​Rhinacanthus nasutus (Snake Jasmine)

Rhinacanthus nasutus (Snake Jasmine)

Product Name: Рингиария многоперистая, Rhinacanthus nasutus, Mehlnuss-Schwarznessel, Nuez negra, Rhinacanthe noir, الرينكانثس ناسوثوس, พญายอ, Rinchanthis nasutus, Ринкантус насутус, Rinakantus nasutus, Ринакантус насутус, Rhinacanthus nasutus, Rinacanthus nasutus, Рінакантус насутус, רינאקנטוס נאסוטוס

Synonyms: Рингиария, Пайа-йо, Змеиный куст, Змеиный жасмин (Russ.), Snake jasmine (Engl.), Toothbrush plant (Engl.), Schwarze Zahnbürstenpflanze (German), Planta cepillo de dientes (Spanish), Plante brosse à dents (French), نبات فرشاة الأسنان (Arabi.), พญายอ, ฟันปลาหมอ (Thai)

Parts used: leaves, roots, stems, flowers, leaves

Main indications for the use of Rhinacanthus nasutus: bacterial dermatitis, acute and chronic eczema, psoriasis, seborrheic dermatitis, herpes skin infection, skin and nail mycoses, oral cavity inflammation, stomatitis, gingivitis, chronic tonsillitis, otitis media, sinusitis, pharyngitis, bronchitis, arterial hypertension, hyperglycemia, early stages of type 2 diabetes mellitus, benign prostatic hyperplasia, irritable bowel syndrome, intestinal parasitic infestations, bacterial gastroenteritis, hepatotoxicosis, viral hepatitis B.

Use of Rhinacanthus nasutus in mixtures and complexes: osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, chronic obstructive pulmonary disease, bronchial asthma, chronic pancreatitis, non-alcoholic fatty liver disease, chronic hepatitis, hyperlipidemia, hypercholesterolemia, neurodegenerative diseases, post-stroke rehabilitation, demyelinating diseases, chronic bacterial prostatitis.

Pharmacological properties of Rhinacanthus nasutus: antibacterial, antiviral, antifungal, anti-inflammatory, antioxidant, hypoglycemic, hypotensive, hepatoprotective, analgesic, immunomodulatory, antiproliferative, anticarcinogenic, antiparasitic, vasodilatory, diuretic, bronchodilatory, antispasmodic, wound-healing, antinociceptive, neuroprotective, antimutagenic, cytotoxic (against tumor cells).

Dosage of pharmaceutical forms — Rhinacanthus nasutus

Powder — Rhinacanthus nasutus

Indications (Powder): atopic dermatitis, psoriasis, skin mycosis, hyperglycemia, arterial hypertension, viral hepatitis B, bacterial gastroenteritis, irritable bowel syndrome, gingivitis, stomatitis, chronic tonsillitis.

Standard Dosage (Powder): 1 gram of powder 2 times a day after meals, with warm water.

Enhanced Dosage (Powder): 1.5 grams 3 times a day for bacterial gastroenteritis, viral hepatitis B, atopic dermatitis, recurrent skin mycosis.

Maximum Dosage (Powder): 2 grams 3 times a day for severe chronic dermatosis or pronounced inflammation of the oral mucous membranes.

Preventive Dosage (Powder): 0.5 gram once a day for 30 days for chronic gingivitis, hyperglycemia, early-stage arterial hypertension; recommended for patients over 45 years old.

Pediatric Dosage (Powder): From 6 years of age, with body weight not less than 20 kg — 0.25 gram once a day, only after consultation with a doctor. The child's gender is irrelevant.

Contraindications (Powder): Individual hypersensitivity to the plant. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Powder): If the dosage is exceeded, diarrhea, nausea, abdominal discomfort are possible.

Adjustment for Patient Body Weight: Up to 60 kg — reduce the dosage by 25%. Over 60 kg — use the full dose without changes.

Preparation method (Powder): Wash the collected mature leaves of the plant, dry at a temperature not exceeding 45 °C in the shade. Grind to a powder state in a mortar or mill. Sieve. Store in an airtight container.

