Radioprotection of mice by lactoferrin against irradiation with sublethal X-rays

Abstract

The influence of a host defense protein, lactoferrin (LF), contained in exocrine secretions such as milk, on radiation disorder was investigated. A total of 25 C3H/He mice in each of two groups were maintained with 0.1% LF-added and LF-free diets, respectively, for one month. The mice were then treated with single whole-body X-ray irradiation at a sublethal dose (6.8 Gy), and the survival rate after irradiation was investigated. The survival rate at 30 d after irradiation was relatively higher in the LF group than in the control group (LF-free), (85 and 62%, respectively). The body weight 15 d after X-ray irradiation was also significantly greater in the LF group than in the control group. The hemoglobin level and hematocrit value were higher in the LF group at 5 d before X-ray irradiation. Another 52 mice underwent whole-body X-ray irradiation at the sublethal dose (6.8 Gy), and then LF was intraperitoneally injected once at 4 mg/animal to half of them. The survival rate in LF-treated mice 30 d after irradiation was 92%, significantly higher than in mice treated with saline (50%) (P = 0.0012). In addition, LF showed hydroxyl radical scavenger activity in vitro. These findings suggest that LF may inhibit radiation damage.

Exploring the oncoproteomic response of human prostate cancer to therapeutic radiation using data‐independent acquisition (DIA) mass spectrometry

“…Other proteins with significant differential abundances have been previously determined to be radiation-responsive (in some cases radioprotective), including Ras GTPase-activating-like protein IQGAP2, 26 Lactotransferrin, 27 Serpin Family H Member 1/Hsp47, 28 and Ferrodoxin Reductase. 29 Statistical identification of radiation-response proteins also recapitulated several putative protein drivers of radiation resistance recently discovered in in vitro models of prostate cancer.…”

Identification of the protective mechanisms of Lactoferrin in the irradiated salivary gland

“…Previous studies have shown that LF has radioprotective effects 18 . The direct additional effects of LF on SMGs were analyzed after irradiation of the organ culture.…”

“…Previous studies have shown that LF has radioprotection effects only for lethality 18 , but the detailed mechanism of these effects is unclear. We cultured E12.5 SMGs for 24 h and then added 0.1 mg/ml LF to the culture for 48 h (Fig.…”

“…Recently, LF has been shown to have radioprotective effects 18 , but the mechanisms for this activity have not been determined. In the present study, we investigated the effects of LF in sublethal irradiation studies on cell proliferation, cell signaling pathways, and alteration of the cell-cycle using both ex vivo submandibular salivary gland (SMG) organ culture and salivary glands in vivo .…”

Salivary lactoferrin is transferred into the brain via the sublingual route

“…LF has various functions including infection defense, 2) antiinflammatory, 3) antioxidant, 4) visceral fat-reduction, 5) and anti-cancer effects; 6) and protection from the effects of radiation. 7) LF passes through the blood-brain barrier, [8][9][10] ; for example, peripheral administration of LF has been shown to decrease stress-induced anxiety by activating the μ-opioid receptor. 1) The salivary glands play an important role in the maintenance of homeostasis in the oral cavity by secreting various substances such as epidermal growth factor (EGF) 11) and brain-derived neurotrophic factor 12) as well as antimicrobial substances such as LF.…”