Anti-inflammatory latex proteins of the medicinal plant Calotropis procera: a promising alternative for oral mucositis treatment.

OBJECTIVE AND DESIGN: Oral mucositis (OM) is an intense inflammatory reaction progressing to tissue damage and ulceration. The medicinal uses of Calotropis procera are supported by anti-inflammatory capacity. PII-IAA, a highly homogenous cocktail of laticifer proteins (LP) prepared from the latex of C. procera, with recognized pharmacological properties was tested to treat OM. MATERIALS AND SUBJECTS: Male Golden Sirius hamsters were used in all treatments. TREATMENT: The latex protein samples were injected i.p. (5 mg/Kg) 24 h before mucositis induction (mechanical trauma) and 24 h later. METHODS: Histology, cytokine measurements [ELISA], and macroscopic evaluation [scores] were performed. RESULTS: PII-IAA eliminated OM, accompanied by total disappearance of myeloperoxidase activity and release of IL-1b, as well as reduced TNF-a. Oxidative stress was relieved by PII-IAA treatment, as revealed by MDA and GSH measurements. PII-IAA also reduced the expression of adhesion molecules (ICAM-1) and Iba-1, two important markers of inflammation, indicating modulatory effects. Histological analyses of the cheek epithelium revealed greater deposition of type I collagen fibers in animals given PII-IAA compared with the control group. This performance was only reached when LPPII was treated with iodoacetamide (IAA), an irreversible inhibitor of proteolytic activity of cysteine proteases. The endogenous proteolytic activity of LPPII induced adverse effects in animals. Candidate proteins involved in the phytomodulatory activity are proposed. CONCLUSIONS: Therapy was successful in treating OM with the laticifer protein fraction, containing peptidases and osmotin, from Calotropis procera. The effective candidate from the latex proteins for therapeutic use is PII-IAA.

Protein fraction of Calotropis procera latex protects against 5-fluorouracil-induced oral mucositis associated with downregulation of pivotal pro-inflammatory mediators.

Oral mucositis is an important dose-limiting and costly side effect of cancer chemotherapy. Soluble proteins obtained of the latex of Calotropis procera have been extensively characterized as anti-inflammatory in different experimentally induced inflammatory conditions, including arthritis and sepsis. In this study, the phytomodulatory laticifer proteins (LP) were challenged to regress the inflammatory events associated with 5-fluorouracil-induced oral mucositis. We also evaluated the expression of pro-inflammatory cytokines and inducible enzymes, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Oral mucositis was induced in hamsters by two injections of 5-fluorouracil (5-FU; 60 and 40 mg/kg, i.p., on experimental days 1 and 2, respectively). LP (5 mg/kg, i.p.) was injected 24 h before and 24 h after mechanical trauma of the cheek pouches. A normal control group received only saline. On day 10, the animals were sacrificed, and the cheek pouches were excised for macroscopic and histopathological analysis, myeloperoxidase activity measurement, and immunohistochemical assessment of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), iNOS, and COX-2. LP significantly inhibited macroscopic histopathological scores and myeloperoxidase activity compared with the 5-FU control group. 5-Fluorouracil also induced marked immunostaining of TNF-α, IL-1ß, iNOS, and COX-2 on inflamed conjunctive and epithelial tissue compared with the normal control group. Such damage was significantly inhibited (p < 0.05) by LP treatment compared with the 5-FU group. These findings demonstrate an anti-inflammatory effect of LP on 5-FU-induced oral mucositis. The protective mechanism appears to involve inhibition of the expression of iNOS, COX-2, TNF-α, and IL-1ß.