Tag: arginine

L-Arginine in Restoring ‘Immune Dysregulation’ in Long COVID: It’s the Therapeutic Role Beyond the Routine Dietary Supplement!

Abstract:

COVID-19 pandemic is over now and we are in great peace of relief after three years. This pandemic has observed significant impact on quality of life globally and the put unforgettable imprints on history of mankind. Reason for more havoc in this pandemic was less studied virus by medical scientists regarding its pathophysiology, available treatment options and lack of effective vaccine to tackle this dragon. COVID-19 is the first observed and reported pandemic of corona virus related global disease apart from its previous SARS and MERS. Fast track developments in medical treatment options due to this ultrafast digital and artificial intelligence techniques have curtailed mortality on large scale globally.
Although mortality is significantly reduced, morbidity is documented on a large scale worldwide in this pandemic. Morbidity due to COVID-19 now called as ‘Long COVID’, which is underreported & half-heartedly evaluated globally. Long COVID is related to persistent immune dysregulation occurs during evolution of COVID-19 as natural trend of disease.
Immune dysregulation has documented during course of active viremia, during recovery of viral illness and after post viral phase. Immune dysregulation occurs in ‘selected group’ of cases irrespective of disease severity and vaccination status and observed in cases with negligible illness to advanced one mandates further research. Thus, Immune dysregulation in COVID-19 is predominant cause for long covid and leading to brainstorming effect on medical scientists and researchers as of today.
Globally, one third of recovered or affected cases of COVID-19 are facing long covid and needs prompt treatment options to tackle this dragon related long term effect on body. ‘Immunomodulatory’ or immunity modifying agents are the primary targets to curtail immune dysregulation and long covid. Some experts recommend ‘disease modifying agents’ to treat long covid cases. Still, many miles to go to reach to effective treatment options for long covid and we don’t have effective options for this ‘health issue of global concern’.
L-Arginine is amino acid with multiple beneficial effects such as immunomodulatory effects which will regulates immunological response in inhibit dysregulated immune system additional to its universally known antioxidant, vasodilatory and regenerative and cellular proliferation effects on immune cells. These Immunomodulatory and or diseases modifying effects of L-Arginine makes it the future candidate with ‘game changer’ role for management of Long covid resulting from immune dysregulation as a core pathophysiologic pathway of this Dragon Pandemic.
Source: Patil, Dr Shital, Patil, Swati, Gondhali, Gajanan. L-Arginine in Restoring ‘Immune Dysregulation’ in Long COVID: It’s the Therapeutic Role Beyond the Routine Dietary Supplement!  South Asian Journal of Life Sciences, 5(4):60-74. https://www.researchgate.net/publication/373217918_L-Arginine_in_Restoring_%27Immune_Dysregulation%27_in_Long_COVID_It%27s_the_Therapeutic_Role_Beyond_the_Routine_Dietary_Supplement (Full text)

Immunometabolic rewiring in long COVID patients with chronic headache

Abstract:

Almost 20% of patients with COVID-19 experience long-term effects, known as post-COVID condition or long COVID. Among many lingering neurologic symptoms, chronic headache is the most common. Despite this health concern, the etiology of long COVID headache is still not well characterized. Here, we present a longitudinal multi-omics analysis of blood leukocyte transcriptomics, plasma proteomics and metabolomics of long COVID patients with chronic headache. L

ong COVID patients experienced a state of hyper-inflammation prior to chronic headache onset and maintained persistent inflammatory activation throughout the progression of chronic headache. Metabolomic analysis also revealed augmented arginine and lipid metabolisms, skewing towards a nitric oxide-based pro-inflammation. Furthermore, metabolisms of neurotransmitters including serotonin, dopamine, glutamate, and GABA were markedly dysregulated during the progression of long COVID headache.

Overall, these findings illustrate the immuno-metabolomics landscape of long COVID patients with chronic headache, which may provide insights to potential therapeutic interventions.

