Dugesia Dorotocephala Research Articles

Testing Simarouba amara’s therapeutic effects against weedicide-induced tumor-like morphology in planarians

According to the World Health Organization, cancer is a leading cause of death globally. The disease’s prevalence is rapidly increasing in association with factors including the increased use of pesticides and herbicides, such as glyphosate, which is one of the most widely used herbicide ingredients. Although chemotherapy is currently the most common option for treatment, its high cost and rates of side effects make it less accessible to economically disadvantaged patients. Natural antioxidants and phytochemicals are being tested as anti-cancer agents due to their antiproliferative, antioxidative, and pro-apoptotic properties. Simarouba amara is one such plant and contains several alkaloid derivatives known to inhibit cancerous growth. Thus, we aimed to investigate the potential role of S. amara extract as a therapeutic agent against glyphosate-induced toxicity and tumor-like morphologies in regenerating and homeostatic planaria (Dugesia dorotocephala). We hypothesized that S. amara would reduce and prevent tumor-like lesions and toxicity in planarians exposed to glyphosate. We conducted several assays to determine the efficacy of Simarouba extract in reducing tumor-like lesions and morphological changes, increasing survival rate, mitigating blastema reduction, and maintaining locomotive velocity in glyphosate-exposed planarians. In three sets of trials, planarians treated with S. amara extract after glyphosate-induced toxicity showed higher negative phototaxicity compared to those treated with spring water after glyphosate exposure. S. amara also significantly increased the survival rate, subdued tumor-like lesions, and mitigated blastema reduction in glyphosate-exposed planarians compared to those treated with spring water. The results show that S. amara extract possesses therapeutic effects against weedicide-induced toxicity.

TRPA-1 in Planaria: Exploring Regeneration and Avoidance in the Presence of Irritants

Planaria are a genus of freshwater flatworms widely studied for their regenerative properties. Regeneration is possible because planarians have large populations of stem cells, called neoblasts, distributed throughout their bodies. Planaria and humans share a gene that encodes for the transient receptor potential ankyrin 1 (TRPA-1), which is an ion channel that, in humans, activates pain, cold, and itch reception. In planarian cells, TRPA-1 is a receptor for heat and chemical irritation, and it is activated by reactive oxygen species produced in response to subsequent tissue damage. In this study, we investigate TRPA-1 activation in amputated Dugesia dorotocephala. In the first experiment, we aim to explore TRPA-1 activation during the planarian regeneration process. We exposed amputated worms to three known activators of TRPA-1 during regeneration and observed regeneration over 7 days. In the second experiment, we explored the relationship between TRPA-1 distribution and irritant avoidance. We placed amputated worms onto plates with irritants and tested the amputated worm pieces’ individual avoidance. We observed that while TRPA-1 may not be directly involved in regeneration, activation in response to irritants can slow secondary tissue regeneration. Additionally, we observed that irritant avoidance is stronger in worm heads, where TRPA-1 is primarily localized.

Effects of Cannabidiol on Dugesia Dorotocephala Head Regeneration

The endocannabinoid system regulates synaptic transmissions. It is comprised of two G protein-coupled receptors, cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2), a degradation system and the endocannabinoids, a group of lipidic ligands. The connection between JNK, cannabinoids, and regeneration has led to the hypothesis that cannabinoids impact both regeneration and the levels of the enzymes required for the regenerative process. Thus, by encouraging neoblasts to enter the M phase, cannabinoids would speed up effective regeneration. These regeneration pathways may have implications in cancer research. In addition, CB1 reception suppresses the growth of hepatocellular carcinoma, indicating that the endocannabinoid system may be a possible course of treatment for cancer patients. CB2 receptors in nonimmune cells have revealed the benefits of agonists on osteoporosis and post‐ischemic heart failure. In order to understand the effects of cannabidiol on the regenerative process and neural transmission, we conducted experiments on Dugesia dorotocephala. Dugesia dorotocephala is an ideal candidate for the endocannabinoid model because they are more genetically uniform than most natural populations and their regeneration is specifically tied to cannabinoid receptors. We transversally cut twenty-four Dugesia dorotocephala to analyze differences in head regeneration in solutions with varying amounts of cannabidiol. We found that Dugesia dorotocephala in CBD solutions have a faster rate of head regeneration, yet our results were not statistically significant. The increased rate of head regeneration in Dugesia dorotocephala in CBD solution may be attributed to the stimulation of neoblasts to enter the M-Phase of the cell cycle. Keywords: cannabidiol (CBD), planaria, regeneration, endocannabinoid

