20-Hydroxyecdysone, from Plant Extracts to Clinical Use: Therapeutic Potential for the Treatment of Neuromuscular, Cardio-Metabolic and Respiratory Diseases

There is growing interest in the pharmaceutical and medical applications of 20-hydroxyecdysone (20E), a polyhydroxylated steroid which naturally occurs in low but very significant amounts in invertebrates, where it has hormonal roles, and in certain plant species, where it is believed to contribute to the deterrence of invertebrate predators. Studies in vivo and in vitro have revealed beneficial effects in mammals: anabolic, hypolipidemic, anti-diabetic, anti-inflammatory, hepatoprotective, etc. The possible mode of action in mammals has been determined recently, with the main mechanism involving the activation of the Mas1 receptor, a key component of the renin-angiotensin system, which would explain many of the pleiotropic effects observed in the different animal models. Processes have been developed to produce large amounts of pharmaceutical grade 20E, and regulatory preclinical studies have assessed its lack of toxicity. The effects of 20E have been evaluated in early stage clinical trials in healthy volunteers and in patients for the treatment of neuromuscular, cardio-metabolic or respiratory diseases. The prospects and limitations of developing 20E as a drug are discussed, including the requirement for a better evaluation of its safety and pharmacological profile and for developing a production process compliant with pharmaceutical standards.

Phytoecdysteroids Do Not Have Anabolic Effects in Skeletal Muscle in Sedentary Aging Mice

Skeletal muscle mass and strength are lost with aging. Phytoecdysteroids, in particular 20-hydroxyecdysone (20E), increase protein synthesis in C2C12 skeletal muscle cells and muscle strength in young rats. The objective of this study was to determine whether an extract from Ajuga turkestanica (ATE), enriched in phytoecdysteroids, and 20E affect skeletal muscle mass and fiber size, fiber type, activation of the PI3K–Akt signaling pathway, and the mRNA levels of MAFbx, MuRF-1, and myostatin in sedentary aging mice. Aging male C57BL/6 mice (20 months old) received ATE, 20E, or vehicle (CT) once per day for 28 days or a single acute dose. Treatment did not alter body, muscle, or organ mass; fiber cross-sectional area; or fiber type in the triceps brachii or plantaris muscles. Likewise, protein synthesis signaling markers (i.e., phosphorylation of Akt^Ser473 and p70S6k^Thr389) measured after either 28 days or acutely were unchanged. Neither ATE nor 20E treatment for 28 days affected the mRNA levels of MAFbx, MuRF-1, and myostatin. In conclusion, these data indicate that phytoecdysteroid treatment does not alter muscle mass or fiber type, nor does it activate protein synthesis signaling in the skeletal muscle of sedentary aging mice.

Ethnomedicinal Uses, Phytochemistry, Pharmacology, and Toxicology of Species from the GenusAjugaL.: A Systematic Review

The present review is aimed at providing a comprehensive summary of the botanical characteristics, ethnomedicinal uses, phytochemical, pharmacological, and toxicological studies of the genus Ajuga L. The extensive literature survey revealed Ajuga L. species to be a group of important medicinal plants used for the ethnomedical treatment of rheumatism, fever, gout, sclerosis, analgesia, inflammation, hypertension, hyperglycemia, joint pain, palsy, amenorrhea, etc., although only a few reports address the clinical use and toxicity of these plants. Currently, more than 280 chemical constituents have been isolated and characterized from these plants. Among these constituents, neo-clerodane diterpenes and diterpenoids, phytoecdysteroids, flavonoids, and iridoids are the major bioactive compounds, possessing wide-reaching biological activities both in vivo and in vitro, including anti-inflammatory, antinociceptive, antitumor, anti-oxidant, antidiabetic, antimicrobial, antifeedant, antidiarrhoeal, hypolipidemic, diuretic, hypoglycaemic, immunomodulatory, vasorelaxant, larvicidal, antimutagenic, and neuroprotective activity. This review is aimed at summarizing the current knowledge of the ethnomedicinal uses, phytochemistry, biological activities, and toxicities of the genus Ajuga L. to reveal its therapeutic potentials, offering opportunities for future researches. Therefore, more focus should be paid to gathering information about their toxicology data, quality-control measures, and the clinical application of the bioactive ingredients from Ajuga L. species.

The minor ecdysteroids from Ajuga turkestanica

INTRODUCTION

Ajuga turkestanica is a plant used in traditional medicine for its high ecdysteroid content, including the presence of the particularly active turkesterone, which possess efficient anabolic activity.

OBJECTIVES

To isolate and identify minor ecdysteroids present in a semi-purified plant fraction containing ca. 70% turkesterone.

MATERIAL AND METHODS

Multi-step preparative HPLC (combining RP- and NP-HPLC systems) was used to purify the different components present in the turkesterone fraction. Isolated compounds were identified by high-resolution mass spectrometry and 2D-NMR.

RESULTS

Fourteen ecdysteroids (including turkesterone and 20-hydroxyecdysone) were isolated. Seven of these, all bearing an 11α-hydroxy group, were previously unreported.

CONCLUSION

Ajuga turkestanica ecdysteroids are characterised by the abundance of 11α-hydroxylated compounds and by the simultaneous presence of 24C, 27C, 28C and 29C ecdysteroids. It is expected that even more ecdysteroids are to be found in this plant since the starting material for this study lacked the less polar ecdysteroids. The simultaneous presence of 20-hydroxyecdysone and turkesterone (its 11α-hydroxy analogue) as the two major ecdysteroids suggests that every ecdysteroid is probably present in both 11α-hydroxy and 11-deoxy forms.

Ecdysteroid Profiles of Two Ajuga species, A. iva and A. remota

Phytoecdysteroids are plant analogues of insect moulting hormones and are used by plants to repel or disturb phytophagous insects. They are also active on mammals and present in many plants used in traditional medicine. The Ajuga genus contains several such species, which occur in various pharmacopoeias. We report the isolation and identification of major and minor ecdysteroids present in two Ajuga species, A. iva and A. remota, both of which are used as medicinal plants in Africa. Three minor ecdysteroids (abutasterone, ponasterone A and sidisterone) have been found for the first time in the Ajuga genus.