Background Pneumoconiosis is a chronic inflammatory disease that cannot be completely cured. Therefore, how to control lung inflammation and delay of the body aging is one of the keys to treating pneumoconiosis. The studies in past two decades suggested that many small molecule drugs are able to enhance cardiopulmonary function.

Objective To explore the effects of homeopathic dosing and combined dosing of β-nicotinamide mononucleotide and taurine on experimental silicosis in rats.

Methods Seventy-two SD specific pathogen-free rats were randomized into 4 groups (18 mice in each group): negative control group (ultrapure water, without dust), positive control group, homeopathic treatment group, co-administered treatment group. One mL of quartz dust suspension was injected into the rat trachea by disposable non-exposed tracheal injection method (50 mg·mL⁻¹) to establish a rat silicosis model. Rats were administered by gavage since the 4th day after dust exposure. The homeopathic treatment group rats received taurine solution (0.03 g·mL⁻¹) in the morning and β-nicotinamide mononucleotide (0.03 g·mL⁻¹) in the afternoon; the co-administered treatment group rats received a mixed solution (0.015 g·mL⁻¹ β-nicotinamide mononucleotide + 0.015 g·mL⁻¹ taurine) twice, in the morning and afternoon respectively. The positive and negative control groups received equivalent of ultrapure water in the morning and afternoon. All groups of rats were administered 5 d a week for a total of 6 weeks. The rats were neutralized after 6 weeks of administration. Organ coefficient, lung hydroxyproline content, whole lung dry and wet weights, whole lung free silica content, and cell count and classification in lung lavage fluid were measured and calculated, and lung histopathological changes in lung samples were observed.

Results Compared with the positive control group, the whole lung wet weight, whole lung dry weight , total cell count, neutrophil rate, lung organ coefficient, lung hydroxyproline content, and whole lung free silica content were reduce in the homeopathic treatment group, and the co-administered treatment group (P＜0.05). Compared with the negative control group, the total cell count, neutrophil rate, lung organ coefficient, lung hydroxyproline content, and whole lung free silica content were elevated in the homeopathic treatment group and the co-administered treatment group, the whole lung dry weight was elevated in the co-administered treatment group, and those differences were all statistically significant (P＜0.05). The rat lung histopathological results showed that, in the positive control group, round or oval nodules were formed in the lung tissue, which were phagocytic cellular nodules, and the alveolar structures in some areas still existed. The histopathological changes in the homeopathic treatment group and the co-administered treatment group were similar to those of the positive group, but less severe. No pathological change was observed in the lung tissue of the negative control group.

Conclusion Some improvement and dust removal in experimental silicosis rats by homeopathic dosing and combined dosing of β-nicotinamide mononucleotide and taurine are observed.