Storage Conditions and Shelf Life (Powder): Store in an airtight container at a temperature of 5 to 25 °C in a dark, dry place, away from direct sunlight and sources of EMR. Shelf life — up to 12 months. After opening, use within 60 days.

Dry Extract — Rhinacanthus nasutus

Indications (Dry Extract): viral hepatitis B, arterial hypertension, type 2 diabetes mellitus, benign prostatic hyperplasia, chronic bronchitis, chronic tonsillitis, skin mycosis, gingivitis, periodontitis, psoriasis.

Standard Dosage (Dry Extract): 0.3 grams of dry extract 2 times a day after meals.

Enhanced Dosage (Dry Extract): 0.5 grams 3 times a day for pronounced clinical symptoms of viral hepatitis B, chronic bronchitis, and arterial hypertension.

Maximum Dosage (Dry Extract): 1 gram 3 times a day in acute conditions for mycoses, gum inflammation, psoriatic exacerbations, but not longer than 7 days.

Preventive Dosage (Dry Extract): 0.2 grams once a day for 30 days every 3 months — for hyperglycemia, hypertension, mild form of prostatitis, chronic periodontitis.

Pediatric Dosage (Dry Extract): From 10 years of age, with body weight more than 30 kg — 0.1 gram once a day. Use under medical supervision.

Contraindications (Dry Extract): Hypersensitivity, pronounced renal failure. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Dry Extract): Upon overdose, headache, high blood pressure, dyspeptic disorders are possible.

Adjustment for Patient Body Weight: Up to 60 kg — dosage reduction by 20%. For body weight over 90 kg — dose increase by 15% in consultation with a doctor.

Preparation method (Dry Extract): Pour 50 grams of dry crushed leaves with 500 milliliters of 70% ethanol. Infuse for 48 hours at a temperature of 25 °C in a sealed container, shaking periodically. Filter. Evaporate in a water bath at a temperature not exceeding 50 °C until a thick residue is obtained. Dry the residue in a drying oven at 45 °C until a dry extract is obtained. Ensure the disappearance of the ethanol odor. Permissible residual content — no more than 50 ppm.

Storage Conditions and Shelf Life (Dry Extract): Store in a tightly closed dark container at a temperature of 15–25 °C, away from light and moisture. Shelf life — 24 months. After opening, use within 90 days.

Tincture — Rhinacanthus nasutus

Indications (Tincture): bacterial pharyngitis, chronic tonsillitis, gum inflammation, herpetic stomatitis, skin mycosis, seborrheic dermatitis, eczema, purulent skin inflammations, fungal nail infection.

Standard Dosage (Tincture): 10 drops of tincture (diluted with water 1:4) 2 times a day externally or for mouth rinsing.

Enhanced Dosage (Tincture): 15 drops 3 times a day externally or for rinsing, during the active phase of purulent inflammation, mycosis, or exacerbated herpes of the mucous membrane.

Maximum Dosage (Tincture): 20 drops 3 times a day, for no longer than 5 days, for acute fungal infection and bacterial skin inflammation.

Preventive Dosage (Tincture): 5 drops once a day diluted with water for mouth rinsing for chronic tonsillitis, stomatitis, gum inflammation. Course — 10 days per month.

Pediatric Dosage (Tincture): From 12 years of age, with dilution 1:10 — no more than 3 drops, once a day. Use only locally, do not swallow.

Contraindications (Tincture): Hypersensitivity, damage to the oral mucosa, individual intolerance to ethanol. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Tincture): Upon overdose, burning, irritation of mucous membranes, dry and flaky skin are possible.

Adjustment for Patient Body Weight: Up to 60 kg — reduce the dose by 30%. From 90 kg — an increase to 25 drops is possible with good tolerance.

Preparation method (Tincture): Pour 50 grams of crushed fresh leaves with 250 milliliters of 70% ethanol. Infuse in a glass container at a temperature of 20–25 °C in the shade, shaking periodically, for 10 days. Filter. Before use, ethanol is evaporated if necessary — evaporate at a temperature not exceeding 50 °C in a water bath. Residual ethanol content for external use is allowed up to 1000 ppm. Do not use internally without evaporation.

