Silicaceous material

[Catsumi]

Silicaceous materials are odd

https://www.nature.com/articles/srep15343

There, that should send you down a rabbit hole.

[Sonny Taylor]

There, that should send you down a rabbit hole.

Oh yeah. I started speed reading at

In this work, a hot-compression technique was used to quench silica glass from high temperature (1100 °C) and high pressure (up to 8 GPa) conditions, which leads to density increase of ~25% and Young’s modulus increase of ~71% relative to that of pristine silica glass.

[Catsumi]

There, that should send you down a rabbit hole.

Oh yeah. I started speed reading at

In this work, a hot-compression technique was used to quench silica glass from high temperature (1100 °C) and high pressure (up to 8 GPa) conditions, which leads to density increase of ~25% and Young’s modulus increase of ~71% relative to that of pristine silica glass.

Good start Sonny. You just never know when that odd particle of information will come in handy

Might help win a scrabble game.

[Catsumi]

Crater dimensions. What type and size of impactor. Probably not by much tho. Just makes me think silicate would have different properties at extreme temps and pressures we haven't had a chance to directly measure outside of a lab fortunately. Probably shudda mentioned that when I first posted. And maybe it's a half baked thought process that got me there to think of that when I went into that link.

Silicates and their offsprings are just as interesting and mysterious as all phases of water are.

I know this is off topic and subject to removal, but am finally reading the intriguing book about bananas, https://orl.bibliocommons.com/item/show/486637111

history and oncoming demise of the Cavendish variety that we enjoy eating, by the billions of tons, worldwide. Investigators were digging in what turned out to be a very ancient banana plantation in Papua,
New Guinea. How did they come to know it was a banana plantation as it’s not as if the plants have a sturdy trunk, as trees do…it was because tiny siliceous material was found, analyzed and showed the definite structure of banana plants of today.

Think of those structures as if they were a wire cage, holding the photosynthetic cells in place to aid growing towards the sun. They are called ‘phytoliths’, something I’d not known about until now

Anyway, buy and eat as many bananas as you can. Until a new reservoir of genetic material is found, the fruit may soon succumb to its mortal enemy, a fungus that is spreading faster with each day

I do know about horsetail weed that is also based on silica-phyto combinations, a horrible weed that comes up from earth’s centre, you simply cannot eradicate it without a nuclear bomb’s assistance. However, on the bright side, natives and early settlers used the weed as an effective scouring pad to clean pots.

More to come if the gods of Castanet allow.

[Catsumi]

Ferri, this ^^^ is off topic as I well know

Could you split off the conversation into a new thread in Sciences as it would be a better thread to continue the discussion?

Water and silicates are a passion for us nerds

[ferri]

Here you go! I got sidetracked and didn't let you know it had been split from the other thread. :)

[Glacier]

Silica is likely as carcinogenic on the lungs as asbestos, but is so widely used that it's not as regulated.

Sorry, I'm Mr. Fun today.

Carry on...

[OldBlindDog]

I do know about horsetail weed that is also based on silica-phyto combinations, a horrible weed that comes up from earth’s centre, you simply cannot eradicate it without a nuclear bomb’s assistance. However, on the bright side, natives and early settlers used the weed as an effective scouring pad to clean pots.

More to come if the gods of Castanet allow.

Today I learned that horsetail contains nicotine. No wonder why I enjoyed playing with them as a kid.

[Catsumi]

I do know about horsetail weed that is also based on silica-phyto combinations, a horrible weed that comes up from earth’s centre, you simply cannot eradicate it without a nuclear bomb’s assistance. However, on the bright side, natives and early settlers used the weed as an effective scouring pad to clean pots.

More to come if the gods of Castanet allow.

Today I learned that horsetail contains nicotine. No wonder why I enjoyed playing with them as a kid.

Bless your little black heart as you sent me down another rabbit hole! Here’s a nifty compilation of the components are that make that hated weed. Turns out to be a witches brew of good and not so good items.

If you haven’t been schooled in organic compounds (as I have, but not to the degree found in linked below) you can skip over and just look at what I bolded.

Nicotine presence is in doubt, neither proven or disproven absolutely as it doesn’t seem to have worthwhile amounts to fret over.

Horsetail, as we know it here, has cousins, living elsewhere on the globe. It is not found in Australasia or Antarctica.

Just look at and gasp in admiration what this prehistoric plant carries around in its corporeal body! Everything., (Almost) to support life, ir make you damn sick.

I hope you take a little time to skim thru as it won’t match mine in bolding the highlights.

