Vitamin D1 versus ecdysteroids: Growth effects on cell regeneration and malignant growth in insects are similar to those in humans

Abstract

Polyhydroxylated derivatives of 6-keto,7-dehydrocholesterol (ecdysteroids) are common constituents of various plants. In 1965, they were accidentally discovered in the search for the insect moulting hormone. These biologically important natural compounds are neither insect hormones nor inducers of insect ecdysis. Due to their strong anabolic, vitamin D-like effects in insects, domestic animals and humans, I propose the use of the arbitrary term vitamin D 1 . The present paper describes the effects of vitamin D 1 on the growth and regeneration of excised epidermal cells of the tobacco hornworm, Manduca sexta (Sphingidae). The periods of programmed cell death and cell proliferation (histolysis and histogenesis, respectively) exactly coincide in insects with endogenous peaks of increased concentration of vitamin D 1 . Epidermal cells communicate with each other, creating a mutually integrated tissue, connected by mechanical, chemical, electrical, ionic or other so far incompletely known factors. After natural cell death, or after the artifi cial removal of some epidermal cells, the neighbouring cells that lose communication integrity, begin to divide mitotically to replace the disconnected part. Cell divisions are arrested as soon as the integrity of the living tissue is established. During insect ontogeny, the application of juvenile hormone causes regenerating epidermal cells to repeat the previous morphogenetic programme (i.e., development of patches of larval tissue on the body of a pupa, or metathetely). Conversely, the application of vitamin D 1 (20-hydroxyecdysone) caused the regenerating cells to prematurely execute a future morphogenetic programme (i.e., development of patches of pupal tissue on the body of a larva, or prothetely). Among the key features of insect regeneration, is the arrest of cell divisions when tissues resume living cell-to-cell integrity. This prevents the formation of aberrant groups of cells, or tumours. It is well established that the main physiological systems of insects (e.g., circulatory, respiratory, neuro-endocrine) are structurally and functionally similar to corresponding systems in humans. Thus the basic principles of cell regeneration and the role of vitamin D 1 in insects may also be valid for humans. The common vitamins D 2 (ergocalciferol) or D 3 (cholecalciferol), are exclusively lipid soluble secosterols, which require activation by UV irradiation and hydroxylation in the liver. By contrast, the neglected vitamin D 1 is a natural derivative of polyhydroxylated 7-dehydrocholesterol of predominantly plant origin, which is both partly a water and partly a lipid soluble vitamin. It neither requires UV irradiation, nor hydroxylation due to 6 or 7 already built-in hydroxylic groups. Like other vitamins, it enters insect or human bodies in plant food or is produced by intestinal symbionts. Vitamin D 1 causes strong anabolic, vitamin D-like effects in domestic animals and in humans. I am convinced that avitaminosis associated with a defi ciency of vitamin D 1 in human blood may...

Effects of dietary supplementation of Achyranthes aspera extract on growth performance, digestibility, innate immunity, antioxidant capacity, and disease resistance of juvenile Pacific white shrimp, Penaeus vannamei

“…IGF‐BP, present in extracellular fluids, was reported to enhance IGF‐I bioactivity (Sara & Hall, 1990). Sláma (2019) reported that ecdysteroids have a strong anabolic effect and act like vitamin D in insects and animals. Insect growth depends on the periodic replacement of the exoskeleton.…”

Intraluminal Farnesol and Farnesal in the Mealworm's Alimentary Canal: An Unusual Storage Site Uncovering Hidden Eukaryote Ca2+-Homeostasis-Dependent “Golgicrine” Activities

“…During metamorphosis the titer of ecdysteroids rises to high concentrations and contributes to the remodeling of the body, while the titer of JHs falls to zero. Recently, Sláma et al (54) has put forward the concept "vitamin D 1 " for presenting the water-soluble anabolic steroid of plant origin (55) that also displays "molting hormone" activity in insects and crustaceans. This real vitamin D occurs in high concentrations in some plants.…”

“…The stem cells may need growth factors, but their identity remains largely unclear. Yet, an interesting novel insight has recently been advanced by Sláma (54). He suggested that the molting hormone of insects and other arthropods, namely 20-hydroxyecdysone the titer of which is high during metamorphosis, is a water-soluble anabolic steroid.…”

Investigations into the human metabolism of ecdysterone

“…6,7 Additionally, numerous food sources and plants employed in traditional medicine have been identified to contain significant amounts of ECDY. [8][9][10][11] In two recent studies, it was demonstrated that after the ingestion of regular meals containing, for example, spinach, considerable concentrations (up to 700 ng/mL) of ECDY were detected in urine. 12,13 Therefore, the presence of ECDY in an athlete's urine alone cannot prove an illicit administration, and further studies seemed warranted.…”