Phytochemicals in Skeletal Muscle Health: Effects of Curcumin (from Curcuma longa Linn) and Sulforaphane (from Brassicaceae) on Muscle Function, Recovery and Therapy of Muscle Atrophy

Abstract

The mobility of the human body depends on, among other things, muscle health, which can be affected by several situations, such as aging, increased oxidative stress, malnutrition, cancer, and the lack or excess of physical exercise, among others. Genetic, metabolic, hormonal, and nutritional factors are intricately involved in maintaining the balance that allows proper muscle function and fiber recovery; therefore, the breakdown of the balance among these elements can trigger muscle atrophy. The study from the nutrigenomic perspective of nutritional factors has drawn wide attention recently; one of these is the use of certain compounds derived from foods and plants known as phytochemicals, to which various biological activities have been described and attributed in terms of benefiting health in many respects. This work addresses the effect that the phytochemicals curcumin from Curcuma longa Linn and sulforaphane from Brassicaceae species have shown to exert on muscle function, recovery, and the prevention of muscle atrophy, and describes the impact on muscle health in general. In the same manner, there are future perspectives in research on novel compounds as potential agents in the prevention or treatment of medical conditions that affect muscle health.

Keywords: curcumin; phytochemicals; skeletal muscle; sulforaphane.

Figure 1

Curcumin chemical structure. (a) Ceto form. (b) Enol form. Created with BioRender.com.

Figure 2

Curcumin metabolites. (a) Curcumin-glucurunoside. (b) Dihydrocurcumin-glucurunoside. (c) Tetrahydrocurcumin-glucurunoside.

Figure 3

(a) Myofibril structure in healthy muscles. (b) Effects of curcumin on human skeletal muscle. Curcumin inhibits inflammation and muscle damage by hampering NF-kB and the proinflammatory interleukins TNF-α, IL-1β, and IL-6, as well as the proteasome complex system for protein muscle degradation integrated by ubiquitin ligases atrogin 1, muscle atrophy F-box (MAFbx), and muscle RING finger-1 (MUFR-1). Curcumin reduces oxidative-stress-enhancing antioxidant cell defenses and promotes anabolic signaling, myofibril integrity, mitochondrial function, and satellite cell commitment and recruitment for muscle repair. Created with BioRender.com.

Figure 4

Sulforaphane, basic chemical structure. Created with BioRender.com.

Figure 5

(a) Sulforaphane effects on Nrf2 signaling pathway. Sulforaphane promotes dissociation of Nrf2 from its negative regulator Keap1 leading to nuclear translocation and binding to the specific DNA sequence antioxidant response element (ARE) within small musculo-aponeurotic fibrosarcoma proteins (sMaf) inducing the antioxidant protein expression. (b) Effects of sulforaphane on skeletal muscle. Sulforaphane inhibits NF-κB inflammatory signaling and reduces muscle oxidative damage biomarkers such malonaldehyde (MDA), lactate dehydrogenase (LDH), and creatin phospho-kinase (CPK). Sulforaphane is capable of promoting mitochondrial biogenesis, improving aerobic endurance capacity, and enhancing satellite cell activation and proliferation. Created with BioRender.com.