Ashwagandha May Attenuate Neuroinflammation and Anxiety Associated with Obesity

by | Apr 2, 2018 | 2017, Ashwagandha, Botanicals, Obesity

Written by Angeline A. De Leon, Staff Writer. Ashwagandha significantly reduced weight, anxiety levels, and levels of circulating proinflammatory cytokines in the participating Ashwagandha fed rats.

ashwagandha - botanicalsDecades of research have culminated in the recognition of obesity as an inflammatory condition 1, one in which activation of the innate immune system is continuous, resulting in increased circulation of pro-inflammatory cytokines such as TNFα and IL-6 2. The low-grade inflammation associated with obesity is not only implicated in various cardiometabolic disorders such as diabetes and cancer 3, but through its influence on gut microbiota, appears to also contribute to the development of neuropsychiatric disorders like depression and anxiety 4. When inflammatory cytokines cross the blood-brain barrier, neuroinflammation of the central nervous system is caused, affecting neurotransmitter and neuroendocrine activity and thereby increasing the prevalence of negative affect and depression-like symptoms 5. It is for this reason that obese individuals, when age-matched to the general population, report up to a 30% relative increase in symptoms of depression 5. Withania somnifera, commonly known as Ashwagandha, is highly regarded in Ayurvedic Medicine, with applications ranging from cardiorespiratory endurance in athletes 6 to general stress resistance 7. Recently, clinical studies have demonstrated that high concentration, full-spectrum root extract of W. somnifera may be helpful in managing weight loss in obese subjects under chronic stress 8. By reducing serum levels of cortisol and other psychological markers of stress, ashwagandha enables better regulation of eating behavior while simultaneously protecting against oxidative damage and neuroinflammation 9. To test the anti-neuroinflammatory potential of W. somnifera and its benefits for emotional functioning, a study 10 published in the Journal of Neuroinflammation investigated the effects of ashwagandha supplementation on anxious behavior in an animal model of diet-induced obesity.

Young adult female rats were assigned to one of four groups: a low-fat diet group fed with regular chow feed (LFD); a high-fat diet group fed with chow containing 30% fat by body weight (HFD); a low-fat diet plus extract group fed with regular chow feed plus dry leaf powder of W. somnifera at 1mg/g of body weight (LFDE); or a high-fat diet plus extract group fed with chow containing 30% fat by body weight plus W. somnifera (HFDE). Feeding regimen was maintained for 12 weeks, and anxiety was induced using the elevated plus maze (EPM) test. At the end of the trial, animals were sacrificed and immunohistochemical testing was carried out to measure various inflammatory markers as well as levels of leptin and insulin.

Analyses revealed the following key findings:

Ashwagandha supported the management of body weight- LFDE rats demonstrated a 10.2% reduction in weight after 12 weeks of supplementation with W. somnifera. Additionally, although caloric intake was highest in the HFDE group initially, it was reduced by 40.63% at the end of the trial.

Ashwagandha suppressed anxiety-like behavior- Exploratory behavior (based on number of entries and crossings in maze), representing relative absence of anxiety, was significantly higher in HFDE rats, in comparison to all other treatment groups (p ≤ 0.05).

Ashwagandha modulated expression of pro-inflammatory cytokines- In comparison to HFD rats, HFDE rats exhibited a relative decrease in circulating levels of pro-inflammatory cytokines TNFα, IL-1β, and IL-6 (p ≤ 0.05), whereas HFD experienced a significant upregulation in the hippocampus region (p ≤ 0.05 in comparison to LFD).

Overall, results support the anxiolytic and anti-inflammatory properties of W. Somnifera, demonstrating the ability of ashwagandha to reduce anxiety-like behavior and dysregulation of inflammatory molecules. Current findings suggest that the medicinal plant should be considered a potential therapeutic strategy for mitigating the adverse effects of obesity and its associated co-morbid conditions. However, it would be important to replicate preliminary findings in human subjects first.

Source: Kaur T and Kaur G. Withania somnifera as a potential candidate to ameliorate high fat diet-induced anxiety and neuroinflammation. Journal of Neuroinflammation. 2017; 14: 201. DOI: 10.1186/s12974-017-0975-6.

© The Author(s). 2017 Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)

Click here to read the full text study.

Posted April 2, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

References:

  1. Dinh CH, Szabo A, Camer D, Yu Y, Wang H, Huang X-F. Bardoxolone methyl prevents fat deposition and inflammation in the visceral fat of mice fed a high-fat diet. Chemico-biological interactions. 2015;229:1-8.
  2. Trayhurn P, Beattie JH. Physiological role of adipose tissue: white adipose tissue as an endocrine and secretory organ. Proceedings of the Nutrition Society. 2001;60(3):329-339.
  3. Duncan BB, Schmidt MI, Pankow JS, et al. Low-grade systemic inflammation and the development of type 2 diabetes: the atherosclerosis risk in communities study. Diabetes. 2003;52(7):1799-1805.
  4. Castanon N, Lasselin J, Capuron L. Neuropsychiatric comorbidity in obesity: role of inflammatory processes. Frontiers in endocrinology. 2014;5:74.
  5. Sharma S, Fulton S. Diet-induced obesity promotes depressive-like behaviour that is associated with neural adaptations in brain reward circuitry. International journal of obesity. 2013;37(3):382.
  6. Choudhary B, Shetty A, Langade DG. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults. Ayu. 2015;36(1):63.
  7. Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of Ashwagandha root in reducing stress and anxiety in adults. Indian journal of psychological medicine. 2012;34(3):255.
  8. Choudhary D, Bhattacharyya S, Joshi K. Body weight management in adults under chronic stress through treatment with Ashwagandha root extract: a double-blind, randomized, placebo-controlled trial. Journal of evidence-based complementary & alternative medicine. 2017;22(1):96-106.
  9. Anwer T, Sharma M, Pillai KK, Khan G. Protective effect of Withania somnifera against oxidative stress and pancreatic beta-cell damage in type 2 diabetic rats. Acta Pol Pharm. 2012;69(6):1095-1101.
  10. Kaur T, Kaur G. Withania somnifera as a potential candidate to ameliorate high fat diet-induced anxiety and neuroinflammation. Journal of neuroinflammation. 2017;14(1):201.