The effect of the consumption of the probiotic B. infantis on ethanol withdrawal symptoms in planaria (Dugesia dorotocephala)

Alcohol use disorder is a chronic, relapsing disease that affects millions of Americans every day. There are limited treatment options for alcohol dependence and alcohol withdrawal symptoms, including depression and anxiety. Previous studies have shown that probiotics can decrease depression in rodents during maternal separation and anxiety in humans. Therefore, we hypothesized that the ethanol-withdrawn planaria who consumed probiotics would have decreased withdrawal symptoms as measured by increased motility compared to the ethanol-withdrawn planaria that were not fed probiotics. The ethanol-withdrawn planaria had a statistically significant decrease in motility compared to the control group, while the planaria that consumed probiotics had no statistically significant change in motility compared to the control group. We determined that there was a statistically significant difference between the ethanol and probiotics-treated group and the control group. Additionally, there was a statistically significant difference between the ethanol and probiotics-treated group and the ethanol-withdrawn group, confirming our hypothesis. Although the results indicated that the consumption of probiotics were unable to significantly counteract the effects of ethanol withdrawal symptoms in planaria, the probiotics significantly increased the ethanol-withdrawn planaria’s motility as compared to the ethanol-withdrawn group that was not given probiotics. Given these results, probiotics have the potential to reduce the symptoms of alcohol withdrawal in humans.

How an energy drink affects planarians: a high school investigation

Many students consume energy drinks without knowing or thinking about the adverse side effects. The purpose of this article is to share student procedures and results after testing the effects of a popular energy drink, Red Bull, on Dugesia Dorotocephala planarians (flatworms). Planarians are animals with neurotransmitters systems that are similar to mammals and teachers can use these flatworms in the classroom to teach students about the harmful effects of drug use. In this article, we discuss how a teacher uses the 5E model to assist 9–12 grade high school student participants of the Science Education Against Drug Abuse Program (SEADAP) with the design and development of their science fair project. This article also focuses on how there are statistically significant differences in planarian motility, stereotypy, and time spent in the light after conditioned place preference in Red Bull and its active chemical ingredients.

Modulation of Planaria Regeneration by Resolvin D1 and the Omega-3 Fatty Acid Precursor 17-Hydroxy Docosahexaenoic Acid

Omega-3 fatty acids (FA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) have long been consumed as medical supplements for their far-reaching health benefits, ranging from alleviating asthma symptoms to mitigating kidney and inflammatory diseases like colitis and diabetes. These fatty acids produce a variety of lipid mediator metabolites including maresins, protectins, and resolvins, and are essential for aiding the resolution pathways in inflammation. However, their roles in regenerative responses are relatively unknown. We decided to investigate the effect of Resolvin D1 (RvD1) in Dugesia dorotocephala regeneration, as RvD1is the most widely studied lipid mediator. We foundthat regenerating planaria released significantly higher amounts of RvD1 in water than control and that D. dorotocephala could synthesize their own RvD1 from the omega-3 FA precursor 17-hydroxy docosahexaenoic acid (17-HDHA). We also observed that both RvD1 and 17-HDHA enhanced regeneration responses in planaria by using eye scoring and a modified cell metabolism assay (MTT). We conclude that planarians may utilize similar biosynthetic pathways to mammals in producing resolvins and that resolvins hold immense potential in enhancing regenerative responses in tissues.

Effects of Ivermectin Exposure on Regeneration of D. dorotocephala Planaria: Exploiting Human-Approved Ion Channel Drugs as Morphoceuticals.

