Gastroprotective effects of oleuropein and thymol on indomethacin-induced gastric ulcer in Sprague-Dawley rats.

Ethnopharmacological studies demonstrated that thymol (Thym) and oleuropein (Ole) have therapeutic potential for gastric ulcers. The molecular mechanism underlying the gastroprotective effects of these compounds have not been elucidated yet especially for their individual and combination use at high dose. Therefore, this study was conducted to explore their gastroprotective mechanisms on indomethacin (Indo)-induced gastric ulcer model. Ole (50,100, 250, and 500 mg/kg) and Thym (50,100, 200, and 500 mg/kg) were orally administered to the rats 10 min before the induction of ulcer with Indo. The combination of 500 mg/kg doses of Ole and Thym were applied. The gastric mucosa was evaluated histopathologically. Moreover, TAC/TOS, tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), endothelial nitric oxide synthase (eNOS), and caspase-3 levels were assessed by ELISA and the caspase-3 and TNF-α expressions were quantified by qRT-PCR. Indo-induced histopathological changes while Ole and Thym pretreatment prevented these effects. Unlike the 500 mg/kg dose of Ole treatment, the 500 mg/kg dose of Thym administration enhanced these damages. The decreased TAC, PGE2 levels and increased TOS, eNOS, TNF-α, caspase-3 levels were obtained in Indo group. However, these changes were reversed by Ole and Thym groups except the 500 mg/kg dose of Thym and the combination treatment groups. Similar trends were observed in the caspase-3 and TNF-α expression levels. These results demonstrated that enhanced inflammation, oxidant/antioxidant imbalance, and apoptotic activities were occurred in Indo, 500 mg/kg dose of Thym and the combination treatment groups while not in the other groups. The findings demonstrated the gastroprotective ability of Ole and low doses of Thym in gastric ulcer models.

The propolis and boric acid can be highly suitable, alone/or as a combinatory approach on ovary ischemia-reperfusion injury.

PURPOSE: Ovarian ischemia-reperfusion (IR) damage continues to be a serious infertility problem. The oxidative stress plays central role in the development of IR injuries. Activation of antioxidants decreases IR injuries; however, the efficacy of antioxidant agents remains controversial. Unfortunately, there has been no evidence for medicinal use of boric acid (BA) and propolis (Prop) on ovarian IR injury on rats so far. This study will provide to reveal the potential applications of the Prop and BA in ovarian IR therapy. METHODS: The Sprague-Dawley rats were randomized into five groups: I-control, II-IR, 3 h of ischemia and 3 h of reperfusion, III and IV-a signal dose of oral BA (7 mg/kg) and Prop (100 mg/kg) alone 1 h before induction of IR, V-Prop and BA together 1 h before induction of IR. SOD (superoxide dismutase), CAT (catalase), GSH (glutathione), MPO (myeloperoxidase), MDA (malondialdehyde), and IL-6 (interleukin-6) levels were quantified by ELISA and the TNF-α (tumor necrosis factor-α), 8-OHdG (8-hydroxylo-2'-deoxyguanosin) and Caspase-3 expressions were performed by immunohistochemical analyses. RESULTS: BA and Prop pretreatment significantly reduced MPO, MDA, and IL-6 levels and pathologic score in IR rats, with no effects in control group. These agents used in therapy also decreased TNF-α, 8-OHdG and Caspase-3 protein expressions increased by IR. Furthermore, BA and Prop combination showed significant ameliorative effects on ovary injury caused by IR through acting as an antioxidant, anti-inflammatory and antiapoptotic agent. CONCLUSION: BA and Prop alone and especially in combination could be developed as therapeutic agents against ovary IR injury.

Evaluating the toxic and beneficial effects of lichen extracts in normal and diabetic rats.

Lichens can be used as a novel bioresource for natural antioxidants. However, there is need for further investigations to validate the lichens used in medicinal remedies. In this study, the effects of Cetraria islandica and Pseudevernia furfuracae lichen species in streptozotocin (STZ)-induced diabetes were evaluated. Diabetic rats were treated with aqueous lichen extracts (250 and 500 mg/kg/day) for 2 weeks starting at 72 h after STZ injection. On the 14th day, animals were anesthetized, and then metabolic and biochemical parameters were evaluated between control and treatment groups. Pancreatic histology and ß-cell mass were examined by hematoxylin and eosin and insulin immunohistochemistry stainings. Our findings revealed that these lichen species could be used safely in this dose range. In addition, C. islandica extracts showed prominent results compared to the doses of P. furfuracae extract for antioxidant capacity. However, the protectivity of C. islandica extract was inadequate against diabetes-induced pancreatic damages via forming oxidative stress. In conclusion, the usage of C. islandica might serve for early intervening in the risk reduction of type 1 diabetes.

The effects of Cetraria islandica and Pseudevernia furfuracea extracts in normal and diabetic rats.

