Phloretin either alone or in combination with duloxetine alleviates the STZ-induced diabetic neuropathy in rats

Diabetic neuropathy (DN) is one of most disabling disorder complicating diabetes mellites (DM), which affects more than 50% of the all diabetic patients during the disease course. Duloxetine (DX) is one of the first-line medication that approved by FDA for management of DN, nevertheless, it is too costly and has many adverse effects. Recently, phloretin (PH) exhibited powerful euglycemic, antihyperlipidemic, antioxidant, and anti-inflammatory activities. Therefore, we investigated the in vivo possible antineuropathic activity of phloretin, besides, its modulating effects on duloxetine potency, in a rat model of DN. Twelve-week-old male Wistar rats received a single intraperitoneal injection of 55 mg/kg STZ to induce DM. Either DX (30 or 15 mg/kg dissolved in distilled water), PH (50 0r 25 mg/kg dissolved in 0.5% DMSO) or a combination of 15 mg/kg DX and 25 mg/kg PH, used daily orally for 4 weeks to treat DN, starting from the end of the 4^th week of DM development, when DN confirmed. Our finding showed that both DX and PH dose-dependently improved behavioral parameters (with the superiority of DX), sciatic nerve tissue antioxidant state, and suppressed tissue inflammatory cytokine, besides, they abrogated the tissue histopathological changes (with the superiority of PH). Moreover, DX augmented the DM metabolic disturbance and hepatic dysfunction, however, PH effectively amended these disorders. Furthermore, the low-dose combination of both, had the merits of both medications, with the alleviation of their disadvantages. Therefore, phloretin could be a promising agent in the management of DN either alone or in combination with duloxetine.