Πέμπτη 24 Οκτωβρίου 2019

Ethanolic extract of cashew apple inhibits lipid metabolism and ameliorates obesity in atherogenic diet-induced obese rats
Thatiparthi Jhansyrani, Dodoala Sujatha, Koganti Bharathi, KVSRG Prasad

Asian Pacific Journal of Tropical Biomedicine 2019 9(10):405-414

Objective: To evaluate the anti-obesity activity of ethanolic extract of cashew apple using various in vitro and in vivo models. Methods: Phytochemical screening was carried out in ethanolic extract of cashew apple, followed by quantification of phenol and flavonoid. Antioxidant potential was evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) scavenging assays. The inhibitory effect of ethanolic extract of cashew apple on α-amylase and pancreatic lipase was also studied. In addition, anti-obesity activity was determined in two in vivo models, lipid emulsion model and atherogenic diet-induced obese rat model. Levels of postprandial plasma triglycerides were assessed in lipid emulsion model, whereas serum lipid profile, in vivo antioxidants and histopathological studies of the carotid artery and liver were performed in an atherogenic diet-induced obese model. Results: Phytochemical screening revealed the presence of carbohydrates, alkaloids, polyphenols, terpenoids, and steroids. The in vitro assays showed inhibition of α-amylase and pancreatic lipase and strong antioxidant potential. Ethanolic extract of cashew apple showed significant and time- dependent inhibitory activity on postprandial triglycerides after administration of lipid emulsion for 5 h. Ethanolic extract of cashew apple at 200 and 400 mg/kg on day 60 showed a significant reduction in body weight, body mass index and atherogenic index, whereas lipid profile and liver function marker levels in the serum were decreased in a dose-dependent manner at time intervals (day 0, 20, 40, and 60) compared to the atherogenic diet-induced obese rats. Histological observations showed reduced non-alcoholic fatty liver deposits and decreased atherosclerotic fatty streak plaques (carotid artery) after treatment with ethanolic extract of cashew apple. Conclusions: Ethanolic extract of cashew apple ameliorates obesity, which may be partly mediated by its delayed absorption of cholesterol and carbohydrates.

Effect of alpha-lipoic acid supplementation on blood pressure, renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats
Chandran Govindasamy, KNS Sirajudeen

Asian Pacific Journal of Tropical Biomedicine 2019 9(10):415-423

Objective: To investigate the effect of alpha-lipoic acid (ALA) supplementation on systolic blood pressure (SBP), renal oxidant-antioxidant status and renal damage in spontaneously hypertensive rats (SHR) and SHR administered with Nω-nitro-L-arginine methyl ester (L-NAME). Methods: Male rats were divided into four groups (SHR, SHR+ALA, SHR+L-NAME, SHR+ALA+L-NAME). The respective group of rats was administered with ALA (100 mg/ kg/day) from age 4 weeks to 28 weeks and L-NAME (25 mg/kg/day) from age 16 weeks to 28 weeks. SBP was measured every two weeks and twenty four hour urine was collected at 4 weeks, 16 weeks and 28 weeks for estimation of protein, creatinine and N-acetyl-β-D-glucosaminidase. At the end of 28 weeks, rats were sacrificed and blood and kidneys collected for assessment of blood creatinine, kidney thiobarbituric acid reactive substances, protein carbonyls, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, glutathione disulfide, glutathione, total antioxidant status and nitric oxide as well as histopathological examination. Results: ALA supplementation significantly reduced SBP of SHR and SHR+L-NAME rats when compared to their respective non-supplemented groups. Renal oxidant status markers including thiobarbituric acid reactive substances and protein carbonyls were significantly reduced on SHR and SHR+L-NAME rats supplemented with ALA at 28 weeks as well as ALA supplementation significantly increased renal antioxidants including superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione and glutathione/ glutathione disulfide ratio at 28 weeks. No significant change in nitric oxide levels was observed between the ALA supplemented and non-supplemented groups. Renal dysfunction was ameliorated on ALA supplementation as evidenced by significant reduction in urine protein levels, N-acetyl-β-D-glucosaminidase activity and significant increase of creatinine clearance in SHR and SHR+L-NAME at 28 weeks. Renal histopathological examination showed that ALA supplementation prevented vascular damage in SHR and ameliorated glomerular damage in SHR+L-NAME at 28 weeks. Conclusions: ALA has hypotensive and renoprotective effects on both SHR and SHR+L-NAME, which could be due to its ability to ameliorate oxidative stress in the kidneys.

