Abstract

Background:
In Sudan, people have long used Glinus lotoides L., a plant from the Molluginaceae family to fight parasitic infections, calm stomach problems, and treat inflammation. The same is true for several other regions where this herb grows wild.

Aim:
This study aimed to comprehensively analyze the phytochemical composition of the ethanolic extract of G. lotoides aerial parts using GC-MS and evaluate its antimicrobial, antiparasitic, antioxidant, and toxicological profiles using in vitro (brine shrimp lethality, MTT cytotoxicity) and in vivo (acute oral toxicity in rats) assays.

Methods:
Aerial parts were collected from central Sudan (coordinates: 15°30'N, 32°35'E; sandy loam soil), dried, and extracted using 70% ethanol. GC-MS analysis was performed for the identification of compounds. Antibacterial activity was tested against four standard bacterial strains using the agar well diffusion method. The antiparasitic activity against Giardia lamblia (phylum Metamonada, family Hexamitidae) was assessed in vitro. Antioxidant activity was evaluated using the DPPH radical-scavenging assay across a concentration range (10-100 μg/mL). Acute oral toxicity was assessed in vivo in adult male Albino Wistar rats following an adaptation of OECD Guideline 423, with assessment of behavioral, hematological, biochemical, and histopathological parameters.

Results:
GC-MS analysis identified 13 major compounds, with lupeol (51.12%) and lup-20(29)-en-3-ol acetate (25.83%) as the major constituents. The extract demonstrated potent antibacterial activity against Bacillus subtilis (32 mm inhibition zone), Pseudomonas aeruginosa (19 mm), and Escherichia coli (18 mm), but no activity against Staphylococcus aureus. Moderate antiparasitic activity against G. lamblia (IC₅₀: 7.2 μg/mL) and antioxidant activity (67.77% DPPH inhibition at 100 μg/mL; IC₅₀: 68.4 μg/mL) were observed. The brine shrimp lethality assay showed moderate toxicity (LD₅₀: 785.4 μg/mL). The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on Vero cells indicated non-cytotoxicity (IC₅₀ > 100 μg/mL). In vivo, no mortality or behavioral changes were observed at doses up to 2000 mg/kg. Hematological analysis revealed mild increases in the PCV and RBC counts within the normal physiological range. Biochemical analysis revealed slight elevations in AST levels at higher doses, whereas ALT levels remained normal. Corrected serum sodium levels remained within normal limits. Histopathological examination revealed normal architecture at doses ≤1000 mg/kg, with mild necrosis observed only at 2000 mg/kg.

Conclusion:
G. lotoides exhibits promising antimicrobial, antiparasitic, and antioxidant activities with a favorable safety profile at doses of up to 1000 mg/kg. The high concentration of lupeol supports its traditional use as an anti-inflammatory agent. The NOAEL was identified as 1000 mg/kg, and the LD₅₀ exceeded 2000 mg/kg in the rat model.

Key words: Acute toxicity; Antimicrobial; Glinus lotoides, Lupeol; Sudan.