Source: Foo SS, Chen W, Jung KL, Azamor T, Choi UY, Zhang P, Comhair SA, Erzurum SC, Jehi L, Jung JU. Immunometabolic rewiring in long COVID patients with chronic headache. bioRxiv [Preprint]. 2023 Mar 6:2023.03.06.531302. doi: 10.1101/2023.03.06.531302. PMID: 36945569; PMCID: PMC10028820. https://www.biorxiv.org/content/10.1101/2023.03.06.531302v1.full (Full text)

Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome

Abstract:

Long-COVID syndrome is associated with high healthcare costs, but its pathophysiology is not yet fully understood. Inflammation, renal impairment or disturbance of the NO system emerge as potential pathogenetic factors. We aimed to investigate the relationship between symptoms of long-COVID syndrome and serum levels of cystatin-c (CYSC), orosomucoid (ORM), l-arginine, symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA). A total of 114 patients suffering from long-COVID syndrome were included in this observational cohort study.

We found that serum CYSC was independently associated with the anti-spike immunoglobulin (S-Ig) serum level (OR: 5.377, 95% CI: 1.822-12.361; p = 0.02), while serum ORM (OR: 9.670 (95% CI: 1.34-9.93; p = 0.025) independently predicted fatigue in patients with long-COVID syndrome, both measured at baseline visit. Additionally, the serum CYSC concentrations measured at the baseline visit showed a positive correlation with the serum SDMA levels. The severity of abdominal and muscle pain indicated by patients at the baseline visit showed a negative correlation with the serum level of L-arginine.

In summary, serum CYSC may indicate subclinical renal impairment, while serum ORM is associated with fatigue in long-COVID syndrome. The potential role of l-arginine in alleviating pain requires further studies.

Source: Zavori L, Molnar T, Varnai R, Kanizsai A, Nagy L, Vadkerti B, Szirmay B, Schwarcz A, Csecsei P. Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome. J Pers Med. 2023 Feb 19;13(2):371. doi: 10.3390/jpm13020371. PMID: 36836605; PMCID: PMC9958557. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9958557/ (Full text)

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Abstract:

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis.

A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence.

Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03).

The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p < 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Source: Tosato M, Calvani R, Picca A, Ciciarello F, Galluzzo V, Coelho-Júnior HJ, Di Giorgio A, Di Mario C, Gervasoni J, Gremese E, Leone PM, Nesci A, Paglionico AM, Santoliquido A, Santoro L, Santucci L, Tolusso B, Urbani A, Marini F, Marzetti E, Landi F; Gemelli against COVID-19 Post-Acute Care Team. Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial. Nutrients. 2022 Nov 23;14(23):4984. doi: 10.3390/nu14234984. PMID: 36501014; PMCID: PMC9738241. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9738241/ (Full text)

Decreased nitric oxide-mediated natural killer cell activation in chronic fatigue syndrome

Abstract:

BACKGROUND: L-Arginine (L-Arg), one of the essential amino acids, has been reported to have an immunomodulatory effect. The precise mechanism of the L-Arg-induced natural killer (NK) cell activation remains unresolved,and the effect of L-Arg on NK cells in chronic fatigue syndrome (CFS) patients has not been estimated.

METHODS: NK cell function was evaluated in 20 subjects with CFS and compared with that in 21 healthy individuals.

RESULTS: In healthy control subjects, NK activity was significantly increased after treatment with L-Arg, an NK function enhancer, for 24 h, whereas the same treatment failed to enhance NK activity in the CFS patients. We thus focused on L-Arg metabolism, which involves nitric oxide (NO) production through NO synthase (NOS). The expression of inducible NO synthase (iNOS) transcripts in peripheral blood mononuclear cells was not significantly different between healthy control subjects and CFS patients. The L-Arg-mediated NK cell activation was abolished by addition of NG-monomethyl-L-arginine, an inhibitor for iNOS. Furthermore, incubation with S-nitroso-N-acetyl-penicillamine, an NO donor, stimulated NK activity in healthy control subjects but not in CFS patients.

CONCLUSION: These results demonstrate that the L-Arg-induced activation of NK activity is mediated by NO and that a possible dysfunction exists in the NO-mediated NK cell activation in CFS patients.

 

Source: Ogawa M, Nishiura T, Yoshimura M, Horikawa Y, Yoshida H, Okajima Y, Matsumura I, Ishikawa J, Nakao H, Tomiyama Y, Kanayama Y, Kanakura Y,Matsuzawa Y. Decreased nitric oxide-mediated natural killer cell activation in chronic fatigue syndrome. Eur J Clin Invest. 1998 Nov;28(11):937-43. http://www.ncbi.nlm.nih.gov/pubmed/9824439