Transformative applications in regenerative medicine await increased control of processes implementing repair and remodeling of complex living structures. Recent work reveals ion channel drugs as a powerful toolkit for modulating endogenous bioelectric circuits that control growth and form in vivo and in vitro. It is therefore especially important to develop assays in model systems that will enable the testing of these "morphoceuticals"-compounds with predictable effects on anatomical structure. The regenerative planaria are an ideal model system for this purpose. Several studies have shown a role for bioelectric signaling in planarian regeneration, but these have focused on Dugesia japonica and Schmidtea mediterranea. It is not known how the alterations of ion channel activity would affect regeneration in other species of planaria-an important aspect of building robust computational models of bioelectric circuits. Here, the effect of ivermectin (IVM), a chloride channel opener drug commonly used to combat heartworm is tested, on regeneration in a new species of planaria: Dugesia dorotocephala. Exposure to IVM during regeneration results in patterning abnormalities, such as bifurcated tails with partial heads, as well as delayed regeneration. These data extend our understanding of the effects of human-approved ion channel drugs on regenerative processes.

Chronic Toxicity of Ferric Iron for North American Aquatic Organisms: Derivation of a Chronic Water Quality Criterion Using Single Species and Mesocosm Data

Iron is a common pollutant in waters near coal and hard rock mine disturbances. The current 1000 µg/L total recoverable chronic criterion for iron (Fe) for protection of aquatic life in the United States was developed using very limited data in 1976 and has not been revised since. To develop a more scientifically based criterion, several chronic laboratory toxicity experiments (> 30 days) were conducted with ferric Fe at circumneutral pH on a taxonomically diverse group of organisms including brown trout (Salmo trutta), mountain whitefish (Prosopium williamsoni), boreal toad tadpoles (Bufo boreas), the oligochaete worm Lumbriculus variegatus, the mayfly Hexagenia limbata, and the planarian Dugesia dorotocephala. Results of these tests and those of previously published toxicity data were used to derive a Final Chronic Value (FCV) of 499 µg/L by using the US Environmental Protection Agency’s recommended methods based on single species toxicity tests. In addition to single species toxicity tests, ferric Fe toxicity experiments (10 days) were performed on mesocosms containing naturally colonized communities of benthic macroinvertebrates. Fourteen genera in the mesocosms occurred at sufficient densities to estimate an iron concentration resulting in 20% reduction in abundance (EC20). Three of these taxa had EC20s less than the FCV of 499 µg/L derived from single species tests: the mayfly Epeorus sp. (335 µg/L), the caddisfly Micrasema sp. (356 µg/L), and midge Tanytarsini (234 µg/L). When mesocosm results were included, the FCV was lowered to 251 µg/L. These findings support the suggestion that modernization of water quality criteria should include data generated from mesocosm experiments and other lines of evidence.

Differential expression of disulfide reductase enzymes in a free-living platyhelminth (Dugesia dorotocephala).

A search of the disulfide reductase activities expressed in the adult stage of the free-living platyhelminth Dugesia dorotocephala was carried out. Using GSSG or DTNB as substrates, it was possible to obtain a purified fraction containing both GSSG and DTNB reductase activities. Through the purification procedure, both disulfide reductase activities were obtained in the same chromatographic peak. By mass spectrometry analysis of peptide fragments obtained after tryptic digestion of the purified fraction, the presence of glutathione reductase (GR), thioredoxin-glutathione reductase (TGR), and a putative thioredoxin reductase (TrxR) was detected. Using the gold compound auranofin to selectively inhibit the GSSG reductase activity of TGR, it was found that barely 5% of the total GR activity in the D. dorotocephala extract can be assigned to GR. Such strategy did allow us to determine the kinetic parameters for both GR and TGR. Although It was not possible to discriminate DTNB reductase activity due to TrxR from that of TGR, a chromatofocusing experiment with a D. dorotocephala extract resulted in the obtention of a minor protein fraction enriched in TrxR, strongly suggesting its presence as a functional protein. Thus, unlike its parasitic counterparts, in the free-living platyhelminth lineage the three disulfide reductases are present as functional proteins, albeit TGR is still the major disulfide reductase involved in the reduction of both Trx and GSSG. This fact suggests the development of TGR in parasitic flatworms was not linked to a parasitic mode of life.

