A Comparative Antibacterial, Antioxidant, and Antineoplastic Potential of Rauwolfia serpentina (L.) Leaf Extract with Its Biologically Synthesized Gold Nanoparticles (R-AuNPs)

Abstract

Rauwolfia serpentina (R. serpentina), belonging to the family Apocynaceae, is a renowned medicinal herb for its different pharmacological activities such as antibacterial, antifungal, anti-inflammatory, and antiproliferative characteristics. This study has done a comparative assessment of the antibacterial, antioxidant, and anti-cancer activity of R. serpentina aqueous leaf extract (RSALE) with encapsulated gold nanoparticles (R-AuNPs). The R-AuNPs are prepared so that they are significant in size, monodispersed, and extremely stable. Their characterization was done by numerous parameters, including UV-visible spectroscopy (528 nm), transmission electron microscopy (~17 d. nm), dynamic light scattering (~68 d. nm), and zeta-potential (~−17 mV). Subsequently, a potent antibacterial activity was depicted via RSALE and R-AuNPs when examined by disc diffusion against various Gram-positive and Gram-negative bacterial strains. The obtained zones of inhibition of RSALE (100 mg/mL) were 34 ± 0.1, 35 ± 0.1, 28.4 ± 0.01, and 18 ± 0.01, although those of R-AuNPs (15 mg/mL) were 24.4 ± 0.12, 22 ± 0.07, 20 ± 0.16, and 17 ± 0.3 against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (MTCC 8114), and Streptococcus pyogenes (ATCC 19615), respectively. However, no zone of inhibition was obtained when tested against Proteus vulgaris (MTCC 1771). Furthermore, the obtained MIC values for Staphylococcus aureus were 0.91, 0.61, and 1.15 mg/mL; for Escherichia coli, 0.79, 0.36, and 1.02 mg/mL; for Bacillus subtilis 0.42, 0.27, and 0.474 mg/mL; and for Streptococcus pyogenes, 7.67, 3.86, and 8.5 mg/mL of pure RSALE, R-AuNPs, and Amoxicillin (control), respectively, incorporating that R-AuNPs have been shown to have a 1.4-fold, 2.1-fold, 1.5-fold, and 1.9-fold enhanced antibacterial activity in contrast to pure RSALE tested against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Streptococcus pyogenes, and Proteus vulgaris, respectively. Additionally, an enhanced antioxidant potential was detected in R-AuNPs compared to RSALE evaluated by the 2,2-Diphenyl-1-Picryl Hydrazyl Radical Scavenging (DPPH) Ferric reducing antioxidant power (FRAP) assay. The determined IC 50 values of RSALE and R-AuNPs were 0.131 ± 0.05 and 0.184 ± 0.02 mg/mL, and 0.110 ± 0.1 and 0.106 ± 0.24 mg/mL via the FRAP and DPPH assays, respectively. In addition, the anti-cancer activity against the human cervical cancer (Hela) cell line was evaluated, and the MTT assay results revealed that R-AuNPs (IC50 88.3 µg/mL) had an enhanced anti-cancer potential in contrast to RSALE (171.5 µg/mL). Subsequently, the findings of this study indicated that R. serpentina leaves and their nanoformulation can be used as a potent source for the treatment of the above-mentioned complications and can be used as a possible agent for novel target-based therapies for the management of different ailments.

Identification of Potential Poly (ADP-Ribose) Polymerase-1 Inhibitors Derived from Rauwolfia serpentina: Possible Implication in Cancer Therapy

“…The traditionally used medicinal herb R. serpentina has been reported to possess anticancer properties [ 27 ]. Previously, the potential antiangiogenic bioactive compounds of R. serpentina were identified by targeting VEGFR-2 using the molecular docking approach [ 22 ].…”

Elucidating Antiangiogenic Potential of Rauwolfia serpentina: VEGFR-2 Targeting-Based Molecular Docking Study

“…R. serpentina is traditionally used for its various health benefits. Recent studies also report the anticancer properties of the plant [ 12 ]. In this study, we investigated the phytoconstituents of R. serpentina against human VEGFR-2 to identify its potential inhibitors by using a molecular docking approach.…”

“…Rauwolfia serpentina, found in the Himalayan mountain range of India and Southeast Asia, is a valuable medicinal herb that belongs to the Apocynaceae family [ 10 , 11 ]. This plant is known for its pharmacological properties, such as antihypertensive, antibacterial, antifungal, anti-inflammatory, and anticancer activities [ 12 ]. The phytochemical constituents of medicinal herbs are the key to their therapeutic potential as they can be utilized as precursors for novel drug development.…”

Pharmacological Efficacy of Tamarix aphylla: A Comprehensive Review

“…Plant phytochemical substances have been investigated in numerous experiments to discover the molecular basis of their interaction with medicines and illnesses [ 150 ]. However, plants are potentially toxic due to their chemical components; as a result, certain plants employed in traditional medicine are intrinsically harmful [ 151 , 152 , 153 ]. T. aphylla (L. Karst) methanol extract was examined for acute toxicity.…”