Phellinus species is a mushroom used as traditional medicine in Eastern Asia. Research on Phellinus baumii (PB) is relatively limited; however, it has been reported to have antioxidant, DNA damage-protecting, immunostimulating, and antidiabetic activities. In our previous study on anti-inflammatory properties in lipopolysaccharide-stimulated RAW 264.7 cells and the various bioactive components of PB, we propose that PB could exert immune enhancing effects. Therefore, our current study aimed to investigate the immune-enhancing effect on immunosuppressed mice. Different concentrations of PB extract (0, 50, 100, 200, and 400 mg/kg body weight) were given to mice via oral gavage for 6 weeks accompanied by intraperitoneal cyclophosphamide administration to induce immunosuppression. A bone marrow micronucleus test was performed in mice to screen for potential genotoxic compounds. Splenocyte viability and proliferation, splenic and peritoneal natural killer cell activities, and hematological markers were then measured. Cytokines in the spleen and serum, as well as splenic mRNA levels of nuclear factor-κB; interferon-γ; tumor necrosis factor-α; and interleukin (IL)-1β, IL-6, and IL-12, were determined in mice. As a result, PB ameliorated T- and B-lymphocyte proliferation, splenic and peritoneal NK cell activities, bone marrow cells, hematological markers, cytokine levels, and T-lymphocyte numbers. Moreover, serum and spleen cytokine levels and mRNA expression were elevated in the PB groups compared to controls. Our results suggest that the PB extract can be used as a potent immunomodulator under immunosuppressive conditions. Thus, PB may be used as a potent biofunctional and pharmaceutical material to potentially enhance human immunity.

中文翻译：

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桑黄增强环磷酰胺诱导的免疫抑制小鼠的免疫反应

桑黄属一种蘑菇，在东亚用作传统药物。桑黄（PB）的研究相对有限；然而，据报道它具有抗氧化、DNA 损伤保护、免疫刺激和抗糖尿病活性。在我们之前对脂多糖刺激的 RAW 264.7 细胞的抗炎特性和 PB 的各种生物活性成分的研究中，我们提出 PB 可以发挥免疫增强作用。因此，我们目前的研究旨在研究对免疫抑制小鼠的免疫增强作用。不同浓度的 PB 提取物（0、50、100、200 和 400 mg/kg 体重）通过口服管饲法给予小鼠 6 周，同时腹腔注射环磷酰胺以诱导免疫抑制。在小鼠中进行骨髓微核试验以筛选潜在的基因毒性化合物。然后测量脾细胞活力和增殖、脾和腹膜自然杀伤细胞活性以及血液学标志物。脾脏和血清中的细胞因子，以及核因子-κB 的脾脏 mRNA 水平；干扰素-γ；肿瘤坏死因子-α；在小鼠中测定了白细胞介素 (IL)-1β、IL-6 和 IL-12。因此，PB 改善了 T 和 B 淋巴细胞增殖、脾脏和腹膜 NK 细胞活性、骨髓细胞、血液学标志物、细胞因子水平和 T 淋巴细胞数量。此外，与对照组相比，PB 组的血清和脾细胞因子水平以及 mRNA 表达升高。我们的结果表明，PB 提取物可在免疫抑制条件下用作有效的免疫调节剂。