Assessment of the Anti-Acne Properties of Some Medicinal Plants and Development of an Herbal Anti-Acne Formulation

<b>Background</b>: Acne is a prevalent dermatological condition characterized by the blockage of hair follicles and sebaceous glands, leading to the formation of acne. The anaerobe pathogen <i>Cutibacterium acnes</i> (formerly known as <i>Propionibacterium acnes</i>) plays an essential role in the pathogenesis of acne, for which generally antimicrobial treatment is required. Acne is a substantial health concern, and continuing research is being conducted to discover novel and efficacious remedies. The antimicrobial activity of plants has been demonstrated in numerous studies, and they are still targeted organisms in drug development. Studies showing that plants are effective against acne pathogens have also been reported. <b>Methods</b>: The antimicrobial activity of the hydroethanolic extracts prepared from 30 plant species was determined against <i>C. acnes</i> standard strains (<i>C. acnes</i> Scholz and Kilian ATCC 11827 and ATCC 11828) and 30 clinical isolates in our preliminary screening. Since acne is an inflammatory skin disease, the anti-inflammatory effect of six active extracts against <i>C. acnes</i> was determined through the in vitro inhibition of collagenase, lipoxygenase (LOX), hyaluronidase and xanthine oxidase (XO) enzymes. <b>Results</b>: <i>Cotinus coggygria</i> Scop. leaf extract displayed the highest hyaluronidase and collagenase inhibition (79.75% and 52.52%, respectively), while the extract from the aerial parts of <i>Helichrysum arenarium</i> (L.) Moench demonstrated a potent XO inhibitory effect (82.51%). Therefore, these two extracts have been chosen for further studies, and LC/MS-MS was used to determine the phenolic profiles of these extracts. <b>Conclusions</b>: Subsequently, nanoemulgels were formulated with the active extracts to develop a prototype herbal anti-acne product, and characterization studies of the formulations were conducted.