Hands-On Classroom Activities for Exploring Regeneration and Stem Cell Biology with Planarians

Regeneration has long fascinated humanity, and its documentation has progressed from simple descriptive observations to the intense molecular and cellular investigations of today. The overarching goal of this work is to make the key methods and tools being used in modern regeneration and stem cell biology research accessible to docents and students in the classroom. We have designed a series of experimental activities with accompanying protocols using four inexpensive, commercially available planarian species indigenous to North America: Girardia sp., Dugesia dorotocephala, Phagocata morgani, and Phagocata gracilis. These planarians are fast and robust regenerators, and can easily be maintained in the classroom. The activities presented here can be used to guide students through hypothesis-driven experiments, and range from simple manipulations aimed at high school students (e.g., planarian husbandry, feeding, and cutting experiments) to gene expression and protein function analyses suitable for college students. Regeneration time courses, the more complex whole worm in situ hybridizations, and RNA interference for gene knock-down experiments are described for each of the four species. Cumulatively, the suggested methods and experiments will facilitate the exploration of animal regeneration biology and promote curiosity-driven, hands-on application of the scientific method.

Pharmacodynamic Modulation of Motility by Glycine Administration in Dugesia Dorotocephala

The glycinergic neurotransmission system is a potential pharmacological target for pain and muscle spasm relief therapy. Planarians are attractive model organisms for neuropharmacological research, due to their simplicity and neurotransmitters shared with mammals. In this study, planarians were exposed to glycine, caffeine, midazolam and ondansetron separately and to successive associations of glycine/caffeine, glycine/midazolam and glycine/ondansetron. Effects on motility were examined by a grid crossing assay. Results showed a dose-dependent reduction of motility by glycine, partially reversed by caffeine and midazolam, but not by ondansetron. Midazolam caused an intense decrease of motility, but not significantly lower than glycine. Ondansetron-treated planarians showed decrease motility compared with controls, but not with glycine or midazolam. These results are consistent with data obtained from higher organisms, showing that planarians can be used as model organisms for glycinergic pharmacological research.

Avoidance behavior in two sympatric planaria species: effects of conspecific and heterospecific chemical alarm cues

In many aquatic animals, predator avoidance can be stimulated by chemical cues, including those released by injured prey (alarm cues). Alarm cues of both conspecific and heterospecific origin have been identified within several fish taxa, where phylogenetic conservation of the cue-response complex is common. Turbellarian flatworms (planaria) are among the simplest animals known to respond to chemical cues released by injured conspecifics. We examined how two locally sympatric planaria species respond to conspecific and heterospecific chemical cues using macerated tissue suspensions. Brown (Girardia tigrina) and black (Dugesia dorotocephala) planaria both exhibited avoidance behavior when presented conspecific cues. Despite a significant twofold difference in body size (black > brown), stimulus prepared from a single (1×) individual of either species elicited avoidance. Increasing brown planaria cue concentration by macerating two individuals (2×) produced a significant increase in conspecific avoidance. Heterospecific stimuli produced asymmetric results. Black planaria avoided the brown planaria stimulus, but only in the higher concentration (2×) trials. Brown planaria did not consistently exhibit avoidance of the black planaria stimulus and some brown subjects approached and consumed black planarian tissues. Our results expand the demonstrated occurrence of alarm cues among planaria and suggest that avoidance behavior can be mediated by multiple environmental and intrinsic factors in freshwater Turbellaria.

English

Cancer is a major health problem, not only in developed countries, but also in developing countries where the number of cancer-related ailments is growing. Chemotherapy is the most commonly used treatment option but side effects associated with its use necessitates the search for alternatives. Over 80% of the population in developing countries relies on ethnomedicinal plants for primary healthcare including cancer. There are concerns about the safety and efficacy of such ethnomedicines but unfortunately, the prerequisite laboratory set up for such evaluation is usually lacking. An inexpensive, sensitive, field oriented assay would greatly facilitate and improve research into alternative anticancer plant based medicinal therapies. This study proposes to evaluate the suitability of Dugesia dorotocephala as an alternative laboratory method for antiproliferative properties of indigenous plant extracts. Brown planaria, D. dorotocephala maintained under laboratory settings were divided into three groups, each containing a minimum of three planaria. Each planaria was dissected into two using a sterile scalpel. The tail section was transferred into a 24 well plate, after measuring its length in mm. Root and bark extracts of Colophospermum mopane and Schinziophyton rautanenii were prepared at concentrations (5 and 20 µg/ml) and incubated with dissected planaria for 8 days, fresh extracts were replaced every two days and the planaria was observed for its length in addition to the development of eye spots. Planaria regeneration was observed in control wells receiving no treatment, however, a growth promoting effect was exhibited by S. rautanenii root extract in a time and concentration dependant manner at 5 µg/ml. An anti-proliferative effect was observed for S. rautanenii bark extracts and this was observed at both concentrations, with the higher extract of 20 µg/ml exhibiting more growth antiproliferative activity. The extract of C. mopane root had a cytotoxic effect at concentration 20 µg/ml, causing planaria death. The use of Planaria represents an inexpensive, quantifiable, field oriented method to evaluate the effect of indigenous plant extracts in the absence of cell culture. This method is capable of distinguishing between different treatments, extract concentrations as well as time points. Key words: Dugesia dorotocephala, plant extracts, anti-proliferative, alternative method.

