Immunomodulatory and antitumor effects of shilajit and glycine: Natural metabolic modulators targeting breast and liver cancer

Table 2 Roles of glycine in cancer biology

Role	Pathway/target	Evidence	Implication
Metabolic substrate	One-carbon metabolism (SHMT, GLDC)	Supports nucleotide synthesis and methylation	Tumor proliferation, metabolic vulnerability
Redox defense	Glutathione synthesis	Maintains antioxidant pools	Protects normal cells; tumor paradox
Immunomodulation	Glycine receptor, NF-κB	Suppresses IL-6/IL-8, reduces inflammation	Mitigates therapy-induced toxicity
Tissue protection	Anti-fibrosis, ischemia-reperfusion	Prevents fibrosis, protects the liver/kidney	Beneficial in HCC and comorbidities
Tumor suppression	Anti-angiogenesis, apoptosis	Reduced metastasis in breast cancer models	Adjuvant potential

SHMT: Serine hydroxymethyltransferase; GLDC: Glycine decarboxylase; NF-κB: Nuclear factor-kappa B; HCC: Hepatocellular carcinoma; IL: Interleukin.