Effects of co-treatment of Plasmodium berghei-infected mice with aqueous extract of Ocimum gratissimum leaves and primaquine on glucose-6-phosphate dehydrogenase activity, hematological, and antioxidant parameters

BACKGROUND

It has been observed that most malaria patients especially G6PD-deficient patients usually experience oxidative stress and severe anemia when treated with primaquine. This calls for the need to search for a treatment option that will ameliorate these side effects.

OBJECTIVE

The effect of co-treatment of malaria with aqueous extract of Ocimum gratissimum leaves (AEOGL) and primaquine on G6PD activity, antioxidant indices and hematological parameters in Plasmodium berghei-infected mice was investigated.

MATERIALS AND METHODS

Thirty mice divided into six groups of five mice each were recruited for this study. Whilst Group 1 (G1) served as the negative control (group not infected with plasmodium parasite), Groups 2 to 6 (G2-G6) were inoculated intraperitoneally with 0.2 ml of 1 × 10⁵/ml Plasmodium berghei (NK 65 strain) infected erythrocytes. G2 (parasite control) received no treatment. Groups 3,4,5 and 6 were administered 0.25 mg/kg bw of primaquine only; 100 mg/kg b. w of AEOGL +0.25 mg/kg bw of primaquine; 200 mg/kg b. w of AEOGL +0.25 mg/kg bw of primaquine; 200 mg/kg b. w of AEOGL respectively, for 14 days.

RESULTS

Treatment with only primaquine gave the highest mean malaria parasite clearance (82.10 ± 0.45 percent), followed by 100 mg/kg b. w of AEOGL + Primaquine (75.59 ± 0.47 percent), 200 mg/kg b. w of AEOGL + Primaquine (67.35 ± 0.67 percent), and AEOGL alone (55 ± 0.56 percent). In comparison with the untreated malaria groups, co-treatment with AEOGL + Primaquine produced a significant (p < 0.05) increase in G6PD activity, serum ascorbate, reduced glutathione, catalase activity, and a significant (p < 0.05) decrease in malondialdehyde level in a dose-dependent pattern and also a significant (p < 0.05) rise in packed cell volume, haemoglobin, and red blood cell count, unlike treatment with only primaquine which resulted in a non-significant (P > 0.05) difference in these parameters.

CONCLUSION

Co-treatment of Plasmodium berghei-infected mice with AEOGL and primaquine improved the G6PD activity, hematological parameters and antioxidant status relative to treatment with only primaquine.

Antimalarial herbal drugs: a review of their interactions with conventional antimalarial drugs

Development of resistance by malaria parasites to conventional antimalarial drugs has rejuvenated the exploration of herbal medicine as alternatives. Also, the increasing rate of the use of herbal antimalarial remedies in combination with conventional antimalarial drugs (both synthetic and semi-synthetic) has inspired researchers to validate their herb-drug interaction effects. This review evaluated the interaction outcomes between herbal antimalarial drugs in combination with conventional antimalarial drugs. With the aid of electronic databases, Pubmed and Google scholar, articles related to this subject were sourced from English peer reviewed scientific journals published from 2003 to 2020. Search terms used include “antimalarial-herbal drugs interaction”, “antimalarial medicinal plant interactions with conventional antimalarial drugs”, “drug-herbal interactions, “antimalarial drugs and medicinal plants”. Synergistic, antagonistic and none effects were reported among 30 studies reviewed. Among 18 in vivo studies on P. berghei and P. yoelii nigerense infected mice model, 14 showed synergism, 3 showed antagonism and 1 involving three plants showed both effects. Among 9 in-vivo studies involving normal animal (non-infected), 2 showed antagonism, 2 showed synergism and 5 showed none-effects. Two (2) studies on human volunteers and one (1) in vitro quantitative study showed that Garcinia kola reduced plasma concentrations of quinine and halofantrine. Generally, majority of herbal antimalarial drugs showed synergistic effects with CAMDs. Vernonia amygdalina was the most studied plant compared to others. Consequently, herbal remedies that produced synergistic effects with conventional antimalarial drugs may be prospects for standardization and development of antimalarial-medicinal plant combination therapy that could curtail malaria resistance to conventional antimalarial therapies.