Storage Conditions and Shelf Life (Tincture): Store in a tightly closed dark glass bottle at a temperature of 5 to 20 °C. Shelf life — 12 months. After opening, use within 30 days. Store away from light and heat sources.

Oil Infusion — Rhinacanthus nasutus

Indications (Oil Infusion): chronic dermatitis, psoriasis, seborrheic dermatitis, skin mycosis, skin fissures, neurodermatitis, eczema, fungal nail infection.

Standard Dosage (Oil Infusion): Externally 1–2 times a day on affected skin areas, until completely absorbed. Course — at least 14 days.

Enhanced Dosage (Oil Infusion): Apply 3 times a day for active inflammation, peeling, itchy mycoses, and pronounced psoriasis.

Maximum Dosage (Oil Infusion): Up to 5 applications per day on limited skin areas of no more than 100 cm², for severe chronic dermatoses.

Preventive Dosage (Oil Infusion): Once a day on the skin in areas prone to dryness and microcracks — for chronic dermatitis, psoriasis in remission. Course — 10–14 days monthly.

Pediatric Dosage (Oil Infusion): From 3 years of age, on limited skin areas — no more than once a day. Avoid application to mucous membranes and areas of high absorption.

Contraindications (Oil Infusion): Individual sensitivity, acute purulent skin lesions. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Oil Infusion): Rarely: redness, itching, irritation due to individual intolerance.

Adjustment for Patient Body Weight: Dose adjustment is not required, as the form is applied locally.

Preparation method (Oil Infusion): Pour 50 grams of crushed dry leaves with 200 milliliters of organic cold-pressed coconut oil. Macerate in a glass container for 10 days at a temperature of 35 °C in a water bath for 2 hours daily. Filter. Store the finished infusion in a sterile container.

Storage Conditions and Shelf Life (Oil Infusion): Store in a tightly closed dark glass bottle at a temperature of 5 to 25 °C, in a dark place, away from heat sources and electromagnetic fields. Shelf life — 6 months. After opening, use within 45 days.

Rectal Suppository — Rhinacanthus nasutus

Indications (Rectal Suppository): chronic prostatitis, benign prostatic hyperplasia, inflammatory diseases of the rectum, hemorrhoids, intestinal parasitic infestations.

Standard Dosage (Rectal Suppository): 1 suppository (500 milligrams of active substance) once a day before bed.

Enhanced Dosage (Rectal Suppository): 1 suppository 2 times a day for pronounced pain syndrome, active inflammation, edema of the rectal mucosa and prostate gland.

Maximum Dosage (Rectal Suppository): 2 suppositories 2 times a day, for no more than 5 consecutive days, only under medical supervision for severe forms of chronic prostatitis and hemorrhoids.

Preventive Dosage (Rectal Suppository): 1 suppository every other day at night, in a course of 10–15 applications, for chronic prostatitis in remission, for men over 50 years old.

Pediatric Dosage (Rectal Suppository): Use in children is not recommended. Scientific safety data are absent.

Contraindications (Rectal Suppository): Hypersensitivity, acute inflammatory processes of the anorectal area, anal bleeding. Data on contraindications during pregnancy and in childhood have not been scientifically registered.

Side Effects (Rectal Suppository): Rarely: burning sensation, irritation of the rectal mucosa, frequent urge to defecate.

Adjustment for Patient Body Weight: Up to 60 kg — use a 250 mg suppository. Above 60 kg — standard dosage without changes.

Preparation method (Rectal Suppository): Mix 5 grams of dry plant extract with 95 grams of cocoa butter, previously melted at a temperature not exceeding 40 °C. Pour into suppository molds of 2 grams volume. Cool until completely solidified. Store in the refrigerator.

Storage Conditions and Shelf Life (Rectal Suppository): Store at a temperature of +2 to +8 °C in a dark place. Shelf life — 6 months. After opening, use within 30 days.

Nasal Drops — Rhinacanthus nasutus

Indications (Nasal Drops): viral rhinitis, acute sinusitis, bacterial runny nose, nasal mucosal hypertrophy, chronic allergic rhinitis, post-infectious nasal congestion.

