Further insight into the bioactivity of the freshwater sponge Ochridaspongia rotunda

Abstract

Context: Bioprospection has become a dynamic scientific field that explores novel possibilities for the implementation of natural products in medicine and pharmacy. Compared to marine species from all kingdoms, freshwater species have been highly neglected.Objective: This work focuses on the screening of acetylcholinesterase inhibitory (AChE) and mutagenic activities of the acetone extract (obtained by maceration) of the freshwater sponge Ochridaspongia rotunda Arndt (Malawispongiidae) in vitro.Materials and methods: AChE inhibitory activity was evaluated both in liquid (five different concentrations of the extract, from 1 to 100 μg/mL) and in solid (seven different concentrations of the extract, from 0.5 to 10.0 μg) by methods well described in literature, while mutagenicity was estimated using the Ames test (four different concentrations of the extract, from 0.106 to 1.328 mg/plate).Results:Ochridaspongia rotunda acetone extract exhibited promising AChE inhibitory activity in a dose-dependent manner both in liquid (IC50 23.07 μg/mL) and in solid (1.50 μg). Furthermore, the Ames test revealed no sign of mutagenicity at any concentration tested. Its FTIR spectrum coupled with the positive Liebermann?Burchard, Salkowski and Zak color reactions (tests) indicated the presence of sterol compounds.Discussion and conclusion: The screened extract may inspire a search for novel anticholinesterase therapeutic agent(s) potentially used in the treatment of Alzheimer's disease. Further research will be directed toward its detailed chemical analysis along with addressing the issue of a real producer of the natural product(s) responsible for the AChE activity observed.

Chemical Composition and Biological Activities of Metania and Drulia (Metaniidae) Freshwater Sponges from Amazonia

“…The only report in literature of anticholinesterase activity of freshwater sponges was a study with the acetone extract obtained from a Serbian sponge, Ochridaspongia rotunda, that showed an AChE IC 50 of 23.07 μg/mL. [10] Although the inhibitory activity observed in our study is moderate (IC 50 = 1.04 mg/mL), the research is relevant since it is the first report of this kind of activity for Amazonian freshwater sponges. This result is also promising because it encourages the evaluation of activity against other targets related to AD, such as β-amyloid and neurofibrillary tangles, besides the isolation and identification of the individual components of the extract for future evaluation in order to check if the activity comes from a single substance or from synergism.…”

“…These sterols were only identified in marine sponges such as Spongionella gracilis. [23,25,26] The m/z 425 ion proposes the possible existence of the 24isopropenylcholesta-5,22-dien-3β-ol (10), which has already been identified in the marine sponge Aplysina fistularis. [23,27] The 24-ethyl-25-methylcholesta-5,22dien-3β-ol (11), suggested by m/z 427, showed fragments at m/z 408, 393, 35, 300 and 285.…”

“…Since sterol compounds have been already reported about some biological activities, among which, inhibitory activity against AChE becomes promising. [10] Acetylcholinesterase Inhibitory Activity Methanolic extracts from Amazonian freshwater sponges were evaluated at the concentration of 1.0 mg/mL for the ability of inhibiting AChE from electric eel (Electrophorus electricus), EeAChE, and BChE from Equine serum, EqBChE. None of the extracts were able to inhibit EqBChE.…”

“…[8,9] Although the diversity of their secondary metabolites is low, when compared to marine sponges, more than 100 unusual and rare fatty acids, phospholipids and sterols have been described in freshwater sponges. [10] Marine sponges have already demonstrated a great biological potential for the treatment of diseases, such as Alzheimer's and Malaria, which are currently a major public health problem. As it had been demonstrated a certain degree of chemical similarity between freshwater and marine sponges, it can be proposed that Amazonian sponges are a potential source of new bioproducts to the treatment of those diseases.…”

Planctopirus ephydatiae, a novel Planctomycete isolated from a freshwater sponge

“…Those are either endemic or ubiquitous [61] and belong to the single monophyletic order Spongilina [101]. Until now, only a few studies focused on bacteria related to these freshwater sponges and their potential in small molecule production [16,41,43,42,84,85,46,71]. Even though different bacterial strains belonging to the phyla Actinobacteria and Proteobacteria were isolated from freshwater sponges before, no strain has been characterized and validly described [46,4,44,70].…”