The Search for MET or a MET Homolog Expressed by Dugesia Dorotocephala

The mechanisms controlling morphallactic regeneration are among the most complex and well studied of all biological processes [1]. Since the 18 th century planaria have severed as a model organism for the study of regeneration due to their immense developmental plasticity [3], simple body plan and relative abundance [1]. In our investigation, fresh water brown planaria (Dugesia dorotocephala) will be examined i) to determine if this species of Platyhelminthes express MET or a MET homolog, ii) the extent of HGF/MET influence during re-epithelialization following planarian bisection, iii) and whether intracellular signals responsible for planarian recovery are consistent with those activated by human hepatocytes following trauma.

COMPARATIVE RESEARCH ON THE SEXUALIZATION OF FISSIPAROUS PLANARIANS TREATED WITH SUBSTANCES CONTAINED IN SEXUAL PLANARIANS

SUMMARY Previous research had shown that asexual specimens of fissiparous Dugesia gonocephala s.l. stopped fissioning and developed a hermaphroditic genital apparatus if fed for several weeks on the crushed tissues of sexually mature Polycelis nigra Ehr., a non-fissiparous planarian. The present research shows that the sexualizing substance, probably a neurosecretion, is also present in the tissues of sexually mature Dugesia lugubris s.l., Dugesia dorolocephala (Woodworth), Dugesia anceps Kenk and Dendrocoelum lacteum (O. F. Muller), in concentrations which may differ according to the species but without any zoological specificity. There is a clear different in the capacity of each fissiparous species or strain to react to the sexualizing substances: while many asexual strains of Dugesia gonocephala s.l., Dugesia tigrina (Girard) and Dugesia Pdorotocephala (race from Sabino) reacted more-or-less positively to the treatment, agamic Dugesia dorotocephala, Dugesia mediterranea Benazzi et al. (fissiparous rac...

Genotoxicity and oxidative stress induced by cadmium and zinc in the planarian, Dugesia dorotocephala

This study sought to determine the DNA damage, and the lipoperoxidative effect, as well as changes in the superoxide dismutase (SOD) and catalase (CAT) activities induced by CdSO4 (Cd), and ZnSO4 (Zn), in addition to two different mixtures of the metals. Planarian Dugesia dorotocephala collected in the Ignacio Ramirez reservoir, Mexico, adapted to laboratory conditions, and exposed to the metals in a controlled system was used. Initially, LC50 at 96 h of exposure was determined and the result obtained were 0.69 mg/L for Cd, 11.99 mg/L for Zn, 10.28 mg/L for mix 1, and 8.11 mg/L for mix 2. Then, the comet assay showed a DNA damage increase induced by Cd (0.13 and 0.2 mg/L) as high as 94% over the control level; the effect by Zn (from 0.2 to 2.7 mg/L) was clearly lower, although statistically significant with the high concentrations tested. As regards the two mixtures, we observed a concentration dependent increase. Similarly, in respect to lipoperoxidation, we found a strong effect by Cd, a slight effect by Zn, and a concentration dependent effect induced by the mixtures. Finally, the activity of the tested enzymes was modified by the metals in relation to the concentration applied. Keywords: Zinc, cadmium, planarian, DNA damage, oxidative stress African Journal of Biotechnology Vol. 12(25), pp. 4028-4038

