Inter-relationship of plasma markers of oxidative stress and thyroid hormones in schizophrenics

<p>Abstract</p> <p>Background</p> <p>The relationship of oxidative stress to thyroid hormones has not been studied in the schizophrenics. The present study determined the status and interrelationship of plasma markers of oxidative stress, nitric oxide and thyroid hormones in thirty (17 males and 13 females) newly diagnosed patients with acute schizophrenia before initiation of chemotherapy. Twenty five (13 males and 12 females) mentally healthy individuals served as controls. Patients and controls with history of hard drugs (including alcohol and cigarette), pre-diagnosis medications (e.g. antiparkinsonian/antipsychotic drugs), chronic infections, liver disease and diabetes mellitus were excluded from the study. Plasma levels of total antioxidant potential (TAP), total plasma peroxides (TPP), nitric oxide (NO), malondialdehyde (MDA), thyroxine (T4), tri-iodothyronine (T3) and thyroid stimulating hormone (TSH) were determined in all participants using spectrophotometric and enzyme linked immunosorbent assay (ELISA) methods respectively. Oxidative stress index (OSI) was calculated as the percent ratio of total plasma peroxides and total antioxidant potential.</p> <p>Findings</p> <p>Significantly higher plasma levels of MDA (p < 0.01), TPP (p < 0.01), OSI (p < 0.01), T3 (p < 0.01) and T4 (p < 0.05) were observed in schizophrenics when compared with the controls. The mean levels of TAP, NO and TSH were significantly lower in schizophrenics (p < 0.01) when compared with the controls. The result shows that T3 values correlate significantly with MDA (p < 0.05) and TPP (p < 0.01) in schizophrenics.</p> <p>Conclusions</p> <p>Higher level of TPP may enhance thyroid hormogenesis in schizophrenics. Adjuvant antioxidant therapy may be a novel approach in the treatment of schizophrenic patients.</p

In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku I’yu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities. Methods Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined. Results Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC50 values of 166.50 ± 5.50 μg/mL and 160.20 ± 27.92 μg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC50 of 167.83 ± 23.82 μg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC50 values of 34.49 ± 4.31 μg/mL and 47.72 ± 1.65 μg/mL, respectively, which were significantly lower (p < 0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of the extracts did not correlate with the total phenolic, total flavonoid, FRAP or DPPH. For ACE inhibition, IC50 values ranged between 266.27 ± 6.91 to 695.17 ± 15.38 μg/mL. Conclusions The tested Australian medicinal plant extracts inhibit glucose-induced fluorescent AGEs, α-amylase, α-glucosidase and ACE with extracts of Petalostigma species showing the most promising activity. These medicinal plants could potentially be further developed as therapeutic agents in the treatment of hyperglycaemia and hypertension

Sage (Salvia pilifera): determination of its polyphenol contents, anticholinergic, antidiabetic and antioxidant activities

In this work, we determined for the first time the Salvia pilifera Montbret &amp; Aucher ex Bentham as an important source for natural products with antioxidant and antidiabetic potentials. In this context, methanol (MESP) and water (WESP) extracts were prepared from aerial parts of S. pilifera. Also, it was evaluated for antioxidant profile by eight distinguishes bioanalytical methods and inhibition effects against enzymes linked to different diseases, namely butyrylcholinesterase (BChE), acetylcholinesterase (AChE), ?-glycosidase and ?-amylase. Also, the polyphenolic compositions of MESP and WESP were evaluated by high performance liquid chromatography and tandem mass spectrometry (LC–MS/MS). Fourteen phenolics were identified in the evaporated MESP and thirteen phenolic compounds were identified in the lyophilized WESP. Also, we performed the antioxidant properties of both extracts. In order to estimate the capacity of MESP and WESP to act as antioxidants, 1,1-diphenyl-2-picryl-hydrazyl radicals (DPPH·), 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS·+) and N,N-dimethyl-p-phenylenediamine radicals (DMPD·+), scavenging activities, ferric ions (Fe3+), Fe3+-TPTZ and cupric ions (Cu2+) reducing assays were studied. MESP and WESP were found as potent effective DPPH· (IC50: 7.05 and 8.56 µg/mL), ABTS·+ (IC50: 3.52 and 4.76 µg/mL) and DMPD·+ (IC50: 28.92 and 30.95 µg/mL) scavenging effects. On the other hand, MESP and WESP showed the potent inhibition effects against AChE (IC50: 94.93 and 138.61 µg/mL), BChE (IC50: 60.05 and 99.13 µg/mL), ?-glycosidase (IC50: 23.28 and 36.47 µg/mL) and ?-amylase (IC50: 46.21 and 97.67 µg/mL) enzymes. This study will be an innovative and guider for further studies for antioxidant properties for industrial or medicinal plants. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.King Saud University, KSUS.A. would like to extend his sincere appreciation to the Distinguished Scientist Fellowship Program at King Saud University for funding this research