*3.3. Antioxidant Activity*

Figure 3 presents the radical scavenging potential of the GLSE, GLFE, GLAE, and GLRE extracts. The results showed that the antioxidant activity of different plant parts varied significantly and appeared in a concentration-dependent manner. Likewise, GLAE extracts had higher antioxidant properties, as represented by the lower half-maximal inhibitory concentration (IC50) (718.40 ± 14.025 μg mL<sup>−</sup>1). Furthermore, all other plant part extracts, except GLRE extracts, possessed a better radical scavenging potential, indicating the presence of higher amounts of antioxidant compounds. The results showed that the ABTS+ radical scavenging potential of different *G. littoralis* extract parts varied significantly (*p* < 0.05), with GLAE extracts exhibiting higher ABTS radical scavenging activity (16,348.41 ± 1315.26 μg mL<sup>−</sup>1). Comparatively, the GLRE extract showed the lowest antioxidant activity (Figure 3). Two different antioxidant assays were carried out, and these antioxidant assays were positively and significantly correlated with TPC and TFC of *G. littoralis* (Table S1).

**Figure 3.** Antioxidant activity (DPPH and ABTS radical assay) in *G. littoralis* extracts. Mean values followed by the same letter are not significantly different based on the DMRT (*p* < 0.05). GLSE: *G. littoralis* leaf, stem extracts, GLFE: *G. littoralis* fruit extracts, GLAE: *G. littoralis* all extracts, GLRE: *G. littoralis* root extracts.
