Ginsenoside Rg1 Reduces Oxidative Stress Via Nrf2 Activation to Regulate Age-Related Mesenchymal Stem Cells Fate Switch Between Osteoblasts and Adipocytes.

Background: An important feature of aging cells is the gradual loss of physiological integrity. As aging progresses, MSCs change preferring to differentiate toward adipocytes rather than osteoblasts. Oxidative stress accumulation is an important factor in age-related bone loss. Many experiments have demonstrated the good therapeutic effect of Ginsenoside (Rg1) on oxidative stress injury. In this study, we investigated the effect of Rg1 on the osteogenic-adipogenic differentiation balance of bone marrow mesenchymal stem cells (BMMSC).

Objective: To analyze the potential application value of Rg1 in the treatment of senile osteoporosis.

Methods: BMMSCs were isolated from healthy donors of different ages and identified based on isotype and by multi-differentiation induction. Rg1 was used to treat BMMSCs, The differentiation propensity was analyzed by induction of differentiation assay. Antioxidant capacity of BMMSCs as measured by oxidative stress product assay Related mechanism studies were confirmed by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), immunofluorescence, western blotting, and inhibitor treatment. Moreover, Observation of the effects of Rg1 on aging BMMSCs under conditions by treatment of aged mice with Rg1 injections.

Results: Rg1 treatment rescued age-induced switch of BMMSCs differentiation fate in vitro. In elderly people, Rg1 markedly increased osteogenic differentiation of BMMSCs by decreasing oxidative stress, while inhibiting adipogenic differentiation. However, this effect was abolished in BMMSCs by an Nrf2-inhibitor. Notably, aging mice showed a reduction in adipocyte distribution in the bone marrow and a decrease in oxidative stress products after a 3-month period of Rg1 treatment.

Conclusion: We have uncovered a novel function for Rg1 that involves attenuating bone loss via Nrf2 antioxidant signaling, which in turn may potentially be utilized as a therapeutic agent for improving osteogenic differentiation in aging BMMSCs.