Long-term treatment with royal jelly improves bleomycin-induced pulmonary fibrosis in rats

Abstract

This study investigated the anti-fibrotic potential of royal jelly (RJ) powder against bleomycin-induced pulmonary fibrosis in rats. The rats were given RJ orally (25, 50, and 100 mg/kg per day) for 7 consecutive days before the administration of single intratracheal instillation of bleomycin (BLM) at 7.5 IU/kg. RJ doses were continued for 21 days after BLM exposure. Fibrotic changes in the lungs were studied by cell count and analysis of cytokine levels in the bronchoalveolar lavage fluid (BALF), histopathological examination, and assaying oxidative stress biomarkers in lung tissue. The results showed that BLM administration significantly increased the fibrotic changes, collagen content, and levels of malondialdehyde and decreased total thiol and glutathione peroxidase antioxidant contents in the rats' lung tissue. An increase in the level of cell counts and pro-inflammatory and pro-fibrotic cytokines such as TNF-α and TGF-β in BALF was observed. Also, it significantly decreased IFN-γ, an anti-fibrotic cytokine, in BALF. However, RJ (50 and 100 mg/kg) reversed all of these biochemical indices as well as histopathological alterations induced by BLM. The present study demonstrates that RJ, by its antioxidant and anti-inflammatory properties, attenuates oxidative damage and fibrosis induced by BLM.

Anti-Cancer and Protective Effects of Royal Jelly for Therapy-Induced Toxicities in Malignancies

“…Pulmonary fibrosis, one of the most severe adverse events in patients treated with bleomycin (BLM), is associated not only with a reduced QOL but with lethal respiratory discomfort. In rats, cell count and content of pro-inflammatory and pro-fibrotic cytokines in the bronchoalveolar lavage fluid (BALF) were increased by the administration of an intra-tracheal instillation of BLM (7.5 IU/kg); however, such pathological increases were reversed by the oral administration of RJ (50 and 100 mg/kg) for 7 days consecutively prior to BLM administration [ 43 ]. In addition to such biochemical markers, they also reported that RJ suppressed histological alterations induced by BLM [ 43 ].…”

“…In rats, cell count and content of pro-inflammatory and pro-fibrotic cytokines in the bronchoalveolar lavage fluid (BALF) were increased by the administration of an intra-tracheal instillation of BLM (7.5 IU/kg); however, such pathological increases were reversed by the oral administration of RJ (50 and 100 mg/kg) for 7 days consecutively prior to BLM administration [ 43 ]. In addition to such biochemical markers, they also reported that RJ suppressed histological alterations induced by BLM [ 43 ]. Unfortunately, there is little information on the anti-fibrotic effects of RJ or other components in bee honey in BLM-induced pulmonary fibrosis.…”

“…Other investigators also showed similar significant changes in GSH and MDA levels in the kidney tissues of mice [ 66 ]. Furthermore, it was also reported that RJ decreased the tissue content of MDA, which was increased by an anti-cancer agent, in the lung tissue of rats treated with bleomycin [ 43 ]. The GSH-Px level in the prostate was significantly higher in rats administered with cyclophosphamide and RJ than those administered cyclophosphamide only [ 51 ] and similar findings was also reported in the lung of rats treated with bleomycin [ 43 ].…”

“…Furthermore, it was also reported that RJ decreased the tissue content of MDA, which was increased by an anti-cancer agent, in the lung tissue of rats treated with bleomycin [ 43 ]. The GSH-Px level in the prostate was significantly higher in rats administered with cyclophosphamide and RJ than those administered cyclophosphamide only [ 51 ] and similar findings was also reported in the lung of rats treated with bleomycin [ 43 ]. In rats treated by MTX, the plasma MDA levels in the MTX and RJ-treated group were significantly lower than those in the MTX-treated group and the plasma levels of SOD and GSH-Px in the MTX and RJ-treated group were higher than those in MTX-treated group [ 52 ].…”

Royal jelly: a natural therapeutic?

“…In a study on immunodeficient mice, 1% RJ consumption resulted with significant regulation of cytokine release and T, B cell reponses [62]. An interesting recent study indicated that long-term RJ consumption caused strong reduction in pulmonary fibrosis and suppression in proinflammatory cytokines and IFNγ [63]. These immunoregulatory activities caused a questionnaire whether RJ may be a solution to autoinflammatory diseases.…”