WO2016162493A1

WO2016162493A1 - Treatment of paronychia with indigo naturalis or indigo-producing plant extract

Info

Publication number: WO2016162493A1
Application number: PCT/EP2016/057778
Authority: WO
Inventors: Philippe Andres; Laurent Chantalat; Yin-Ku Lin
Original assignee: Galderma Sa
Priority date: 2015-04-09
Filing date: 2016-04-08
Publication date: 2016-10-13

Abstract

A pharmaceutical or cosmetic composition comprising Indigo Naturalis or Indigo-producing plant extract for treating paronychia, and a method of treating paronychia comprising administering a therapeutically effective amount of Indigo Naturalis or Indigo-producing plant extract to a subject in need thereof are described.

Description

TREATMENT OF PARONYCHIA WITH INDIGO NATURALIS OR

INDIGO-PRODUCING PLANT EXTRACT

TECHNICAL FIELD

The present invention relates to a use of an Indigo Naturalis or Indigo-producing plant extract, particular in a use for treating perionyxis and paronychia.

BACKGROUND

Paronychia is an inflammation of the nail fold and presents as painful periungual erythema associated with oedema and sometimes with purulence. Acute paronychia is usually caused by infection. Chronic paronychia is an inflammatory dermatosis of the nail folds, with secondary effects on the nail matrix, nail growth and soft-tissue attachments. It may be associated with infection on the background of the dermatosis. The dermatosis may be directly due to mechanical factors or an irritant associated with wet work or caustic materials. Alternatively, it may be on the background of atopy or psoriasis, where minor provocation can result in active disease. Paronychia has also been reported as a side effect of chemotherapies.

Treatment is a combination of avoidance of precipitants, hand care and medication. Topical therapy requires a combination of steroids and antimicrobials. Because of the 'mixed' aetiology of the inflammation, many clinicians use antiseptic or antibiotic/anticandida/steroid creams in the chronic phase. Incision is not indicated unless the condition enters an acute tender purulent phase, where removal of the proximal third of the nail may help.

SUMMARY

The present invention relates to an Indigo Naturalis or Indigo-producing plant extract that is effective for treating paronychia and pharmaceutical or cosmetic compositions comprising said Indigo Naturalis or Indigo-producing plant extract.

In one aspect, the present invention provides a pharmaceutical or cosmetic composition comprising Indigo Naturalis or Indigo-producing plant extract for treating paronychia. In another aspect, the present invention provides use of Indigo Naturalis or Indigo-producing plant extract in the preparation of a medicament for treating paronychia.

In further aspect, the present invention provides Indigo Naturalis or Indigo-producing plant extract for treating paronychia.

In another aspect, the present invention provides a method of treating paronychia comprising administering therapeutically effective amount of Indigo Naturalis or Indigo-producing plant extract to a subject (e.g. human) in need thereof.

In a particular embodiment, the Indigo Naturalis or Indigo-producing plant extract of the invention comprises indirubin in an amount of at least 65%, preferably 65-90% w/w of the extract.

In the present invention, paronychia in nail is suffering from nail infection or not suffering from nail infection. In some embodiments, paronychia is caused by Candida albicans. In some embodiments, paronychia is caused by Staphylococcus aureus. In some embodiments, paronychia is caused by chemotherapies. In some embodiments, paronychia is caused by nail psoriasis, atopic dermatitis, or a chemotherapy.

In another aspect of the present invention, the present invention provides use of Indigo Naturalis or Indigo-producing plant extract in the preparation of a medicament for treating paronychia.

In some embodiments, paronychia is caused by Staphylococcus aureus. In some embodiments, paronychia is caused by chemotherapies.

The Indigo Naturalis extract or Indigo-producing plant extract includes any extract obtained from an Indigo Naturalis or Indigo-producing or Indigo-bearing plant as starting material.

DESCRIPTION OF DRAWINGS

Figure 1

Al and CI : Two patients that had chronic paronychia A2 and C2: Improvements have been shown in the patients after treated by Indigo Naturalis extract.

DETAILED DESCRIPTION

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art.