Hydroalcoholic extract of licorice (Glycyrrhiza glabra L.) root attenuates ethanol and cerulein induced pancreatitis in rats
Sarmishta Srikantam, Geetha Arumugam

Asian Pacific Journal of Tropical Biomedicine 2019 9(10):424-433

Objective: To evaluate the therapeutic potential of hydroalcoholic extract of licorice root against ethanol and cerulein induced chronic pancreatitis in rats. Methods: The phytochemical profile of hydroalcoholic extract of licorice root was determined by high performance liquid chromatography (HPLC) and gas chromatography coupled to mass spectrometry (GC-MS). Chronic pancreatitis was induced in male albino Wistar rats by feeding them a diet containing ethanol (0%-36% of total calories) for 4 weeks and cerulein (20 μg/kg b.wt, i.p.) thrice a week for 3 weeks. Lipase and amylase in serum, lipid peroxides and antioxidants including reduced glutathione, glutathione peroxidase, superoxide dismutase and catalase in pancreas were determined. Inflammatory response was measured by myeloperoxidase in the pancreas, caspase-1 and the concentrations of IL-1 β and IL-18 in serum. Moreover, histological evaluation of the pancreas and liver was carried out. Results: Different flavonoids and saponins were identified in the hydroalcoholic extract of licorice root through HPLC and GC-MS. A marked increase in the levels of serum lipase, amylase, lipid peroxides, caspase-1, myeloperoxidase, IL-1 β , and IL-18 and a marked decrease in the levels of antioxidants were observed after ethanol and cerulein administration. Treatment with hydroalcoholic extract of licorice root attenuated these changes. In addition, histological observation confirmed the protective effect of the extract in the pancreas and liver against inflammatory changes induced by ethanol and cerulein. Conclusions: The licorice root extract attenuates ethanol and cerulein induced pancreatitis in rats probably due to its antioxidant phytonutrients since ethanol and cerulein-induced production of reactive oxygen species contributes to severe inflammation in the pancreas.

Bioguided isolation of antimicrobial polyphenols from Cuspidaria convoluta leaves and their synergistic effect with antibiotics
Carola A Torres, Mario A Sturla, Ana M Romero, María A Judis

Asian Pacific Journal of Tropical Biomedicine 2019 9(10):434-442

Objective: To identify and isolate phenolic compounds from Cuspidaria convoluta, and to evaluate their antibacterial activity and synergistic effect with antibiotics. Methods: The crude extract was prepared by maceration with methanol (5%). The dry extract was suspended in water and fractionated successively. The most active extract was selected by its antibacterial activity and its total phenol content was determined by spectrophotometry and by HPLC-MS/MS. Bioactive fractions of the most active extract were separated by column chromatography and evaluated by bioautography. Isolated compounds were identified. Minimum inhibitory concentration (MIC) of these compounds was determined by microdilution broth method, and synergism with antibiotics (ampicillin, gentamicin and oxacillin) was tested by checkerboard and time-kill assays. Results: Coumaric acid, catechin/epicatechin, and luteolin were purified and identified from the extract. There was an increase in the antibacterial activity of antibiotics when they were combined with these compounds. The combination of luteolin and ampicillin had the most potent antibacterial activities. The MICs of oxacillin for each of methicillin-resistant Staphylococcus aureus strains were reduced between 4 and 8-fold when these strains were coincubated with sub-MIC (≤ ½ MIC) levels of these compounds, demonstrating that the combination had synergistic effect for all cases. Conclusions: Cuspidaria convoluta contains important pharmacologically active substances that can be used to improve antibiotic efficacy.

Prediction of T cell and B cell epitopes of the 22-, 47-, 56-, and 58-kDa proteins of Orientia tsutsugamushi
Li-Na Niu, Ting-Ting Fu, Man-Ling Chen, Yu-Ying Dong, Jin-Chun Tu, Zi-Hao Wang, Si-Qi Wang, Xuan Zhao, Nai-Xu Hou, Qian Chen, Qiang Wu

Asian Pacific Journal of Tropical Biomedicine 2019 9(10):443-448

Objective: To predict B cell and T cell epitopes of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins. Methods: The sequences of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins which were derived from Orientia tsutsugamushi were analyzed by SOPMA, DNAstar, Bcepred, ABCpred, NetMHC, NetMHC II and IEDB. The 58-kDa tertiary structure model was built by MODELLER9.17. Results: The 22-kDa B-cell epitopes were located at positions 194-200, 20-26 and 143-154, whereas the T-cell epitopes were located at positions 154-174, 95-107, 17-25 and 57-65. The 47-kDa protein B-cell epitopes were at positions 413-434, 150-161 and 283-322, whereas the T-cell epitopes were located at positions 129-147, 259-267, 412-420 and 80-88. The 56-kDa protein B-cell epitopes were at positions 167-173, 410-419 and 101-108, whereas the T-cell epitopes were located at positions 88-104, 429-439, 232-240 and 194-202. The 58-kDa protein B-cell epitopes were at positions 312-317, 540-548 and 35-55, whereas the T-cell epitopes were located at positions 415-434, 66-84 and 214-230. Conclusions: We identified candidate epitopes of 22-kDa, 47-kDa, 56-kDa and 58- kDa proteins from Orientia tsutsugamushi. In the case of 58-kDa, the dominant antigen is displayed on tertiary structure by homology modeling. Our findings will help target additional recombinant antigens with strong specificity, high sensitivity, and stable expression and will aid in their isolation and purification.

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