Somewhere in Facebookdom a fellow cheloniophile posted the virtues of pumpkin as an anti worming method for tortoises.  “I promptly said “no it doesn’t.” ‘

But I looked more and there is some wiggle room to suggest it might be somewhat ‘helpful’.

The following abstract indicates that a semi refined form of extracts from the seeds can inhibit nematode proliferation. Not elimination, but a reduction in proliferation.  Many people who look at gut biome (the organisms that cohabitant in the gut) think some worm loads are important and somewhat associated with good health.  But an overabundance is unhealthy. 

Abstract: A significant number of studies report growing resistance in nematodes thriving in both humans and livestock. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficiency of Curcubita pepo (C. pepo) L. hot water extract (HWE), cold water extract (CWE) or ethanol extract (ETE) on two model nematodes: Caenorhabditis elegans (C. elegans) and Heligmosoides bakeri (H. bakeri). Methods: Raman, IR and LC-MS spectroscopy analyses were performed on the studied plant material to deliver qualitative and quantitative data on the composition of the obtained extracts: ETE, HWE and CWE. The in vitro activity evaluation showed an impact of C. pepo extracts on C. elegans and different developmental stages of H. bakeri. The following in vivo experiments on mice infected with H. bakeri confirmed inhibitory properties of the most active pumpkin extract selected by the in vitro study. All of the extracts were found to contain cucurbitine, aminoacids, fatty acids, and-for the first time-berberine and palmatine were identified. All C. pepo seed extracts exhibited a nematidicidal potential in vitro, affecting the survival of L1 and L2 H. bakeri larvae. The ETE was the strongest and demonstrated a positive effect on H. bakeri eggs hatching and marked inhibitory properties against worm motility, compared to a PBS control. No significant effects of pumpkin seed extracts on C. elegans integrity or motility were found. The EtOH extract in the in vivo studies showed anthelmintic properties against both H. bakeri fecal egg counts and adult worm burdens. The highest egg counts reduction was observed for the 8 g/kg dose (IC50 against H. bakeri = 2.43; 95% Cl = 2.01–2.94). A decrease in faecal egg counts (FEC) was accompanied by a significant reduction in worm burden of the treated mice compared to the control group. Conclusions: Pumpkin seed extracts may be used to control of Gastrointestinal (G.I.) nematode infections. This relatively inexpensive alternative to the currently available chemotherapeutic should be considered as a novel drug candidate in the nearest future.

The C. elegans nematode is a standard/common model organism for many life science and ecology/evolution studies. It looks like the ethanol extract was most effect with an inhibitory effect on C. elegans in mice guts.

How does that translate to tortoises eating pumpkin and getting the compound likely to inhibit nematodes “cucurbitacin”?  I’d say not likely.  Tortoises engulf mouthfuls of pumpkin and swallow, there is no chewing action.  That seeds might get broken open and cucurbitine is released such that anti worm activity is happening is remote.  Tortoises are great seed distributors, meaning the seed will sprout from their feces.  Mice on the other hand would chew that seed up eating it in a way that might contribute to nematode inhibition.

Why would the pumpkin evolve to have this compound cucurbitacin in the first place?  My presumptive answer is: most likely the mildly poisonous nature of cucurbitacin would inhibit the mice themselves from eating all the seeds so that better seed distributors, like what happens with tortoises, could move those seeds around.  The compound is also in the flesh, it’s the bitter taste. Cucurbitacin inhibits many insects from eating the flesh of pumpkins.  Pumpkins bought in the grocery store have little cucurbitacins in the flesh, nobody wants to eat bitter tasting melons.  Wild-type pumpkins have much higher amounts of cucurbitacins in their flesh.

There are many many peer reviewed articles in scientific literature looking at all kinds of properties that pumpkins have that might be used in human and agriculture medicine.  I found no clinical trials (controlled experiments) indicating that eating domestic pumpkins inhibits worm proliferation.  There are several studies in Chinese languages (with English abstracts) that indicate it’s a forgone conclusion that pumpkin will reduce worms loads in people.  But no clinical trial type study published in English.

Pumpkin (all squashes for that matter) can be a good diet variable to keep the food plate interesting for your tortoise.  I do not find any solid evidence that it will  inhibit worm populations in the tortoise gut.  But it might?

There are 6 research papers I found that describe different plants that have anthelmintic activity.

The most interesting to me is that there is a synergistic effect from compounds in opuntia cactus, Anthelmintic properties are in the complex of compounds – flavonoids, saponins and tannins were the fractions with the greatest activity in all of the in vitro (petri dish, not the actual animals) assays. These substances are known for anthelmintic properties that act synergistically to inhibit eggs from hatching. In Veterinary Parasitology 226 (2016) 65–68 ‘Ovicidal and larvicidal activity of extracts of Opuntia ficus-indica against gastrointestinal nematodes of naturally infected sheep.’ Yes in sheep not tortoises.  Again chewers not gulpers.

For a more through review of this phenomena see Rajeswari, V.D., 2014. Anthelmintic activity of plants: a review. Res. J. Phytochem. 8, 57–63.