Psoriasis is a common chronic skin condition affecting 125 million people globally (2-3% of the global population). This autoimmune disease is characterized by dry, itchy patches of the skin as a result of the rapid build up of cells – specifically hyperproliferation of keratinocytes.[1] Keratinocytes are the skin cells that make up the majority of the epidermis. They’re responsible for the simple, yet vital role of separating yourself from the environment. [2]   

We at SciZenna are always analyzing new research and have found two studies that specifically investigated the effects of topical black seed oil and it’s possible antipsoriatic properties. Black seeds (Nigella Sativa) and black seed oil have been described as having anti-inflammatory behavior – and the research is beginning to back it up.[1][3]

The first study, conducted by the JSS College of Pharmacy located in Ooty, India, examined the antipsoriatic activity of the ethanolic extract of Nigella Sativaon mice with psoriasis on their tails. The researchers split the mice up into three groups – the first group was left untreated, the second group was treated with a tazarotene gel (an expensive topical acne treatment), and the third group was treated with a 95% ethanolic extract of Nigella Sativaseeds. This treatment was applied once daily for fourteen days to the tails of the mice. Then, the tail skin was examined. The researchers looked for the degree of healthy skin differentiation – also known as the degree of orthokeratosis. The researchers found that the Nigella Sativa produced a significant degree of othokeratosis (71.36±2.64%) and was on par with the standard tazarotene gel (90.03±2.00%) – the control group did not fair as well with only 17.30±4.09% degree of orthokeratosis. Interestingly, the black seed treatment group had the most significant increase in relative epidermal thickness of ~113%. The researchers concluded that black seeds may need to be considered more seriously as a possible natural strategy to managing psoriasis due to its antipsoriatic activity shown in the study.[3]

In the second study, researchers from the Faculty of Medicine of Tanta University and Suez University – both located in Egypt, tested black seed oil against Imiquimod (IMQ)-induced psoriasis on the shaved backs of mice. IMQ-induced psoriasis is used as a model to generate psoriasis in a controlled setting, and was performed simply by applying a cream containing IMQ to the shaved backs of mice once daily for ten days. The researchers divided mice into three groups: Group 1 received a control treatment of just Vaseline, and no psoriasis-inducing IMQ cream, Group 2 received just the psoriasis-inducing IMQ cream, and Group 3 received the psoriasis-inducing IMQ cream as well as topically applied pure black seed oil – 5 mg/kg. The researchers monitored and quantified the onset of lesion growth over the course of the ten days using light and electron microscopy.[1]

The results confirmed the suspicions of the researchers. The control group had no inflammatory responses as expected, and Group 2 had the most severe inflammatory response – since this group only received the psoriasis-inducing cream. Group 3 however, had a significantly reduced inflammatory response – this was the group that received not only the psoriasis-inducing cream, but also the black seed oil topical treatment cream. Due to copyright we were unable to insert the graph depicting the inflammatory response as a function of time – however, the article depicts that not only was the initial onset of inflammation greatly reduced compared to no treatment, but the inflammation actually began to recede at the sixth day mark of treatment.[1]

Using a light microscope, the researchers examined skin samples from each group at 400x magnification and counted the number of inflammatory cells observed. The control had the lowest value of inflammatory cell infiltrate at 5.8±0.43 (this group only received Vaseline) and Group 3 had the highest value of inflammatory cell infiltrate at 143.25±6.76 (this group received only the psoriasis-inducing cream). This confirmed that the psoriasis-inducing IMQ cream was increasing inflammatory cell proliferation. However, Group 2, the group that was treated with the psoriasis-inducing IMQ cream as well as black seed oil only had an inflammatory cell infiltrate value of 7.4±1.23, that’s a 94.8% decrease in inflammatory cell proliferation compared to the group that received only the psoriasis-inducing IMQ cream.[1] This clearly indicates that the black seed oil is suppressing the inflammatory response caused by the psoriasis-inducing IMQ cream.    

The researchers concluded “that the oil ofN. Sativa is capable of suppressing the hyperproliferation and abnormal differentiation of keratinocytes and that black seed oil can be used as an adjuvant topical therapy for the treatment of psoriasis.”[1] The hypothesis for why black seed oil and psoriasis are interactive is due to the main active component within black seed oil – thymoquinone. The researchers propose that thymoquinone, based on historical research, has been known to have antioxidant behavior and may be inhibiting certain inflammatory pathways. The researchers also refer to the first study within this post, stating that the effects black seed oil have on proper epidermal cell differentiation also plays a significant role.[1] 

Although these two articles are restricted to mice, the results are promising. Further research is needed to draw any definite conclusions, however there’s clearly a trend forming that black seed oil and epidermal health can be a synergistic relationship.