Indigo Naturalis, also known as Qingdai, is obtained from one or more plants including Indigofera tinctoria L., Baphicacanthus cusia (Nees) Bremek (syn. Strobilanthes cusia (Nees), Persicaria tinctoria (Aiton) Spach. (syn. Polygonum tinctorium Aiton, P. tinctorium Lour.), Isatis tinctoria L. (syn. Isatis indigotica Fort.) and S. formosanus, such as from the plant leaves or stems, and the leaves and/or stems, after harvest and collection, may be processed by, for example, fermentation. Qingdai is the current name for Indigo Naturalis. Indigo Naturalis is usually a dark-blue powder. It is obtained from Indigo-bearing or Indigo-producing plants with a NaOH or KOH aqueous solution and corresponds to a mixture of around 5-15% organic compounds including alkaloids among which indigo and indirubin are present, and 85-95 % inorganic compounds such as calcium carbonate and calcium hydroxide.

An Indigo Naturalis or Indigo-producing plant extract, as used herein, refers to an extract from Indigo Naturalis or from the leaves and/or stems (or a part thereof) of one or more Indigo-bearing plant or Indigo-producing plant, where the extraction may be performed by using organic solvents and/or non-organic solvents, or a combination thereof. The extract may include at least one enriched ingredient (having a higher w/w percentage than that existing in Indigo Naturalis) such as tryptanthrin, isatin, indirubin, indigo, or qingdainone. The extract may be a solid, liquid, or any form in-between (e.g., semi-solid).

In a particular embodiment, the Indigo Naturalis or Indigo-producing plant extract is enriched in indirubin, for example the extract may contain indirubin in an amount of at least contain indigo in an amount of 0.1%- 15% w/w of the extract. The extract may also contain tryptanthrin and/or qingdainone each in an amount of 0.1-5% w/w.

One example of the Indigo Naturalis or Indigo-producing plant extract is an ethyl acetate extract (EA-extract), which may be prepared as illustrated by Example 2 in this application. The content of each ingredient in the extract may vary. As an example, the extract may contain indirubin in an amount of at least 65% w/w of the extract, for example, 65%-90% w/w of the extract. The extract may further contain indigo in an amount of 0.1%- 15% w/w of the extract. The extract may also contain tryptanthrin and/or qingdainone each in an amount of 0.1 -5% w/w.

A further example of Indigo Naturalis extract is an oil extract, particularly an olive oil extract. An oil extract can be prepared according to the method disclosed in the patent US 8,784,905. More specifically, the oil extract of Indigo Naturalis is an oil-extracted product of Indigo Naturalis which is obtained by a process comprising extracting Indigo Naturalis powder with an oil under heating, optionally followed by a refining treatment by filtration. More preferably, in said process, the oil-extracted product is obtained after the refining treatment has a decreased indigo content. In said process, extracting Indigo Naturalis powder is more particularly conducted at an elevated temperature not higher than 155° C, and preferably conducted at a temperature ranging from 100° C. to 1 55° C. The oil used in said process is preferably selected from the group consisting of vegetable oils, animal oils, mineral oils, and combinations thereof. More preferably, the oil is a vegetable oil and can be selected from the group consisting of olive oil, cottonseed oil, sesame oil, sunflower seed oil, peanut oil, wheat germ oil, soybean oil, jojoba oil. evening primrose oil, coconut oil. palm oil. sweet almond oil. aloe oil, apricot kernel oil. avocado oil, borage oil, hemp seed oil, macadamia nut oil, rose hip oil, pecan oil, hazelnut oil. sasanqua oil. rice bran oil. shea butter, corn oil, camellia oil, grape seed oil, canola oil. castor oil, and combinations thereof. The content of each ingredient in the extract may vary. As an example, the extract may contain indirubin in an amount of at least 65% w/w of the total amount of extracted alkaloids, for example, 65%-90% w/w of the total amount of extracted alkaloids. The extract may further contain indigo in an amount of 0.1%- 15% w/w of the total amount of extracted alkaloids. The extract may also contain tryptanthrin and/or qingdainone each in an amount of 0.1-5% w/w of the total amount of extracted alkaloids.

