Moringa oleifera Extract Extenuates Echis ocellatus Venom-Induced Toxicities, Histopathological Impairments and Inflammation via Enhancement of Nrf2 Expression in Rats

Abstract

Echis ocellatus snakebite causes more fatalities than all other African snake species combined. Moringa oleifera reportedly possesses an antivenom property. Therefore, we evaluated the effectiveness of M. oleifera ethanol extract (MOE) against E. ocellatus venom (EOV) toxicities. Thirty male rats were grouped as follows (n = 5): Group 1 (normal control received saline), groups 2 to 6 were administered intraperitoneally, 0.22 mg/kg (LD50) of EOV. Group 2 was left untreated while group 3 to 6 were treated post-envenoming with 0.2 mL of polyvalent antivenom, 200, 400, and 600 mg/kg of MOE respectively. MOE significantly (p < 0.05) normalized the altered haematological indices and blood electrolytes profiles. MOE attenuated venom-induced cellular dysfunctions, characterized by a significant increase in NRF2, and concomitant downregulation of increased antioxidant enzymes (SOD and CAT) activities in the serum and heart of the treated rats. MOE normalized the elevated TNF-α and IL-1β in serum and heart tissues. Furthermore, the IgG titre value was significantly (p < 0.5) higher in the envenomed untreated group compared to the MOE-treated groups. Hemorrhagic, hemolytic and coagulant activities of the venom were strongly inhibited by the MOE dose, dependently. Lesions noticed on tissues of vital organs of untreated rats were abolished by MOE. Our findings substantiate the effectiveness of MOE as a potential remedy against EOV toxicities.

Keywords: Echis ocellatus; Moringa oleifera; antivenom; inflammation.

Figure 1

Effects of M. oleifera ethanol extract on electrolytes levels of rats challenged with E. ocellatus venom. Data are expressed as mean ± SD (n = 3). Bars with different letters are statistically distinct (p < 0.05). (a) Na⁺ concentration; (b) Cl⁺ concentration; (c) K⁺ concentration; (d) Ca²⁺ concentration. PVA: polyvalent antivenom; Na⁺: sodium ion; K⁺: potassium ion; Cl⁻: chloride ion; Ca²⁺: calcium ion.

Figure 2

Effects of M. oleifera extract on MDA (a), SOD (b), and CAT (c) activities, and Nrf2 levels (d) in the sera of rats challenged with E. ocellatus venom. Data are expressed as mean ± SD (n = 3). Bars with different letters are statistically distinct (p < 0.05). PVA: polyvalent antivenom; CAT: catalase; SOD: superoxide dismutase; MDA: malondialdehyde; NRF2: nuclear factor erythroid 2–related factor 2.

Figure 3

Effects of M. oleifera extract on MDA (a), SOD (b), and CAT (c) activities, and Nrf2 levels (d) in the heart of rats challenged with E. ocellatus venom. Data are expressed as mean ± SD (n = 3). Bars with different letters are statistically distinct (p < 0.05). PVA: polyvalent antivenom; CAT: catalase; SOD: superoxide dismutase; MDA: malondialdehyde; NRF2: nuclear factor erythroid 2–related factor 2.

Figure 4

Effects of M. oleifera extract on TNF: α, IL: 1β in serum and heart tissues, and immunoglobulin G levels in challenged with E. ocellatus venom. Data are expressed as mean ± SD (n = 3). Bars with different letters are statistically distinct (p < 0.05). (a) serum TNF: α; (b) heart TNF: α; (c) serum IL: 1β; (d) heart IL: 1β; (e) serum IgG. PVA: polyvalent antivenom; TNF: α-Tumour necrosis factor-alpha; IL: 1β-interleukin-1 beta; IgG: immunoglobulin G.

Figure 5

Coagulant activity of M. oleifera extract against E. ocellatus venom. Data are expressed as means ± S.D. of three individual experiments (n = 3). Group 1: distilled water/citrated plasma (normal control), Group 2: venom/citrated plasma (venom control), Group 3: venom/citrated plasma/100 mg/kg extract, Group 4: venom/citrated plasma/200 mg/kg extract, Group 5: venom/citrated plasma/300 mg/kg extract, Group 6: venom/citrated plasma/0.2 mL polyvalent antivenom.

Figure 6

Histological evaluation of the brain of envenomed treated rats (×400).Group 1 (normal control): neurons appeared normal, Group 2 (venom control): vacuolation and inflammatory cells infiltration, foci of degeneration, and necrosis of neurons, Group 3 (antivenom control): neurons appeared fairly normal, Group 4 (venom/200 mg/kg extract): normal appearance of neurons, Group 5 (venom/400 mg/kg extract): neurons appear fairly normal, Group 6 (venom/600 mg/kg extract): neurons appeared normal.

Figure 7

Histological examination of the heart of envenomed treated rats (×400) Group 1 (normal control): cardiomyocytes appeared normal, Group 2 (venom control): multiple foci of thinning and attrition of cardiomyocyte and epicardia hemorrhages, Group 3 (antivenom control): extensive foci of mild pallor of the cardiomyocytes, Group 4 (venom/200 mg/kg extract): focus of the cardiomyocytes, Group 5 (venom/400 mg/kg extract): few foci and mild pallor of the cardiomyocytes, Group 6 (venom/600 mg/kg extract):cardiomyocytes appeared normal.

Figure 8

Histological examination of the kidneys of envenomed treated rats (×400). Group 1 (normal control): Normal and no foci of flattening of tubular epithelial cells, Group 2 (venom control): a cystic dilated appearance of foci of tubules, Group 3 (antivenom control): tubules appeared normal, Group 4 (venom/200 mg/kg extract): extensive foci of flattening of epithelium of tubules, Group 5 (venom/400 mg/kg extract): focus of marked flattening of epithelium of tubules, Group 6 (venom/600 mg/kg extract): few foci of tubular epithelial cells.