. Abstract

The Equisetum genus, Equisetaceae family, is widely distributed worldwide and may be the oldest nonextinct genus on Earth. There are about 30 known species, which are very often used in traditional medicine with diverse applications. This review aimed to compile scientific reports about Equisetumspecies with relevant pharmacological properties and/or therapeutic potential for kidney diseases. Our bibliographic survey demonstrates that the most widespread traditional use of Equisetum is as a diuretic, followed by the treatment of genitourinary diseases (kidney diseases, urethritis, kidney stones, and others), inflammation, wound healing, rheumatic diseases, prostatitis, and hypertension. The most popular species from the Equisetum genus with medicinal use is E. arvense L., whose diuretic effect was confirmed in animal models and clinical trials. The species E. bogotense Kunth also demonstrated the beneficial effect of inducing diuresis in both experimental and clinical assays. Several other species have also been studied regarding their therapeutic potential, showing different biological actions. Regarding the chemical composition, it contains many active constituents, such as alkaloids, flavonoids, phenol, phytosterols, saponins, sterols, silicic acid, tannin, triterpenoids, and volatile oils. However, despite the widespread traditional use, many species need to be explored in detail for scientific validation of popular use. Indeed, the species of the Equisetum genus have great potential in the management of kidney disorders.

1. Introduction

The genus Equisetum, belonging to the Equisetaceae family, from Equisetales order and Equisetopsida class, is a genus of perennial plants that reproduce by spores not seeds, widely distributed worldwide, only absent in Australasia and Antarctica [1, 2]. It may be the oldest nonextinct genus on Earth, originating from the end of the Paleozoic era, about 300 million years ago. There are about 30 known species, with the majority consisting of small plants, which rarely reach a meter in height. Its varied species are adapted to grow in temperate, tropical, and cold regions. They are often used in traditional medicine with diverse applications in many countries, having mainly anti-inflammatory and diuretic activities [3].

The species of Equisetum genus are known by the common name of “horsetail” in English-speaking countries, “cola de caballo” in Spanish-speaking countries, “prêle des champs” in France, “ackerschachtelhalm” in Germany, “tsukushi” in Japan, and “cavalinha” in Brazil. Its name is of Latin origin, composed of “equi” (horse) and “setum” (tail), that is, horse tail [4–6]. The most popular species from the Equisetum genus with medicinal use is E. arvense L., which has already demonstrated many biological properties, such as antioxidant, antitumoral, antimicrobial, smooth muscle relaxant, anticonvulsant, sedative, antianxiety, antinociceptive, anti-inflammatory, antidiabetic, diuretic, platelet aggregation inhibitory, osteoblastic response promoting, and antileishmanial effects (for review see [7]). However, many other species are also known for their popular usage and common indications for diuretic purposes and kidney disorders, as will be addressed in this review.

For that, this review’s objective was to compile the data found in the literature about Equisetum species with relevant pharmacological properties for the treatment of kidney disorders, especially associated with arterial hypertension. We have collected reports from ethno botanical textbooks, and scientific articles from books and journals indexed online in the databases PubMed (https://www.ncbi.nlm.nih.gov/pubmed), Science Direct (http://www.sciencedirect.com/), and Medline (https://www.nlm.nih.gov/bsd/pmresources.html). We will discuss popular uses, toxicological data, phytochemical composition, and pharmacological evidence of these species in the next topics. The main findings are summarized in tables for each theme.

2. Traditional Applications and Toxicological Information

Studies that describe this genus’s traditional applications, summarized in Table 1, show that the oral administration is the most common route for its use, using the infusion or decoction of the aerial parts as the main method of preparation [1, 9, 42]. The most widespread traditional use of Equisetum is as a diuretic [1, 12, 33, 34, 41, 42], followed by the treatment of genitourinary diseases (kidney diseases, urethritis, kidney stones, and others) [10, 16, 25, 26, 33, 34, 37–39], inflammation [10, 20–22, 27, 40], wound healing [21, 28, 39, 41], rheumatic diseases [9, 19, 31, 34, 39], prostatitis [33, 36, 40], and hypertension [1, 21, 27].