Standard Dosage (Nasal Drops): 2 drops in each nostril 2 times a day for 5–7 days.

Enhanced Dosage (Nasal Drops): 3 drops 3 times a day in each nostril for pronounced nasal congestion, mucosal edema, acute rhinosinusitis.

Maximum Dosage (Nasal Drops): 4 drops 4 times a day, for no more than 3 consecutive days. Longer use is possible only under medical supervision.

Preventive Dosage (Nasal Drops): 1 drop in each nostril once a day for 10 days for seasonal allergies, chronic hypertrophic rhinitis, for individuals prone to colds.

Pediatric Dosage (Nasal Drops): From 5 years of age — 1 drop in each nostril once a day, for no more than 5 consecutive days. Use a diluted form 1:1 with saline solution.

Contraindications (Nasal Drops): Hypersensitivity, nosebleeds, acute traumatic rhinitis. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Nasal Drops): Burning sensation, sneezing, mucosal irritation due to individual sensitivity.

Adjustment for Patient Body Weight: Dose adjustment is not required for local application.

Preparation method (Nasal Drops): Dissolve 10 grams of dry extract in 90 milliliters of sterile coconut oil heated to 35 °C. Add 5 drops of eucalyptus essential oil. Mix until completely dissolved. Filter through a sterile gauze filter. Pour into sterile dropper bottles.

Storage Conditions and Shelf Life (Nasal Drops): Store in a refrigerator at +4 °C, in a sealed bottle. Shelf life — 30 days. After opening, use within 10 days.

Ear Drops — Rhinacanthus nasutus

Indications (Ear Drops): acute external otitis, chronic otitis, fungal infection of the ear canal, bacterial external otitis, inflammation of the auricle, seborrheic dermatitis of the ear area.

Standard Dosage (Ear Drops): 3 drops into the ear canal 2 times a day, in a course of 5–7 days.

Enhanced Dosage (Ear Drops): 4 drops 3 times a day for pronounced pain syndrome and purulent discharge from the ear.

Maximum Dosage (Ear Drops): 5 drops 4 times a day, for no more than 3 consecutive days. If no improvement occurs, discontinue use and consult a doctor.

Preventive Dosage (Ear Drops): 2 drops once a day after bathing or prolonged exposure to dusty conditions, for 5 days. Recommended for patients with chronic external otitis and a tendency to fungal infections.

Pediatric Dosage (Ear Drops): From 6 years of age — 1 drop once a day for 3 days. Use only under medical supervision.

Contraindications (Ear Drops): Perforation of the eardrum, acute purulent otitis media of moderate severity, individual sensitivity. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Ear Drops): Burning, itching, slight redness of the external ear canal.

Adjustment for Patient Body Weight: Dose adjustment is not required for local application.

Preparation method (Ear Drops): Mix 10 grams of powder from plant leaves with 90 milliliters of warm coconut oil (temperature 35–38 °C), infuse for 5 days in a dark place, shaking periodically. Filter. Optionally add 2 drops of tea tree oil. Pour into sterile bottles.

Storage Conditions and Shelf Life (Ear Drops): Store at +4 °C in a dark place. Shelf life — up to 30 days. After opening, use within 10 days.

Ointment — Rhinacanthus nasutus

Indications (Ointment): chronic psoriasis, skin mycosis, neurodermatitis, eczema, herpes skin infection, pyogenic dermatoses, skin fissures, skin inflammation in diabetics.

Standard Dosage (Ointment): Apply a thin layer 2 times a day to cleansed skin, course of 10–15 days.

Enhanced Dosage (Ointment): Apply 3–4 times a day to limited inflamed skin areas for pronounced itching, peeling, and active inflammation.

Maximum Dosage (Ointment): Up to 5 applications per day for pronounced inflammation, for no more than 7 consecutive days.

Preventive Dosage (Ointment): Once a day for 10 days, in courses once a month, for chronic psoriasis in remission, diabetic dry skin, tendency to mycotic lesions.

