Antioxidant and anti-aging effects of polysaccharides extracted from Camellia oleifera branches

Camellia oleifera Abel is extensively cultivated for edible oil, generating abundant leaves, shells, and branches as by-products. However, the bioactivity of polysaccharides from these different tissues remains poorly characterized. To valorize these agricultural wastes, six crude polysaccharides were extracted from the leaves, shells, and branches of C. oleifera using hot water extraction (HWE) and ultrasound-assisted hot water extraction (USHWE). Their physicochemical properties were compared, and in vitro anti-inflammatory effects were evaluated to identify the most promising fraction. The active polysaccharide was purified, and its in vivo anti-aging potential was investigated in Caenorhabditis elegans.

Physicochemical characterization revealed distinct structural and compositional differences among the six polysaccharides. Notably, the polysaccharide obtained from branches by HWE (HWE-Branch), which possessed a high total sugar content (35.35%), showed the most potent suppression of lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) and interleukin-1β (IL-1β) expression in RAW264.7 macrophages, exceeding the effect of dexamethasone. This fraction was purified to yield a homogeneous polysaccharide designated C. oleifera branch polysaccharide (CBP). In C. elegans, CBP extended lifespan in a concentration-dependent manner; at 4 mg mL^-1, the median lifespan increased by 32.6% compared with the control. Under cyclic heat stress, 4 mg mL^-1 CBP maintained 38.38% survival after four cycles, whereas all control nematodes died. Furthermore, CBP significantly reduced intracellular reactive oxygen species (ROS) and lipofuscin levels. At 4 mg mL^-1, ROS fluorescence intensity decreased from 48.84% to 21.79% and lipofuscin from 25.03% to 10.23%.

Purified C. oleifera branch polysaccharide CBP showed strong anti-aging effects in C. elegans by scavenging ROS, attenuating lipofuscin accumulation, and enhancing stress resistance. These findings indicate that CBP is a promising natural ingredient for anti-aging interventions and support the valorization of C. oleifera processing by-products. © 2026 Society of Chemical Industry.