Comparing the relative changes of the STAT3 gene in the lung tissue of Wistar rats through the swimming training illustrated no considerable difference compared to the control group. The findings of the current research showed that the implementation of aerobic swimming exercises does not cause a significant difference in the relative changes of the STAT3 gene in the lung tissue of the trained rats. Regarding the swimming training, it has been well-known that swimming offers protection against exercise-induced bronchoconstriction (EIB) primarily due to the warm and humid air found in indoor pools. This reduces the cold, dry air exposure that typically triggers EIB in other sports. Furthermore, swimming recruits actively and strengthens the respiratory muscles and improves the elasticity of the chest wall, contributing to superior long-term lung function (
20). Moreover, several studies have illustrated that a 12-week aerobic program, such as submaximal swimming, bolsters respiratory muscle strength (like the diaphragm), boosting oxygen efficiency and reducing breathlessness. This approach is highly effective for improving function and quality of life in chronic conditions like chronic obstructive pulmonary disease (COPD) and asthma (
21-
23).
Research investigating the immediate impact of physical activity on healthy tissues has shown that skeletal muscle produces cytokines, specifically IL-6 as a myokine, which in turn stimulates STAT3 phosphorylation and its activity. It has been reported that acute aerobic exercise, by increasing myokines and activating the IL-6-STAT3 signaling pathway, contributes to the improvement of damaged peripheral nerves (
24). It was also revealed that increased activity of the IL-6-STAT3 signaling pathway caused muscle hypertrophy in rats as a result of resistance training (
25). The difference in the findings of this research and the above findings can be related to the type of exercises performed in the two studies. In this case, Ashour et al. (
24) investigated the role of IL-6 and the STAT3 pathway in peripheral nerve injury (PNI) and the effect of exercise on nerve regeneration. They demonstrated that the combination of pre- and post-conditioning exercise showed better results than post-conditioning alone and concluded that exercise-induced IL-6 is valuable for nerve regeneration, and the IL-6/STAT3 pathway could be a therapeutic target for PNI (
24). Furthermore, it has been illustrated that a single bout of exercise rapidly increased IL-6 and SOCS3 mRNAs alongside STAT1 and STAT3 phosphorylation, upregulating CyclinD1 and cMyc while downregulating MyoD and Myf5 (
26). The second point is that the STAT3 pathway's activation is determined by the cytokine source. Since intense exercise activates STAT3 and can alter neutrophil genes, the resulting tissue damage may mimic a pathological inflammatory state, overriding the muscle's metabolic signaling. Therefore, pathological conditions in the tissue lead to an increase in this signaling pathway (
27).
Regarding the exercise intervention, submaximal swimming (training + NNK) significantly decreased STAT3 gene expression in NNK-exposed rat lungs compared to NNK alone. Adding the supplement did not further enhance this STAT3 reduction. Thus, the study concludes that 12 weeks of swimming has an anti-inflammatory role by reducing STAT3 gene expression, suggesting low-intensity aerobic exercise may suppress the JAK-STAT3 pathway. Low-intensity aerobic exercise can be effective in reducing the asthma phenotype by changing the JAK-STAT signaling pathway in the airway epithelium (
28). Hence, the JAK-STAT3 signaling pathway, which is activated by inflammation and increased IL-6 through macrophages, can be reduced through endurance exercise (
29). The comparison of 60 minutes of swimming and running training in chronic kidney inflammation showed that the activity of the STAT3 oncogene is downregulated in both types of training. Although no significant difference was seen between the type of exercise and STAT3 reduction (
30). On the other hand, it was shown in research that the number of nodules and abnormal hyperplastic cells in the lungs of rats in the group of aerobic and anaerobic exercises following the urethane carcinogen was significantly lower than the control group (
31).