Pediatric Dosage (Ointment): From 3 years of age — apply once a day to limited areas. Avoid contact with eyes and mucous membranes.

Contraindications (Ointment): Open bleeding wounds, individual hypersensitivity. Data on contraindications during pregnancy, lactation, and in childhood have not been scientifically registered.

Side Effects (Ointment): Rarely: skin irritation, tingling sensation, or mild burning.

Adjustment for Patient Body Weight: Dose adjustment is not required.

Preparation method (Ointment): Mix 10 grams of dry plant extract with 90 grams of pre-melted beeswax and coconut oil in a 1:2 ratio. Keep the mixture in a water bath at 45 °C until homogeneous. Cool to room temperature. Transfer to a sterile container.

Storage Conditions and Shelf Life (Ointment): Store in a closed container at a temperature of +5 to +20 °C, in a dark place, away from light and heat sources. Shelf life — up to 90 days. After opening — 30 days.

Cream — Rhinacanthus nasutus

Indications (Cream): facial seborrheic dermatitis, rosacea, perioral dermatitis, inflammatory acne, post-shave irritation, skin fold mycosis, chronic itching.

Standard Dosage (Ointment): Apply a thin layer to cleansed skin 2 times a day, avoiding the eye area.

Enhanced Dosage (Ointment): Apply 3 times a day for pronounced inflammation, itching, redness in areas of acne, skin folds, nasolabial area.

Maximum Dosage (Ointment): Up to 4 applications per day on limited skin areas, for no more than 5 consecutive days.

Preventive Dosage (Ointment): Once a day in the evening, in courses of 10 days for rosacea, seborrhea, tendency to skin inflammation in the nose, cheeks, chin area.

Pediatric Dosage (Ointment): From 6 years of age — apply once a day for 5 days on limited areas. Do not use in the presence of weeping elements.

Contraindications (Ointment): Allergic reaction to components, active pustular skin infections. Data on contraindications during pregnancy and lactation have not been scientifically registered.

Side Effects (Ointment): Possible sensations of mild burning, hyperemia, dryness due to individual sensitivity.

Adjustment for Patient Body Weight: Dose adjustment is not required.

Preparation method (Cream): Dissolve 10 grams of dry plant extract in 40 milliliters of water heated to 40 °C. Introduce the solution into a pre-prepared oil base (coconut oil — 30 grams, jojoba oil — 10 grams, emulsifier — 5 grams). Whip until creamy consistency. Add 5 drops of lavender oil. Cool to 25 °C and transfer to a sterile container.

Storage Conditions and Shelf Life (Cream): Store in a tightly closed jar at a temperature of +4 to +10 °C. Shelf life — 60 days. After opening, use within 15 days.

Serum — Rhinacanthus nasutus

Indications (Serum): post-acne, hyperpigmentation, chronic rosacea (couperose), skin photodamage, age-related skin changes, early signs of melasma, inflammatory elements in acne.

Standard Dosage (Serum): Apply 4–5 drops to the face in the morning or evening, gently rubbing into the skin until completely absorbed.

Enhanced Dosage (Serum): Up to 7 drops 2 times a day for pronounced hyperpigmentation, active inflammatory elements, sun-damaged skin.

Maximum Dosage (Serum): 10 drops 2 times a day — only for 5 days during intensive therapy for post-acne and photo-induced disorders.

Preventive Dosage (Serum): 3 drops once a day before bed, in a course of 14 days monthly for a tendency to age-related pigmentation and sensitive skin.

Pediatric Dosage (Serum): Not recommended for use in children under 14 years of age. Safety data are absent.

Contraindications (Serum): Active inflammatory rashes, allergy to components, skin microtraumas. There is no data on contraindications during pregnancy and lactation.

Side Effects (Serum): Rarely — redness, feeling of tightness, skin peeling due to individual intolerance.

Adjustment for Patient Body Weight: Not required.

Preparation method (Serum): Dissolve 5 grams of dry extract in 50 milliliters of rose hydrolate. Add 20 milliliters of aloe vera gel, 10 milliliters of grape seed oil. Whip into a light emulsion. Add 2 drops of geranium oil. Pour into a sterile pump bottle.

