Green synthesis of silver nanoparticles using seed extract of Alpinia katsumadai, and their antioxidant, cytotoxicity, and antibacterial activities

Abstract

A rapid green approach for synthesizing of silver nanoparticles using Alpinia katsumadai seed extract is described and their antioxidant, antibacterial and cytotoxicity activities evaluated.

Alga‐mediated facile green synthesis of silver nanoparticles: Photophysical, catalytic and antibacterial activity

“…Conventional physical and chemical methods of syntheses are often complicated and cumbersome, requiring high energy consumption with low conversion yield. Besides being expensive, such methods employ hazardous reducing agents, organic solvents and non‐biodegradable stabilizing agents and are thus environmentally harmful . The reagents used during such preparative processes get deposited on the surface of the newly formed nanoparticles, rendering them unsuitable for clinical and biomedical applications.…”

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“…It is important to mention that despite a wide variety of studies existing in the literature, antimicrobial activity has generally been evaluated in the same microorganisms even though there is a large amount of bacteria, fungi and viruses of clinical importance that could be studied. Also, when existing studies are analyzed (Table 1), most suggest that biosynthesized silver nanoparticles are biocompatible and may have therapeutic use potential in humans; however, if we review the studies summarized in Table 1 very few carry out biocompatibility tests in normal cells [8,10,14,15,18,26,27]. These tests provide crucial information on the ranges of safety and cytotoxicity of the biosynthetized nanoparticles, information that result fundamental to can be designed future experiments with biomedical applications in preclinical and clinical models.…”

“…A key point in anticancer therapy is to have drugs or molecules that are highly selective to kill cancer cells. In the literature there are green silver nanoparticles with anticancer activity but their cytotoxic effects have not been evaluated in normal cells [21,30,33,37,39,42], others show that there is little selectivity for cancer cells [14,34] and other studies show encouraging anticancer activity due to a better degree of selectivity [32,35,36,40,41,43,45]. An advantage of the use of medicinal plant extracts is the opportunity to be able to functionalize silver nanoparticles to enhance their anticancer effect and improve their specificity of action on cancer cells without affecting nontumor cells; this represents a challenge for scientists.…”

“…As shown in Table 1 [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], the antimicrobial effect of the green silver nanoparticles, mainly their antibacterial [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and antifungal action [10,[12][13][14]17,18,[23][24][25], has been widely reported. It is important to mention that despite a wide variety of studies existing in the literature, antimicrobial activity has generally been evaluated in the same microorganisms even though there is a large amount of bacteria, fungi and viruses of clinical importance that could be studied.…”

“…Another important fact is about the physical nature of the nanoparticles with respect to their size, most of the studies obtained nanoparticles with sizes greater than 10 nm in diameter [8,[10][11][12][13][14][15][16][17][19][20][21][22][23][24][25][26][27]; it would be interesting to know their effects with sizes smaller than 10 nm since there is evidence that their biological effects also dependent on size [28]. Furthermore, for a better comparative analysis of the therapeutic potential of green silver nanoparticles, it is important to include in future experiments reference drugs that are currently the most used and effective in antimicrobial therapy in humans (cephalosporins, quinolones, and macrolides) [29], since most studies existing do not include used-commercial drugs as control [8][9]11,[13][14][15][16]18,[20][21] or it is included drugs used in the past. Finally, the plant extracts used in the green synthesis of nanoparticles contain a large variety of functional groups that can be added to the chemical structure of the silver nanoparticle, in this sense the existing studies have not fully evaluated the role that can have the chemical functionalization in the biological activity of the nanoparticles, the studies included in the present review discuss very little to the regard, being a critical factor that can explain the variability in the antimicrobial effect of the different types of silver nanoparticles that are biosynthesized.…”