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Welcome to the Homepage of my blog exploring the effects and history of various toxic substances. In this blog, I have pages discussing the toxicity of glufosinate (an herbicide), DMSO (a solvent), gold (elemental), and stinging nettles (the annoying, but useful, species of plant). Below are some introductory sites on the various topics covered in this blog.

Glufosinate: https://www.mda.state.mn.us/glufosinate-herbicide

DMSO: https://www.webmd.com/vitamins/ai/ingredientmono-874/dimethylsulfoxide-dmso#:~:text=Dimethylsulfoxide%20(DMSO)%20is%20a%20chemical,used%20intravenously%20or%20by%20IV).

Gold: https://www.rsc.org/periodic-table/element/79/gold

Stinging nettle: https://www.healthline.com/nutrition/stinging-nettle

I selected glufosinate because I have heard so much about the potential for common non-industrial herbicides (e.g. Roundup) to cause health complications. An herbicide is a chemical that causes a toxic effect in an herb, so why is it also causing a toxic effect in humans? I chose DMSO because I have used it so many times in organic chemistry lab and I wanted to learn more about it. I chose gold because gold is one of the most beautiful elements and has so many incredible properties to justify its use as a currency and store of value for thousands of years. I selected stinging nettles to investigate of all the plants available because I seem to be a stinging nettle magnet when I walk around the woods in my hometown. I frequently walk out of the forest with the tell-tale signs of stinging nettle exposure, and I wanted to learn more about them because of that personal experience.

Below are some introductory videos concerning the topics.

Glufosinate:

DMSO:

Gold:

Stinging nettle:

 

Enjoy!
Connor

Stinging Nettle Toxicity

Background and Mechanism

Urtica dioica, commonly referred to as “stinging nettle,” is a species of plant famous for the uncomfortable burning and itching that results when an individual brushes up against one of the plants in the Urtica genus. This genus contains 46 species in total (Kregiel et al., 2018). Sting nettles can be found on every continent other than Antarctica, but the species originated in Europe (Urtica Dioica L., 2021). Stinging nettles target the epidermis and can inflict this uncomfortable feeling due to spiny processes on the leaves that can cause contact urticaria. The small needles contain histamines and other chemicals that are deposited in the skin of the unsuspecting passerby that activate inflammation and pain processes in the area of local contact (Nettles Uses, 2021).

Toxicity and Beneficial Effects

https://www.britannica.com/plant/stinging-nettle

Other than histamine, stinging nettle plants inject formic acid, acetylcholine, and serotonin into the skin (Kregiel et al., 2018). Exposure to chemicals such as these cause a local immune response including the recruitment of prostaglandins and increased blood flow, carrying immune cells, to the area. Stinging nettles can be considered locally toxic due to this effect; however, there is no evidence of carcinogenicity due to exposure to stinging nettles. In fact, the administration of the plant as a supplement shows some promise in bolstering the immunity of fish cultivated in fish-farms (De Vico et al., 2018).

 

Symptoms and Treatment

Stinging nettle exposure in homo sapiens is clearly defined by increased redness and subjective feelings of itching and burning on and around the exposed area of the skin. These symptoms can be mitigated or alleviated by rapid application of soap and water to the area. Application of cold therapy in the form of ice may reduce swelling and feelings of discomfort (Stinging Nettles, 2021). Interestingly, the

plant known as “jewelweed” that frequently grows next to stinging nettle plants also offers some relief from these symptoms. Affected individuals can chew on jewelweed plants and apply the makeshift poultice to the exposed area of skin. It’s hypothesized that saponin, a chemical in jewelweed, is responsible for this effect (Motz et al., 2015).

