Herbal Intervention for Scabies: Development and Standardization of Naregamia Alata Based Polyherbal Powder

Scabies is a highly contagious skin disease caused by Sarcoptes scabiei, affecting millions globally, especially in developing countries. Although conventional treatments such as permethrin and ivermectin are effective, their use is limited by resistance, toxicity, and recurrence. Herbal medicines have gained increasing attention due to their safety, affordability, and therapeutic potential⁽¹⁾. Medicinal plants such as Naregamia alata, Azadirachta indica, and Curcuma longa are well known for their antimicrobial, anti-inflammatory, and antiparasitic properties and have been traditionally used in the management of skin disorders. Therefore, the present study aims to develop a polyherbal powder formulation and evaluate its pharmacognostic, physicochemical, and antimicrobial properties⁽²⁾.

Naregamia alata is a small medicinal herb from the Rutaceae family, commonly found in tropical regions of India and used in traditional Ayurvedic medicine. It is known for its anti-inflammatory and antimicrobial properties and is used to treat skin diseases, wounds, and digestive disorders. Azadirachta indica is a medicinal tree widely found in India and used in Ayurveda for its antimicrobial and anti-inflammatory properties. It is commonly used to treat skin diseases, infections, and dental problems. Curcuma longa is a perennial herb known for its active compound curcumin, which has strong antioxidant and healing effects. It is widely used for wounds, inflammation, and digestive disorders^.(3)

                      Fig 1 : Naregamia alata                        Fig 2  :  Curcuma long           Fig3:  Azadirachta indica

MATERIALS AND METHODS

Collection & authentication of plant materials

Fresh leaves of Naregamia alata, Azadirachta indica, and rhizomes of Curcuma longa were collected from different regions of Kerala and authenticated by a qualified expert.

Pharmacognostical evaluation

Morphological characteristics (color, odor, taste, size, and shape) and microscopical features of Naregamia alata leaves were evaluated using standard parameters.⁽⁴⁾

Phytochemical studies

Hydroalcoholic extraction was performed by macerating 5 g of powdered Naregamia alata leaves in ethanol:water (70:30) for 7 days, followed by filtration and evaporation to dryness⁽⁵⁾.The extract was dissolved in ethanol and was used to test the presence of bioactive compounds like alkaloids, flavonoids, carbohydrates, tannins, polyphenols, terpenoids, sterols, saponins, glycosides, proteins & amino acids. ⁽⁶⁾

Preparation of polyherbal powder

Dried plant materials of Naregamia alata, Azadirachta indica, and Curcuma longa were powdered separately, sieved & mixed thoroughly to obtain a uniform blend, and stored in airtight containers ^(7,8).

Table 1:  Formulation of polyherbal powder

Standardization of polyherbal powder

Organoleptic evaluation

The formulation was evaluated for color, odor, taste, and texture using sensory observation methods.

Physicochemical evaluation

Moisture Content (Loss on Drying)

Moisture content was determined by drying the sample to constant weight and calculated as percentage weight loss. ⁽⁹⁾

Moisture content (LOD) = Initial weight-Final weightInitial weight

Ash value

Total ash, acid-insoluble ash, and water-soluble ash were determined to evaluate inorganic content and purity of the formulation.

Total Ash =weight of ashweight of sample

Acid-Insoluble Ash = weight of acid insoluble residueweight of sample

Water-Soluble Ash = weight of water soluble residueweight of sample

pH

The pH was measured by preparing a 1% aqueous suspension of the powder and determining the value using pH paper.⁽¹⁰⁾

Extractive Value

Alcohol-soluble and water-soluble extractive values were determined by maceration and evaporation to dryness, indicating the amount of active constituents present.

Particle size & flow properties

Angle of repose

Determined by fixed funnel method to assess flowability of the powder.

θ=tan

Bulk density

Measured to evaluate packing ability and compressibility.

Bulk density =  Mass of powderBulk volume

Tapped density = Mass of powderTapped volume

Carr’s Index and Hausner’s Ratio

Calculated from bulk and tapped densities to determine flow properties of the formulation.⁽¹¹⁾

Carr’s index = Tapped density-Bulk densityTapped density ×100

Hausner’s ratio = Tapped densityBulk density

Thin layer chromatography

TLC analysis was performed using curcumin as a standard marker. The sample and standard solutions were spotted on silica gel plates and developed using ethanol:water (1:9) solvent system. The plates were observed under UV light, and similarity in spot position confirmed the presence of phytoconstituents.⁽¹²⁾

In-vitro antimicrobial activity

Antimicrobial activity was evaluated against Escherichia coli using agar well diffusion method. The formulation was introduced into wells of inoculated nutrient agar plates and incubated at 37°C for 24 hours & zone of inhibition was measured .⁽¹³⁾

Polyherbal powder-milk interaction study

1.Organoleptic and immediate-use observation study

The formulation was mixed with warm milk showed no curdling, precipitation, foul odor, or abnormal color change up to 30 minutes. A uniform yellow color was observed, indicating good compatibility and suitability for immediate consumption.

