Efficacy of Dipterocarpus alatus oil combination with Rhinacanthus nasutus leaf and Garcinia mangostana pericarps against canine demodicosis

Background and Aim: Canine demodicosis is a skin disease that is a major global health problem in dogs. Ivermectin is a drug of choice for treatment, but it may cause toxicity in dogs carrying multidrug resistance mutation-1 gene mutations. Hence, alternative herbal medicines are used instead of the drug, such as Dipterocarpus alatus oil (YN oil), Rhinacanthus nasutus leaf (WC), and Garcinia mangostana pericarps (MG) extracts. This study aimed to determine the efficacy of D. alatus oil, R. nasutus leaf, and G. mangostana pericarp extracts on canine demodicosis in vivo. Materials and Methods: Twenty-five mixed-breed dogs with localized demodicosis were examined. Dogs were diagnosed with demodicosis through deep skin scraping and screened with the inclusion criteria. Five dogs of each group were treated in five treatment groups (ivermectin, YN oil, YN oil+WC, YN oil+MG, and YN oil+WC+MG) for 1 month. The individual dogs were clinically evaluated, and the dermatological lesions were monitored daily for 60 days. Results: Dermatological lesion improvement was predominantly observed in the group of dogs treated with YN oil+WC. This was evidenced by the disappearance of the hyperpigmentation and lichenification on day 28 post-treatment and alopecia on day 56 post-treatment. Moreover, no allergic or clinical signs were observed during treatment. Conclusion: YN oil+WC is an alternative herbal medicine that could be used for the treatment of localized canine demodicosis.

Qualitative Phytochemical analysis of Rhinacanthus nasutus

Rhinacanthus nasutus (Nagamalli) is a small slender shrub widely distributed in India, South East Asia and China. This herb is being used for treating snake bite by irula tribes in the remote villages of Nilagiri hills. The plant possesses a wide spectrum of phytochemical substances. The current study is aimed at measuring the qualitative phytochemistry of Rhinacanthus nasutus cultivated at herbal garden of Veterinary College and Research Institute, Orathanadu. The results suggest that the leaves and root of Rhinacanthus nasutus are potential sources for healthy phytochemicals especially alkaloids and phenols

ANTIBACTERIAL POTENTIAL ETHANOL EXTRACT OF KAYU RACUN LEAF (Rhinacanthus nasutus) AGAINST Staphylococcus aureus AND METHICILLIN RESISTANT Staphylococcus aureus

The excessive use of antibiotics in the treatment of infections or diseases caused by Staphylococcus aureus is the main cause of antibiotic resistance. Methicillin-resistant S. aureus (MRSA) strains are a serious problem because of their wide distribution in the clinical environment and the living community, so it is necessary to search for antibacterial sources from natural products and traditional medicines such as Kayu racun leaves (Rhinacanthus nasutus). Information regarding the content of the active ingredient and the antibacterial potential of the ethanol extract of Kayu racun leaves is still limited. This study aims to test the phytochemical and antibacterial activity of the ethanol extract of Kayu racun leaves against S. aureus and MRSA bacteria by invitro. The research used an experimental method and was divided into two stages, namely; Phytochemical test of the ethanol extract of Kayu racun leaves using the Thin Layer Chromatography (TLC) method and the antibacterial activity test of the ethanol extract of Kayu racun leaves against S. aureus and MRSA using the paper disc diffusion method. Based on the research results, it can be concluded that the ethanol extract of Kayu racun leaves contains alkaloids, phenols, and flavonoids. The best antibacterial activity was found at a concentration of 100 mg/ml with an inhibition zone diameter of 26.20 mm against S. aureus and 17.90 mm against MRSA.

Anti-oxidant, pediculicidal and pesticidal activities of leaves of Rhinacanthus nasutus (Linn) grown in Sri Lanka

Rhinacanthus nasutus is an ethnomedical plant used in the traditional system of medicine for treating skin diseases. As no adequate studies available on R. nasutus grown in Sri Lanka, this study aimed on exploring anti-oxidant, anti-parasitic and pesticidal activity of leaves of the plant. Antioxidant capacity of the crude extract of leaves was evaluated using DPPH free radical scavenging assay and FRAP assay using ascorbic acid and FeSO4.7H2O as the standards respectively. Pediculicidal efficacy was carried out against head lice using 0.0010% (w/v) methanolic, ethyl acetate and aqueous extracts of leaves by following modified filter paper diffusion bioassay. Pesticidal activity of leaves was evaluated using modified filter paper contact bioassay against mealybugs, P. marginatus, resides on papaw and guava trees. The IC50 value of DPPH assay was found to be 514.3 μgmL-1 and FRAP value was found to be 594.33±2.93 μmol Fe2+/g in anti-oxidant assay. The LT50 (median Lethal Time) values for 0.0010% (w/v) concentration of methanolic, ethyl acetate and aqueous extracts were 263, 347 and 676 min respectively in pediculicidal assay. LC50 (50% mortality) value was found to be 0.0011% (w/v) after 240 minutes whereas LT50 values of 0.0020% (w/v) of methanol, ethyl acetate and aqueous fractions of R. nasutus for adult were found as 31, 124 and 189 hours and for nymph were 14, 18 and 29 hours respectively in pesticidal assay. Accordingly, methanolic extract was effective in controlling nymph stage of mealybug life cycle than adults with the LC50 of 0.0015% (w/v) within 14 hours. This study confirmed promising pediculicidal and pesticidal activity and significant anti-oxidant capacity of leaves of R. nasutus. Asian J. Med. Biol. Res. December 2020, 6(4): 754-760

