Indigofera tinctoria leaf extract mediated green synthesis of silver and gold nanoparticles and assessment of their anticancer, antimicrobial, antioxidant and catalytic properties

Figures & data

Figure 1. (a) Photograph of plant Indigofera tinctoria, (b) (1) Photograph of Indigofera tinctoria leaf extract, (2) silver nanoparticles (AgNP- tinctoria), and (3) gold nanoparticles (AuNP- tinctoria), (c) UV-vis. spectrum of AgNP- tinctoria, and (d) UV-vis. spectrum of AuNP- tinctoria.

Figure 2. (a) FTIR spectrum of (1) Indigofera tinctoria leaf extract, (2) AgNP- tinctoria, and (3) AuNP- tinctoria (c) XRD pattern of AgNP- tinctoria, and (d) XRD pattern of AuNP- tinctoria

Figure 3. (a, b and c) TEM images of AgNP- tinctoria, at different magnification, (d) HR-TEM image of AgNP- tinctoria, (e) SAED pattern of AgNP- tinctoria, and (f) particle size distribution histogram of AgNP- tinctoria, (g) EDX Spectrum of AgNP- tinctoria, (h, i and j) TEM images of AuNP- tinctoria, at different magnification (k) SAED pattern of AuNP- tinctoria, (l) HR-TEM image of AuNP- tinctoria, and (m) particle size distribution histogram of AuNP- tinctoria, and (n) EDX Spectrum of AuNP- tinctoria.

Figure 4. (a) Morphological changes induced on treated A549 cancer cell by (a) Indigofera tinctoria, (b) AgNP- tinctoria, and (c) AuNP- tinctoria, and (d) Cytotoxicity studies for Indigofera tinctoria leaf extract, AgNP- tinctoria, and AuNP- tinctoria towards A549 cancer cells.

Table 1. The results of ANOVA and Tukey’s test (for anticancer studies).

		ANOVA results
		Concentration 6.25 μg/ml (F = 165.6***)	Concentration 12 μg/ml (F = 172.1***)	Concentration 25 μg/ml (F = 43.49***)	Concentration 50 μg/ml (F = 38.07***)	Concentration 100 μg/ml (F = 167.1***)
Post-hoc Tukey’s test results
		Mean difference (I–J)
(I) type	(J) type	Concentration6.25 μg/ml	Concentration12 μg/ml	Concentration25 μg/ml	Concentration50 μg/ml	Concentration100 μg/ml
Indigofera tinctoria leaf extract	AgNP- tinctoria	15.10***	16.01***	7.753***	10.07***	10.39***
Indigofera tinctoria leaf extract	AuNP- tinctoria	9.573***	11.15***	3.830***	3.993*	6.997**
AgNP- tinctoria	AuNP- tinctoria	−5.527**	−4.853**	−3.923**	−6.073**	−3.393***

***, **and *indicate significance at 1% level, 5% level and 10% level, respectively.

Figure 5. (a) Illustration of the antimicrobial activity of AgNP- tinctoria and AuNP- tinctoria against various human pathogenic microorganisms using agar well diffusion method. [(A) Control, (B) Indigofera tinctoria leaf extract, (C) AuNP- tinctoria, and (D) AgNP- tinctoria] (b) Bar diagram showing zone of inhibitions (mm) of Indigofera tinctoria leaf extract, AgNP- tinctoria, and AuNP- tinctoria and (c) Antioxidant activities of AgNP- tinctoria, AuNP- tinctoria, and Indigofera tinctoria extract compared to ascorbic acid.

Table 2. The results of ANOVA and Tukey’s test (for antioxidant studies).

		ANOVA results
		Concentration 12.5 μg/ml (F = 977.7***)	Concentration 25 μg/ml (F = 2654***)	Concentration50 μg/ml (F = 1932***)	Concentration100 μg/ml (F = 3562***)	Concentration 200 μg/ml (F = 4812***)
Post-hoc Tukey’s test results
		Mean difference (I–J)
(I) type	(J) type	Concentration12.5 μg/ml	Concentration25 μg/ml	Concentration50 μg/ml	Concentration100 μg/ml	Concentration200 μg/ml
Indigofera tinctoria leaf extract	AgNP- tinctoria	−20.67***	−28.98***	−31.22***	−36.13***	−39.10***
Indigofera tinctoria leaf extract	AuNP- tinctoria	−10.23***	−9.137***	−6.047***	−13.47***	−19.56***
AgNP- tinctoria	AuNP- tinctoria	10.45***	19.84***	25.17***	22.66***	19.54***

***, ** and *indicate significance at 1% level, 5% level and 10% level, respectively.

Figure 6. (a) and (b) Reduction reactions of o-nitroaniline and, p-nitroaniline using NaBH4 without nanocatalysts; (c) and (d) reduction reactions of o-nitro aniline using AgNP-tinctoria and AuNP-tinctoria nanocatalysts; (e) and (f) reduction of p-nitroaniline using AgNP-tinctoria, and AuNP-tinctoria nanocatalysts.