Jewelweed: https://en.wikipedia.org/wiki/Impatiens_capensis

 

References

De Vico, G., Guida, V., & Carella, F. (2018). Urtica dioica (Stinging Nettle): A Neglected Plant With Emerging Growth Promoter/Immunostimulant Properties for Farmed Fish. Frontiers in Physiology, 0. https://doi.org/10.3389/fphys.2018.00285

Kregiel, D., Pawlikowska, E., & Antolak, H. (2018). Urtica spp.: Ordinary Plants with Extraordinary Properties. Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry, 23(7), 1664. https://doi.org/10.3390/molecules23071664

Motz, V. A., Bowers, C. P., Kneubehl, A. R., Lendrum, E. C., Young, L. M., & Kinder, D. H. (2015). Efficacy of the saponin component of Impatiens capensis Meerb.in preventing urushiol-induced contact dermatitis. Journal of Ethnopharmacology, 162, 163–167. https://doi.org/10.1016/j.jep.2014.12.024

Nettles Uses, Benefits & Dosage—Drugs.com Herbal Database. (n.d.). Drugs.Com. Retrieved July 27, 2021, from https://www.drugs.com/npp/nettles.html

Stinging nettles. (n.d.). Ministry of Health NZ. Retrieved July 27, 2021, from https://www.health.govt.nz/your-health/conditions-and-treatments/accidents-and-injuries/bites-and-stings/stinging-nettles

Urtica dioica L. | Plants of the World Online | Kew Science. (n.d.). Plants of the World Online. Retrieved July 27, 2021, from http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:260630-2

DMSO Toxicity

Background and Common Uses

A liquid ubiquitous to organic chemistry labs in universities across the world, dimethyl sulfoxide is a useful solvent with a wide range of applications in chemical research and industry. DMSO is manufactured via chemical synthesis involving a fluoride displacement reaction (Wang et al., 2012). Using advanced techniques such as 3D modeling of liver and heart cells exposed to DMSO, researchers found that DMSO can cause transcription errors, microRNA deregulation, and significant methylation disruption exhibited across the entire genome (Verheijen et al., 2019). Because of these effects, the researchers suggest further research into the use of DMSO as a solvent used in cryopreservation. However, other research supports the conclusion that DSMO is not genotoxic or carcinogenic in the short term (Hartwig, 2017). Further research is necessary to determine the potential for carcinogenicity in the longer term via subchronic and chronic exposure studies.

Dimethyl sulfoxide - Wikipedia

https://en.wikipedia.org/wiki/Dimethyl_sulfoxide

DMSO Recovery, Engineering & Environmental | Gaylord Chemical

https://www.gaylordchemical.com/process-safety-and-technology/dmso-recovery-engineering-environmental/

 

Mechanistically, DMSO is known to easily cross membranes. For this reason, among others, it is a choice solvent for laboratory injection procedures. It is used in some cases to treat amyloidosis, skin conditions, and inflammation (DMSO, 2021). DMSO may act as an anti-inflammatory agent by suppressing prostaglandin, cytokines, and phosphorylation involved in the inflammatory process (Elisia et al., 2016).

Biological Effects and Treatment

DMSO is capable of crossing the skin and the blood brain barrier; therefore, it is nonspecific with regards to its target organ(s). The most frequently occurring adverse reactions caused by DMSO involve the gastrointestinal system and the skin. A review of clinical trials involving DMSO concluded that nausea, vomiting, and stomach cramps are common symptoms of DMSO poisoning (Kollerup Madsen et al., 2019).

Amazon.com : Dmso Cream With Aloe Vera, Rose Scented : Body Gels And Creams : Beauty

https://www.amazon.com/Dmso-Cream-Aloe-Vera-Scented/dp/B0070Z7KME

Treatment of DMSO poisoning is difficult because it distributes throughout the body. Physicians can work to maintain physiologically appropriate levels of ions, hydration, and oxygen saturation while observing patients exposed to DMSO.

 

Click the links below to view short videos about DSMO.

https://www.webmd.com/vitamins-and-supplements/dmso-uses-and-risks

https://www.sigmaaldrich.com/US/en/substance/dimethylsulfoxide781367685?context=product

 

 

 

 

References

DMSO (dimethylsulfoxide): Health Benefits, Side Effects, Uses, Dose & Precautions. (n.d.). RxList. Retrieved July 6, 2021, from https://www.rxlist.com/dmso_dimethylsulfoxide/supplements.htm