Another example of Indigo Naturalis or Indigo-producing plant extract is an extract prepared by a process comprising the following steps:

a) an extraction step: extracting Indigo Naturalis or the leaves and/or stems of one or more Indigo-bearing plants or Indigo-producing plants, preferably selected from the group consisting of Indigofera tinctoria L., Baphicacanthus cusia (Nees) Bremek (syn. Strobilanthes cusia (Nees)), Persicaria tinctoria (Aiton) Spach. (syn. Polygonum tinctorium Alton, P. tlnctorium Lour.) and Isatls tinctoria L. (syn. Isatls Indlgotlca Fort.) and/or Strobilanthes Formosanus, with a first polar solvent or moderately polar solvent to obtain a mixture of extraction; b) a filtration step: filtering the mixture of extraction to obtain a filtrate; c) a concentration step: concentrating the filtrate to obtain a crude extract; d) a washing step: washing the crude extract with a non-polar solvent, and optionally a second polar solvent, to obtain a washing mixture; and

e) a filtration step: filtering the washing mixture to obtain a refined extract optionally after a drying step, for example, according to a conventional method for drying.

In a particular embodiment, a crude extract obtained from the concentration step c) is subjected to the following procedure for at least one cycle till obtaining a refined extract: the crude extract is washed by a solvent (step d)), and filtered (step (e)) to yield a refined extract, optionally followed by a drying step. According to a specific embodiment, the washing step d) and filtration step e) are performed by only one cycle to obtain the refined extract. When more than one cycle is applied, the same or different solvents for washing can be used. Further, the crude extract can be washed with a solvent under reflux, the mixture can be cooled to room temperature and then filtered to yield a refined extract, optionally followed by a drying step. In a preferred embodiment, two cycles are performed. Particularly, the crude extract obtained by the concentration step c) is washed in a non- polar solvent, preferably hexane (step d) and filtered (step e), optionally followed by a drying step. The hexane extract is then washed by an organic polar solvent, preferably ethanol (step d) and then filtered (step e) to obtain a refined extract, optionally followed by a drying step.

Optionally, a micronization step is performed after step e), providing thereby a refined extract having a particle size between 25 and 35 μιη, preferably of about 30 μιη.

In another preferred embodiment, when the refined extract is micronized in the last step, 99% of the obtained particles are less or equal to 30 μηι.Ιη a preferred embodiment, a refined extract may be prepared by a process comprising the following steps consisting of: a) (i) adding an extracting solvent, a polar or moderately polar solvent (such as an alcohol or ethyl acetate), to Indigo Naturalis powder to yield a mixture; (ii) heating and stirring the mixture for a period of time (e.g. , 30 min, 1 hour, 2 hours); b) (iii) filtering the heated mixture while hot to remove insoluble by-products to yield a filtrate; c) (iv) concentrating the filtrate to yield a crude extract; d) (v) adding a washing solvent (for example, water a non-polar and/or a polar solvent or a mixture thereof) to the crude extract to yield a washing mixture; (vi) heating and stirring the washing mixture for a period of time (e.g. , 30 min, 1 hour, 2 hours); e) (vii) filtering the washing mixture, for example at room temperature (e.g. 18-35°C) to collect a refined extract; optionally (viii) repeating steps (v) to (vii) until the amount of indirubin (% w/w) in the refined extract is more than 55% (w/w), preferably more than 65%> (w/w) as measured by HPLC method, and optionally (ix) drying the residue according to a conventional method (e.g., air-drying, lyophilization) to obtain a dried extract. The washing solvent in steps (v) and (viii) can be the same or different.

In a more preferred embodiment, a refined extract is prepared by a process comprising the steps of:

a) extracting Indigo Naturalis with ethanol at reflux between 2 and 8 hours, b) filtering the mixture at a temperature not less than 65°C to obtain a filtrate, c) concentrating the filtrate, to obtain a crude extract, said crude extract is optionally filtered (with addition of water) in order to remove completely the solvent and the last components still present in the solvent and dried, d) (i) washing the crude extract with hexane at a temperature not less than 50°C between 15 and 60 min,

(ii) filtering at room temperature the mixture obtained at step d) (i) to obtain a product, optionally rinsing it with ethanol and water

(iii) washing the product obtained at step d) (ii) with ethanol at reflux, and e) filtering at room temperature the washing mixture obtained at step d) and drying the resulting product at a temperature less than 80°C to obtain an extract which is optionally micronized.

