Hexane fraction of Globimetula braunii induces mitochondria-mediated apoptosis in Plasmodium berghei -infected mice.

Background: Apoptosis is a common pathology in malaria and most antimalarial drugs induce apoptosis during chemotherapy. Globimetula braunii is an African mistletoe used for the treatment of malaria but its effect on mitochondria-mediated apoptosis is not known.
Methods: Malarial infection was induced by the intraperitoneal injection of NK 65 strain Plasmodium berghei -infected erythrocytes into mice which were treated with graded doses (100-400 mg/kg) of methanol extract (ME), and fractions of n -hexane, dichloromethane, ethylacetate and methanol (HF, DF, EF and MF) for 9 days after the confirmation of parasitemia. Artequine (10 mg/kg) was used as control drug. The fraction with the highest antiplasmodial activity was used (same dose) to treat mice infected with chloroquine-resistant (ANKA) strain for 5 consecutive days after the confirmation of parasitemia. P-alaxin (10 mg/kg) was used as control drug. On the last day of the treatment, liver mitochondria were isolated and mitochondrial Permeability Transition (mPT) pore opening, mitochondrial F ₀ F ₁ ATPase (mATPase) activity, lipid peroxidation (mLPO) and liver deoxyribonucleic acid (DNA) fragmentation were assessed spectrophotometrically. Caspases 3 and 9 were determined by Enzyme-Linked Immunosorbent Assay (ELISA) technique. Cytochrome c, P53, Bcl-2-associated X protein (Bax), and B-cell lymphoma-2 (Bcl2) were determined via immunohistochemistry. Phytochemical constituents of the crude methanol extract of Globimetula braunii were determined via the Gas Chromatography-Mass Spectrometry (GC-MS) analysis.
Results: There was large amplitude mPT induction by malaria parasites, extract and fractions of Globimetula braunii . At 400 mg/kg, HF significantly ( p  < 0.01) downregulated mATPase activity, and mLPO in both (susceptible and resistant) models, caused DNA fragmentation ( P  < 0.0001), induced caspases activation, P53, bax and cytochrome c release but downregulated Bcl2 in both models. The GC-MS analysis of methanol extract of Globimetula braunii showed that α-amyrin is the most abundant phytochemical.
Conclusion: The n -hexane fraction of Globimetula braunii induced mitochondrial-mediated apoptosis through the opening of the mitochondrial pore, fragmentation of genomic DNA, increase in the levels of P53, bax, caspase 3 and 9 activation and cytochrome c release with concomitant decrease in the level of Bcl2. α-Amyrin is a triterpene with apoptotic effects.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2022 The Authors.)