Combination astragaloside IV and artesunate preserves blood-brain barrier integrity by modulating astrocytes and tight junction proteins in Plasmodium yoelii infection.

BACKGROUND: Astragaloside IV (ASIV), a natural compound from Astragalus membranaceus, exerts neuroprotective and anti-inflammatory effects in various pathologies. Its role in Plasmodium yoelii (Py) 17XL-induced inflammation leading to blood-brain barrier (BBB) damage remains undefined. Artesunate (ART), the frontline therapy for severe malaria, has encountered resistance and unresolved neurological sequelae. This study investigated the anti-inflammatory properties of ASIV combined with ART in Py-infected mice. METHODS: Sixty-five Institute of Cancer Research mice were randomized into 5 groups: sham, Py, Py-ART, Py-ASIV, and Py-ASIV + ART. Mice in Py groups were infected with Py 17XL. Either 25 mg/kg ASIV alone or 25 mg/kg ASIV plus 2.4 mg/kg ART was administered intraperitoneally for 5 days. Survival rate/time, parasitemia, neurological status, histopathology, and biochemical indices were evaluated. RESULTS: Although ASIV alone partially suppressed parasitemia, combination therapy significantly prolonged survival and mitigated neurological deficits. Both ASIV and ASIV + ART reduced IL-1β and TNF-α expression in serum and brain, attenuated BBB leakage (Evans blue assay), and preserved BBB integrity by decreasing astrocytic glial fibrillary acidic protein and aquaporin-4 while upregulating the tight junction proteins occludin and zonula occludens-1. CONCLUSIONS: ASIV exhibited modest antiparasitic action and robust anti-inflammatory effects, alleviating BBB disruption when combined with ART in Py 17XL-infected mice. These findings provide an essential basis for further preclinical exploration of ASIV as an adjunct therapy in severe malaria.