Pharmacological evaluation of Ashwagandha highlighting its healthcare claims, safety, and toxicity aspects

Withania somnifera, commonly known as "Ashwagandha" or "Indian ginseng" is an essential therapeutic plant of Indian subcontinent regions. It is regularly used, alone or in combination with other plants for the treatment of various illnesses in Indian Systems of Medicine over the period of 3,000 years. Ashwagandha (W. somnifera) belongs to the genus Withania and family Solanaceae. It comprises a broad spectrum of phytochemicals having wide range of biological effects. W. somnifera has demonstrated various biological actions such as anti-cancer, anti-inflammatory, anti-diabetic, anti-microbial, anti-arthritic, anti-stress/adaptogenic, neuro-protective, cardio-protective, hepato-protective, immunomodulatory properties. Furthermore, W. somnifera has revealed the capability to decrease reactive oxygen species and inflammation, modulation of mitochondrial function, apoptosis regulation and improve endothelial function. Withaferin-A is an important phytoconstituents of W. somnifera belonging to the category of withanolides been used in the traditional system of medicine for the treatment of various disorders. In this review, we have summarized the active phytoconstituents, pharmacologic activities (preclinical and clinical), mechanisms of action, potential beneficial applications, marketed formulations and safety and toxicity profile of W. somnifera.

LIR Motif-Containing Hyperdisulfide β-Ginkgotide is Cytoprotective, Adaptogenic, and Scaffold-Ready

Grafting a bioactive peptide onto a disulfide-rich scaffold is a promising approach to improve its structure and metabolic stability. The ginkgo plant-derived β-ginkgotide β-gB1 is a highly unusual molecule: Small, hyperdisulfide, and found only in selected ancient plants. It also contains a conserved 16-amino-acid core with three interlocking disulfides, as well as a six-amino-acid inter-cysteine loop 2 suitable for grafting peptide epitopes. However, very little is known about this recently-discovered family of molecules. Here, we report the biophysical and functional characterizations of the β-ginkgotide β-gB1 from G. biloba. A circular dichroism spectroscopy analysis at 90 °C and proteolytic treatments of β-gB1 supported that it is hyperstable. Data mining revealed that the β-gB1 loop 2 contains the canonical LC3 interacting region (LIR) motif crucial for selective autophagy. Cell-based assays and pull-down experiments showed that β-gB1 is an adaptogen, able to maintain cellular homeostasis through induced autophagosomes formation and to protect cells by targeting intracellular proteins from stress-mediated damage against hypoxia and the hypoxia-reoxygenation of induced cell death. This is the first report of an LIR-containing peptide natural product. Together, our results suggest that the plant-derived β-ginkgotide is cytoprotective, capable of targeting intracellular proteins, and holds promise as a hyperdisulfide scaffold for engineering peptidyl therapeutics with enhanced structural and metabolic stability.

Evaluation of adaptogenic and anti-stress effects of Ranahamsa Rasayanaya-A Sri Lankan classical Rasayana drug on experimental animals

Various types of stress not only harm the mental function, but also cause diseases by weakening body defenses. Rasayana therapy has an advantage over the conventional Kayachikitsa treatment in such conditions, as it is capable of counteracting the stress, promote the adaptogenic abilities of the body, enhance mental endurance, etc. These are the some of parameters for evaluation the rasayana effect of a drug, therefore the same have been studied to assess the rasayana effect of Ranahamsa Rasayanaya (RR). Experimental models such as forced swimming induced hypothermia and stress induced gastric ulcer formation have been carried out befitting on Charles Foster strain albino rats to determine the rasayana effect of RR. Statistically highly significant decrease in forced swimming induced hypothermia and non-significant decrease in gastric ulcer formation were observed in the treatment groups, when compared to the stress control group. These results show the probable adaptogenic and anti-stress activities of the test drug. The study results support the claims made by the Sri Lankan traditional practitioners that, the test drug is a potent rasayana formulation.

Attenuation of Acute and Chronic Restraint Stress-induced Perturbations in Experimental Animals by Nelumbo nucifera Gaertn

Aqueous extract of leaves of Nelumbo nucifera was investigated on acute stress (immobilization stress)-induced biochemical alterations in Swiss mice. The animals were also subjected to acute physical stress (swimming endurance test) and acute chemical stress (writhing test) to gauge the antistress potential of the extract. Further to evaluate the antistress activity of Nelumbo nucifera in chronic stress condition, fresh Wistar rats were subjected to cold restraint stress (4 degrees for 1 h) for 7 days after 21 days of pretreatment with the extract. Stimulation of hypothalamus pituitary adrenal axis in stressful condition alters plasma glucose, triglyceride, cholesterol, total protein and corticosterone levels. Pretreatment with the extract significantly ameliorated the stress-induced variations in these biochemical levels in both acute and chronic stress models. The extract treated animals showed increase in swimming endurance time and reduced number of writhes in physical and chemical-induced stress models respectively. Treatment groups also reverted back perturbed neurotransmitter levels (norepinephrine, dopamine and 5-hydroxytryptamine) in brain as well as increase in adrenal gland weights and atrophy of spleen caused by cold chronic stress. In mice immunized with sheep red blood cells, treatment groups subjected to restraint stress prevented the humoral immune response to the antigen. Histopathological studies of adrenal gland of stress control group revealed vacuolar degeneration, loss of architecture and formation of lesions in the cortex, which was reversed by extract treatment. The results indicate that aqueous extract of Nelumbo nucifera has significant adaptogenic activity against a variety of biochemical, histological, physiological and immunological perturbations in acute and chronic stress models.