Biometric Effects of Ethanolic and Methanolic Earthworm (Eudrilus eugeniae) Cast Extracts in Wistar Rat

Earthworm cast is an earthworm byproduct with an untapped therapeutic potential. This study evaluated the morphological effect of ethanolic and methanolic cast extracts on Wistar rats. Fifteen (15) adult female rats (197±46 g) were randomly assigned into three groups (n = 5) after two weeks of acclimatization. The control was subjected to distilled water (DW), treatment (T1) to 15% Ethanolic cast extract (ECE) and treatment (T2) to 15% Methanolic cast extract (MCE). Administration was done via free drinking with feeding ad libitum for four weeks. Morphological indices were evaluated using standard methods, while PCA was used to determine the association between parameters. Results showed that the control, gradual and steady increases in measured parameters, ECE exhibited consistently higher values while the MCE demonstrated early but fluctuating responses. Body weight revealed rapid early gains in the MCE group at day 7 (18%) and delayed but increases in the ECE at day 28 (11%), whereas the control showed typical gradual growth at day 28 (7%). Organ–body weight ratios were largely stable, with notable variations in liver and stomach, reflecting organ-specific responses to extract administration. PCA identified three major patterns of organ variability: general organ enlargement, a liver–gut metabolic axis, and independent heart variation. In conclusion, the findings indicate that ECE exerts the most pronounced and sustained biometric effects, whereas MCE induces early but less stable responses. Therefore, earthworm cast extracts can serve as bioactive agents for growth promotion and organ-specific modulation, providing a foundation for further mechanistic and safety studies.