A method of treatment for treating, at least partly preventing, inhibiting or reducing tissue deterioration, injury or damage due to a periodontal disease or disease of oral mucosa, or for restoring tissue adversely affected by the disease, in a subject, and/or for downregulating NF-kappaB or suppressing NF-kappaB mediated action in a body, organ, tissue or cell, includes administering to a subject, body, organ, tissue or cell an effective amount of a composition including a peptide agent including at least one of Thymosin beta 4 (Tβ4), an isoform of Tβ4, an N-terminal fragment of Tβ4, a C-terminal fragment of Tβ4, Tβ4 sulfoxide, an LKKTET peptide or conservative variant thereof, an LKKTNT peptide or conservative variant thereof, a KLKKTET peptide or conservative variant thereof, an LKKTETQ peptide or conservative variant thereof, Tβ4ala, Tβ9, Tβ10, Tβ11, Tβ12, Tβ13, Tβ14, Tβ15, gelsolin, vitamin D binding protein (DBP), profilin, cofilin, depactin, DnaseI, vilin, fragmin, severin, capping protein, β-actinin, acumentin, an actin-sequestering peptide, an actin binding peptide, an actin-mobilizing peptide, an actin polymerization-modulating peptide, or a stimulating agent that stimulates production of an effective amount of the peptide agent in the subject, body, organ, tissue or cell.