extraction efficiency with 70% methanol is principally due to extraction of wide range of compounds present in Pseudevernia furfuracea
The optimum extraction yield observed from the successive extraction is likely due to the better mass transfer from the substrate, which is clearly visible in the scanning electron microscopy (SEM) image (Supplementary Figure S1)
Summary
Bioactive secondary metabolites of natural origin are extremely useful in food, pharmaceutical, agrochemical, nutraceutical and cosmeceutical industries due to their multifaceted biological activities such as antioxidant, antimicrobial, anticancer and antifungal (Goel et al, 2011; Sisodia et al, 2013; Goel et al, 2014; Newman and Cragg, 2016; Goel et al, 2020). Natural product derived antioxidants have been shown to exhibit strong protective effects against a variety of chronic health problems by postponing the damage caused by oxidative stress (Liu 2003) Antioxidants and their associated benefits is currently a subject of intensive research due to an increase in lifestyle disorders associated with stress and in line with this some lichens have been explored for their antioxidant potential through the last decade (Manojlovic et al, 2012; Kosanic et al, 2013; Kosanicet al., 2014; Kumar et al, 2014; Zugic, 2016). It was rationalized that the extraction procedure is an important prerequisite for the comprehensive exploration of the beneficial effects of the species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
