Nephroprotective, cytotoxic and antioxidant activities of Euphorbia paralias

Abstract

Objective: To investigate the effect of the ethyl acetate fraction of the aerial parts of E. paralias L. F. Euphorbiaceae on nephroprotective, cytotoxic, and antioxidant.

Methods: different spectroscopic and spectrophotometric methods were applied to identify phytoconstituents. The nephroprotective potential of E. paralias ethyl acetate fraction (Ep EtOAc) was evaluated in male rats with thioacetamide-induced kidney injury, as wll as cytotoxic activity was evaluated using a viability assay, and the antioxidant activity was evaluated using the DPPH method. Results: quantitative estimation of total phenolics and flavonoids of E. paralias was performed using unique spectrophotometric methods. The polyphenolic compounds gallic acid (1), ellagic acid (2), kaempferol-3-O-(6″-O-galloyl-β-D-glucopyranoside) (3), quercetin-3-O-β-D-glucopyranoside (4) and quercetin-3-O-β-D-arabinoside (5) were isolated from the ethyl acetate fraction of the aerial parts of E. paralias. The thioacetamide administration resulted in marked nephrotoxicity, but pretreatment with Ep EtOAc significantly attenuated the nephrotoxicity through alteration of kidney biomarkers, thereby improving the redox status of the tissue and restoring serum biochemical parameters nearly to normal levels. This study revealed a significant cytotoxic and strong antioxidant effect. Conclusion: we conclude that the Ep EtOAc may be used in the future as nephroprotective, cytotoxic, and antioxidant agent derived from a natural source.

Keywords: Antioxidant; Cytotoxic; Euphorbia paralias; Nephroprotective; Polyphenolic.

Fig. 1

Total content of phenolics and flavonoids (mg GAE and mg RE, respectively) of the total methanolic extract of the aerial parts of Euphorbia paralias L. GAE: gallic acid equivalent, RE: rutin equivalent.

Fig. 2

Chemical structures of compounds (1–5) isolated from the total methanolic extract of the aerial parts of Euphorbia paralias L.

Fig. 3

Effects of pretreatment with Ep or Sil on kidney enzymes in rats with thioacetamide-induced kidney injury. Groups of Sprague–Dawley rats were pretreated orally with Sil (100 mg/kg body weight) or Ep ethyl acetate fraction (200 mg/kg body weight) daily for four consecutive weeks and then orally gavaged with saline (control) or TAA two times per week. The effects of pretreatment with Ep or Sil were analyzed by serum levels of (A) creatinine (CR), (B) urea (UR), (C) albumin (AL), and (D) total protein (TP). p ≤ 0.05 was considered significant. ^aCompared with the control group. ^bCompared with the TAA group, n = 6. Control, saline-treated healthy control rats; Ep, E. paralias ethyl acetate fraction; Sil, silymarin; TAA, thioacetamide.

Fig. 4

Effects of pretreatment with Ep and Sil on enzymes related to oxidative stress in the kidneys of rats with thioacetamide-induced kidney injury. Sprague–Dawley rats were pretreated orally with Sil (100 mg/kg body weight) or Ep ethyl acetate fraction (200 mg/kg body weight) daily for four consecutive weeks and then orally gavaged with saline (control) or TAA two times per week. The effects of pretreatment with Ep or Sil on oxidative stress markers in the kidney were analyzed by measuring levels of (A) glutathione (GSH), (B) catalase (CAT), and (C) superoxide dismutase (SOD) in kidney homogenates. p ≤ 0.05 was considered significant. ^aCompared with the control group. ^bCompared with the TAA group, n = 6. Control, saline-treated healthy control rats; Ep, E. paralias ethyl acetate fraction; Sil, silymarin; TAA, thioacetamide.

Fig. 5

Effects of pretreatment with Ep and Sil of TAA-treated rats on (A) kidney weight/body weight ratio (Kid W/BW) and (B) body weight (BW). p ≤ 0.05 was considered significant. ^aCompared with the control group. ^bCompared compared with the TAA group, n = 6. Control, saline-treated healthy control rats; Ep, E. paralias ethyl acetate fraction; Sil, silymarin; TAA, thioacetamide.

Fig. 6

Light photomicrograph showing the histopathology of kidneys from rats with thioacetamide-induced kidney injury (H&E, 400 × ). A (Cont gp): Renal medulla showing normal collecting tubules (CT), epithelial lining (black arrow), and interstitium (blue arrow). B (TAA gp): Small-sized glomerulus (G) with widened Bowman’s space (BS), proximal tubules with edematous lining (black arrow) with intra-tubular debris (blue arrow), and areas of interstitial hemorrhage (yellow arrow). C (Sil + TAA gp): Congested edematous glomerulus (G), proximal tubules with edematous and apoptotic epithelial lining with partial loss of brush borders (black arrow), and congested blood vessels (blue arrow). D (Ep + TAA gp): Renal medulla showing collecting tubules (CT) with edematous epithelial lining (black arrow) and congested BV (blue arrow). Cont, saline-treated healthy control rats; Ep, E. paralias ethyl acetate fraction; Sil, silymarin; TAA, thioacetamide.

Fig. 7

Light photomicrograph showing the histopathology of kidneys from rats with thioacetamide-induced kidney injury (Masson’s trichrome stain, 400 × ). A (Cont gp): Normal collagen distribution in glomeruli (black arrow) and around tubules (red arrow). B (TAA gp): Excess collagen is present in glomeruli (black arrow) and around tubules (yellow arrow). C (Sil + TAA gp): Normal collagen distribution in glomeruli (black arrow) and around tubules (red arrow). D (Ep + TAA gp): Excess collagen in glomeruli (black arrow) and around tubules (red arrow). Cont, saline-treated healthy control rats; Ep, E. paralias ethyl acetate fraction; Sil, silymarin; TAA, thioacetamide.

Fig. 8

Cytotoxic activity of E. paralias ethyl acetate fraction against the HEPG₂ liver cancer cell line in comparison with doxorubicin (standard cytotoxic drug).

Fig. 9

Scavenging activity (%) of ethyl acetate fractions of E. paralias (Ep) and ascorbic acid. The radical scavenging effect of Ep was determined using the DPPH and was calculated by the following formula: Radical scavenging % = [(A_control − A_sample) / A_control] × 100.