The bioactivities of polysaccharides isolated from the edible epiphyte Vertebrata lanosa and their respective low-molecular-weight (LMW) biopolymers were investigated in this study. A sequential extraction procedure was carried out on ethanol-treated and non-treated algae biomass to yield polysaccharides of a hybrid nature, containing two agaran-type polysaccharides, namely funoran and porphyran. The molecular weights of native polysaccharides ranged from 500 to 5520 kDa. Selected native samples were further subjected to ultrasonication (60‒180 min) to yield LMW fractions ranging from 62 to 131 kDa. A comparative analysis between the ethanol-treated (B1) and non-treated (B2) samples revealed variations in the molecular weights of native polysaccharides with influence from the respective extraction conditions. The different antioxidant assays further showed a synergistic effect of molecular weight, sulfate, and sugar acids on the capacity of both native and depolymerized samples. A significantly high neutralization efficiency against hydroxyl radicals (up to 95%) was recorded in LMW samples. The inhibition of α-glucosidase enzymeby the tested samples was shown to be highest in the LMW polysaccharides prepared using room temperature extracted fractions. In vitro assays using selected native fractions showed no cellular toxicity on RAW264.7 macrophages using 0.5‒32 µg/mL polysaccharide concentration. A trend that indicated influences of the pre-ethanol treatment and the type of precipitant used was also observed in the amounts of nitric oxide (NO) produced. Overall, produced NO in comparison to LPS was recorded in amounts that indicated immunomodulatory effects. Additionally, the treated cells recorded phagocytosis effect which highly varied in comparison with indicates a stimulatory effect on macrophages. These findings have in all, shown different levels of bioactive effects of the hybrid agaran isolated from V. lanosaand its potential application for nutraceutical related applications.