Ethanol Extract of Myrtle (Myrtus communis L.) Berries as a Remedy for Streptozotocin-Induced Oxidative Stress in Rats

Unveiling the Chemical Profiling Antioxidant and Anti-Inflammatory Activities of Algerian Myrtus communis L. Essential Oils, and Exploring Molecular Docking to Predict the Inhibitory Compounds against Cyclooxygenase-2

Considering the large spectrum of side effects caused by synthetic drugs and the development of natural alternatives utilizing Algerian flora, this study aimed to place a spotlight on the chemical profile and antioxidant and anti-inflammatory activities of Myrtus communis L. essential oils (MCEOs). In this study, essential oils (EOs) were collected via hydro-distillation of the plant's leaves, and a chemical constituent analysis was performed using gas chromatography-mass spectrophotometry (GC-MS). The in vitro antioxidant activity was evaluated using DPPH, ABTS, and hydroxyl radical scavenging tests. The in vitro anti-inflammatory capacity was estimated by studying the antidenaturation effect using bovine serum albumin (BSA) as a protein model. The in vivo anti-inflammatory activity was carried out by utilizing the classical model of carrageenan-induced paw edema in rats, using diclofenac (DCF) as the reference drug. Moreover, the molecular interaction of the compounds obtained from the GC-MS analysis was studied within the binding site of cyclooxygenase-2 (COX-2) using an in silico approach as the confirmatory tool of the in vitro and in vivo experiments. The GC-MS analysis revealed that MCEOs were mainly composed of oxygenated monoterpenes (70.56%), oxygenated sesquiterpenes (3.1%), sesquiterpenes (4.17%), and monoterpenes (8.75%). Furthermore, 1,8-cineole was the major compound (19.05%), followed by cis-geranyl acetate (11.74%), methyl eugenol (5.58%), α-terpineol (4.62%), and β-myrcene (4.40%). MCEOs exhibited remarkable concentration-dependent free radical scavenging activity, with an IC50 of 15.317 ± 0.340 µg/mL, 18.890 ± 2.190 µg/mL, and 31.877 ± 0.742 µg/mL for DPPH, ABTS, and hydroxyl radical, respectively. The significant in vitro anti-inflammatory activity due to the inhibition of BSA denaturation was proportional to the EO concentration, where the highest value was recorded at 100 μg/mL with an approximately 63.35% percentage inhibition and an IC50 of 60.351 ± 5.832 μg/mL. MCEOs showed a good in vivo anti-inflammatory effect by limiting the development of carrageenan-induced paw thickness. The in silico study indicated that, among the 60 compounds identified by the GC-MS analysis, 9 compounds were observed to have a high binding energy to cyclooxygenase-2 as compared to diclofenac. Our study revealed that EOs from Algerian Myrtus communis L. can be considered to be a promising candidate for alleviating many debilitating health problems and may provide new insights in the fields of drug design, agriculture, and the food industry.

Effect of Streptozocin on the Langerhans Islands in the pancreas of birds

In the current study, birds (Columba livia ) were used as a new model to study the effect of streptozotocin on the pancreas gland and the blood glucose level. Three concentrations of 75,65,55 mg/kg were adopted for five consecutive days with one IP dose daily. The experimental animals showed a gradual rise in blood glucose the average glucose in the first week of the experiment was usual for the three groups compared with the control group, while there was a significant change in the blood glucose level in the three groups at the end of the experiment (4th week), where the average glucose in the streptozotocin groups was 55 mg/kg (213.80 ± 12.43) mg/dl and the group 65 mg/kg(282.60 ± 16.78) mg/dl and a group of 75 mg/kg( 371.0 ± 38.39) mg/dl. Keywords: Streptozocin, Langerhans islands, pancreas.

p-Synephrine ameliorates alloxan-induced diabetes mellitus through inhibiting oxidative stress and inflammation via suppressing the NF-kappa B and MAPK pathways

Oxidative stress and inflammation play important roles in the development of diabetes mellitus. p-Synephrine, the primary pharmacologically active protoalkaloid in Citrus species, has been popularly consumed as a dietary supplement for weight loss management. However, the effects of p-synephrine on diabetes mellitus and the action mechanisms have not been clearly elucidated. In this study, the in vitro antioxidant effects of p-synephrine were evaluated. The data showed that p-synephrine treatment exhibited significant scavenging effects against DPPH, ABTS and OH radicals and showed high reducing power. Diabetic mice were developed by alloxan injection, followed by p-synephrine administration to investigate its hypoglycemic effects in vivo. The results showed that p-synephrine intervention significantly prevented alloxan-induced alteration in body weight, organ indexes, serum uric acid content and serum creatinine content. Meanwhile, p-synephrine application significantly improved the lipid profiles, superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) contents in the serum and kidneys of diabetic mice and reduced the malondialdehyde (MDA) content in the serum of diabetic mice. Further assays suggested that p-synephrine treatment improved alloxan-induced decreases of glucose tolerance and insulin sensitivity. Also, p-synephrine supplementation altered histopathological changes in the kidneys and interscapular brown adipose tissues in diabetic mice. In addition, p-synephrine administration inhibited renal inflammation through suppressing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) gene expression levels, as well as CD45 expression levels. The anti-inflammatory effects were probably involved in the regulation of nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation. In conclusion, p-synephrine application significantly ameliorated alloxan-induced diabetes mellitus by inhibiting oxidative stress via suppressing the NF-κB and MAPK pathways.

Liposomal Formulations to Improve Antioxidant Power of Myrtle Berry Extract for Potential Skin Application

Many substances in plant extracts are known for their biological activities. These substances act in different ways, exerting overall protective effects against many diseases, especially skin disorders. However, plant extracts’ health benefits are often limited by low bioavailability. To overcome these limitations, drug delivery systems can be employed. In this study, we evaluated the antioxidant power of an ethanolic extract from Myrtus communis L. (myrtle) berries through colorimetric tests (DPPH and FRAP). The antioxidant activity was also verified by using fibroblast cell culture through cellular Reactive Oxygen Species (ROS) levels measurements. Moreover, the myrtle extract was formulated in phospholipid vesicles to improve its bioavailability and applicability. Myrtle liposomes were characterized by size, surface charge, storage stability, and entrapment efficiency; visualized by using cryo-TEM images; and assayed for cytocompatibility and anti-ROS activity. Our results suggest that myrtle liposomes were cytocompatible and improved the extract’s antioxidant power in fibroblasts, suggesting a potential skin application for these formulations and confirming that nanotechnologies could be a valid tool to enhance plant extracts’ potentialities.