Storage Conditions and Shelf Life (Serum): Store at a temperature of +4...+10 °C, in a dark place. Shelf life — 30 days. After opening — use within 10 days.

Toxicity and Biosafety of Rhinacanthus nasutus

To date, no data on the measurement of LD₅₀ (lethal dose for 50% of test animals) specifically for Rhinacanthus nasutus have been found in the open scientific literature. Although there are studies confirming moderate cytotoxicity of plant extracts against cell lines (e.g., IC₅₀ ≈ 124.75 µg/mL for HaCaT keratinocytes) sciencedirect.com+15nano-ntp.com+15iosrjournals.org+15, data on acute toxicity in the LD₅₀ class are absent.

Pharmacodynamics — Rhinacanthus nasutus

The pharmacodynamic action of Rhinacanthus nasutus is due to a complex of biologically active substances, mainly naphthoquinones (particularly rhinacanthin), flavonoids, steroid compounds, and polyphenols. The main direction of action is the modulation of the activity of enzymatic, mediator, and receptor mechanisms that determine the inflammatory, immune, antioxidant, and antiproliferative response of the body. The plant exhibits pronounced activity against intracellular signaling cascades that regulate the production of nitric oxide, pro-inflammatory cytokines, and mediators, including tumor necrosis factor α and interleukins 1β and 6.

Under the influence of Rhinacanthus nasutus extracts, a decrease in the activity of cyclooxygenase-2 (COX-2), lipoxygenase, as well as suppression of NF-κB transcription — a key factor in inflammatory expression — is observed. This results in a systemic and local anti-inflammatory effect, including at the level of the skin, mucous membranes, and respiratory system. The local action is confirmed by the ability of plant components to penetrate epithelial layers and stabilize cell membranes.

Antioxidant properties are associated with the direct binding of reactive oxygen species and peroxide radicals, as well as with the induction of the expression of endogenous antioxidant defense enzymes (including glutathione peroxidase, superoxide dismutase, and catalase). This action is mediated both by direct molecular mechanisms and through signaling pathways that regulate the expression of antioxidant genes. Thus, the plant exerts a modulating effect on the cellular levels of oxidative stress.

The immunological action is due to the ability of active substances to suppress the release of inflammatory mediators and reduce the expression of adhesion molecules on the surface of immunocompetent cells. The ability to suppress phagocytic hyperactivity and stabilize T-helper function has been experimentally confirmed. An indirect effect on the humoral response, including the regulation of immunoglobulin production, is also observed.

Special attention in the pharmacodynamic profile of Rhinacanthus nasutus is given to antimicrobial activity, realized by disrupting the integrity of bacterial and fungal membranes, as well as inhibiting the synthesis of pathogen proteins. In vitro studies demonstrate direct cytotoxicity of active components against a number of bacterial strains and dermatophytes. Antiviral activity has also been confirmed in experimental models: it is realized by inhibiting viral replication and blocking the interaction of the virus with cellular receptors.

The pharmacodynamic effect on the skin and mucous membranes includes keratolytic activity, antipruritic, and wound-healing effects. This ensures the use of the drug in external forms, especially for dermatological and dental purposes.

At the level of target systems, Rhinacanthus nasutus acts on the cutaneous-mucosal, immune, endocrine, and partially nervous systems, realizing its effects both at the systemic and local levels. The structure of naphthoquinones and flavonoids suggests their interaction with cell membranes, cytochrome P450 enzymes, ion channels, and apoptosis regulatory proteins.

Pharmacokinetics — Rhinacanthus nasutus

Reliable pharmacokinetic studies devoted exclusively to Rhinacanthus nasutus are extremely limited in open peer-reviewed sources to date. Therefore, the description of the pharmacokinetic properties of this taxon is possible based on an analysis of the properties of its main groups of biologically active compounds, as well as taking into account the pharmacokinetics of the dosage forms characteristic of it: powder, dry extract, alcohol tincture, and oil infusion.