2. pH stability study

The pH of the polyherbal extract (~8.0), milk (~6.5), and the mixture (~8.0) showed no significant variation, indicating absence of interaction and good pH stability.

3. Short-term stability study

The formulation remained stable for 1 hour without any changes in color, odor, or phase separation, confirming compatibility within the normal consumption period.

4. Centrifugation study

No difference in precipitate formation was observed between milk and the formulation mixture after centrifugation, indicating physical stability and no interaction.^(14,15)

RESULTS & DISCUSSION

Collection & authentication of plant materials

Fresh healthy leaves of Naregamia alata were collected  from Thiruvallur, Vadakara, Kerala , fresh leaves of Azadirachta indica from Payangadi, Kannur, Kerala and mature rhizomes of Curcuma longa from Payyannur, Kannur, Kerala. The collected plants were authenticated by Dr. Athira Chandran, Associate professor, MVR Ayurveda Medical College, Parassinikadavu, Kannur.

Pharmacognostical Evaluation

Morphological evaluation

Table 2: : Morphological characterization

Microscopical Evaluation

Transverse section

Numerous free hand sections of leaf were taken, stained using safranin and mounted.

Fig 4: TS of Naregamia alata

TS of Naregamia alata include:

1. Upper epidermis: Consist of single layer of elongated and compactly arranged cell.
2. Palisade: Elongated tightly packed cells seen beneath upper epidermis.
3. Mesophyll: Loosely arranged cells between epidermal layers, spongy in nature.
4. Vascular bundle: Contains cells that appear to be xylem and phloem. The purple or violet color is often due to the specific stain saffranin used in microscopy.
5. Xylem: Radially arranged cells towards centre, for water transport.
6. Phloem: Seen around xylem, for food transport.
7. Collenchyma cells: Unevenly thickened, mainly at corner, thickening due to cellulose and pectin.
8. Lower epidermis: Outermost single layer on the lower surface of leaves.
1. Trichomes: Unicellular, elongated, curved structure, thick walled and tapering towards the tip.

Powder microscopy

The leaves of Naregamia alata were powdered and stained with phloroglucinol and dilute HCl, then observed under microscope.

                     (a)                                        (b)                                          (c)                                       (d)

            (a) Stone cells                       (b) Fibre                       (c) Trichome fragments         (d) Oil globules

Fig 5: Powder microscopy of leaves of Naregamia alata

Phytochemical studies

10g of powdered leaves of Naregamia alata was subjected to hydro alcoholic extraction.

Table 3: Phytochemical screening of Naregamia alata leaf extract

Preparation of polyherbal powder

25g of Naregamia alata based polyherbal powder was prepared by mixing Naregamia alata,

Azadirachta indica and Curcuma longa in powdered form.

Fig 6: Formulation of polyherbal powder

Standardization of polyherbal powder

Organoleptic evaluation

Table 4: Organoleptic evaluation

Physicochemical evaluation

Table 5: Physicochemical evaluation

Particle size and flow properties                           

Table 6: Particle size and flow properties

The study shows that the prepared polyherbal powder formulation have a good flow property.

Thin Layer Chromatography

TLC analysis of hydroalcoholic extracts of Curcuma longa, Naregamia alata, and Azadirachta indica was performed using ethanol:water (1:9) solvent system revealed Rf values of 0.79, 0.837 and 0.89 respectively. Comparison with standard curcumin (Rf 0.923) indicates that Curcuma longa and Naregamia alata contain curcumin-like polyphenolic compounds with slightly higher polarity, whereas Naregamia alata extract contains compounds with nearly identical polarity to curcumin, likely curcumin-like polyphenols or moderately polar flavonoids. These results confirm the presence of flavonoid and phenolic constituents in all extracts.

                                               (a)                                       (b)                                  (c)

Fig 7: TLC chromatogram of (a)Naregamia alata (b)Cucruma longa (c)Azadirachta indica

In-vitro Antimicrobial activity

Table 7: Determination of antimicrobial activity

                                (a) Control         (b)  Standard                              (c)  Sample

Fig 8: Zone of inhibition of antimicrobial activity of Naregamia alata based polyherbal powder extract