Assessment of antioxidant and cytotoxicity activities against A-549 lung cancer cell line by synthesized reduced graphene oxide nanoparticles mediated by Camellia sinensis

Abstract

Camellia sinensis (green tea leaves) which acts as a reducing agent was used for the reduction of graphene oxide (GO) to obtain reduced graphene oxide (RGO). Anionic surfactant SDS was used to enhance the stability of synthesized reduced graphene oxide nanoparticles. Characterized reduced graphene oxide nanoparticle grain size was calculated to be 3.92 nm from the X-ray diffraction method, whereas zeta potential was measured - 35.23 ± 5.45 mV at room temperature. Antioxidant and cell cytotoxicity against A-549 lung carcinoma cells were also studied. Phytochemical content of Camellia sinensis imparts feasible DPPH activity of 85.98 ± 2.49% against RGO, whereas ABTS scavenging activity was found to be 88.87 ± 1.74% followed by measurement of the total phenolic content of 842 ± 13.33 µg/gm. RGO at concentration 400 µg/ml showed an optimum level of hemolysis at pH 7.4 (4.92 ± 1.20%) than pH 5.6 (11.15 ± 0.03%). Cytotoxicity activity studied by MTT assay of RGO on A-549 lung carcinomas cells was compared with drug doxorubicin. The bandgap energy of RGO was calculated to be 3.97 eV from absorption data, hence reveals the generation of oxidative stress in the A-549 lung cancer cell line. Thus, the surfactant and phytochemicals found in Camellia sinensis enhanced the stability of RGO, thereby providing enough energy to destabilize the target cells without affecting healthy cells, hence suggests its role in therapeutics application.

Supplementary information: The online version contains supplementary material available at 10.1007/s13205-021-03015-z.

Keywords: Antioxidant; Band gap energy; Cytotoxicity; Hemolytic activity; Polyphenol; Reduced graphene nanoparticle.

Fig. 1

The UV–visible spectra of synthesized GO and RGO

Fig. 2

XRD diffractogram of (a) GO; and (b) RGO

Fig. 3

Major bands of a FT-IR spectrum of (a) GO; and (b) RGO

Fig. 4

The measurement of FRSA through DPPH assay of AA, RGO, GO, and GP at different concentrations. All readings were expressed as mean ± SD. (ns) Symbolize no statistical significance (p < 0.05) difference among RGO and Trolox (Std). (****) denotes p < 0.0001 indicate significant difference in GO and GP with Trolox (Std)

Fig. 5

The measurement of FRSA through ABTS assay of Trolox, RGO, GO, and GP at different concentrations. All readings were expressed as mean ± SD. (ns) Symbolize no statistical significance (p < 0.05) difference among RGO and AA (Std). (***) denotes p < 0.001 indicate significant difference in GO and GP with AA (Std)

Fig. 6

The hemolysis activity on erythrocytes at (a) pH 7.4; and (b) pH 5.6 of synthesized RGO, GO, and GP. All readings were expressed as mean ± SD. (**) denotes p < 0.01 and (****) denotes p < 0.0001 significant difference among the GO and GP with respect to RGO

Fig. 7

The cell cytotoxicity effect of doxorubicin, doxorubicin + RGO, RGO, GO and GP in mitochondrial activity in dose-dependent manner treated with different concentration measured for 12 h. All readings were expressed as mean ± SD; (**) denotes p < 0.01 and (***) denotes p < 0.001 significant difference in GP and GO from Doxorubicin + RGO