Date Published: September 30, 2015
Publisher: Public Library of Science
Author(s): Nagla A. El-Shitany, Lamiaa A. Shaala, Aymn T. Abbas, Umama A. Abdel-dayem, Esam I. Azhar, Soad S. Ali, Rob W. M. van Soest, Diaa T. A. Youssef, Cheng Huang.
Marine sponges are found to be a rich source of bioactive compounds which show a wide range of biological activities including antiviral, antibacterial, and anti-inflammatory activities. This study aimed to investigate the possible anti-inflammatory, antioxidant and immunomodulator effects of the methanolic extract of the Red Sea marine sponge Xestospongia testudinaria. The chemical composition of the Xestospongia testudinaria methanolic extract was determined using Gas chromatography-mass spectroscopy (GC-MS) analysis. DPPH (2, 2-diphenyl-1-picryl-hydrazyl) was measured to assess the antioxidant activity of the sponge extract. Carrageenan-induced rat hind paw edema was adopted in this study. Six groups of rats were used: group1: Control, group 2: Carrageenan, group 3: indomethacin (10 mg/kg), group 4–6: Xestospongia testudinaria methanolic extract (25, 50, and 100 mg/kg). Evaluation of the anti-inflammatory activity was performed by both calculating the percentage increase in paw weight and hisopathologically. Assessment of the antioxidant and immunomodulatory activity was performed. GC-MS analysis revealed that there were 41 different compounds present in the methanolic extract. Sponge extract exhibited antioxidant activity against DPPH free radicals. Xestospongia testudinaria methanolic extract (100 mg/kg) significantly decreased % increase in paw weight measured at 1, 2, 3 and 4 h after carrageenan injection. Histopathologically, the extract caused a marked decrease in the capillary congestion and inflammatory cells infiltrate. The extract decreased paw malondialdehyde (MDA) and nitric oxide (NO) and increased the reduced glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) activity. It also decreased the inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1 β(IL-1β) and IL-6. The results of this study demonstrated the anti-inflammatory, antioxidant, and immunomodulatory effects of the methanolic extract of the Red Sea sponge Xestospongia testudinaria (100 mg/kg).
Inflammatory reaction is a common physiologic response which protects the host from many harmful stimuli such as toxins, local injuries and pathogens . Uncontrolled inflammation is considered as one of the pathophysiologic causes of most chronic diseases, including chronic inflammatory diseases, diabetes, cancer and cardiovascular diseases [2–3]. Over the years, reactive nitrogen species and reactive oxygen species (ROS) are found to play a key role in inflammation . In addition, extensive scientific reports described the role played by various proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1 β(IL-1β) and IL-6 in inflammation . Nowadays, non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed therapeutics for the treatment of many inflammatory diseases . However, the long-term administration of these NSAIDs causes many harmful effects including gastrointestinal ulcers and bleeding and renal damage . Therefore, the need for new anti-inflammatory drugs with fewer adverse effects is mandatory .
Assessment of anti-inflammatory activity of marine natural products from sponges using carrageenan-induced inflammation in the rat paw is the most common assay [25,26]. In the current study, Xestospongia testudinaria methanolic extract revealed significant anti-inflammatory activity at a dose of 100mg/ kg even than the indomethacin treated group. Several compounds possess varied chemical structures and potent anti-inflammatory activity has been isolated from marine sponges . In the present study, GC-MS analysis revealed five compounds exhibit antiinflamatory activity, Propanoic acid , Pyrimidine , Glutamine . Also GC-MS revealed the presence of several fatty acids as (Tetradecanoic acid, Oleic acid, Octadecadiynoic acid, Octanoic acid) with sterol derivative 3α-(Trimethylsiloxy) cholest-5-ene. Pervious study on sea star found that, maximum antiinflammatory activity was obtained after combination of steroid and fatty acid . Hexadecanoic acid possesses anti-inflammatory and antioxidant activity [31,32].
The results of this study demonstrated that pretreatment with the methanolic extract of the Red Sea marine sponge Xestospongia testudinaria prevents carrageenan-induced acute local inflammation in rats. The protective effect is based on the augmentation of antioxidant enzyme system which in turn causes a reduction in the oxidative stress measures. Xestospongia testudinaria methanolic extract may also prevent acute local inflammation through inhibition of proinflammatory cytokines formation.
Future study is warneted with orally consumed extract instead of injected intraperitoneal. In addition, bioassay guided fractionation of the crude Xestospongia testudinaria methanolic extract is important.