Depending on inclusion and exclusion criteria total 40 patients of palmer arsenical keratosis patients (both male and female; age range 18- 60 years) will be recruited from an arsenic affected area. Study population will be divided randomly into two equal groups: one group will receive vitamin E capsules (200 mg) plus placebo and another group will receive vitamin E capsule plus N. sativa capsules (500 mg) twice daily for 12 weeks. Drinking water (50 mL) and urine (50 mL) samples will be collected before starting the study and estimate the amount of total arsenic in order to confirm the diagnosis. Nail (approx. 1 g) and blood (5 mL) samples will be collected both before and completion of the study to see the efficacy and safety of the drug. Clinical examinations will be done at regular interval (two weeks). Clinical features and adverse effects will be recorded using a structured data collection sheet. Plasma cholesterol, vitamin E, and total antioxidant, serum transaminase, billirubin, creatinine levels and arsenic level in nail will be measured to evaluate the effectiveness of N. sativa on palmer arsenical keratosis patients