# New Insights into Potential Anti-Aging Effects of a Dietary Supplement from Chlorella Growth Factor and γ-PGA in Aged SAMP8 Mice

## TL;DR

This study shows that combining CGF and γ-PGA dietary supplements improves aging-related decline in mice by reducing oxidative damage and enhancing cognitive and motor functions.

## Contribution

The study demonstrates the synergistic anti-aging effects of CGF and γ-PGA in SAMP8 mice for the first time.

## Key findings

- Combined CGF and γ-PGA supplementation significantly improved locomotor activity and cognitive function in aged SAMP8 mice.
- The combination treatment led to the greatest reduction in brain 8-OHDG levels, indicating reduced oxidative DNA damage.
- Long-term supplementation with CGF and γ-PGA protected against aging-related functional decline in SAMP8 mice.

## Abstract

This study aimed to investigate the combined efficacy and potential synergistic benefits of CGF and γ-PGA in SAMP8 mice. Specifically, we assessed behavioral and aging indices, cognitive performance, and brain levels of 8-OHDG to determine whether natural antioxidant supplementation could alleviate both molecular damage and functional impairment associated with aging. This integrative approach provides new insights into the role of combined nutritional strategies in promoting healthy aging.

Aging is closely associated with oxidative stress, which contributes to functional decline and increased vulnerability to neurodegenerative diseases. Natural antioxidants, such as Chlorella Growth Factor (CGF) and γ-polyglutamic acid (γ-PGA), possess antioxidant and anti-aging properties; however, their combined effects remain unknown. This study investigated the potential synergistic effects of CGF and γ-PGA supplementation in senescence-accelerated mouse-prone 8 (SAMP8) mice, a model characterized by early cognitive decline, locomotor deficits, and elevated oxidative DNA damage. Three-month-old male SAMP8 mice (n = 40) were divided into four groups: control, CGF (49.2 mg/kg BW/day), γ-PGA (20.5 mg/kg BW/day), and combined CGF + γ-PGA (69.7 mg/kg BW/day), and were treated for 13 weeks. Behavioral and physiological assessments included locomotor activity, aging index, and cognitive function (passive and active avoidance tests). Biochemical analysis focused on brain 8-hydroxy-2′-deoxyguanosine (8-OHDG) as a biomarker of oxidative DNA damage. Supplementation with CGF and γ-PGA, particularly in combination, significantly improved locomotor activity, aging scores, and cognitive functions. Notably, the combined treatment yielded the greatest reduction in brain 8-OHDG levels. These findings indicate that CGF and γ-PGA, when administered together, exert enhanced protective effects against functional and molecular aging. In conclusion, long-term supplementation with CGF and γ-PGA protects against aging-related decline in SAMP8 mice. This study highlights the potential of CGF and γ-PGA as safe, natural candidates for the development of functional foods or nutraceuticals aimed at promoting healthy aging and reducing oxidative stress-associated disorders.