Biosynthesis of silver nanoparticles mediated by Houttuynia cordata leaf extract: Characterization and improvement of anti-inflammatory activity

Abstract

Silver nanoparticles (Ag-NPs) were synthesized in an eco-friendly manner using aqueous Houttuynia cordata leaf extract (HLE). HLE mediated Ag-NPs (Ag-NPs/HLE) exhibited surface plasmon resonance with a maximum absorbance at 450 nm. The mean diameter of Ag-NPs was 23 nm, and their crystalline structure was confirmed via X-ray diffraction analysis. Fourier-transform infrared spectroscopy indicated that hydroxyl, carboxyl, and ketone groups of sugar or polyphenolics were involved in Ag-NPs synthesis. The contribution of reducing sugars to the reduction of Ag ions was found to be greater than that of polyphenols. NO production in LPS stimulated RAW 264.7 macrophages was more effectively inhibited by Ag-NPs/HLE than by chemically synthesized Ag-NPs. The production of the major inflammatory mediators, PGE 2 and TNF-α was decreased by 73% and 66%, respectively, upon the addition of 10 μg/mL Ag-NPs/HLE. Ag-NPs biosynthesized using HLE showed improved anti-inflammatory activity compared to conventional Ag-NPs owing to the incorporation of phytochemicals. Biosíntesis de nanopartículas de plata mediada por el extracto de hojas de Houttuynia cordata: caracterización y mejoramiento de la actividad antiinflamatoria RESUMEN En este estudio se sintetizaron nanopartículas de plata (Ag-NPs) de una forma amigable con el medio ambiente, empleando para ello el extracto acuoso de la hoja de Houttuynia cordata (HLE). Las Ag-NPs mediadas por HLE (Ag-NPs/HLE) presentaron resonancia plasmónica de superficie con una absorción máxima de 450 nm. Se constató que el diámetro medio de las Ag-NP fue de 23 nm, confirmándose su estructura cristalina mediante el análisis de difracción por rayos-X. A través de una espectroscopia infrarroja transformada de Fourier se comprobó que los grupos de azúcar hidroxilo, carboxilo y cetona o polifenólicos intervinieron en la síntesis de las Ag-NPs. Asimismo, se comprobó que la contribución de los azúcares reductores a la disminución de los iones de Ag es mayor que la de los polifenoles. La producción de NO en los macrófagos 264.7 RAW estimulados por LPS [lipopolisacáridos] fue inhibida de manera más eficaz por las Ag-NPs/HLE que por las Ag-NPs de síntesis química. Cuando se adicionaron 10 μg/mL de Ag-NPs/HLE, la producción de los principales intermediarios inflamatorios, PGE 2 yTNF-α, disminuyó en 73% y 66%, respectivamente. Las Ag-NPs biosintetizadas utilizando HLE muestran mayor actividad antiinflamatoria en comparación con las Ag-NPs convencionales, debido a la incorporación de fitoquímicos.

Evaluating Antioxidant Performance, Biosafety, and Antimicrobial Efficacy of Houttuynia cordata Extract and Microwave-Assisted Synthesis of Biogenic Silver Nano-Antibiotics

“…Among them, the functional groups corresponding to 3396 cm −1 , 2927 cm −1 , and 1630 cm −1 are alcohols (O-H stretching) or amines (N-H stretching), alkanes (C-H stretching), and conjugated dienes (C=C stretching) or amines (N-H stretching). Here, 1403 cm −1 corresponds to the polysaccharide-protein of HC extract, and the functional groups corresponding to 1310 cm −1 and 1073 cm −1 are phenols (O-H bending) and alcohols (C-O stretching), and the corresponding functional groups above are similar to previously reported pieces of literature reported by Kim et al [23] and Cheng et al [33]. In addition, we found that microwave-assisted AgNPs had several former peaks from the HCE at the vibration frequencies of 3434 cm −1 , 1602 cm −1 , 1370 cm −1 , and 1000 cm −1 , respectively, corresponding to alcohols (O-H stretching) and conjugated dienes (C=C stretching) or amines (N-H stretching), polysaccharide proteins of HC extract, and alcohols (C-O stretching).…”

“…This study is focused on enhancing the antioxidant and antibacterial activity of biogenic AgNPs. Nevertheless, various nanoparticles, including gold nanoparticles (AuNPs) and copper oxide nanoparticles (CuO NPs), have previously been produced using extracts from the Houttuynia cordata plant [21][22][23]. Sreekanth et al employed Houttuynia cordata leaf extracts to create highly stable and crystalline AuNPs, which exhibited superior inhibitory effects on Gram-negative bacteria compared to Gram-positive bacteria, resulting in larger inhibition zones [21].…”

“…This cytotoxicity was attributed to alterations in the PI3k/AKT/mTOR signaling pathway and the induction of apoptosis. Furthermore, Kim et al utilized aqueous Houttuynia cordata leaf extract to synthesize AgNPs with heightened anti-inflammatory activity [23]. As far as we know, there are currently no published reports on using Houttuynia cordata extract for synthesizing microwave-assisted AgNPs and evaluating their potential health benefits.…”

Green synthesis of silver nanoparticles using Houttuynia cordata Thunb rhizome extracts and their antibacterial potential against common foodborne pathogens

“…The SPR for metallic NPs is the primary mechanism that imparts colour to NP suspensions. Kim & Imm (2018) and Chhatre et al (2012) posited that the SPR absorption, which depends on the size, composition, shape, presence of adsorbed species, refractive indices of metal and surrounding medium and the distance between neighbouring MPs, influences the formation of the characteristic colour of AgNPs due to the collective oscillation of nanoparticle electrons and periodic changes in the electromagnetic field.…”