In another preferred embodiment, when the refined extract is micronized in the last step, the particle size is around 99% in the range 25 to 35 μιη, preferably of about 30 μιη.

As used herein, "about" or "around" will be understood by a person of ordinary skill in the art and will vary to some extent on the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art given the context in which it is used, "about" or "around" will mean up to plus or minus 20%>, preferably 10%> of the particular term.

The term "refined extract", as used herein, refers to a solid, semi-solid or oily extract which contains less than 10%> (w/w) of water and/or solvents used in the process for preparing the said refined extract. A refined extract is more preferably characterized by an increase amount of active ingredients, including alkaloids among which indigo, indirubin, tryptanthrin, and/or qingdainone are present, preferably enriched in indirubin, compared to Qingdai or Indigo Naturalis. More specifically, the refined extract according to the invention comprises at least 60%>, or more preferably more than 65 %, (w/w) of active ingredients, including indigo, indirubin, tryptanthrin, and/or qingdainone.

The term "crude extract", as used herein, refers to a solid, semi-solid or oily extract which contains less than 15% (w/w) (e.g., 5-15%, 5-10%) of water and/or solvents used in the process for preparing the refined extract. The crude extract is less enriched in indirubin, than the refined extract as compared to Qingdai or Indigo Naturalis. The crude extract is obtained by the concentration step c) according to the invention. The concentration step is more particularly carried out by sending the filtrate to a concentrator (for instance at reduced pressure), as to remove water and/or solvents used in the process and concentrating thereby the active ingredients present in the extract, including indigo, indirubin, tryptanthrin, and/or qingdainone.

"one cycle", as used herein, refers to the two steps of the washing step d) and filtration step e) which are performed sequentially once, "two cycles", as used herein, refers to the two steps of the washing step d) and filtration step e) which are performed sequentially twice.

According to a specific embodiment, the Indigo Naturalis or Indigo-producing plant extract according to the invention is an oil extract as defined above or an extract of Indigo-producing plant obtained by the process as above detailed comprising steps (a)-(e), optionally including one of the above described specific embodiments.

A therapeutically effective amount refers to a dose level of an Indigo Naturalis or

Indigo-producing plant extract that yields a therapeutic benefit (for example, amelioration, reduction or cure of the diseases, disorder or symptoms of paronychia) to a patient on average.

The present invention provides a composition comprising an Indigo Naturalis or Indigo-producing plant extract for treating paronychia, preferably for treating paronychia topically. The extract may be used directly without further formulation or included in a pharmaceutical or cosmetic composition that comprises the extract.

The extract may comprise indirubin in an amount of at least 65% w/w of the extract, for example, 65%-90% w/w of the extract. It may further comprise indigo in an amount of 0.1%- 15% w/w of the extract, and in another further embodiment, the extract may also comprise indigo in an amount of 0.1%- 15% w/w of the extract and tryptanthrin and/or qingdainone each in an amount of 0.1-5% w/w of the extract. The compositions, methods or uses of the invention may be used alone (i.e., in replacement of current treatments) or in combination with current treatments to improve their efficacy.

In an embodiment, Indigo Naturalis or Indigo-producing plant extract is used as the sole active ingredient (e.g. as a single therapy). According to this embodiment, the composition preferably comprises an Indigo Naturalis or Indigo-producing plant extract as the sole active ingredient.

In another embodiment, the Indigo Naturalis or Indigo-producing plant extract can be used in combination with at least one other therapy.

The pharmaceutical composition may be formulated into a suitable dosage form for topical or oral administration using technology well known to those skilled in the art. The pharmaceutical composition can additionally comprise a pharmaceutically acceptable carrier such as those widely employed in the art of drug-manufacturing. For instance, the pharmaceutically acceptable carrier may include one or more of the following agents: solvents such as olive oil, olive oil refined, cottonseed oil, sesame oil, sunflower seed oil, peanut oil, wheat germ oil, soybean oil, jojoba oil, evening primrose oil, coconut oil, palm oil, sweet almond oil, aloe oil, apricot kernel oil, avocado oil, borage oil, hemp seed oil, macadamia nut oil, rose hip oil, pecan oil, hazelnut oil, sasanqua oil, rice bran oil, shea butter, corn oil, camellia oil, grape seed oil, canola oil, castor oil, and combinations thereof, preferably olive oil refined, emulsifiers, suspending agents, decomposers, binding agents, excipients, stabilizing agents, chelating agents, diluents, gelling agents, thickening agent such as beeswax and/or petroleum jelly, preservatives, lubricants, absorption delaying agents, liposomes, antioxidants such as butylhydroxytoluene or butylhydroxyanisole and the like. A topical formulation suitable for the pharmaceutical composition according to the present invention may be an emulsion, a gel, an ointment, a cream, a patch, an embrocation, an aerosol, a spray, a lotion, a serum, a paste, a foam, or a drop. In some embodiments, the pharmaceutical composition is formulated into an external preparation by admixing the extract according to the present invention with a base such as those that are well known and commonly used in the art.

