Gymnema inodorum Leaf Extract Improves Cardiac Function in Experimental Mice Infected with Plasmodium Berghei

Abstract

Malaria-associated cardiac injury has been reported to be the primary cause of death due to severe malaria. The discovery of substances showing a protective effect on cardiac injury during malaria infection is urgently needed. Hence, the purpose of this study was to evaluate the efficacy of Gymnema inodorum leaf extract (GIE) on cardiac function in mice infected with Plasmodium berghei. ICR mice were treated with 1 × 10⁷ infected red blood cells of P. berghei ANKA (PbANKA), administered orally with GIE in 100, 250 and 500 mg/kg body weight of mice. Creatine phosphokinase (CPK) and echocardiography were carried out. It was found that CPK and heart-weight to body-weight (HW/BW) ratios were significantly higher in untreated mice than the healthy control. Moreover, impaired cardiac function in the untreated group was observed as indicated by changes in echocardiography. Interestingly, GIE exerted a protective effect on cardiac injury induced by PbANKA infection. Our results demonstrated that the parasitemia percentage, CPK, HW/BW ratio, and echocardiography in GIE treated mice were improved. However, there was no significant difference between GIE dosages. Therefore, GIE possessed a cardio-protective effect during malaria infection in mice.

Keywords: cardiac function; gymnema inodorum; malaria; pbANKA.

Figure 1.

Malaria-associated cardiac injury and effect of GIE on parasitemia. (A) Monitoring parasitemia percentage and CPK level during 10 days post-infection. (B) Positive correlation between parasitemia and CPK level. (C) GIE treatment reduced the parasitemia percentage in 4-day PbANKA-infected mice. Results were expressed as mean + SEM. H: healthy; UN: untreated; GI100, GI250, and GI500: GIE treatment of 100, 250 and 500 mg/kg body weight of mice, respectively; CQ: CQ treatment of 10 mg/kg body weight of mice.

Figure 2.

Effect of GIE on CPK level in PbANKA infection in mice. H: healthy; UN: untreated; GI100, GI250, and GI500: GIE treatment of 100, 250 and 500 mg/kg body weight of mice, respectively; CQ: CQ treatment of 10 mg/kg body weight of mice.

Figure 3.

Effect of GIE on HW/BW in PbANKA infection in mice. H: healthy; UN: untreated; GI100, GI250 and GI500: GIE treatment of 100, 250 and 500 mg/kg body weight of mice, respectively; CQ: CQ treatment of 10 mg/kg body weight of mice.

Figure 4.

Effect of GIE on cardiac function in PbANKA infection in mice. Echocardiography was performed, as indicated by the parameters, including (A) LVIDs, (B) ESV, (C) EF, and (D) FE. Results were expressed as mean + SEM. H: healthy; UN: untreated; GI100, GI250 and GI500: GIE treatment of 100, 250 and 500 mg/kg body weight of mice, respectively; CQ: CQ treatment of 10 mg/kg body weight of mice.

Figure 5.

Microscopic observation of H&E staining. (A) Transverse sections of whole heart observed malaria pigment deposit (green arrow) and vacuolar degeneration (star) under 100x microscope in healthy (H), untreated (UN), GIE-treated (GI100, GI250 and GI500) and CQ-treatment. (B) Represents score of malaria pigment deposit and (C) shows score of vascular degeneration from 3 mice. Scale bar: 20 μm.