Long-term effects of photobiomodulation therapy on blood pressure in obese rats induced by a high-fat diet.

The main cardiovascular disease risk associated with obesity is hypertension. The therapeutic use of photobiomodulation therapy (PBM) is suggested for the treatment of wound healing, osteoarthritis, and arterial diseases. However, few studies have measured how red laser (at 660 nm) acts over hypertension, and any of those studies used experimental obesity model. The aim of the study was an attempt to evaluate the long-term effect of PBM on systolic blood pressure in an animal model of obesity, induced by a high-fat diet (HFD). Our results indicate that PBM carried out 3 days a week was able to prevent the increase in blood pressure (133.75 ± 4.82 mmHg, n = 8) induced by a high-fat diet (150.00 ± 4.57 mmHg, n = 8; p < 0.05), restore nitric oxide levels (control: 31.7 ± 5.5 µM, n = 8; HFD + PBM: 29.9 ± 3.7 µM, n = 8 > HFD: 22.2 ± 2.9 µM, n = 8, p < 0.05), decrease lipoperoxidation (control: 1.65 ± 0.25 nM, n = 8; HFD + PBM: 2.05 ± 0.55 nM, n = 8 < HFD: 3.20 ± 0.47 nM, n = 8; p < 0.05), and improve endothelial function (pD2 control: 7.39 ± 0.08, n = 8 > pD2 HFD + PBM: 7.15 ± 0.07, n = 8 > HFD: 6.94 ± 0.07, n = 8; p < 0.05). Our results indicate that PBM prevents the elevation of blood pressure in an obese animal model by a mechanism that involves improvement of endothelial function through an antioxidant effect.

Copper (II) and 2,2'-bipyridine complexation improves chemopreventive effects of naringenin against breast tumor cells.

Cancer is the second leading cause of death worldwide and there is epidemiological evidence that demonstrates this tendency is emerging. Naringenin (NGEN) is a trihydroxyflavanone that shows various biological effects such as antioxidant, anticancer, anti-inflammatory, and antiviral activities. It belongs to flavanone class, which represents flavonoids with a C6-C3-C6 skeleton. Flavonoids do not exhibit sufficient activity to be used for chemotherapy, however they can be chemically modified by complexation with metals such as copper (Cu) (II) for instance, in order to be applied for adjuvant therapy. This study investigated the effects of Cu(II) and 2,2'-bipyridine complexation with naringenin on MDA-MB-231 cells. We demonstrated that naringenin complexed with Cu(II) and 2,2'-bipyridine (NGENCuB) was more efficient inhibiting colony formation, proliferation and migration of MDA-MB-231 tumor cells, than naringenin (NGEN) itself. Furthermore, we verified that NGENCuB was more effective than NGEN inhibiting pro-MMP9 activity by zymography assays. Finally, through flow cytometry, we showed that NGENCuB is more efficient than NGEN inducing apoptosis in MDA-MB-231 cells. These results were confirmed by gene expression analysis in real time PCR. We observed that NGENCuB upregulated the expression of pro-apoptotic gene caspase-9, but did not change the expression of caspase-8 or anti-apoptotic gene Bcl-2. There are only few works investigating the effects of Cu(II) complexation with naringenin on tumor cells. To the best of our knowledge, this is the first work describing the effects of Cu(II) complexation of a flavonoid on MDA-MB-231 breast tumor cells.