Thymoquinone as an add-on Therapy for the Management of Patients With Diabetic Peripheral Neuropathy

The goal of this clinical trial is to evaluate the efficacy of thymoquinone as an adjuvant treatment with pregabalin in the management of diabetic peripheral neuropathy for both sexes older than 18 years. The main questions it aims to answer are: * Whether the use of thymoquinone could improve diabetic neuropathy and be confirmed by a nerve conduction study? * Could thymoquinone improve oxidative stress and inflammation by using these parameters (visfatin, calprotectin, malondialdehyde)? * Does thymoquinone improve neuropathic pain by using the VAS scale for pain?