Preliminary Study on the Rodenticidal Effect of Pong-Pong (Cerbera odollam) Seed Powder against Sprague-Dawley Rats

Aims: Pong-pong (Cerbera odollam) is a poisonous plant species that has potent cardiotoxic effects. In Malaysia, its fruit, referred to as ‘buah tikus’ (rat’s fruit), has been traditionally used as a rodent repellent. This study evaluated the rodenticidal effects of pong-pong seed powder based on acute oral toxicity and palatability under laboratory conditions against Sprague-Dawley albino rat, Rattus norvegicus.

Study Design: The acute oral toxicity test was done according to the Organization for Economic Cooperation and Development (OECD) Guideline 420 and the free choice feeding test was conducted according to Palmateer (1974).

Place and Duration of Study: Animal Laboratory at AMTREC Building, Malaysian Agricultural Research and Development Institute (MARDI) Headquarters, Serdang, Selangor, Malaysia, between May 2023 to May 2024.

Methodology: Pong-pong fully ripe fruits (red colour) were collected from Sekinchan, Sabak Bernam, Selangor. The fruits were sliced into halves for the seeds, cleaned, dried and ground into powder. The seed powder was administered orally by mixing the prescribed dose into the rat food bait. The acute oral toxicity test was done according to the OECD Guideline 420, administering a single high dose of 5 g/kg of body weight. The palatability was determined by using a free choice feeding test between treated bait (mixed with Pong-pong seed powder) with that of the untreated bait.

Results: Results indicated a higher susceptibility in female rats, with 83% mortality compared to 33% in males. Based on the palatability results, the acceptance rate of female rats was 25.6% which is lower compared to 44.2% in males. This implies that the females are more sensitive to the seed powder in the baits and significantly reduce their intake of the treated bait when an alternative food is available.

Conclusion: Although the preliminary findings demonstrated acute oral toxicity of pong-pong seed powder in rats, further research is needed to confirm its efficacy as a rodenticide.