Phytochemical and GC-MS analysis of Thevetia peruviana fruit methanol extract as an anti-rodenticide potential against balb C rats

Abstract

Rodents have remained a menace to humans, hence there is need to evaluate for anti-rodent activity of cheap and environment friendly control methods. This study aimed at evaluating the anti-rodenticidal activity of Thevetia (T.) peruviana fruit methanol extract. T. peruviana fruit was sampled, dried and extracted using methanol/water in the ratio of 3:1 by volume. Phytochemicals; alkaloids, phenols, flavonoids, glycosides, saponins, and tannins were determined qualitatively and quantitatively in the fruit extract. The extract was then characterized using Fourier Transform Infrared (FTIR) and Gas Chromatography Mass Spectrophotometer (GC-MS). Anti-rodent activity of the extracts was determined on a total of 25 mice with body weights of 20-25 g. The animals 8-12 weeks' old were grouped into 5 cages (5 animals per cage), marked and allowed to acclimatize with laboratory conditions of 25 °C, warm or less humid for 5 days with enough water and food. Extract dose (between 0.3 and 0.5 g of extract/kg body weight) was then administered in a single dose by gavage using intubation canula for 7 days and the animals observed for any toxicity and mortality. The data was subjected to probit analysis and ANOVA. Phytochemical screening showed that the extracts contained glycosides, phenols, saponins, alkaloids, triterpenoids, and flavonoids in different abundance. T. peruviana fruit contained 125.13 $\pm$ 1.04 mg/g in GAE phenolic content, 85.70 mg/g in RE of dry weight of flavonoids, 10.50 $\pm$ 0.01 mg/g in TAE of Tannins, 16.50$\pm$ 0.21 mg/g alkaloid content, and 8.28$\pm$ 0.11 mg/g saponin content. The FTIR spectrophotometer depicted O - H, CH₂, C[bond, double bond]O, C-O-C functional groups in wave numbers of 3335, 2932, 1599, and 1001 cm^-1 respectively. The T. peruviana fruit methanol extracts depicted high acute toxicity with an average of 300 mg/kg upon oral administration in Balb C mice species. The fruit extract from T. peruviana revealed presence of alkaloids, phenols, glycosides, saponins, tannins. These participated synergistically in killing the rats and the postmortem examination report indicated that the tested extract induced a number of physical changes in the mice and therefore the T. peruviana's fruit extract can be utilized as a natural alternative anti-rodent in agriculture production before and after harvesting.

Keywords: Anti-rodenticide; GC-MS; Secondary metabolites; Thevetia peruviana.