According to a specific embodiment, the compositions, methods or uses of the invention are suitable for a topical treatment of a skin disease caused by a bacterium.

In some embodiments, the dosage and the frequency of administration of the pharmaceutical composition according to the present invention may vary depending on the following factors: the severity of the disease to be treated, the route of administration, and the weight, age, physical condition and response of the subject to be treated. In further or additional embodiments, the amount of the extract is in the range of about 0.001 to about 1000 mg/kg body weight/day, for example, about 0.01 to about 500, 300, or lOOmg/kg body weight/day. In further or additional embodiments, administration can be performed daily or even several times per day, if necessary. By way of examples, the extract of the invention can be administered once, twice, three, four, five or six times a week or more, or once, twice, three or four times a day or more. Duration of the treatment may vary and depends on the severity of the disease. It may last for instance from one week to several months (such as from 2, 3, 4, 5, 6 or 7 weeks to 12, 18, 24, 30, or 36 weeks).

Additionally, the present invention provides a cosmetic composition comprising the extract. The composition may be present in a form adapted for topical application comprising a cosmetically or dermatologically acceptable carrier or medium. "Cosmetically or dermatologically acceptable" means media which are suitable for a use in which they come into contact with the skin or human skin appendages without posing a risk of toxicity, intolerance, instability, allergic reaction, etc. In the cosmetic composition, the extract may be previously solubilized in one or more cosmetically or dermatologically acceptable solvents, such as water, glycerol, ethanol, propylene glycol, butylene glycol, dipropylene glycol, ethoxylated or propoxylated diglycols, cyclic polyols, petroleum jelly, a vegetable oil or any mixture of these solvents.

The composition according to the invention may contain 0.001-10 mg, for example 0.01-1 mg of one or more active ingredients per lg composition. The present invention provides a method of treating paronychia, comprising administering a therapeutically effective amount of an Indigo Naturalis or Indigo-producing plant extract to a subject in need thereof. The extract and compositions above can be used in the treatment or alleviation of a disease or condition. By treatment it is meant at least an alleviation of the symptoms associated with the pathological condition afflicting the subject, where alleviation is used in a broad sense to refer to at least a reduction in the magnitude of a parameter, e.g. symptom, associated with the pathological condition being treated. As such, treatment also includes situations where the pathological condition, or at least symptoms associated therewith, are completely inhibited, e.g., prevented from happening, or stopped, e.g., terminated, such that the host no longer suffers from the pathological condition, or at least the symptoms that characterize the pathological condition. As such, treatment includes both curing and managing a disease condition. Accordingly, the extract and compositions above can be used in the treatment or alleviation of paronychia.

The efficacy of the extract and compositions can be evaluated by in vivo models with respect to their activities in treating diseases or disorders, for example, clinically trials on humans.

The novel features of the present invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present application will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the present invention are utilized.

While embodiments of the present invention have been shown and described herein such embodiments are provided by way of example only. It should be understood that the above described embodiments may be combined if compatible and various alternatives to the embodiments of the present invention described herein may be employed in practicing the present invention. Those ordinary skilled in the art will appreciate that numerous variations, changes, and substitutions are possible without departing from the present invention. It is intended that the following claims define the scope of aspects of the present invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art. All documents, or portions of documents, cited in the present invention including, without limitation, patents, patent applications, articles, books, manuals, and treatises are hereby expressly incorporated by reference in their entirety for any purpose.

The percentage herein is expressed by weight relative to the weight of the extract, unless otherwise specified.

