Calcium Imaging Identifies Neuroactive Natural Products from Philippine Seaweeds
Franches Rigel B. Jalos (a*), Michael Y. Roleda (a), and Lilibeth A. Salvador-Reyes (a)

(a) Marine Science Institute, University of the Philippines Diliman, Quezon City, Philippines

Abstract

The Philippines ranks among the worlds leading seaweed producers and harbors over 1,065 taxa of marine macroalgae. Seaweeds have long been utilized for diverse applications, including as food, fertilizers, animal feed, and in traditional medicine for the management of various conditions such as rheumatoid arthritis, asthma, cough, diarrhea, abdominal pain, and goiter. In this study, 57 species collected from seven provinces in the Philippines were evaluated for neuroactivity using the Dorsal Root Ganglion (DRG) assay. DRG neurons isolated from 20 to 60 days postnatal ICR mice were loaded with the calcium-sensitive Fura 2AM dye and monitored using calcium imaging. Intracellular calcium levels were measured through alternating excitation at 340 and 380 nm in response to KCl stimulation. Following treatment, the 340/380-nm ratiometric calcium traces revealed that 27 seaweed extracts displayed neuroactivity at 1 ug/mL, with at least 40% of the DRG neurons showing a response. The extracts exhibited distinct neuroactive profiles: 21 induced an increase in intracellular calcium levels in DRG neurons, whereas 6 inhibited calcium influx. These results reveal the neuroactive potential of natural products derived from Philippine seaweed extracts, offering promising avenues for neuroscience and biotechnological applications.

Keywords: Philippine seaweeds, natural products, neuroactivity, Dorsal Root Ganglion Assay, calcium imaging

Topic: Biochemistry