Lichens are symbiotic organisms composed of a fungus joined to a photosynthesizing partner that can be either an alga or a cyanobacterium. They can be used as a novel bioresource for natural antioxidants. However, there is also a need for further studies to validate the lichens used in medicinal remedies. This study covers a previously unrecognized effects of Cetraria islandica (CIAE) and Pseudevernia furfuracea (PFAE) in streptozotocin (STZ)-induced diabetes. In experimental design, control or diabetic rats were either untreated or treated with aqueous lichen extracts (250-500 mg/kg/day) for 2 weeks starting at 72 h after STZ injection. On day 14, animals were anesthetized, metabolic and biochemical parameters were appreciated between control and treatment groups. The histopathology of kidney was examined using four different staining methods: hematoxylin-eosin (H&E), periodic acid-Schiff (PAS), Masson trichrome and Congo red. Our experimental data showed that increasing doses of CIAE and PFAE did not have any detrimental effects on the studied parameters and the malondialdehyde level of kidney. CIAE extract showed prominent results compared to doses of PFAE extract for antioxidant capacity. However, the protective effect of CIAE extract was inadequate on diabetes-induced disorders and kidney damages. Moreover, animals subjected to diabetes mellitus (DM) therapy did not benefit unfortunately from the usage of increasing lichen doses due to their unchanged antioxidant activity to tissue. The results obtained in present study suggested that CIAE and PFAE are safe but the power of these is limited because of the intensive oxidative stress in kidney of type 1 diabetic rats. It is also implied that CIAE extract is especially suitable for different administration routes in DM.

Effects of lichen extracts on haematological parameters of rats with experimental insulin-dependent diabetes mellitus.

The prevalence of diabetes mellitus in the world is steadily increasing. Oxidative stress contributes to the development of diabetic complications, including diabetic haematological changes. Lichens are used as food supplements and are also used as possible natural antioxidant, antimicrobial and anticancer agents. We hypothesized that antioxidant activity of lichens may decrease hyperglycaemia-induced oxidative stress and prevent the development of diabetic complications, including abnormality in haematological condition. Therefore, the effects of Cetraria islandica water extract (CIWE) and Pseudevernia furfuracea water extract (PFWE) on the haematological parameters of rats with type 1 DM were investigated for the first time in the present study. Control Sprague-Dawley or streptozotocin (STZ)-induced diabetic rats were either untreated or treated with water lichen extracts (5-500 mg/kg body weight (bw)/day) for 2 weeks, starting at 72 h after STZ injection. On day 14, animals were anaesthetized and haematological and metabolic parameters were determined between control and experimental groups. In addition, the total oxidative stress (TOS), a specific indicator of oxidative stress, and the total antioxidant capacity (TAC) were measured by biochemical studies. In diabetic rats, CIWE of 250-500 mg/kg bw dose showed more prominent results when compared with doses of PFWE for TAC. The results obtained in the present study suggested that the antioxidant activities of lichens might be the possible reason behind the observed antihaematological status. However, the protective effect of lichen extracts were inadequate on diabetes-induced microcytic hypochromic anaemia. In addition, the extracts have no effect on metabolic complications. Our experimental data showed that high doses of CIWE and PFWE alone have no detrimental effect on blood cells and TOS status of plasma. Hence, they are safe and suitable for different administration routes.

Helichrysum plicatum DC. subsp. plicatum extract as a preventive agent in experimentally induced urolithiasis model.

ETHNOPHARMACOLOGICAL RELEVANCE: Since ancient times, various herbal preparations have been used in treatment of urolithiasis, which is basically formation of calcium oxalate stones in kidney. The aim of our study is to assess the effects of Helichrysum plicatum DC. subsp. plicatum (HP) as a preventive agent in experimentally induced urolithiasis model in rats. MATERIALS AND METHODS: The efficacy of 125, 250, and 500 mg/kg HP extract was studied in 1% ethylene glycol and 1% ammonium chloride-induced urolithiasis for 21 days in rats. The weight difference and the levels of calcium, magnesium, phosphorus, urea nitrogen, creatinine and uric acid in both serum and 24h-urine were measured. The calcium oxalate (CaOx) and pH were defined in urine. Histo-pathological analyses in kidneys were also performed. RESULTS: The rats' weights were higher in HP groups than urolithiasis group. Urolithiasis caused a significant increase in both serum and urine biochemical parameters compared to healthy rats. HP extract decreased levels of these parameters. Urine CaOx level was high in urolithiasis rats, whereas it was decreased by HP extract. Histopathological examinations revealed extensive intratubular crystal depositions and degenerative tubular structures in urolithiasis group, but not in HP treatment groups. CONCLUSION: More studies will be necessary to elucidate the antiurolithiatic activity of HP. Nonetheless, having a beneficial effect in preventing and eliminating CaOx deposition into kidneys, HP extract may be a potential drug for urolithiasis treatment.