Delpinium uncinatum mediated green synthesis of AgNPs and its antioxidant, enzyme inhibitory, cytotoxic and antimicrobial potentials

PLOS ONE RESEARCH ARTICLE Delpinium uncinatum mediated green synthesis of AgNPs and its antioxidant, enzyme inhibitory, cytotoxic and antimicrobial potentials Hina Rehman ID1, Waqar Ali1*, Mohammad Ali2, Nadir Zaman Khan1, Muhammad Aasim1, Ayaz Ali Khan1, Tariq Khan1, Muhammad Ali3, Ashaq Ali4, Muhammad Ayaz5, Muzamil Shah3, Syed Salman Hashmi ID3* a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Department of Biotechnology, University of Malakand, Chakdara, Lower Dir, Pakistan, 2 Centre for Biotechnology and Microbiology, University of Swat, Swat, Pakistan, 3 Department of Biotechnology, Quaid-iAzam University, Islamabad, Pakistan, 4 Center for Excellence in Science and Applied Technology, Islamabad, Pakistan, 5 Department of Pharmacy, University of Malakand, Chakdara, Lower Dir, Pakistan * (SSH); (WA) Abstract OPEN ACCESS Citation: Rehman H, Ali W, Ali M, Khan NZ, Aasim M, Khan AA, et al. (2023) Delpinium uncinatum mediated green synthesis of AgNPs and its antioxidant, enzyme inhibitory, cytotoxic and antimicrobial potentials. PLoS ONE 18(4): e0280553. https://doi.org/10.1371/journal. pone.0280553 Editor: Majed Ahmed M. Al-Shaeri, King Abdulaziz University, SAUDI ARABIA Received: August 19, 2022 Accepted: January 3, 2023 Published: April 4, 2023 Copyright: © 2023 Rehman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: The author(s) received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist. Green synthesis of nanoparticles is becoming a method of choice for biological research due to its environmentally benign outcomes, stability and ease of synthesis. In this study, silver nanoparticles (AgNPs) were synthesized using stem (S-AgNPs), root (R-AgNPs) and mixture of stem and root (RS-AgNPs) of Delphinium uncinatum. The synthesized nanoparticles were characterized by standardized techniques and evaluated for their antioxidant, enzyme inhibition, cytotoxic and antimicrobial potentials. The AgNPs exhibited efficient antioxidant activities and considerable enzyme inhibition potential against alpha amylase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. S-AgNPs showed strong cytotoxicity against human hepato-cellular carcinoma cells (HepG2) and high enzyme inhibitory effect (IC50 values 27.5μg/ml for AChE and 22.60 μg/ml for BChE) compared to R-AgNPs and RS-AgNPs. RS-AgNPs showed significant inhibition of Klebsiella pneumoniae and Aspergillus flavus and exhibited higher biocompatibility (<2% hemolysis) in human red blood cells hemolytic assays. The present study showed that biologically synthesized AgNPs using the extract of various parts of D. uncinatum have strong antioxidant and cytotoxic potentials. Introduction Nanobiotechnology has emerged as a flourishing scientific field dedicated to the synthesis of multifunctional nanoparticles (NPs) by using green processes and biological resources [1]. NPs due to their small size (1–100 nm) and unique surface area to volume ratio exhibit interesting physical and biochemical properties [2, 3]. NPs can be synthesized by physical and chemical methods however, there are certain limitations associated with these methods. PLOS ONE | https://doi.org/10.1371/journal.pone.0280553 April 4, 2023 1 / 21 PLOS ONE D. uncinatum mediated AgNPs—Rehman et al. 2022 Synthesis using physical methods is energy consuming and is therefore economically not feasible. Chemical methods can generate toxic and hazardous waste. Alternatively, biological methods are safe, simple, rapid and cost effective [4]. Among the biological resources, enzymes, microorganisms, fungi and whole plants or specific parts of a plant have been used for NPs synthesis [5, 6]. Plants are by far the most widely exploited biological source for the synthesis of NPs. This is due to the fact that plant secondary metabolites actively participate in capping and stabilization of NPs [7]. Additionally, plants are easily available, and cheapest source among biological resources which makes their use in NPs biosynthesis more common [8]. Diverse applications of plant based NPs are reported in different fields like health, food, environment, cosmetics, optics, electronics, space industries, drug and gene delivery, chemical industries, energy, single electron transistors, light emitters and nonlinear optical devices etc. [9]. Noble metal NPs, like silver NPs (AgNPs) are studied extensively due to their multifunctional nature [10, 11]. In ancient times, the use of silver (Ag) was very popular owing to its antimicrobial potential. The modern era therefore exploits the nano form of silver i.e. AgNPs in a number of biomedical applications [12]. Apart from this, AgNPs have also been used for a number of applications including viral inhibition assays, anti-cancer activities, wound dressing, food preservatives and water treatment [13]. AgNPs have also been used extensively as antifungal, antioxidant, anti-inflammatory and anti-angiogenic agents [14]. Green synthesis of AgNPs is frequently reported using medicinal plants. The use of medicinal plants is preferred for biosynthesis of NPs since they have been extensively studied and their biochemical profile is well documented. Moreover, the use of medicinal plants for biosynthesis of NPs eliminates the use of noxious chemicals that are critical for capping and stabilization of NPs [15]. The species of Delphinium are found mostly at the high altitude of the western region of Himalayas (2400 to 3650 m). D. uncinatum and related species have been used to treat multiple diseases such as fever, sour throat, cough, cold, gout, vomiting, rheumatism, stomach pain, diarrhea and epilepsy [16, 17]. Different bioactive complex structure compounds like alkaloids e.g. uncinatine, 14-acetylperegrine, 14 acetylvirescenine, condelphine, delbrusine [18, 19], flavonoids, delphinin [20], violdelphin [21], cyanodelphin [22] and phenolic compounds e.g. 2,5,6-trihydroxypiperonylic acid and methyl ester [23] have been reported recently from Delphinium species. The present work aimed to synthesize biologically stable AgNPs using different parts of D. uncinatum, and to evaluate their antioxidant, enzyme inhibition, cytotoxic and antimicrobial potentials. AgNPs ranging in size from 24.6 nm to 32 nm showed excellent potential in all the aforementioned biological assays. The synthesized AgNPs effectively inhibited enzymes like protein kinase, alpha-amylase and cholinesterase suggesting that the NPs have anti-diabetic and anti-inflammatory potential. The antimicrobial potential of the NPs was also comparable to that of standard antibiotic. NPs also proved to effectively scavenge the reactive oxygen spe (...truncated)