Acne vulgaris is a persistent inflammatory condition of the pilosebaceous unit, affecting 85% of people between the ages of 12 and 24, it is regarded as one of the most common diseases in teenagers and young adults.

Catestatin, a peptide derived from chromogranin A (CgA), was first discovered in 1997 as an acute nicotinic-cholinergic antagonist. Later, it was determined that CST is a pleiotropic hormone.

Acne vulgaris is a persistent inflammatory condition of the pilosebaceous unit, affecting 85% of people between the ages of 12 and 24, it is regarded as one of the most common diseases in teenagers and young adults.

Four factors are thought to be linked to the physiopathology of acne: changes in the keratinization process of corneocytes, which results in the development of comedones; follicular proliferation of the bacterium Cutibacterium acnes; increased production of inflammatory mediators, including interleukins (IL)-1β; and increased sebum production by the sebaceous gland.

The distinctive lesions can be classified as either inflammatory (papules, pustules, nodules, and cysts) or non-inflammatory (open/black and closed/white comedones). Both types of lesions cause skin pigmentation and scarring, which need consistent treatment. Lesions are usually found on the chest, upper back, neck, and face.

There are wide variety of topical and oral therapy methods can be used for acne treatment. Topical retinoids, benzoyl peroxide, azelaic acid, and their combinations are considered first-line agents. Oral drugs such as oral antibiotics, isotretinoin, or hormonal therapy may be used to treat refractory or more severe acne.

The most effective treatment for acne is still isotretinoin (13-cis-retinoic acid), an oral retinoid that was licensed in 1982 for the treatment of acne vulgaris. Multiple randomized controlled trials have confirmed that it is more effective than oral antibiotics and placebos at reducing the number of acne lesions.

Oral isotretinoin is the only medication that can cure or prolong remission of moderate to severe acne , avoiding scarring and psychological effects. isotretinoin reduces the size of sebaceous glands, lowers sebum excretion, regulates cell proliferation, decreases keratinization, and modifies the follicles' microenvironment , resulting in a decrease in the number of Cutibacterium acnes. Furthermore, it has immunomodulatory and anti-inflammatory qualities by lowering the expression of monocyte TLR-2, lowering the inflammatory cytokine response, and having anti-neoplastic effects.

Antimicrobial peptides (AMP) have a wide spectrum of antibacterial and immunomodulatory properties against bacteria (Gram positive and Gram negative), viruses and fungi.

Variations in AMP expression in the skin could play a significant role in the pathogenesis of numerous skin conditions, such as acne vulgaris.

Catestatin, a peptide derived from chromogranin A (CgA), was first discovered in 1997 as an acute nicotinic-cholinergic antagonist. Later, it was determined that CST is a pleiotropic hormone.

Catestatin (CST), a versatile 21 amino acid long cationic peptide, derived from the processing of chromogranin A, catestatin is produced by chromaffin cells and neutrophils , retained in chromaffin granules, and produced in the skin upon damage.

Catestatin affects innate immunity, inflammation, blood pressure regulation, and catecholamine inhibition.

Inclusion Criteria:

• Healthy persons of both sexes with moderate and severe acne.

Exclusion Criteria:

• Pregnant and lactating women.
• Immunocompromised patients.
• Severe anemia.
• History of chronic liver disease.
• Hyperlipidemia
• Non-inflammatory acne conditions.
• History of neurologic disorders.
• History of neoplastic disorders.
• History of cardiac disease.
• History of systemic acne treatment for at least 4 weeks prior to inclusion and no topical treatments for at least 2 weeks.
• Cases with known hypersensitivity reaction to isotretinoin.