Antibacterial and antioxidant strategies for acne treatment through plant extracts

Abstract

Acne vulgaris is a chronic skin infection affecting the majority of Indian population. There are several internal and external factors responsible for this infection. The present study emphasizes on screening of medicinal plant extracts against acne causing bacteria and antioxidant activity of these plant extracts. Anti-bacterial activities of methanolic extracts of Rosmarinus officinalis, Pelargonium asperum, Ocimum tenuiflorum, Acacia nilotica, Azadirachta indica, Matricaria chamomilla and Calendula officinalis was carried out using agar well diffusion method against Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus aureus (ATCC 2079), Kocuria sp. (NCBI: Kocuria KM24375), Bacillus subtilis (MTCC 736) and Propionibacterium acnes (ATCC 11827). The results revealed that different plant extracts showed noticeable activity against different test organisms. The plant extracts of R. officinalis, M. Chamomilla and A. nilotica showed significant activity against P. acnes with diameter of 8 mm, 6 mm and 4 mm inhibition zone respectively. The minimum inhibition concentration (MIC) was measured for these three potential plant extracts. The MIC values of extracts of R. officinalis, M. Chamomilla were comparable to standard reference drugs isotretinoin. Since antioxidants also play an important role in the pathophysiology of acne, anti-oxidant activity of plant extracts was also carried out using 1, 1-diphenyl-2-picryl hydrazyl (DPPH) method. Ascorbic acid was used as a standard in anti-oxidant activity assay. The extracts of R. officinalis, A. nilotica and A. indica also exhibited moderate antioxidant activity with IC50 value of 109.3, 136.9 and 108 μg/ml, respectively. The outcome of the study suggested that R. officinalis, M. chamomilla and A. nilotica plant extracts could be possible to use as the natural anti-acne formulations.