Protective Effects of Biscoclaurine Alkaloids on Leukopenia Induced by 60Co- γ Radiation

Abstract

Objective: Leukopenia, a common complication of tumor chemoradiotherapy, contributes serious damage to the hematopoietic, gastrointestinal, and immune systems of the body and can cause delay, discontinuation, or even failure to tumor treatment, thereby greatly threatening human health. The present study aims to investigate the protective effects of biscoclaurine alkaloids (BA) on leukopenia.

Methods: This study was conducted on 60 Kunming mice, which were randomly divided into six groups containing 10 animals each. A hematology analyzer was used to count white blood cells (WBC) in the peripheral blood cell. Mice serum was collected, and the granulocyte-macrophage colony-stimulating factor, vascular cell adhesion molecule 1 (VCAM-1), and interferon-γ (IFN-γ) were detected by enzyme-linked immunosorbent assays. Pathological changes were detected through hematoxylin and eosin staining in the liver and spleen of mice. The spleen and liver ultrastructures were observed via electron microscopy.

Results: Results showed that BA ameliorated WBC, PLT reduction in the peripheral blood and significantly increased the levels of IFN-γ and VCAM-1 in mice serum. BA reduced ionizing radiation-induced injuries to spleen, mitigated the reduction of superoxide dismutase (SOD), and significantly decreased the malonaldehyde (MDA) and xanthine oxidase (XOD) levels in the liver.

Conclusion: BA enhanced the immune and hematopoietic functions and ameliorated the oxidative stress induced by ⁶⁰Co-γ radiation, revealing its therapeutic potential both as a radioprotector and as a radiation mitigator for leukopenia induced by ⁶⁰Co-γ radiation.

Figure 1

Animal treatments. Notes: Mice in the sham-IR group were given an oral gavage with the same volume of vehicle once a day from day −3 to day 15, and did not expose to ⁶⁰Co-γ radiation. IR + vehicle group received the same volume of vehicle by oral gavage once a day from day −3 to day 15, and exposed to ⁶⁰Co-γ radiation at day 0. The rhG-CSF group was exposed to the radiation at day 0 and was subcutaneously injected with rhG-CSF 1 h after the radiation, once a day for 7 days; and the group was given an oral gavage with the same volume of vehicle once a day from day −3 to day 0 and from day 7 to day 15. Mice in the BA group received multiple doses of BA by oral gavage, once a day, from day −3 to day 15. Vehicle: the same volume of 1% carboxymethyl cellulose, once a day, by oral gavage. BA: biscoclaurine alkaloids, at 5, 10, 20 mg/kg, once a day, by oral gavage. rhG-CSF: recombinant human G-CSF, at 100 μg/kg, once a day, by subcutaneous injection.

Figure 2

Effects of BA on peripheral WBC (leucocyte) in mice (mean ± SEM, n=10). Notes: (a) Peripheral WBC of mice at day −3. (b) Peripheral WBC of mice at day 3. (c) Peripheral WBC of mice at day 7. (d) Peripheral WBC of mice at day 15. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001 compared with the sham-IR group at the same time point; ^#P < 0.05 and ^##P < 0.01 compared with the IR + vehicle group at the same time point.

Figure 3

Effects of BA on peripheral Platelets in mice (mean ± SEM, n = 10). Notes: Peripheral PLT of mice at day 15. ^∗P < 0.05, ^∗∗P < 0.01, compared with the sham-IR group; ^#P < 0.05, ^##P < 0.01, compared with the IR + vehicle group.

Figure 4

Effects of BA on peripheral cytokines and cell adhesion molecules (mean ± SEM, n = 10). Notes: (a) Peripheral IFN-γ level. (b) Peripheral GM-CSF level. (c) Peripheral VCAM-1 level. ^∗P < 0.05 and ^∗∗P < 0.01 compared with the sham-IR group; ^#P < 0.05 and ^##P <  0.01 compared with the IR + vehicle group.

Figure 5

Effects of BA on spleen tissues of ⁶⁰Co-γ-irradiated mice stained with HE. (a) Sham + IR. (b) IR + vehicle. (c) rhG-CSF. (d) L-BA. (e) M-BA. (f) H-BA. Sections were stained with HE and viewed at a magnification of ×100. Green arrow: white pulp atrophy. Yellow arrow: red pulp myeloid cells proliferation. Blue arrow: vacuolation.

Figure 6

Effects of BA on the spleen ultrastructure. (a) Sham-IR. (b) IR + vehicle. (c) rhG-CSF. (d) L-BA. (e) M-BA. (f) H-BA. Sections were viewed at a magnification of ×30,000. Green arrow: mitochondrial with normal mitochondrial cristae and complete membrane. Red arrow: mitochondrial with swelling, vacuoles, or even degeneration. Blue arrow: chromatin condensation and margination.

Figure 7

Effects of BA on the antioxidant capacity of ⁶⁰Co-γ-irradiated mice (mean ± SEM, n = 10). Notes: (a) MDA level in mice liver. (b) SOD level in mice liver. (c) XOD level in mice liver. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001, compared with the sham-IR group; ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001, compared with the IR + vehicle group.

Figure 8

Effects of BA on liver tissues of ⁶⁰Co-γ-irradiated mice stained with HE. (a) sham + IR. (b) IR + vehicle. (c) rhG-CSF. (d) L-BA. (e) M-BA. (f) H-BA. Sections were stained with HE and viewed at a magnification of ×100. Green arrow: cellular swelling. Blue arrow: karyopyknosis.

Figure 9

Effects of BA on the liver ultrastructure. (a) Sham-IR. (b) IR + vehicle. (c) rhG-CSF. (d) L-BA. (e) M-BA. (f) H-BA. Sections were viewed at a magnification of ×30,000. Green arrow: mitochondrial with normal mitochondrial cristae and complete membrane. Yellow arrow: mitochondrial with swelling, vacuoles, or even degeneration. Red arrow: rough endoplasmic reticulum fracture. Blue arrow: normal rough endoplasmic reticulum.