Anticancer L-Asparaginase and Phytoactive Compounds From Plant Solanum nigrum Against MDR (Methicillindrug resistant) Staphylococcus aureus and Fungal Isolates

Abstract

L-asparaginase is used in chemotherapy for acute lymphoblastic leukemia and other cancers. L-asparaginase derived from bacterial source triggers immune responses. The current study investigates Solanum nigrum as a novel and latent source of L-asparaginase to minimize immunological reactions. The antitumor activity of SN methanol extract was determined using the potato disc assay. InterPro Chimera and InterPro were used to predict the amino acid sequence of L-asparaginase and its anticancer activity. Purification of the enzyme was carried out to homogeneity of 1.51-fold with a recovery of 61.99%. At optimal conditions of 36.5°C, pH 8.6, and 8.5 g/mL substrate, fruit (crude extract) revealed an L-asparaginase titer of 48.23 U/mL. The molecular weight of the enzyme was calculated to be 32 ± 5 kDa using SDS PAGE. The fruit's total flavonoids and phenolic contents are 0.42 ± .030 g/mL and 94 ± 1.9 mg CAE, respectively. Anti-tumorigenic efficacy was determined to be 66% against Agrobacterium tumefaciens. Additionally, the extract possesses potent antifungal and antibacterial properties. Molecular docking provided the structural motifs and underlying interactions between L-asparaginase, N-acetylglucosamine, murine, and chitin. SN contains high levels of the enzyme L-asparaginase and phytochemicals, making it a potential source of anticancer drugs.

Keywords: L-asparaginase; Solanum nigrum; antibacterial plant; anticancer plants; antifungal plants; flavanoids; polyphenols.

Figure 1.

The experimental results of (A) enzyme purifications, (B) ion exchange, and (C) gel filtration of L-asparaginase from Solanum nigrum.

Figure 2.

Effect of (A) substrate concentration, (B) pH, and (C) temperature on the activity of L-asparaginase from Solanum nigrum.

Figure 3.

(A) Antibacterial assay, regarding Solanum nigrum extract inhibiting the bacterial lawn of B. subtilus (B) antifungal assay, the effect of Solanum nigrum extract on the fungal growth of Aspergillus tamari (C) SDS PAGE depicted molecular weight of S nigrum (32 ± .5 kDa) as compared to the standard proteins, with molecular weights ranging from 6 kDa to 210 kDa. (D) E. coli growth inhibited maximal by 10 g/mL concentration of SN fruit ext. (E) Staphylococcus aureus zones of inhibition by fruit extract of SN as compared to erythromycin control.

Figure 4.

Antitumor activity (Potato disc assay) of methanolic extracts of Solanum nigrum on (Agrobacterium tumefaciens) strain AtSl0105 against Campothacin (30ppm) as control.

Figure 5.

(A) Docking of L-asparaginase with Chitin monomer 2-acetamido-2-deoxy-beta-D-glucopyranose. (B) Functional analysis of L-asparaginase to validate its anti-cancerous activity. (C) The bactericidal potential of flavonoids and phenols; Flavonoids and phenolics (phytochemicals) interaction with a murine component of bacterial cell wall ending up cell death. Both flavonoids and phenols offer a 1 h bond with murine (a component of the bacterial cell wall), with bond lengths 1.98 and 2.285, respectively.

Figure 6.

Solanum nigrum extracts ameliorating apoptotic cascade of cancer/tumor cells by Flavonoids; Bax, Bak, and Bid are regulators of apoptosis. BcL-x, Bad, and BcL-2 are regulatory proteins for apoptosis cascade (inhibited by flavonoids), procaspase-9 and Apaf1 and cytochrome C combine to form apoptosome. Simultaneously, death receptors integrate with procaspase-8, triggering caspase-3 and activating apoptosis.