Antioxidant and antimalarial properties of Sophora exigua Craib. root extract in Plasmodium berghei-infected mice

Abstract

Background Sophora exigua Craib. is commonly used in Thailand to reduce fever and increase postpartum breast milk production in women who have hypogalactia. However, there has been no report on the antioxidant and antimalarial properties of this plant. This study aimed to investigate the antioxidant and antimalarial activities of S. exigua root extract and to evaluate its acute toxicity in mice to confirm its safety. Methods The in vitro antioxidant activities were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide radical, and hydroxyl radical scavenging assays. The in vivo antioxidant activities were determined by detecting the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the livers of malaria-infected mice. The in vivo antimalarial activity was determined by Peters’ 4-day suppressive test in mice infected with Plasmodium berghei ANKA and orally administered S. exigua root aqueous and ethanolic extracts at different doses (200, 400, and 600 mg/kg body weight). In addition, the acute oral toxicity of the plant extracts was assessed in mice at a dose of 2000 mg/kg body weight. Results The ethanolic extract of S. exigua root exhibited inhibition of DPPH radicals, superoxide anions, and hydroxyl radicals, with half maximal inhibitory concentration (IC50) values of 24.63 ± 1.78, 129.78 ± 0.65, and 30.58 ± 1.19 μg/ml, respectively. Similarly, research on the in vivo antioxidant activity indicated that the ethanolic extract of S. exigua root exerted a stronger effect than the aqueous extract. The aqueous extract at doses of 200, 400, and 600 mg/kg had stronger antimalarial activity than the ethanolic extract. The aqueous extract at 600 mg/kg exhibited 60.46% suppression of parasitemia. Increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and blood urea nitrogen (BUN) were detected in the mice treated with 2000 mg/kg ethanolic extract, which was related to the results of histopathological analysis of liver tissue, showing ballooning degeneration of hepatocytes, diffuse hepatic hemorrhage, and infiltration of inflammatory cells. Conclusions This study demonstrated that the ethanolic S. exigua root extract possessed antioxidant properties, and the aqueous extract also had antimalarial activity. Therefore, this plant is an alternative source of new antioxidant and antimalarial agents.

Genus Sophora: a comprehensive review on secondary chemical metabolites and their biological aspects from past achievements to future perspectives

“…Sophora exigua has reported with antimicrobial activities against Candida albicans , Staphylococcus epidermidis , and Pseudomonas aeruginosa (Kaewdana et al 2021 ). Sophoraflavanone G ( 19 ), isolated from S .…”

“…Partial synergistic effects with anti-MRSA antibiotics, such as minocycline, rifampicin, and vancomycin, were also reported. Lavandulyl flavanones were also reported as anti-malarial, anti-inflammatory, and cytotoxic agents (Boozari et al 2019b ; Li et al 2020a ; Kaewdana et al 2021 ).…”

“…Antioxidant activity of the edible flowers of S. viciifolia was reported (Lin et al 2019a ; Guo et al 2020 ). Recently, Kaewdana et al ( 2021 ) found that the ethanolic extract of S. exigua root could inhibit the superoxide anions, DPPH radicals, and hydroxyl radicals, with half-maximal inhibitory concentration (IC 50 ) values of 129.78 ± 0.65, 24.63 ± 1.78, and 30.58 ± 1.19 μg mL −1 , respectively.…”

“…Malaria is a disease caused by Plasmodium parasites, which infect humans and female Anopheles mosquitoes. The lavandulyl flavanones; sophoraflavanone G ( 19 ), leachianone A ( 20 ), and methoxykurarinone ( 24 ), isolated from the roots of S. flavescens , showed moderate antimalarial activities (in vitro) against P. falciparum (Li et al 2020a ; Ma et al 2020b ; Kaewdana et al 2021 ). Their -half-maximal inhibitory concentration (IC50) values were 2.6, 2.1, and 2.4 μM, respectively.…”

“…Sophora exigua Craib is commonly used in Thailand to increase postpartum breast milk production in women who have hypogalactia and reduce fever (Kaewdana et al 2021 ).…”