Table 1

Traditional applications of Equisetum genus stratified by country, species, plant part, and medicinal use.
Studies compiled in this work pointed out that the most popular species from the Equisetum genus with medicinal use is E. arvense L., commonly known as “horsetail”, with uses reported in countries like Brazil, Romania, Germany, Serbia, China, Greece, Portugal, Iran, and Thailand. This species is used mainly as diuretic, to treat inflammation, genitourinary diseases, ulcers, wound healing, dermatitis, hemorrhage, hepatitis, prostatitis, musculoskeletal diseases, and others (Table 1) [12, 20–22, 25, 33, 38, 39, 41, 42]. Nevertheless, Baracho et al. [43] evaluated the acute hepatotoxicity of E. arvense in rats. The extract at 30, 50, and 100 mg/kg did not show mortality in any of the doses at the end of the 14 days of observation, nor did it alter the serum activities of hepatic enzymes compared to the control group. Instead, it produced benign changes in the hepatic morphology. Moreover, Tago et al. [44] evaluated the toxicity of E. arvense in the diet at doses of 0, 0.3, 1, and 3% for 13 weeks in male and female rats. According to the authors, the dosage selections were based on estimated intake for humans, approximately 5 mg/kg daily. No toxicity was detected related to clinical signs, body weight, urinalysis, hematology, serum biochemistry data, organ weights, and histopathological findings. Still, remedies containing E. arvense are not recommended during pregnancy or breastfeeding since little information is available on their safety [45]. Indeed, the species contains thiaminase, an enzyme that destroys thiamine (vitamin B1), and, with long-term use, could lead to vitamin deficiency, a possible cause of neurotoxicity [46].

Another well-cited species is E. telmateia Ehrh., known as “great horsetail” [47], used to treat rheumatism, broken bones, genitourinary diseases, prostatitis, gastrointestinal disorders, inflammation, and hypertension, in addition to its use as diuretic and expectorant in countries like Turkey, Portugal, Iran, and Spain [1, 34, 36, 37, 40]. However, little information is available about its safety. E. giganteum L., commonly called “giant horsetail” [10], is another widespread species mainly in Latin American countries like Brazil, Bolivia, Chile, and Peru, traditionally used to treat *bleep*, heartburn, genitourinary disorders, inflammation, rheumatic diseases, obesity, and as a diuretic [8–11, 18, 28]. Despite its widespread traditional use, no in vivo toxicity studies were conducted so far; however, Alavarce et al. [10] showed no cytotoxic potential of the hydroalcoholic extract of E. giganteum aerial parts (50, 25, 16, 8, and 4 mg/mL) on human palatal epithelial cells and human monocytes using MTT assay.

Similarly to E. giganteum, the species Equisetum bogotense Kunth also grows in Chile, where it is widely used in traditional medicine as a diuretic [48]. As far as we know, there are no cytotoxic studies carried out on animals with this species; however, E. bogotense was subjected to a clinical study where 25 healthy patients received their infusion at an equivalent dose of 0.75 g of the plant per person, daily, for two consecutive days, but no adverse reactions were detected (e.g., *bleep*, asthenia, dizziness, colic, vomiting, palpitations, and hypotension) [18].

Equisetum myriochaetum Schlecht. and Cham. is a plant distributed in Mexico, where it is popularly known as “cola de caballo” [49] and traditionally used for the treatment of diabetes type 2 and kidney disease [14–17]. Regarding toxicological information, Téllez et al. [49] have shown that extracts from E. myriochaetum aerial parts had no acute toxicity detected in Drosophila or in the human micronucleus test in vitro performed with cultured lymphocytes, emphasizing that this species is not genotoxic.

Moreover, Equisetum debile Roxb. ex Vaucher, also known as “horsetail”, is widely distributed throughout Thailand. The local population has been used as a diuretic, wound muscle relaxant, hair growth stimulant, and anti-hair loss treatment. The E. debile extracts showed no cytotoxicity on dermal papilla cell line (1 to 500 μg/mL) and no irritation on chorioallantoic membrane of hen’s eggs (0.5%) [41], but further studies are needed to ensure their safety.

Equisetum palustre L., known as “marsh horsetail” [50], has been traditionally used in Turkey for peptic ulcer, hemorrhoids, and kidney stones treatment [35]. Despite this, E. palustre has been known for its toxicity for livestock, which is related to the presence of thiaminase and the alkaloids palustrine and nicotine [50]. Besides, Milovanović et al. [24] showed that E. palustre, as well as E. arvense L., E. sylvaticum L., E. fluviatile L., and E. telmateia Ehrh. extracts (62.5 μg/ml), showed some genotoxicity, presenting a higher incidence of micronucleus formation than that of the control.

3. Phytochemistry Data of Equisetum Genus

In this topic, we reviewed the phytochemistry data available on the plants’ species of Equisetum genus (Table 2), which have already been presented for their traditional applications. Chemical structures of the compounds identified in the Equisetum genus followed by their names, molecular weights, and references are shown in Figure S1 (Supplementary Material).