Further aspects and advantages of the invention will be disclosed in the following illustrative experimental section.

EXAMPLES 1. Preparation of refined Indigo Naturalis or Indigo-producing plant extracts and analytical methods for analysis

Example 1: Preparation of a refined Indigo Naturalis extract

Qingdai as used in the following preparation is obtained from Delong Pharmaceutical (Indigo 2.62% and Indirubin 0.284% and tryptanthrin 0.0046%).

500g of Qingdai were suspended in 10L ethyl acetate. The mixture was stirred in reflux for two hours, and then filtered at 75°C. The filtrate was concentrated at reduced pressure to yield a dark solid. The crude extract was stirred in 250mL hexane and heated to reflux for one hour. After cooling to room temperature, the suspension was filtered to give a dark residue.

0.50g of the dark residue were refluxed in 25mL hexane again for one hour, and cooled to room temperature, followed by filtration to give a refined extract as a dark red solid 452mg. HPLC: 62.9% indirubin, 12.9% indigo, and 0.53% tryptanthrin. Example 2: Preparation of a refined Indigo Naturalis extract

500g of Qingdai as used in Example 1 were suspended in 10L alcohol (ethanol). The mixture was stirred in refiux for two hours, and then filtered at 75°C. The filtrate was concentrated at reduced pressure to yield a dark solid, which was stirred in 260mL hexane and heated to reflux for one hour. Upon cooling to room temperature, the suspension was filtered to give a dark residue.

0.80g of the dark residue were refluxed in 24mL alcohol (ethanol) for an additional hour, and then cooled to room temperature, followed by filtration to give a refined extract as a dark red solid (538mg). HPLC: 83.6% indirubin, 6.35% indigo, and 0.75%> tryptanthrin.

Example 3: Preparation of a refined Indigo Naturalis extract

500g of Qingdai as used in Example 1 were suspended in 10L ethyl acetate. The mixture was stirred in refiux for two hours, and then filtered while hot. The filtrate was concentrated at reduced pressure to yield a dark solid. The crude extract was stirred in 250mL hexane and heated to reflux for one hour. After cooling to room temperature, the suspension was filtered to give a dark residue.

0.75g of the dark residue were refluxed in 22.5mL ethanol for one hour, and cooled to room temperature, followed by filtration to give a refined extract as a dark red solid (538mg). HPLC: 77.9% indirubin, 15.9% indigo, and 0.56% tryptanthrin.

Example 4: Preparation of a refined Indigo Naturalis extract

500g of Qingdai as used in Example 1 were suspended in 2.1L DMF. The mixture was stirred at 50°C for 40 minutes. Upon cooling to 20°C, the suspension was filtered. The filtrate was concentrated at reduced pressure to yield a dark solid, which was stirred in 130mL hexane and heated to refiux for one hour. Upon cooling to 20°C, the suspension was filtered to give a dark residue.

1.56g of the dark residue was washed with 46.8 ml ethanol, and heated to reflux for one hour, and then cooled to 20°C, followed by filtered to yield a refined extract (766mg). HPLC: 66.3%, indirubin, 9.76% indigo.

Example 5: Preparation of a refined Indigo Naturalis extract

500g of Qingdai as used in Example 1 were suspended in 3L DMF. The mixture was stirred at 30°C for 1 hour, and then filtered. The filtrate was concentrated at reduced pressure to yield a dark solid, which was stirred in 230mL hexane and heated to reflux for one hour. Upon cooling to 20°C, the suspension was filtered to give a dark residue.

1.96g of the dark residue was washed with 59mL 85% ethanol (85% aq. alcohol), and heated to reflux for one hour followed by filtration while hot to yield a refined extract (1.02g). HPLC: 69.4% indirubin, 18.7% indigo, and 0.62% tryptanthrin.

Example 6: Preparation of a refined Indigo Naturalis extract

lOOg of Qingdai was extracted with 2L of ethanol 92% (92% aqueous ethanol) for 2 hours under reflux conditions. Upon completion, the mixture was filtered while hot on AF6 filter (Buchner) to obtain a dark blue -red solution as a filtrate. This filtrate was reduced under vacuum to dryness to give 2.4 g of dry residue. This residue was washed with 120 mL of hexane for lh under reflux. Upon completion, the mixture was cooled to room temperature for 2h then filtered under vacuum to yield 312.9mg of a dark red refined extract.

