IOSR Journal Of Pharmacy And Biological Sciences (IOSR-JPBS) e-ISSN:2278-3008, p-ISSN:2319-7676. Volume 15, Issue 3 Ser. V (May –June 2020), PP 56-63 www.Iosrjournals.Org DOI: 10.9790/3008-1503055663 www.iosrjournals.org 56 | Page Anti-malarial and Immunomodulatory Effects of Ajuga remota and Caesalpinia volkensii Extracts during Plasmodium berghei Infection in Balb/C Mice Lucy W. Kamau 1 , Rebecca Waihenya 3 , Vicky Gent 3 , Ruth Nyakundi 2 and Lucy Ochola 2 1 Kenya-Snakebite Research and Intervention Centre, Institute of Primate Research, Karen, Nairobi, Kenya 2 Tropical and Infectious Diseases, Institute of Primate Research, Karen, Nairobi, Kenya 3 Zoology, College of Pure and Applied Sciences, Jomo Kenyatta University of Agriculture and Technology, Kenya Abstract Background: In the control of malaria, artemisinin-based combined therapies have remained the first line treatment for over a decade. Recent reports from Greater Mekong Sub-region on emerging resistance particularly after recrudescing, has however raised concerns on future effectiveness of the drug. This has led to the need to identify alternative antimalarial treatment strategies. Objective: This study evaluated the anti-malarial and immunomodulatory activity of Ajuga remota and Caesalpinia volkensii leaf extracts in Plasmodium berghei infected Balb/C mice as single and combined therapy. Materials and methods: A. remota and C. volkensii leaf extracts were obtained using ethanol and petroleum ether solvents, respectively. To evaluate the impact of individual and a combination of the two plant extracts, five groups of mice (n=15) were inoculated with 200μl of 10 7 P. berghei parasites. Two, twenty four, forty eight and seventy two hours post infection; group one was not treated; the second group received dihydro-artemisinin (DHA); the third received A. remota extract; the fourth C. volkensii while the last group received the combined at a ratio of 1:1. Animals were monitored for 10 days and parasitaemia recorded on day 2, 4, 5 and 6. At days 0, 6, 8 and 10 post-infection, serum and spleens samples were obtained and levels of P. berghei antigen specific immunoglobulin G (IgG) and interferon-γ (IFN- γ) determined. Results: In vivo antimalarial activity assessed using the 4-day suppressive assay, showed that the highest suppression was by 83.66% with the combination of A. remota and C. volkensii. Suppression with A. remota, C. volkensii and DHA was at -23.31%, 4.34% and 54.2% respectively. IgG and IFN-γ levels in the treated groups were compared to the negative control group. IgG and IFN-γ levels varied during different time points, showing significant differences in various groups. Conclusion: A combination of A. remota and C. volkensii plant extracts was effective at suppressing parasite growth in vivo just as the conventional drug DHA. Administration of the extracts had effects on the levels of IgG and IFN-γ when compared to the baseline samples.Administration of the extracts also affected the IgG and IFN- γ levels as we see their production as compared to the baseline samples. Keywords: Plasmodium berghei, Ajugaremota, Caesalpiniavolkensii, IgG, IFN-γ --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 23-06-2020 Date of Acceptance: 11-07-2020 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Malaria is a vector-borne disease caused by the protozoan parasite Plasmodium. Species known to affect humans include P. falciparum, P. vivax, P. malariae, P. ovale and P. knowlesi [1] . Globally 3.3 billion people are at risk of malaria infection and development of the disease, with Africa carrying the heaviest burden [2] . The highest incidences of malaria-induced morbidity and mortality is caused by P. falciparum [3] with 445 000 number of deaths and infections recorded in 2016 [4] . Chemotherapy remains the most effective way of fighting the disease with drugs such as chloroquine, pyrimethamine, quinine and artemisinin being the most frequently used to treat all human malaria. Artemisinin and its derivatives combined with other anti-malarial (Artemisinin-based Combined Therapies-ACTs) are currently used as the first-line treatment strategy [2] . Intermittent preventive treatment with sulfadoxine- pyrimethamine used during pregnancy has also assisted in protecting women while 15 million children have been protected through seasonal malaria chemoprevention programs in Africa [4] . Despite the success, reduced