Safety of organic silicon (monomethylsilanetriol, MMST) as a novel food ingredient for use as a source of silicon in food supplements and bioavailability of orthosilicic acid from the source

A toxicological evaluation of monomethylsilanetriol (MMST) stabilized in acacia gum, a novel silicon preparation

Monomethylsilanetriol (MMST), a silicon-containing compound, has been sold in dietary supplements. However, toxicological studies on its safety profile are not readily available. To assess the safety of MMST stabilized in acacia gum, a novel delivery form of MMST, in accordance with internationally accepted standards, the genotoxic potential and repeated-dose oral toxicity of Living Silica® Acacia Gum Stabilized Monomethylsilanetriol (formerly known as Orgono Acacia Gum Powder®), a food grade product consisting of 80 ± 10% acacia gum and 2.8% (SD ± 10%) elemental silicon from MMST, was investigated. A bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, an in vivo mammalian micronucleus test, and a 90-day repeated-dose oral toxicity study in rats were performed. No evidence of mutagenicity or genotoxic activity was observed under the applied test systems. In the 90-day study, male and female Hsd.Han Wistar rats were administered daily doses of 0, 500, 1000, and 2000 mg/kg bw/day by gavage. No mortality or treatment-related adverse effects were observed, and no target organs were identified. Therefore, the no observed adverse effects level (NOAEL) was determined as 2000 mg/kg bw/day (201 mg MMST/kg bw/day), the highest dose tested.

Sources, Bioavailability, and Safety of Silicon Derived from Foods and Other Sources Added for Nutritional Purposes in Food Supplements and Functional Foods

Silicon is a microelement that performs a number of important functions in the human body, being involved in the formation and maintenance of normal osteocartilaginous connective tissue, such as skin, hair, and nails, and having beneficial effects in the prevention of cardiovascular and neurodegenerative diseases. Natural sources of silicon include fruits, vegetables, cereals, and mineral water. European and North American diets are generally low in silicon, which correlates with a diet high in processed foods. Dietary silicon deficiency can be overcome by the consumption of high bioavailability silicon-rich foods and the use of silicon supplements. A good form of supplementation is orthosilicic acid (OSA), usually stabilized by the introduction of a methyl group, choline, or vanillin. OSA is naturally found in diatomaceous earth in the form of amorphous silica and extracts from silicon-rich plants, e.g., horsetail (Eguiseti herba L.) and nettles (Urtica dioica L.). This article presents the characteristics of the various sources of silicon and their bioavailability and safety of use, with particular reference to the sources used in functional foods and dietary supplements. There is a great need to produce functional foods containing dietary silicon, together with other scarce mineral components.

Topical monomethylsilanetriol can deliver silicon to the viable skin

OBJECTIVE

Organic silicon has been linked to positive effects on the skin rejuvenation, mainly by the oral route. Thus, the main objective of the present study was to assess whether monomethylsilanetriol (MMST, a source of organic silicon) can deliver silicon to the epidermis and dermis, when applied topically in a cream. Once the hypothesis was confirmed, the present study also evaluated whether the product was toxic to keratinocytes; additionally, its possible antioxidant activity was assessed.

METHODS

The ex vivo skin permeation profile was determined using human skin in Franz-cells equipment; cytotoxicity was assessed using HaCaT keratinocytes. Antioxidant capacity was determined as scavenging activity, measured according to the 1,1-diphenyl-2-picrylhydrazil free radical method.

RESULTS

The permeation percentage was almost 60% of the applied MMST, with a large quantity of drug found in the viable epidermis and dermis. The cell viability assay showed no significant difference in the percentage of viable keratinocytes among the treated groups at the doses used. In terms of antioxidant activity, the IC₅₀ value obtained was 2400 μg mL^-1 . Low antioxidant activity, negligible toxicity for keratinocytes and a significant percentage of permeation were observed.

CONCLUSION

We provide evidence that MMST applied topically can deliver silicon to the skin in biorelevant levels for cosmetic purposes.