Table 2

Phytochemistry of Equisetum genus stratified by species, plant part, method, and compounds.
E. arvense L. contains various chemical compounds such as silicic acid, linoleic acid, oleic acid, stearic acid, linolenic acid and traces of alkaloids (e.g., equisetin, nicotine, palustrine, and palustrinine), glucoside, flavonoids, saponosides, triterpenoids, phytosterols, calcium carbonate, potassium sulfate, potassium chloride, manganese chloride, iron, manganese, and calcium phosphate [39, 52]. Indeed, Veit et al. [51] isolated two styrylpyrone glucosides (3′-deoxyequisetumpyrone and 4′-O-methylequisetumpyrone) from the MeOH extract from the rhizomes of E. arvense. Besides, in the hepatoprotective activity-guided fractionation of the MeOH extract from the aerial parts of E. arvense L. performed by Oh et al. [25], the bioactive EtOAc fraction was subjected to octadecyl-functionalized silica gel flash column chromatography resulting in the isolation of two phenolic petrosins (onitin and onitin-9-O-glucoside) and four flavonoids (apigenin, luteolin, kaempferol-3-O-glucoside, and quercetin-3-O-glucoside). Similarly, Mimica-Duki [52] evaluated the phenolic composition of three different extracts (EtOAc, n-BuOH, and H2O). In this study, quercetin 3-O-glucoside (isoquercitrin) was the main compound in the EtOAc identified by high-performance liquid chromatography with diode-array detection (HPLC-DAD). At the same time, apigenin 5-O-glucoside and kaempferol 3-O-glycoside were detected in considerable amounts. The n-BuOH extract showed higher amounts of isoquercitrin and di-E-caffeoyl-meso-tartaric acid, while the aqueous extract had di-E-caffeoyl-meso-tartaric acid and also two phenolic acids detected. Also, Ganeva et al. [53] isolated terpenoids (taraxerol, β-amyrin, germanicol, α-amyrin, ursolic acid, oleanolic acid, betulinic acid, taraxasterone, and ψ-taraxasterone) and some sterols (isobauerenol, epicholestanol, cholesterol, sitosterol, and 28-isofucosterol) from the aerial parts of this species using preparative thin layer chromatography (PTLC) and gas chromatography-mass spectrometry (GC-MS). In this sense, Fons et al. [55] investigated the volatile profile of fresh aerial parts of E. arvense, also using GC-MS. The plant contained a great biodiversity of isoprenoid flavor precursors (3-hydroxy-7,8-epoxy-β-ionol, (E,E)-pseudoionone, and 3-oxo- -ionol), as well as odorous benzenic derivatives (phenylethanal, 2-phenylethanol, benzaldehyde, and homovanillic acid).

The hydroalcoholic extract of E. arvense sterile stems was also characterized by Milovanović et al. [24]. The authors have found the nonmalonylated quercetin 3-O-glucoside and the free aglycone quercetin as the major constituents, but quercetin 3-O-(6″-O-malonylglucoside), 5-O-caffeoyl shikimic acid, monocaffeoyl-meso-tartaric acid, and dicaffeoyl-meso-tartaric acid were also detected. Besides, Gründemann et al. [22] have also focused on the E. arvense extract’s phytochemical analysis on identifying flavonoids and other polar phenolics. A decoction produced by boiling a part of dry plant material with nine parts of ethanol for 4 h was subjected to the HPLC method to separate the phenolic compounds in the extract later identified by liquid chromatography-mass spectrometry (LC-MS). The major constituents were mono-, di-, and triglycosides of kaempferol, quercetin, apigenin, genkwanin, and protogenkwanin well as mono- and dicaffeoyl-tartaric acid. Besides, three phenolic glycosides, equisetumoside A, equisetumoside B, and equisetumoside C, were isolated from the water-soluble extract of fertile sprouts of E. arvense L., together with uridine, inosine, 2′-deoxyinosine, 2′-deoxycytidine, tryptophan, thymidine, 5-carboxy-2′-deoxyuridine, coniferin, and kaempferol 3-O-β-D-sophoroside-7-O-β-D-glucopyranoside, by Chang et al. [54].

As described in the clinical study conducted by Lemus et al. [18], only a few chemical screenings have been published in the late 1980s and early 1990s demonstrating the presence of -sitosterol, silicic anhydride, flavonoids, and coumarins, as well as isokaemferide and kaempferol derivatives in E. bogotense HBK. Besides, more recently, Tipke et al. [56] identified and quantified the alkaloids present in this species by hydrophilic interaction liquid chromatography high‐performance liquid chromatography tandem mass spectrometry (HILIC HPLC‐MS/MS) in electrospray ionization (ESI). The plant material was powdered using a standard electric coffee grinder and submitted to alkaloids extraction using sulphuric acid. The presence of nicotine, palustrine, and palustridiene was detected; however, only two out of five samples were positive for the compounds. Therefore, the authors stated that more data is necessary to have a clearer picture of the occurrence of alkaloids in this species