Upon oral administration of powder and extract forms, the plant components are absorbed primarily in the proximal parts of the small intestine. Groups of substances, including flavonoids, naphthoquinones, steroid derivatives, and organic acids, are largely subject to presystemic metabolism in the intestinal wall. Hydrophilic components poorly penetrate the lipid barrier and are significantly modified by the intestinal microflora. This results in the formation of active and inactive metabolites, which are subsequently subject to hepatic transformation.

The fat-soluble components contained in the oil infusion are absorbed with the participation of lipid absorption mechanisms. In the presence of cold-pressed oils, especially those with a high degree of emulsifiability, the permeability of enterocyte cell membranes increases. This creates conditions for improved bioavailability of some lipophilic metabolites. At the same time, some of the active substances may enter the lymphatic system and bypass the hepatic barrier at the first stage.

Transdermal application of ointments and creams based on Rhinacanthus nasutus provides mainly local action. However, if the epidermis is damaged or with prolonged use, individual components may penetrate into the systemic circulation. In this case, the active substances undergo hepatic metabolism, including with the participation of conjugation enzymes — glucuronosyltransferase and sulfotransferase.

When applied to mucous membranes (in the form of nasal, ear drops, or rectal suppositories), absorption may be more pronounced due to high vascularization and thin epithelium. This applies to both hydrophilic and lipophilic components. Absorption through the rectal and nasal mucosa is considered particularly active, where rapid entry into the systemic circulation may occur, partially bypassing presystemic metabolism.

The metabolism of most plant components occurs in the liver with the formation of water-soluble conjugates. Microsomal enzyme systems responsible for phases I and II of biotransformation are involved. Some secondary metabolites may undergo enterohepatic circulation. Alcohol tinctures, with proper solvent utilization, demonstrate the same pharmacokinetics as the corresponding dry extracts.

Excretion of metabolites occurs primarily by the kidneys in the form of glucuronides and sulfated compounds. The biliary route of excretion is partially possible, especially for high-molecular-weight compounds. Some volatile components present in the essential oil fraction of the plant may be excreted in exhaled air and through the skin in small amounts. The involvement of intestinal microflora in the reverse transformation and degradation of glycosides is also important, especially with long-term use and chronic oral administration.

Thus, the pharmacokinetic behavior of Rhinacanthus nasutus components depends on the dosage form, routes of administration, and lipophilicity of the active fractions. The most pronounced systemic effect is achieved with oral and rectal administration of extracts, while transdermal and oil forms mainly provide local or tissue-specific action.

Mechanisms of Action — Rhinacanthus nasutus

The action of Rhinacanthus nasutus is mainly due to the content of naphthoquinones (including rhinacanthin-C, -D, -N), flavonoids, and other phenolic compounds, which interact with key biochemical targets. It is known that rhinacanthin-C inhibits the expression of iNOS and COX-2, reducing the release of inflammatory mediators — nitric oxide (NO) and prostaglandin E₂ — in RAW264.7 macrophages  ScienceDirect+15Academia+15jyoungpharm.org+15.

In an animal model, a leaf extract standardized for rhinacanthin-C content demonstrated analgesic and anti-inflammatory activity by suppressing mediators in the early stage of inflammation (histamine, serotonin) and products of prostaglandin biosynthesis Academia.

The antidiabetic potential is described in the form of non-linear (non-competitive) inhibition of α-glucosidase by rhinacanthins-rich extract and rhinacanthin-C, with an enhanced effect when combined with acarbose  ScienceDirect+15ScienceDirect+15Academia+15. Additionally, rhinacanthin-C may potentiate glucose utilization, protect pancreatic cells, and prevent glycation processes  SpringerLink.

Antioxidant properties have also been recorded, due to direct inhibition of pro-oxidant reactions and stabilization of cell membranes. Although specific signaling cascades (NF-κB, MAPK, JAK/STAT) have not been studied in detail for this taxon, the structure of naphthoquinones suggests their influence on these pathways at the level of suppressing the transcription of pro-oxidant and pro-inflammatory genes.

Furthermore, research results show that various rhinacanthins interact synergistically, affecting enzyme systems — for example, they jointly inhibit P450 enzymes in insects, enhancing the effect of insecticides he01.tci-thaijo.org+15SpringerLink+15ScienceDirect+15. This indicates the possibility of enzyme modulation and synergy between compounds.

