Diabetes is one of the main health care problemsworldwide with 5% average increased number of cases every year. According to International Diabetes Federation the prevalence of people with diabetes reached the number of 425 million people in 2017 and estimated rising to 628 million by 2045. Painful Diabetic Neuropathy (PDN) is the most common complication of diabetes affecting 90% of the patients. The symptoms of PDN include numbness, burning, stabbing pain, paraesthesia or hyperesthesiaof both symmetrical limbthat could reduce the quality of life. Several studies have found several therapeutic options to cope with pain in the PDN, but the results are not as satisfactory due to the uncertain pathophysiology of the disease and the limitations of the drug that can be administered because of itspolypharmaceutical side effects. The causes of diabetic neuropathy not only include vascular and metabolic factors but also Reactive Oxygen Species.

There are several therapeutic options that can be administered such as glycemic index arrangement,foot care, symptomatic treatment, and predominantly pain therapy. According to guidelines, there are drugs therapy thatrecommended for PDN, among others, Gabapentin, Pregabalin and anticonvulsants until the pain subsides. Unfortunately, this treatment is only aimed at relieving the symptoms of existing pain but not working on existing pathophysiological mechanisms and fixing sensory deficits of neuropathy trials. Multi-target treatments is needed to attenuate neuronal inflammation, oxidative stress and apoptosis. Additional therapy can be an option to support healing and also the process of metabolic pathophysiology that occurs due to rising glycemic index in the body that causes the work of hexosamine pathway and trigger the formation of ROS and inflammation. There is evidence of research demonstrating the neuroprotective effects of Astaxanthin as oxidative, anti-inflammatory and anti-apoptotic agent. Not only that, Astaxanthin is also a good supplement addition with no toxic effects when consumed, as well as hydrophilic and also lipophilic nature which makes Astaxanthin can penetrate the BBB effectively.

Detailed Description:

This was randomized clinical trial, active comparator, open label, controlled study from the period of November 2020 - November 2021 at Bethesda Hospital, Yogyakarta, Indonesia.

There were 60 painful diabetic neuropathy patients who fulfilled the inclusion and exclusion criteria. Each subject had been followed up from the first day of medication administration until 8 weeks after medication administration.

Ethical approval number ((kosong)) was obtained from Health Research Ethics Committee, Bethesda Hospital Yogyakarta.

The hypothesis of this study:

a. Add on oral astaxanthin to standard treatment in patients with painful diabetic neuropathy is more effective in reducing pain and neuropathic symptoms in 8 weeks of treatment compared with standard treatment, b. Add on oral astaxanthin to standard treatment in patients with painful diabetic neuropathy is as safe as standard treatment.

Inclusion Criteria:

• Male or female
• Adult age (>18 years old)
• Diagnosed as painful diabetic neuropathy based on validated Diabetic Neuropathy Symptoms (DNS) and Diabetic Neuropathy Examination (DNE)

Exclusion Criteria:

• Subjects with significant renal and liver problem
• Subjects with known hypersensitivity to astaxanthin
• Pregnancy and breastfeeding patients
• Patients that enrolled any clinical trial within a month
• Not competent enough in giving approval and answering questionnaires

Open label