The role of nitric oxide

Panabipinoside A and panabipinoside B, two new oleanane triterpenoid saponins from the roots of Panax bipinnatifidus with nitric oxide inhibitory activity

Panax bipinnatifidus belongs to the ginseng genus and it is used in traditional Vietnamese and Chinese medicine. Phytochemical studies of the roots of this plant led to the isolation of two new oleanane triterpenoid saponins, panabipinoside A and panabipinoside B, and three known compounds, ginsennoside Ro, 3- O- β-D-glucopyranosyl-(1→3)- β-glucuronopyranosyl oleanolic acid, and spinasaponin A 28- O-glucoside. Their structures are established by extensive spectroscopic analysis (IR, high-resolution electrospray ionization mass spectrometry, and nuclear magnetic resonance) and by comparison of the spectral data with those reported in the literature. The anti-inflammatory activity of the isolated compounds is evaluated by their inhibition of nitric oxide production in lipopolysaccharide stimulated RAW 264.7 cells. Compounds 2–5 showed inhibitory effects on nitric oxide production with IC50 values of 0.62 ± 0.09, 0.21 ± 0.04, 0.30 ± 0.03, and 0.45 ± 0.05 µg/mL, respectively, compared to value of 8.08 ± 0.09 µg/mL for the positive control compound, NG-monomethyl-L-arginine.

Serum free amino acid levels in rheumatoid arthritis according to therapy and physical disability

BACKGROUND

In presented study the amino acid analysis was performed in serum derived from rheumatoid arthritis patients (RA) according to undertaken therapy and classification of physical disability. The results were compared with previously published data.

METHODS

The levels of 31 free amino acids were determined in 50 serum samples derived from RA subjects and 51 controls. The RA patients were divided into two groups according to the therapy (methotrexate/leflunomide, infliximab/adalimumab/etanercept/tocilizumab, prednisolone/NSAID) and classification of physical disability of the patients. Levels of amino acids were measured by LC-MS/MS. The obtained results were subjected to multivariate statistical tests.

RESULTS

According to the therapy that was being used, threonine differentiated RA patients treated with methotrexate/leflunomide - infliximab/adalimumab/etanercept/tocilizumab (p = 0.00954) and infliximab/adalimumab/etanercept/tocilizumab - prednisolone/NSAID (p = 0.03109), while tryptophan differentiated RA patients treated with methotrexate/leflunomide - infliximab/adalimumab/etanercept/tocilizumab (p = 0.01723). In the functional classification, arginine differentiated RA samples between class III and IV (p = 0.02332), while glycine differentiated them between class I+II and III of the Steinbrocker functional classification (p = 0.03366).

CONCLUSIONS

An analysis of the metabolome profile requires the use of validated bioanalytical methods that are strictly dedicated for this purpose. The obtained results are not accidental (p value less than 0.05), and all of the selected amino acids play an important role in inflammation and immune response. It is suggested that studied amino acids can be considered as a markers for diagnosis of RA and monitoring pharmacotherapy of the disease.

Natural Phytotherapeutic Antioxidants in the Treatment of Mercury Intoxication-A Review

Heavy metals taken into the organism can make the toxic effects on the metabolism in various ways. For example, they may interact with proteins to alter and inhibit their enzymatic and structural functions. Mercury is one of the toxic elements that are widely distributed in nature. Mercury toxicity poses a serious threat to human health. It is an element that causes oxidative stress to increase in individuals, leading to tissue damage. Oxidative stress is the result of the imbalance between the production of oxidative species and cellular antioxidant defense. Phytotherapy continues to play an important role in health care. Natural phytotherapeutic antioxidants, exhibit a broad sequence of biological impacts, including anti-oxidative stress, anti-aging, anti-toxicicity and anticancer. Many studies have also shown that the phytotherapeutic agents play an important role in the removal of mercury from the tissue and in reducing oxidative stress. Our goal in this review was to investigate alternative ways of extracting the mercury in the tissue.

Pharmacological hypothesis: Nitric oxide-induced inhibition of ADAM-17 activity as well as vesicle release can in turn prevent the production of soluble endothelin-converting enzyme

Endothelin‐1 (ET‐1) and nitric oxide (NO) are two highly potent vasoactive molecules with opposing effects on the vasculature. Endothelin‐converting enzyme (ECE) and nitric oxide synthase (NOS) catalyse the production of ET‐1 and NO, respectively. It is well established that these molecules play a crucial role in the initiation and progression of cardiovascular diseases and have therefore become targets of therapy. Many studies have examined the mechanism(s) by which NO regulates ET‐1 production. Expression and localization of ECE‐1 is a key factor that determines the rate of ET‐1 production. ECE‐1 can either be membrane bound or be released from the cell surface to produce a soluble form. NO has been shown to reduce the expression of both membrane‐bound and soluble ECE‐1. Several studies have examined the mechanism(s) behind NO‐mediated inhibition of ECE expression on the cell membrane. However, the precise mechanism(s) behind NO‐mediated inhibition of soluble ECE production are unknown. We hypothesize that both exogenous and endogenous NO, inhibits the production of soluble ECE‐1 by preventing its release via extracellular vesicles (e.g., exosomes), and/or by inhibiting the activity of A Disintegrin and Metalloprotease‐17 (ADAM17). If this hypothesis is proven correct in future studies, these pathways represent targets for the therapeutic manipulation of soluble ECE‐1 production.