Veterinary Research Forum

Abstract Pulmonary fibrosis (PF) is a chronic interstitial lung disease with a progressive damage to the air sacs and deposition of collagen fibers in the lung tissue. The study aimed to explore the effects of Nigella sativa oil (NSO) or thymoquinone (TQ), alone or in combination with dexamethasone (DEX), on the development of bleomycin (BLM)-induced PF. Forty-two male rats were divided into seven groups: Control (CTRL); BLM, received a single dose of BLM on day 0, intratracheally; all remaining groups received BLM, as well. DEX, received DEX daily, intraperitoneally, 1 day before BLM and continued for 14 days; NSO and TQ groups, received daily NSO and TQ, respectively, 7 days before BLM and continued for 35 days; DEX + TQ, received both DEX and TQ; DEX + NSO, received both DEX and NSO. At the end, lung tissues were used for histopathological and biochemical analyses. BLM significantly increased the severity of fibrosis and inflammation compared to the CTRL. Bleomycin also significantly increased the amount of hydroxyproline, however, decreased most antioxidant enzymes in the lung tissue compared to the other groups. Group TQ + DEX significantly reduced the severity of BLM-induced PF as well as alterations in biochemical parameters, lung weight and O2 saturation. Nigella sativa oil slightly reduced BLM-induced PF, however, it caused non-significant hyperemia in lung tissue. Thymoquinone potentiated the effects of DEX on most biochemical and pathological alterations of BLM-induced lung injury much better than NSO. More studies are needed to support the use of NSO and TQ as potential protective agents against PF.

Abstract In this study, the effects of separate and combined intraperitoneal (IP) injections of histidine and dexamethasone were investigated on local inflammation in rats. Local inflammation was induced by subcutaneous (SC) injection of histamine (100 μl, 0.1%) in ventral surface of right hind paw. The thickness of paw was measured at 30 min before and 30, 60, 90, 120, 150 and 180 min after injection of histamine, using a fine caliper. The number of neutrophils in paw tissue sections was counted 3 h after intraplantar (IPL) injection of histamine. The IPL injected histamine elicited an inflammatory response that was characterized by increase of paw thickness and by infiltration of neutrophils in paw tissues. IP injections of histidine at doses of 200 and 400 mg kg-1 and dexamethasone at a dose of 1 mg kg-1 significantly (P < 0.05) decreased both paw thickness and infiltration of neutrophils in paw tissues. In combined treatment, IP injection of histidine (200 mg kg-1) with dexamethasone (1 mg kg-1) produced a more documented response in comparison with histidine and dexamethasone used alone. The results suggested that histidine and dexamethasone have anti-inflammatory activities. Histidine potentiated the anti-inflammatory effect of dexamethasone in histamine-induced local inflammation.