On the other hand, black seed nanocapsules (NNK + supplement) significantly decreased STAT3 phosphorylation in rat lung tissue exposed to NNK. However, exercise intervention (NNK + exercise + supplement) did not result in a statistically greater STAT3 reduction. In line with the findings of this research, some investigators demonstrated in their research that in allergic lung inflammation and rheumatoid arthritis, black seed and its components can improve the complications of these chronic conditions by blocking and suppressing pro-inflammatory factors (
32,
33). Based on this, black seed nanocapsules can reduce STAT3 phosphorylation via IL-6 reduction. It also uses pathways like p53, MAPK, and PPARγ for its anti-tumor effects (
34). Also, as a transcription factor, NF-κB can play a decisive role in various stages of tumor formation, including initiation, progression, invasion, and metastasis by forming chronic inflammatory responses (
35). The activation of NF-κB by nicotine and NNK has been reported in lung cancer cells (
36). In this regard, some reports show that the decrease in STAT3 phosphorylation due to black seed can be associated with the decrease in NF-κB activity (
37). Because STAT3 can also maintain NF-κB (
38). Therefore, it is possible that black seed nanocapsules combined with swimming effectively inhibit STAT3, linking NF-κB suppression to anti-inflammatory effects. In this regard, Sheikhnia et al. showed in a research that the combination of bortezomib with the use of TQ (the main component of black seed) inhibits NF-κB and STAT3 signaling in cancer cells by inhibiting proteasomes (
39).
Moreover, it has been reported that black seed nanocapsules reduce STAT3 phosphorylation, possibly by inhibiting JAK kinases in cancer cells (
39). Black seed nanocapsules may reduce STAT3 phosphorylation by lowering pro-inflammatory cytokines. Inhibiting STAT3 also downregulates anti-apoptosis genes like MCL-1 in cancer cells (
40). Protein blocker of activated STAT (PIAS) is another mechanism that inhibits STAT3 through black seed. These blockers specifically interact with the activated STAT3 and, as a result, inhibit the activity of STAT3 through DNA binding and prevent the expression and induction of the STAT3 gene (
41). Consequently, combining submaximal exercise and black seed nanocapsules helps counteract NNK carcinogens and inflammation via STAT3. This study's primary strength lies in its novel combinatorial approach, simultaneously investigating the effects of endurance exercise (swimming) and a specific nutritional supplement (black seed nanocapsules) on a crucial carcinogenic pathway. Using the NNK carcinogen provides a relevant model for tobacco-related lung cancer, and the inclusion of 8 comprehensive groups allowed for robust comparisons to isolate the specific effects of the training and the supplement. Furthermore, the use of nanocapsules represents a modern, targeted delivery strategy. However, a key limitation is the reliance on STAT3 gene expression as a surrogate marker. While significant, the 12-week duration is insufficient to observe long-term clinical endpoints, such as tumor count or overall survival, limiting direct translational certainty. Future studies must be of longer duration to assess these true carcinogenic outcomes. Additionally, the analysis of secondary morphological outcomes (e.g., lung weight) was descriptive; future research should include inferential statistics for these measures and expand to investigate other complementary inflammatory markers and signaling pathways to fully elucidate the mechanism of action. Finally, findings from the Wistar rat model require confirmation in human clinical trials.
5.1. Conclusions
The results of the present research generally show the effect of submaximal endurance activities and black seed nanocapsules against transcriptional message activator-3, which increases due to environmental carcinogens in the tissue environment, and training and black seed nanocapsule supplementation can partially inhibit this. The invoice should be transcribed. Based on this, regular exercise and natural supplements such as black seed nanocapsules can be mentioned as anti-inflammatory factors against all types of carcinogens. Also, supplements can have such anti-inflammatory properties that they can be used in appropriate doses and for a long time. The findings of this research state that regular aerobic exercise with black seed nanocapsules can be used as a complementary treatment method along with other lung cancer treatment methods; however, more studies are needed to better understand the molecular and cellular mechanisms involved in the beneficial effects of various types of exercise and supplements on lung tissue in lung cancer.