Phytohemagglutinin P (PHA-P) is a naturally occurring lectin, the protein form of PHA.PHA is a selective T-cell mitogen that binds T-cell receptors and enhances HIV-1 replication.

Phytohemagglutinin P (1-10 μg/mL) significantly stimulated PBMC proliferation and induced the expression of multiple cytokines (e.g., IL-2, IFN-γ). Phytohemagglutinin P activity is concentration-dependent and effectively initiates T cell-mediated immune responses[1].

Phytohemagglutinin-P, administered intraperitoneally at doses of 25 and 50 mg/kg daily for 15 days to male Sprague-Dawley rats, resulted in a reduction of longitudinal bone growth, chondrocyte numbers, cartilage plate thickness, metaphyseal hard tissue mass, calcified cartilage core percentage, and osteoblast count per millimeter of bone surface. Furthermore, PHA-P elevated osteoclast quantity, osteoclastic nuclei labeling, and the average nuclei count per osteoclast [1].