Topiramate-antagonism of L-glutamate-induced paroxysms in planarians

We recently reported that NMDA ( N-methyl-D-aspartate) and AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) induce concentration-dependent paroxysms in planarians ( Dugesia dorotocephala). Since the postulated mechanisms of action of the sulfamate-substituted monosaccharide antiepileptic drug topiramate include inhibition of glutamate-activated ion channels, we tested the hypothesis that topiramate would inhibit glutamate-induced paroxysms in our model. We demonstrate that: (1) L-glutamate (1–10 mM), but not D-glutamate, induced dose-related paroxysms, and that (2) topiramate dose-relatedly (0.3–3 mM) inhibited L-glutamate-induced paroxysms. These results provide further evidence of a topiramate-sensitive glutamate receptor-mediated activity in this model.

Removal of Methyl Parathion in Water, by Dugesia dorotocephala

The aim of this study was to determine the efficiency of Dugesia dorotocephala on Methyl parathion removal. An initial concentration of 1.25 microg mL(-1) of MeP was used to evaluate the removal capacity of planarian. A first-order removal kinetics was obtained with a disappearance rate constant (k(r)) of 0.49 days(-1) and 69% efficiency on contaminant removal. This is significantly different (p < 0.5) from the degradation occurring in control systems, leading us to conclude that D. dorotocephala effectively removes MeP from contaminated water.

Genetic divergence in Northamerican freshwater planarians of the Dugesia dorotocephala group (Turbellaria, Tricladida, Paludicola)

The genetic differentiation between the members of the Dugesia (Girardia) dorotocephala group was analyzed by means of multilocus electrophoresis, and comared to that of another planarian secies, D. tahitiensis, also belonging to the subgenus Girardia. The species examined were: D. dorotocephala s.s (2n = 16), D. arizonensis (2n = 8), D. jenkinsae (2n = 8), and the above mentioned D. tahitiensis (2n = 16). The former three species inhabit North America, and show different proportion of fissiparous and sexual individuals; the latter species inhabits Polynesia and is fully asexual. A total of 11 enzyme loci were genetically analyzed: Mdh-1, Mdh-2, Zdh-1, Idh-2, G3pdh, Got-1, Ck, Pgm-2, Ada, Mpi, and Gpi. Low values of observed mean heterozygosity per locus (Ho) were found in the populations studied, ranging from 0 to 0.18 (average 0.08. In asexual populations (except that of D. tahitiensis) fixed heterozygosity was observered in all the individuals for 1 or 2 loci. The genetic divergence between the species examined is very high, with many loci showing discriminating alleles in different taxa (Nei's genetic distance varies from 0.871 to 1.759). The populations of D. dorotocehala s.s., on the contrary, appear to be genetically quite homogenous average D= 0.019), and the genetic distance values are apparently unrelated to their geographic location and to their way of reproduction. The genetic distance between D. tahitiensis, a species not included in the D. dorotocephala group and D. dorotocephala s.s. is 1.314 and hence similar to the D value between two members of;he dorotocephala group: D. dorotocephala and D. jenkinsae (D = 1.303). The genetic relationships among the populations studied were established by UPGMA cluster analysis and multidimensional scaling. The descendence of the North American species with 2n = 8 from a dorotocephala-like ancestor with 2n = 16 is considered. It is suggested that the latter, as well as a tahitiensis-like line, also having 2n = 16, have originated from a common ancestor by geographic isolation.

Attraction of Flatworms at Various Hunger Levels Toward Cues from an Odonate Predator

AbstractDifferent hunger levels can modify a prey’s antipredator behavior in the presence or absence of food. Satiated animals often forego foraging if a predator is nearby, whereas starved animals may risk a predator encounter to search for food. This study evaluated the influence of nutritional state on the behavior of the flatworm Dugesia dorotocephala in the presence of food, predator, and crushed conspecific cues. We found that flatworms are attracted to cues originating from a food source, crushed conspecifics, and a predator (dragonfly larva) compared with control cues. Among the different hunger level treatment groups, levels of satiation had no influence on activity levels but significantly influenced time spent close to and distance from the cue source. Flatworm movement toward predator cues emitted from dragonfly larvae is contrary to our expectations. These results suggest either a unique case of chemical mimicry from the dragonfly larvae or an inherent attraction of planarians to odonate predators that allows them to scavenge the remains of other odonate prey items.