Taken together, the mechanism of action of Rhinacanthus nasutus includes:

• inhibition of key enzyme systems (iNOS, COX-2, α-glucosidase);
• suppression of pro-inflammatory mediators (NO, PGE₂, histamine, serotonin);
• potentiation of antioxidant defense;
• modulation of enzyme cascades and several pathways affecting immune and nervous components (based on known biomechanisms of flavonoids and naphthoquinones).

Synergy — Rhinacanthus nasutus

Synergistic interaction of Rhinacanthus nasutus with other substances has been confirmed at several levels. For example, rhinacanthin-C and rhinacanthins-rich extract exhibit non-competitive inhibition of α-glucosidase and, in combination with acarbose (an enzyme inhibitor), demonstrate an enhanced effect, indicating potentiation of activity between the natural and synthetic inhibitor Academia+15Academia+15Academia+15Academia.

In another study, it was found that several types of rhinacanthins (B, D, G, N) act synergistically, enhancing the inhibitory effect on P450 enzymes in insects, leading to increased toxicity of the insecticide (cypermethrin) in a model system SpringerLink. This interaction, of the additive and potentiating effect type through enzyme modulation, demonstrates the possibility of increasing overall biological activity due to the combination of components from a single plant.

Such examples confirm the functional enhancement of anti-glucosidase activity (systemic effect on carbohydrate metabolism) and protection against toxins (through enzyme induction or inhibitory action), reflecting the systemic and cellular level of synergy in the mechanisms of action of Rhinacanthus nasutus components.

Geography of Use and Traditional Medicine — Rhinacanthus nasutus

Rhinacanthus nasutus, known in Southeast Asia by the folk names "Phaya Yor" (Thai), "Toothbrush plant" (English), and other regional names, has deep roots in the traditional medical systems of India, Thailand, Vietnam, Laos, Cambodia, Sri Lanka, and southern China. The most intensive use is noted in the folk medicine of northern and central Thailand, as well as in the traditional Indian systems of Siddha and Ayurveda. In the cultures of these regions, the plant was traditionally used mainly in the form of decoctions, juices, fresh pounded leaves, and tinctures, which were applied externally and internally. Leaves were often ground into a paste applied to the skin, or used in the form of compresses and wraps. The juice of the plant was used fresh, sometimes in combination with other herbs, as part of compound remedies intended for cleansing and restoring the body.

In Thai tradition, Rhinacanthus nasutus is associated with the concept of balancing vital elements and is used as a "plant of internal cleansing." It is often included in herbal mixtures used in steam baths, as well as in tambun (local herbal compresses used after childbirth and for energy restoration). Among the ethnic groups of northern Thailand, especially the Tai Lue, the plant was considered a plant that "gives coolness to the body" and was used in ritual ablutions during transitional periods of the year.

In the Indian Siddha tradition, Rhinacanthus nasutus leaves were considered a universal remedy for removing body impurities, and crushed leaves were used in rubs during purification rituals. In Malay folklore, the plant was sometimes associated with the concept of "body fire" and was used for cooling, including through fumigation in huts where a sick person was in isolation.

Among Khmer communities, the plant had significance in home herbalism and ritual practices: fresh branches could be used for sprinkling a dwelling for protection from the evil eye, and the ash of burnt leaves as a component in mixtures for protecting newborns. In Thai Buddhist monasteries, the plant was sometimes used as part of a ritual composition applied to the feet of monks during long walking pilgrimages.

Historical mentions of Rhinacanthus nasutus are found in texts from the 18th century as part of handwritten herbal manuscripts in Pali and Khmer, kept in monasteries in Chiang Mai and Phnom Penh. Archaeoethnobotanical findings indicate the possible use of leaves of this plant in dry medical bundles and herbal dressings found in ritual burials of the peoples of northern Thailand.

Thus, the plant has a stable and multifaceted tradition of use in local medical and ritual practices of Southeast Asia, with an entrenched status as a "cleansing plant," used both for health and protective purposes.