In-vitro and In-vivo Antioxidant Activity of Ethanol Leaf Extract of Justicia carnea

Abstract

This study investigated the in-vitro antioxidant activity of ethanol leaf extract of Justicia carnea and its effect on antioxidant status of alloxan-induced diabetic albino rats. The in-vitro antioxidant activity was assayed by determining the total phenol, flavonoids, ascorbic acid, β-carotene and lycopene contents and by using 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, reducing antioxidant power and inhibition of lipid peroxidation antioxidant systems. Oxidative stress was produced in rats by single intraperitoneal injection of 150 mg/kg alloxan and serum concentration of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were determined. Five experimental groups of rats (n=6) were used for the study. Two groups of diabetic rats received oral daily doses of 100 and 200 mg/kg Justicia carnea leaf extract respectively while gilbenclamide (5 mg/ml); a standard diabetic drug was also given to a specific group for 14 days. From the result, the leaf extract contained a higher concentration of flavonoids followed byphenols, ascorbic acid, lycopene and β-carotene. The extract displayed more potent reducing power ability with EC50 of 40 µg/ml compared to BHA (EC50 of 400µg/ml). The percentage DPPH radical scavenging activity of the extract was also higher with EC50 of 200µg/ml and increased with increase in concentration while BHA had EC50of 320µg/ml. The inhibition of lipid peroxidation also increased with increase in concentration with EC50 of 58µg/ml and comparable with BHA (EC50=60µg/ml). The effect of the plant extract on antioxidant enzyme activities was concentration-dependent. Administration of 100mg/kg of the plant extract resulted in a significant decrease (p<0.05) in serum MDA concentration, while 200 mg/kg of the extract caused a significant (p˂0.05) increase in superoxide dismutase (SOD) and catalase activities with a non-significant increase (p>0.05) in the serum level of MDA when compared with the diabetic untreated group. These findings suggest that ethanol leaf extract of Justicia carnea have antioxidant properties and could handle diabetes-induced oxidative stress.

Green Synthesis, Characterization and In-vitro Antioxidant Property of Silver Nanoparticles Using the Aqueous Leaf Extract of Justicia carnea

“…The synthesized AgNPs exhibited a dose-dependent reducing power potential which shows that they are capable of donating an electron and this increased with an increase in concentration when compared to the standards, although not as effective as the standards. This result contradicts the report made earlier by [22,23], where the aqueous extract of J. carnea exhibited a higher ferric reducing potential compared to the standard antioxidant (BHA). This result suggests the presence of reductants in the plant extracts.…”

“…4 and 5) is summarized in (Table 2). The bioactive constituents of J. carnea are flavonoids, phenols, ascorbic acid, with moderate amounts of lycopene and β-carotene [18,22]. The reduction and capping ability of J. carnea may be due to the presence of phenols in its aqueous leaf extract.…”

“…It could be presumed that the synthesized AgNPs has antioxidant potential. The antioxidant potential could be due to the presence of flavonoids, phenols, and carotenoids which are known antioxidants [22] present in the aqueous leave extract.…”

“…It is a medicinal plant used widely in Nigeria reported to have diverse functions, including blood-boosting potential [21]. J. carnea has been reported to exhibit therapeutic properties such as hypoglycemic [21], antidiabetic [22], antioxidant [20,23], antiplasmodial [17], and anti-anemic and alleviation of lipid profile [24,25]. There is no documented scientific and experimental evidence on the use of Justicea carnea leaves in the synthesis of silver nanoparticles.…”