Elisia, I., Nakamura, H., Lam, V., Hofs, E., Cederberg, R., Cait, J., Hughes, M. R., Lee, L., Jia, W., Adomat, H. H., Guns, E. S., McNagny, K. M., Samudio, I., & Krystal, G. (2016). DMSO Represses Inflammatory Cytokine Production from Human Blood Cells and Reduces Autoimmune Arthritis. PLoS ONE, 11(3), e0152538. https://doi.org/10.1371/journal.pone.0152538

Hartwig, A. (2017). Dimethyl sulfoxide (DMSO) [MAK Value Documentation, 2009]. In The MAK-Collection for Occupational Health and Safety (pp. 1122–1134). American Cancer Society. https://doi.org/10.1002/3527600418.mb6768e4617

Kollerup Madsen, B., Hilscher, M., Zetner, D., & Rosenberg, J. (2019). Adverse reactions of dimethyl sulfoxide in humans: A systematic review. F1000Research, 7, 1746. https://doi.org/10.12688/f1000research.16642.2

Verheijen, M., Lienhard, M., Schrooders, Y., Clayton, O., Nudischer, R., Boerno, S., Timmermann, B., Selevsek, N., Schlapbach, R., Gmuender, H., Gotta, S., Geraedts, J., Herwig, R., Kleinjans, J., & Caiment, F. (2019). DMSO induces drastic changes in human cellular processes and epigenetic landscape in vitro. Scientific Reports, 9(1), 4641. https://doi.org/10.1038/s41598-019-40660-0

Wang, Z., Richter, S. M., Gates, B. D., & Grieme, T. A. (2012). Safety Concerns in a Pharmaceutical Manufacturing Process Using Dimethyl Sulfoxide (DMSO) as a Solvent. Organic Process Research & Development, 16(12), 1994–2000. https://doi.org/10.1021/op300016m

Gold

Background

Gold is an elemental metal that has been used throughout history as currency, jewelry, a store of value, and (more recently) a component metal in electronics. After oxygen, in some cases, gold has been mankind’s most desired element for thousands of years. Its 79 protons endow it with the recognizable bright yellow color, and it is commonly found as a “vein” flowing through other minerals or as nuggets. China produces more gold than any other country.

What's Driving Gold Prices So High, And What Might The Future Hold?

(image source: https://www.forbes.com/sites/forbesfinancecouncil/2020/09/22/whats-driving-gold-prices-so-high-and-what-might-the-future-hold/?sh=43671a023b9c)

Properties and Biological Effects

Incredibly, as the most malleable metal on earth, gold can be stretched into a single-atom-wide wire and still bend. It is also highly resistant to chemical transformation and corrosion – so resistant, in fact, that “edible” gold is used to decorate fancy cakes and other dishes. The ingested gold resists digestion and passes through the GI tract unchanged. However, a small amount of gold that is swallowed or inhaled can accumulate as “nanoobjects” in various areas of the body such as the liver and spleen (1). Gold toxicity is being researched because gold is being used more commonly in combination with pharmacological therapies to aid in specificity and delivery. Some mice that were injected with gold disodium thiomalate experienced temporary tubular toxicity upon hepatic and splenic accumulation (2). Furthermore, cellular models have revealed possible genotoxicity, but this has not been demonstrated in animals or humans (3). However, due to gold’s chemical inertness, it does not appear to be toxic in humans based on current literature.

Prostate Cancer Treatment Goes Nanogold

(image source: https://www.genengnews.com/news/prostate-cancer-treatment-goes-nanogold/)

Therapeutic Uses

Gold nanoparticles are being used increasingly in medicine to increase “ease of synthesis, bioinert characteristics, optical properties, chemical stability, high biocompatibility, and specificity” of various therapies (3). Gold nanoparticles are used to research and treat cancer, Alzheimer’s, arthritis, and many more diseases besides (3).

Different applications of gold nanoparticles in diagnosis and therapy.... | Download Scientific Diagram

(image source: https://www.researchgate.net/figure/Different-applications-of-gold-nanoparticles-in-diagnosis-and-therapy-Nanoparticles-are_fig3_322739738)

Gold is not an essential element. Biological life does not need gold in order to grow and live.

