Efficacy and Safety of Using Rhinacanthus nasutus Root Extract Gel Containing 0.2% Rhinacanthin C in Dermatophytosis Patients
Keywords:
Dermatophytosis, Tinea, Rhinacanthus nasutus root extract gel, 0.2% rhinacanthin C (w/w), Clinical TrialAbstract
Rhinacanthus nasutus (L.) Kurz has potential for the treatment of skin diseases such as dermatophytosis, tinea versicolor, and eczema. The primary bioactive compound in R. nasutus is rhinacanthin C, which exhibits strong antifungal activity and is present in high amounts in the root part. Based on its potential biological activities, R. nasutus root extract gel with a standardized rhinacanthin C content was developed for the treatment of fungal skin infections. This study aimed to evaluate the efficacy, safety, and patient satisfaction of using R. nasutus root extract gel containing 0.2% rhinacanthin C (w/w) in the treatment of dermatophytosis. The gel preparation was manufactured, and its quality was assessed following the established specifications prior to clinical evaluation. A clinical study was conducted in 10 patients who applied the gel to skin lesions twice daily for 8 weeks. Treatment outcomes were evaluated at two-week intervals using clinical severity scores, potassium hydroxide (KOH) preparation for mycological examination, and monitoring of adverse events. The results showed that clinical severity scores and fungal detection rates significantly decreased from week 2 through the end of treatment. These findings indicate that the gel has effectively reduced clinical symptoms and eradicated fungi at the lesion sites. No adverse events were observed throughout the 8-week treatment period. Therefore, R. nasutus root extract gel containing 0.2% rhinacanthin C (w/w) can be considered both effective and safe for the treatment of dermatophytosis. Patient satisfaction levels for the gel ranged from satisfied to very satisfied, while patient-reported Global Improvement Scores indicated outcomes from much improved to very much improved. Nevertheless, caution is advised when applying the gel to sensitive skin areas, and its use is not recommended in patients with concurrent dermatophyte and Candida coinfections. Further large-scale randomized double-blind controlled trials are warranted to generate more robust and reliable evidence.
References
Luplertlop N, Suwanmanee S. Dermatophytosis: from bench to bed side. J Trop Med Parasitol 2013; 36: 75−87.
Sacheli R, Havette MP. Antifungal resistance in dermatophytes: genetic considerations, clinical presentations and alternative therapies. J Fungi 2021; 7(11): 983. (23 pages).
Kruithoff C, Gamal A, McCormick TS, Ghannoum MA. Dermatophyte infections worldwide: increase in incidence and associated antifungal resistance. Life 2024; 14(1): 1. (13 pages).
Thiangburanathum W. Dictionary of Thai medicinal plants. 5th ed. Bangkok: Aksornpittaya; 1999.
Thailand Association of Traditional Medicine School Wat Phra Chetuphon (Wat Pho) Tha Thien Pranakorn. Handbook of Thai pharmacist Drug Act B.E. 2510 and ministerial regulation. 2nd ed. Bangkok: Ampolpittaya; 1869.
Kodama O, Ichikawa H, Akatsuka T, Santisopasri V, Kato A, Hayashi Y. Isolation and identification of an antifungal naphthopyran derivative from Rhinacanthus nasutus. J Nat Prod 1993; 56(2): 292−4.
Pruksakorn P, Jaima C, Panyajai P, Mekha N, Autthateinchai R, Dhepakson P. Antifungal activity of Rhinacanthus nasutus (L.) Kurz extract against dermatophytes. J Thai Trad Alt Med 2018; 16(2): 205−17.
Siripong P, Wongseri V, Piyaviriyakul S, Yahaufai J, Chanpai R, Kanokmedakul K. Antibacterial potential of Rhinacanthus nasutus against clinically isolated bacteria from Thai cancer patients. Mahidol J Pharm Sci 2006; 33(1-4): 15−22.
Ebdu A, Chen JL, Jolad SD, Stoddart C, Rozhon E, Kernan M, et al. Two new naphthoquinones with antiviral activity from Rhinacanthus nasutus. J Nat Prod 1996; 59(8): 808−11.
Thongchuai B, Tragoolpua Y, Sangthong P, Trisuwan K. Antiviral carboxylic acids and naphthoquinones from the stems of Rhinacanthus nasutus. Tetrahedron Lett 2015; 56(37): 5161−3.
Bhusal N, Panichayupakaranant P, Reanmongkol W. In vivo analgesic and anti-inflammatory activities of a standardized Rhinacanthus nasutus leaf extract in comparison with its major active constituent rhinacanthin-C. Sonklanakarin J Sci Technol 2014; 36(3): 325−31.
