Exploring the Anthelmintic, Antioxidant, and Cytotoxic Potential of <i>Khaya grandifoliola</i> and <i>Faidherbia albida</i> Extract Combinations: In Vitro Studies on <i>Heligmosomoides polygyrus</i> and <i>Caenorhabditis elegans</i>

Abstract

Background Soil‐transmitted helminth infection is endemic in Chad and constitutes a public health problem, particularly among school‐age children. The aim of this study was to evaluate the synergistic anthelmintic activity of the combined extracts of Khaya grandifoliola and Faidherbia albida used in Chad by traditional practitioners for the treatment of soil‐transmitted helminth infection. Methods The anthelmintic tests using combinations of K. grandifoliola and F. albida followed standard protocol. Combination 1 corresponding to 75% F. albida and 25% K. grandifoliola , Combination 2 corresponding to 50% F. albida and 50% K. grandifoliola , and Combination 3 corresponding to 25% F. albida and 75% K. grandifoliola . The nematocidal activity was assessed on Heligmosomoides polygyrus and Caenorhabditis elegans using the WMicroTracker. L3 larvae of H. polygyrus were obtained after 7 days of coproculture, and L4 of C. elegans. One hundred microliter concentrations of extracts, albendazole, and distilled water were brought into contact with 100 μ L of H. polygyrus suspension in a 96‐well microplate incubated for 20 h at 28°C in the WMicroTracker. The same procedure was adopted for C. elegans , but 180 μ L of OP50 and 19 μ L of C. elegans suspension were mixed with 1 μ L of extracts and incubated at 20°C in the WMicroTracker. The antioxidant activity was assessed by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical, iron reducing power (Frap), hydrogen peroxide (H 2 O 2 ), and nitric oxide (NO). Cytotoxicity was tested on red blood cells. The phytochemical screening was conducted using both qualitative and quantitative methods. Standard procedures were followed to ensure accuracy and reliability. The analysis was aimed at identifying and measuring the bioactive compounds present. Results Combination 2 (50% F. albida and 50% K. grandifoliola ) was the most promising, with an IC 50 of 0.26 and 0.003 mg/mL, respectively, on H. polygyrus and C. elegans . This was followed by Combination 3 with an IC 50 of 0.43 mg/mL for H. polygyrus. Combination 2 and Combination 3 with percentage inhibitions of 98.61 ± 0.98 and 99.14 ± 0.60, respectively, for H. polygyrus and C. elegans did not show a significant difference with respect to albendazole and levamisole. Combination 2 has the capacity to reduce iron with an IC 50 of 2170 ± 3.73 μ g/mL. Ascorbic acid (46.19 ± 0.18 μ g/mL) used as a reference molecule shows a greater capacity than that of combination 2. With regard to H 2 O 2 , Combination 2 inhibited H 2 O 2 slightly less (IC 50 : 0.114 ± 0.02 μ g/mL) than ascorbic acid (IC 50 : 0.108 ± 0.03 μ g/mL). As for DPPH, the combination had a moderately low scavenging activity (17.64 ± 0.18 μ g/mL) compared with ascorbic acid, which had a good scavenging activity (7.23 ± 3.73 μ g/mL). Combination 2 had a very weak effect on NO (IC 50 : 103.5 μ g/mL) compared with ascorbic acid (54.22 ± 3.74 μ g/mL). Conclusion This study provides scientific evidence supporting the traditional use of combined extracts from the two plants in treating helminthiasis. However, nematodes differ in structure, composition, and physiology. Further in vivo studies are needed to understand how Combination 2 affects nematode larvae.