Green and chemically synthesized zinc oxide nanoparticles: effects on in-vitro seedlings and callus cultures of Silybum marianum and evaluation of their antimicrobial and anticancer potential

Figures & data

Figure 1. Schematic illustration summarising the methodology and whole theme of the study.

Figure 2. (A) Control; (B) Plantlet treated with NP3; (C) Plantlet treated with NP2; (D) Plantlets treated with NP1.

Table 1. Effect of C-ZNPs and G-ZNPs on seed germination frequency and plantlets mean root and shoot lengths of S. marianum.

Treatment	%Seed germination frequency	Plantlet mean shoot length (cm)	Plantlet mean root length (cm)
Control	40	3.3	3.5
NP1	39	3.2	2.3
NP2	45	3.4	3.7
NP3	65	5.3	4.3

Table 2. Fresh and Dry weights of plantlets of S. marianum treated with different NPs.

Treatments	FW (g L^−1)	DW (g L^−1)
Control	148	14.4
NP1	107.3	8.66
NP2	161	14.6
NP3	220.4	21.23

Figure 3. Combined effect of different concentrations of PGRs and NPs-treated plantlets’ samples on DPPH activity in callus cultures in response to (a) 2BAP + 1NAA; (b) 5BAP + 1NAA; (c) 1TDZ; and (d) DPPH activity in response to in-vitro whole plantlets.

Figure 4. Combined effect of different concentrations of PGRs and NPs-treated plantlets’ samples on TPC in callus cultures in response to (a) 2BAP + 1NAA; (b) 5BAP + 1NAA; (c) 1TDZ; and (d) TPC in response to in-vitro whole plantlets.

Figure 5. Combined effect of different concentrations of PGRs and NPs-treated plantlets’ samples on TFC in callus cultures in response to (a) 2BAP + 1NAA; (b) 5BAP + 1NAA; (c) 1TDZ; and (d) TFC in response to in-vitro whole plantlets.

Figure 6. Effect of different NPs in combination with different concentrations of BAP, NAA and TDZ on total protein content in (a) Stem, and (b) Root cultures of S. marianum.

Figure 7. Antibacterial activities of callus cultures and in-vitro plantlets grown on different PGRs and treated with C-ZNPs and G-ZNPs. From left to right i.e. (A1–A5) Antibacterial activity against K. pneumonia; (B1–B5) Antibacterial activity against B. subtilis; (C1–C5) Antibacterial activity against E. coli; (D1-D5) Antibacterial activity against L. monocytogenes. From top to bottom i.e. (A1, B1, C1, D1) Control of different bacterial strains; (A2, B2, C2, D2) 5BAP + 1NAA (1: NP1 stem; 2: NP2 root; 3: NP2 stem; 4: NP3 stem; 5: NP3 root); (A3, B3, C3, D3) 2BAP + 1NAA (6: NP1 root; 7: NP2 root; 8: NP2 stem; 9: NP3 root; 10: NP1 stem); (A4, B4, C4, D4) 1TDZ (11: NP1 root; 12: NP1 stem; 13: NP2 root; 14: NP2 stem; 15: NP3 root); (A5, B5, C5, D5) in-vitro plantlets (26: NP2; 27: C-ZNPs; 28: Control; 29: callus-synthesised NPs).

Table 3. Antibacterial zones of inhibition (mm) of callus and in-vitro plantlets-derived C-ZNPs and G-ZNPs.

Samples concentration	Klebsiella pneumonia 0.5 mg L^−1	Listeria monocytogenes 1 mg L^−1	Bacillus subtilis 2 mg L^−1	Escherichia coli 4 mg L^−1
Antibiotic	21 ± 1.8	25 ± 2.2	24 ± 2.0	35 ± 3.2
5BAp + 1NAA
NP1 stem	11 ± 0.8	15 ± 1.2	13 ± 1.1	10 ± 0.7
NP2 root	11 ± 0.8	14 ± 1.2	11 ± 0.8	10 ± 0.7
NP2 stem	12 ± 0.9	13 ± 1.1	14 ± 1.2	11 ± 0.8
NP3 stem	11 ± 0.8	15 ± 1.3	13 ± 1.1	10 ± 0.7
NP3 root	11 ± 0.8	13 ± 1.1	15 ± 1.3	11 ± 0.8
2BAp + 1NAA
NP1 root	12 ± 0.9	12 ± 0.9	13 ± 1.3	12 ± 0.9
NP2 root	17 ± 1.5	14 ± 1.2	15 ± 1.3	15 ± 1.3
NP2 stem	11 ± 0.8	16 ± 1.4	11 ± 0.8	11 ± 0.8
NP3 root	19 ± 1.5	12 ± 0.9	16 ± 1.4	13 ± 1.3
NP1 stem	11 ± 0.8	15 ± 1.2	13 ± 1.1	12 ± 0.9
1TDZ
NP1 root	11 ± 0.8	13 ± 1.1	12 ± 0.9	11 ± 0.8
NP1 stem	11 ± 0.8	12 ± 0.9	12 ± 0.9	11 ± 0.8
NP2 root	14 ± 1.2	15 ± 1.2	13 ± 1.1	12 ± 0.9
NP2 stem	11 ± 0.8	17 ± 1.5	14 ± 1.2	14 ± 1.2
NP3 root	12 ± 0.9	14 ± 1.2	15 ± 1.2	15 ± 1.2
NP3 stem	12 ± 0.9	18 ± 1.4	13 ± 1.1	13 ± 1.1
In-vitro whole plant
NP1	13 ± 1.1	11 ± 0.8	14 ± 1.2	14 ± 1.2
Control	11 ± 0.8	12 ± 0.9	14 ± 1.2	14 ± 1.2
NP3	13 ± 1.1	12 ± 0.9	13 ± 1.1	13 ± 1.1

The highest values are highlighted bold.

Figure 8. Anticancer activity of S. marianum-derived callus treated with C-ZNPs and G-ZNPs against HepG2 cells. (A) Non-treated cells (Negative control); (B) Doxorubicin (Positive control); (C) NP1 Root; (D) NP1 Stem; (E) NP2 Root; (F) NP2 Stem; (G) NP3 Root; (H) NP3 Stem.