Tewtrakul S, tansakul P, Panichayupakaranant P. Effects of rhinacanthins from Rhinacanthus nasutus on nitric oxide, prostaglandin E2 and tumor necrosis factor-alpha releases using RAW264.7 macrophage cells. Phytomedicine 2009; 16(6-7): 581−5.
Tewtrakul S, Tansakul P, Panichayapakaranant P. Anti-allergic principles of Rhinacanthus nasutus leaves. Phytomedicine 2009; 16: 929−34.
Bureau of Drug Control, Food and Drug Administration. National list of essential medicines 2013. Bangkok: The Agricultural Co-operative Federation of Thailand Printing Press; 2013.
Pruksakorn P, Jaima C, Panyajai P, Onthong S, Sriboran S. Variation of rhinacanthin C content in the raw materials of Rhinacanthus nasutus. Int J Pharm Res Appl 2024; 9(3): 865−8.
Pruksakorn P, Jaima C, Sumateewatanakul V, Sa-nguanruang W, Panyajai P, Autthateinchai R, et al. Development and evaluation of Rhinacanthus nasutus root extract gel as an antifungal for the treatment of dermatophytosis. J Thai Trad Alt Med 2021; 19(2): 435−57.
Pruksakorn P, Jaima C, Suppajariyawat P, Sumateewatanakul V, Larpardisorn K, Tongkamsen C, et al. Safety evaluation of Rhinacanthus nasutus root extract gel. J Thai Trad Alter Med 2023; 21(2): 307−26.
Ponka D, Baddar F. Microscopic potassium hydroxide preparation. Can Fam Physician 2014; 60(1): 57.
Smith EB, Noppakun N, Newton RC. A clinical trial of topical terbinafine (a new allylamine antifungal) in the treatment of tinea pedis. J Am Acad Dermatol 1990; 23(4): 790−4.
Millikan LE. Efficacy and tolerability of topical terbinafine in the treatment of tinea cruris. J Am Acad Dermatol 1990; 23(4): 795−9.
Bogaert H, Cordero C, Ollague W, Savin RC, Shalita AR, Zaias N. Multicentre double-blind clinical trials of ciclopirox olamine cream 1% in the treatment of tinea corporis and tinea cruris. J Int Med Res 1986; 14: 210−6.
Poudel I, Tianco EA, Villafuerte LL. Efficacy and safety of neem seed extract compared with clotrimazole in tinea corporis/cruris: a randomized controlled trial. Nepal J Dermatol Venereol Leprol 2018; 16(1): 24−9.
Frosch PJ, Kligman AM. The soap chamber test: a new method for assessing the irritancy of soap. J Am Acad Dermatol 1979; 1(1): 35−41.
Busner J, Targum SD. The clinical global impressions scale applying a research tool in clinical practice. Psychiatry 2007; 4(7): 28−37.
Pugh SL, Torres-Saavedra PA. Fundamental Statistical Concepts in Clinical Trials and Diagnostic Testing. J Nucl Med 2021; 62(6): 757–64.
World Medical Association. WMA Declaration of Helsinki: ethical principles for medical research involving human participants. [online]. 2024; [cited 2025 Dec 2]; [7 screens]. Available from: URL: https://media.tghn.org/medialibrary/2025/07/Declaration_of_Helsinki_2024.pdf.
Council for International Organizations of Medical Sciences (CIOMS), World Health Organization (WHO). International ethical guidelines for health-related research involving humans. [online]. 2016; [cited 2025 Dec 2]; [119 screens]. Available from: URL: https://cioms.ch/wp-content/uploads/2017/01/WEBCIOMS-EthicalGuidelines.pdf.
Good Clinical Practice Network. ICH GCP - ICH E6(R3) guideline on good clinical practice (GCP). [online]. 2025 Jan 23 [cited 2025 Dec 2]. Available from: URL: https://ichgcp.net/ichharmonised-guideline-ich-e6-r3-guidelineon-good-clinical-practice-gcp-step-5.
British Pharmacopoeia Commission. British pharmacopoeia 2018. London: The Stationery Office; 2018.
Havlickova B, Czaika VA, Friedrich M. Epidemiological trends in skin mycoses worldwide. Mycoses 2008: 51(Suppl 4): 2−15.
Herbal Product Division, Thai Food and Drug Administration. Type of herbal products. [online].2023; [cited 2024 Dec 6]; [75 screens]. Available from: URL: https://www.fda.moph.go.th/Herbal/SitePages/Document/product/3.product_allow.pdf.
Patel S, Meixner JA, Smith MB, Mcginnis MR. Superficial mycoses and dermatophytes. In: Tropical dermatology. 2nd ed. [online]. 2017; [cited 2024 Dec 6]; [13 screens]. Available from: URL: https://doi.org/10.1016/B978-0-323-29634-2.00017-1.
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