 

 

References

(1) Świdwińska-Gajewska AM, Czerczak S. Nanozłoto – działanie biologiczne i dopuszczalne poziomy narażenia zawodowego [Nanogold – Biological effects and occupational exposure levels]. Med Pr. 2017 Jun 27;68(4):545-556. Polish. doi: 10.13075/mp.5893.00538. Epub 2017 May 9. PMID: 28584334.

(2) Tonn T, Goebel C, Wilhelm M, Gleichmann E. Gold kinetics under long-term treatment with gold(I) disodium thiomalate: a comparison in three different mouse strains. Br J Rheumatol. 1994 Aug;33(8):724-30. doi: 10.1093/rheumatology/33.8.724. PMID: 8055198.

(3) Adewale OB, Davids H, Cairncross L, Roux S. Toxicological Behavior of Gold Nanoparticles on Various Models: Influence of Physicochemical Properties and Other Factors. International Journal of Toxicology. 2019;38(5):357-384. doi:10.1177/1091581819863130

 

Glufosinate (herbicide)

Source: Streptomyces soil bacteria

Biotransformation: Glufosinate is primarily acetylated when applied and after gaining entry into cells (1).

Toxicokinetics: The herbicide clears from the body at approximately 1.44 L/kg. Furthermore, 86.6 mL were cleared per minute when studied in a single instance of poisoning in a 65 yo male (2).

Carcinogenicity: None yet discovered.

Mechanism of Action (if known): Inhibition of glutamine synthetase that reduces glutamine and impairs photosynthesis (3).

Target organ(s): CNS (4)

Signs and symptoms of toxicity: Unconsciousness, convulsions, drowsiness, memory deficits, apnea, sixth cranial nerve palsy (4).

Historical or unique exposures: See cited papers below by Hirose (65 yo male with acute glufosinate poisoning) and Park (glufosinate intoxication causing CNS adverse reactions). Also, see the following case involving a 53 yo woman who experienced anterograde amnesia after glufosinate exposure (https://www.accjournal.org/m/journal/view.php?number=1141).

Treatments: Based on the few case studies I came across, patients who are exposed to dangerous levels of glufosinate might benefit from hemoperfusion. However, the best course of action is maintaining vital organ function, adequate oxygen intake, and other common measures utilized in ICUs.

Biomarkers: In plants, glufosinate causes decreased glutamine, increased ammonium, and decreased photosynthesis. In humans, glufosinate appears to cause the variety of CNS symptoms that are mentioned above. However, what we know of the toxic symptoms of glufosinate in huamans are based on only a few case studies. Mouse studies reveal CNS effects such as damaged neural stem cells in mouse hippocampi (5).

 

Works Cited

(1) (http://www.inchem.org/documents/jmpr/jmpmono/v99pr06.htm)

(2) Hirose Y, Kobayashi M, Koyama K, Kohda Y, Tanaka T, Honda H, Hori Y, Yoshida K, Kikuchi M. A toxicokinetic analysis in a patient with acute glufosinate poisoning. Hum Exp Toxicol. 1999 May;18(5):305-8. doi: 10.1191/096032799678840110. PMID: 10372751.

(3) Topsy Jewell for Friends of the Earth (December 1998). “Glufosinate ammonium fact sheet”. Pesticides News No.42. Archived from the original on 2015-07-01. Retrieved March 2015.

(4) Park JS, Kwak SJ, Gil HW, Kim SY, Hong SY. Glufosinate herbicide intoxication causing unconsciousness, convulsion, and 6th cranial nerve palsy. J Korean Med Sci. 2013;28(11):1687-1689. doi:10.3346/jkms.2013.28.11.1687

(5) Feat-Vetel J, Larrigaldie V, Meyer-Dilhet G, Herzine A, Mougin C, Laugeray A, Gefflaut T, Richard O, Quesniaux V, Montécot-Dubourg C, Mortaud S. Multiple effects of the herbicide glufosinate-ammonium and its main metabolite on neural stem cells from the subventricular zone of newborn mice. Neurotoxicology. 2018 Dec;69:152-163. doi: 10.1016/j.neuro.2018.10.001. Epub 2018 Oct 10. PMID: 30312642.