Physiological Activities of the Neem and the Comfrey Extracts as Cosmetic Ingredients

Purpose: Recently, research and development on natural materials are actively carried out. It was conducted to confirm the applicability of Neem and Comfrey extracts as natural preservatives and cosmetic ingredients by investigating their antioxidative, antibacterial, and antifungal activities. Methods: Both Neem and Comfrey were extracted with 70% ethyl alcohol as samples, respectively. Their antibacterial and antifungal activities for antioxidative effect and against skin-related bacteria were confirmed by the Paper Disc method. Results: Both extracts were found to be highly effective in antioxidative effects, but the Comfrey extract showed higher total polyphenols and flavonoid content, stronger scavenging capability of 1,1-Diphenyl-2-picryhydrazyl (DPPH) and 2,2'-azino-bis-3-ehtylbenzothiazoline-6- sulfonic acid (ABTS) radicals as well as more robust superoxide dismutase (SOD) like activities than the Neem extract did. After measuring antibacterial and antifungal effects by the Neem and the Comfrey extracts against Staphylococcus epidermidis (S. epidermidis ), Staphylococcus aureus (S. aureus ), Propionibacterium acnes (P. acnes ), Corynebacterium xerosis (C. xerosis ), Pityrosporum ovale (P. ovale ), Malassezia furfur (M. furfur ), Candida albicans (C. albicans ), Trichophyton rubrum (T. rubrum) and Trichophyton mentagrophytes (T. mentagrophytes ), which are related to the skin, it was confirmed that the Neem extract treatment showed clear zones in all 9 bacteria at 5 mg/mL concentration and particularly, 8, 7, and 7 mm clear zones were observed from P. acnes, C. xerosis and T. mentagrophytes , respectively. The Comfrey extract treatment also showed clear zones in all 9 bacteria. Especially, it showed 10, 8, 8, 10, and 11 mm clear zones from P. acnes , C. xerosis , P. ovale , T. rubrum and T. mentagrophytes . From these results, it was confirmed that the Comfrey extract had higher antibacterial and antifungal effects than the Neem extract had, and therefore, both the Neem and Comfrey extracts have excellent antibacterial effects against P. acnes , C. xerosis , and T. mentagrophytes among various bacteria. Conclusion: The Neem and the Comfrey extracts had great antioxidative effects as well as antibacterial and antifungal effects against 9 different skin-related bacteria. Therefore, they can be considered to be useful as natural preservatives and cosmetic ingredients.