Rhinacanthus nasutus “Tea” Infusions and the Medicinal Benefits of the Constituent Phytochemicals

Rhinacanthus nasutus (L.) Kurz (Acanthaceae) (Rn) is an herbaceous shrub native to Thailand and much of South and Southeast Asia. It has several synonyms and local or common names. The root of Rn is used in Thai traditional medicine to treat snake bites, and the roots and/or leaves can be made into a balm and applied to the skin for the treatment of skin infections such as ringworm, or they may be brewed to form an infusion for the treatment of inflammatory disorders. Rn leaves are available to the public for purchase in the form of “tea bags” as a natural herbal remedy for a long list of disorders, including diabetes, skin diseases (antifungal, ringworm, eczema, scurf, herpes), gastritis, raised blood pressure, improved blood circulation, early-stage tuberculosis antitumor activity, and as an antipyretic. There have been many studies investigating the roles of Rn or compounds isolated from the herb regarding diseases such as Alzheimer’s and other neurodegenerative diseases, cancer, diabetes and infection with bacteria, fungi or viruses. There have, however, been no clinical trials to confirm the efficacy of Rn in the treatment of any of these disorders, and the safety of these teas over long periods of consumption has never been tested. This review assesses the recent research into the role of Rn and its constituent compounds in a range of diseases.

Antifungal Activity and Molecular Mechanisms of Partial Purified Antifungal Proteins from Rhinacanthus nasutus against Talaromyces marneffei

Antifungal proteins (AFPs) are able to inhibit a wide spectrum of fungi without significant toxicity to the hosts. This study examined the antifungal activity of AFPs isolated from a Thai medicinal plant, Rhinacanthus nasutus, against the human pathogenic fungus Talaromycesmarneffei. This dimorphic fungus causes systemic infections in immunocompromised individuals and is endemic in Southeast Asian countries. The R. nasutus crude protein extract inhibited the growth of T. marneffei. The anti-T. marneffei activity was completely lost when treated with proteinase K and pepsin, indicating that the antifungal activity was dependent on a protein component. The total protein extract from R. nasutus was partially purified by size fractionation to ≤10, 10–30, and ≥30 kDa fractions and tested for the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). All fractions showed anti-T. marneffei activity with the MIC and MFC values of 32 to 128 μg/mL and >128 μg/mL, respectively. In order to determine the mechanism of inhibition, all fractions were tested with T. marneffei mutant strains affected in G-protein signaling and cell wall integrity pathways. The anti-T. marneffei activity of the 10–30 kDa fraction was abrogated by deletion of gasA and gasC, the genes encoding alpha subunits of heterotrimeric G-proteins, indicating that the inhibitory effect is related to intracellular signaling through G-proteins. The work demonstrates that antifungal proteins isolated from R. nasutus represent sources for novel drug development.

Invitro Efficacy of antioxidant activity in ethanolic and aqueous leaf extracts of Andrographis paniculata Nees and Rhinacanthus nasutus Kurz

Plants are adundantly and are very promisive to be used as source of drugs in many diseases or infections and also it is a main agents of antioxidants which prevents the oxidative stress that are caused by the free radicals. There are numerous studies based on the pharmaceutical and classification of medicinal plants throughout the world. Leaves, fruits, roots are most frequently plant parts used in many research and studies. Here the present study was aimed to evaluate the in vitro antioxidant activity of aqueous and ethanol leaf extracts of Andrographis paniculata Nees and Rhinacanthus nasutus Kurz. Antioxidant is a substance which is used to prevent some types of cell damage in the body. Determination of their in vitro antioxidant activity were carried out by using methods such as DPPH (2,2-diphenyl-1picrylhydrazyl assay), ABTS (2,2′-azinobis (3-ethylbenzothiazolin 6-sulfonic acid assay), FRAP (ferric reducing antioxidant power assay) and SOD (super oxide anion scavenging) assay, H2O2 (hydrogen peroxide radical scavenging) assay. Moreover the ethanolic leaf extracts showed best antioxidant activity than the aqueous leaf extracts. Experimental results reveals that the leaves of A. paniculata have potent antioxidant and free radical scavenging activity than R. nasutus. Further investigation must be done for these two medicinal plants for the discovery of the bioactive compounds.