Curcumin's protective role against fluoride-induced bone damage: Implications for pullet pathology and skeletal biomechanics

Abstract

This study aimed to investigate the effects of dietary fluoride (F) and curcumin (Cur) supplementation on the tibial biomechanical performance, histopathology, and behavior of pullets. Four dietary F levels (0, 400, 800, 1200 mg/kg) supplemented with CUR (0, 200 mg/kg) were used to create 8 experimental groups in Hyline Brown pullets. Behavioral study results showed that supplements of 1200 mg/kg F reduced the percentages of feeding, walking, standing, and preening behaviors while increasing the percentage of lying behavior (P < 0.05). This is associated with F-induced tibial elastic modulus, maximum stress, and stiffness coefficient were reduced and toughness coefficient was increased (P < 0.05). F-induced tibial cortical bone thickened, trabecular bone widened, and excessive accumulation of bone collagen fibers (P < 0.05) in the tibia explained the biomechanical properties reduction in Hyline Brown pullets. Additionally, the loss of antioxidant capacity was mediated by excessive F-accelerated pathological damage to the bone (P < 0.05). Supplementation with 200 mg/kg CUR alleviated abnormal behavior, expansion of the trabecular bone, accumulation of collagen fibers, and loss of antioxidant capacity (P < 0.05). In conclusion, F reduced the antioxidant level of the body, caused tibia histopathological damage, destroyed the tibia biomechanical properties, and caused abnormal behavior of pullets. Supplementation with 200 mg/kg CUR attenuates F-induced oxidative and tibia damage and rectifies abnormal behavioral traits.

Keywords: Antioxidants; Behavior; Histopathology; Skeletal biomechanics; Skeletal fluorosis.

Graphical abstract

Fig. 1

Effects of F exposure on claw and bone structure. (A) X-ray diffraction analysis of the claw of pullets. Optical (left) and X-ray (right) image of pullets’ claw. Red arrows represent abnormal claws. (B) X-ray diffraction analysis of the claw of pullets. (C) The average area of bone trabecular analysis in HE staining. Data were shown as mean ± SEM (n = 6). Black arrows represent normal osteocytes. Red arrows represent porous structures in the bone cortex. Blue arrows represent cracks in the trabecular bone. ^a-c Means with different letters in the column are significantly different (P < 0.05).

Fig. 2

F exposure induced bone cortical and trabecular alterations. (A) HE staining image of tibia sections for bone cortical and trabecular. Yellow arrows represented the pores of bone cortical. Black arrows represented the damaged bone trabecular. (B) Bone cortical thickness analysis in HE staining. (C) Tibia fluoride content analysis. (D) The average area of bone trabecular analysis in HE staining. Data were shown as mean ± SEM (n = 6). ^a–d Means with different letters in the column are significantly different (P < 0.05).

Fig. 3

F exposure induced collagen fibers of the tibia. (A) Masson staining image of tibia sections for collagen fibers of tibia. (B) collagen fibers area percentage of tibia analysis in Masson staining. Data were shown as mean ± SEM (n = 6). ^a–fMeans with different letters in the column are significantly different (P < 0.05).

Fig. 4

Correlation analysis between locomotor behavior and tibia biomechanics. Colors are correlation coefficients, correlations with false discovery rate corrected P < 0.05 are indicated with a star.