280mg of this refined extract were washed with 15 mL of ethanol 92% (92% aqueous ethanol) for lh under reflux. Upon completion the solution was cooled to room temperature, and then filtered to yield 159 mg of a dark red/burgundy refined extract after drying in oven (80°C) for lh30. (0.18%); HPLC: 82.31% indirubin, 8.99% indigo, and 0.81% tryptanthrin.

Example 7: Micronization step

The micronization step of refined Indigo Naturalis or Indigo-producing plant extract obtained in the previous examples is performed with the following equipment:

Micronizer: spiral jet Mill Diameter 200

Feeder: this equipment is used for the dosage of powder to feed the micronizer. The dosage is made thanks to two screws. This system allows a regularity of the flow.

Micronization consists to project grains of powder with jet of air. The contact of grains permits their explosion.

Following parameters of micronization are recorded during the micronization:

Ring pressure: 6 bar

Injector pressure: 3 bar

The flow of powder feed: 25 kg/h

The micronizer allows a cylindrical enclosure - holes around the enclosure for the injection of air.

Powder is introduced in the micronizer; grains are propelled thanks to jet of air. When grains have the good size, they are concentrated in the center of the micronizer and they are breathed. To avoid any contamination by foreign particles or broken pieces of the equipment, an additional sieving (sieve: 700 μιη) is performed.

The step is done manually after the micronization and before the packaging.

A granulometric analysis of the homogeneous product obtained was carried out according to the particular size distribution (PSD) method [Analytical specifications: D99 < 30 μιη].

2. Clinical assay

Here we present two patients (A and C) who had chronic paronychia who were dissatisfied with or did not respond to other treatment methods responding dramatically to topical treatment of Indigo Naturalis extract in oil (Lindioil, the refined olive oil extract prepared in example 2 of U.S. Patent 8,784,905).

The patients' characteristics are shown in tablel . The age of these two patients is 68 (A) and 57 (C) years old.

Patients were instructed to drip and apply one to two drops of Lindioil (0.05ml) onto the nail plate fold and hyponychium of affected nails once or twice daily. The two patients had the paronychia and nail bed discoloration in their fingernails disappear, on average, after 6 months of treatment with Lindioil. The two patients' improvements were made with no adverse side effects.

Table 1. Demographics

Date of

Age, Duration of psoriasis Date of the lesion

Patient Gender treatment

r (skin / nail ), y disappear

start

A 68 Male 35 / 3 20081013 2009061 1

C 57 Male 3 / 2 20090801 20100210

Claims

1. A pharmaceutical or cosmetic composition comprising an Indigo Naturalis or Indigo-producing plant extract for a use in the treatment of paronychia.

2. A pharmaceutical or cosmetic composition for a use according to claim 1, wherein the Indigo Naturalis or Indigo-producing plant extract comprises indirubin in an amount of at least 65% w/w of the extract, preferably 65%>-90%> w/w of the extract.

3. The pharmaceutical or cosmetic composition for a use according to claim 1 or 2, wherein the paronychia is caused by nail psoriasis.

4. The pharmaceutical or cosmetic composition for a use according to claim 1 or 2, wherein the paronychia is caused by Atopic dermatitis.

5. The pharmaceutical or cosmetic composition for a use according to claim 1 or 2, wherein the paronychia is caused by a chemotherapy.

6. An Indigo Naturalis or Indigo-producing plant extract for a use in the treatment of paronychia.

7. The Indigo Naturalis or Indigo-producing plant extract for a use according to claim 6, comprising indirubin in an amount of at least 65% w/w of the extract, preferably 65%-90% w/w of the extract.

8. The Indigo Naturalis or Indigo-producing plant extract for a use according to claim 6 or 7, wherein the paronychia is caused by nail psoriasis.

9. The Indigo Naturalis or Indigo-producing plant extract for a use according to claim 6 or 7, wherein the paronychia is caused by atopic dermatitis.

10. The Indigo Naturalis or Indigo-producing plant extract for a use according to claim 6 or 7, wherein the paronychia is caused by a chemotherapy.