Anti-inflammatory and analgesic effects of human placenta extract

In this study, we investigated the effects of human placenta extract (HPE, Laennec inj.) on pro-inflammatory cytokines and mediators secreted from lipopolysaccharide-stimulated RAW264.7 macrophages. We found that HPE significantly inhibited the production of nitric oxide, tumour necrosis factor-α and cyclooxygenase-2. We studied the anti-inflammatory and analgesic potential of HPE in murine models of inflammation/inflammatory pain. Rats were assigned to six groups and were administered either saline or HPE (0.33, 1, 3 and 6 mL kg⁻¹) intraperitoneally. Diclofenac was used as a positive control. HPE attenuated the swelling of the rat's hind paw. The vascular permeability induced by acetic acid was significantly reduced by HPE. HPE reduced the formation of granuloma in carrageenan air pouch and hind paw oedema in complete Freund's adjuvant-induced chronic arthritis in rats. HPE attenuated writhing episodes. An increase in hot-plate latency was observed in mice receiving HPE. HPE also increased the pain threshold in the Randall-Selitto test. In the tail-flick assay, HPE prolonged the reaction time of rats to radiant heat stimulation. These results suggest that HPE has potent anti-inflammatory and anti-nociceptive activities.