Compositions comprising flavonoid-containing extracts from plants of the genus

1. A method for treating an infestation of head lice in a patient in need thereof by killing the head lice and preventing a final development and a hatching of larvae from lice eggs, the method comprising:

applying an effective amount of a composition on the hair of the patient, the composition comprising:

about 0.1 to 1 wt.-% of at least one isolated Citrus flavonoid selected from the group consisting of naringin, naringenin, hesperetin, and hesperidin; and

2 to 7 wt.-% of at least one cationic surface-active agent selected from the group consisting of

palmitamidopropyltrimonium chloride and behentrimonium chloride.

2. The method as recited in claim 1 , wherein the at least one cationic surface active agent is palmitamidopropyltrimonium chloride.

3. The method as recited in claim 1 , wherein the composition is formulated as a shampoo, a spray, an aerosol, a lotion, a hair conditioner, a gel, a mousse, or as a powder.

4. The method of claim 1 , wherein the composition further comprises 92 to 97.9 wt.-% of additives consisting of:

at least one surfactant selected from an ionic surfactant, an anionic amphoteric surfactant, a zwitterionic surfactant, and a cationic surfactant, which are each respectively not the at least one cationic surface-active agent,

at least one of an emulsifier and an emollient,

at least one vehicle,

at least one hair conditioning agent,

at least one preservative, and

optionally, at least one of an insect killing substance, an antioxidant, a pH adjusting agent, and an adjuvant,

wherein, the respective wt.-%'s add to 100 wt.-%.

5. The method of claim 1 , wherein the at least one isolated Citrus flavonoid comprises naringin and the at least one cationic surface active agent comprises palmitamidopropyltrimonium chloride.

6. The method of claim 1 , wherein the at least one isolated Citrus flavonoid comprises naringenin and the at least one cationic surface active agent comprises palmitamidopropyltrimonium chloride.

7. The method of claim 1 , wherein the at least one isolated Citrus flavonoid comprises hesperetin and the at least one cationic surface active agent comprises behentrimonium chloride.

8. The method of claim 1 , wherein the at least one isolated Citrus flavonoid comprises hesperidin and the at least one cationic surface active agent comprises behentrimonium chloride.

9. A method for treating an infestation of head lice in a patient in need thereof by killing the head lice and preventing a final development and a hatching of larvae from lice eggs, the method comprising:

applying an effective amount of a composition on the hair of the patient, the composition comprising a Citrus flavonoid extract and 2 to 7 wt.-% of at least one cationic surface-active agent selected from the group consisting of palmitamidopropyltrimonium chloride and behentrimonium chloride,

wherein the Citrus flavonoid extract provides to the composition about 0.1 to 1 wt.-% of at least one isolated Citrus flavonoid selected from the group consisting of naringin, naringenin, hesperetin, and hesperidin.

10. The method of claim 9 , wherein the Citrus flavonoid extract is obtained by a process consisting of:

providing a plant material of the genus Citrus,

mixing the plant material with a first solvent to remove essential oils from the plant material,

separating the first solvent containing the essential oils from the plant material, drying the plant material,

mixing the plant material with a second solvent,

concentrating the plant material and the second solvent so as to obtain a syrup,

adding an acid to the syrup to precipitate at least one Citrus flavonoid,

washing the precipitated at least one Citrus flavonoid, and

drying the washed precipitated at least one Citrus flavonoid to obtain the Citrus flavonoid extract.

11. The method of claim 9 , wherein the composition further comprises 92 to 97.9 wt.-% of additives consisting of:

at least one surfactant selected from an ionic surfactant, an anionic amphoteric surfactant, a zwitterionic surfactant, and a cationic surfactant, which are each respectively not the at least one cationic surface-active agent,

at least one of an emulsifier and an emollient,

at least one vehicle,

at least one hair conditioning agent,

at least one preservative, and

optionally, at least one of an insect killing substance, an antioxidant, a pH adjusting agent, and an adjuvant,

wherein, the respective wt.-%'s add to 100 wt.-%.

12. The method of claim 9 , wherein the at least one cationic surface active agent is palmitamidopropyltrimonium chloride.

13. The method of claim 9 , wherein the composition is formulated as a shampoo, a spray, an aerosol, a lotion, a hair conditioner, a gel, a mousse, or as a powder.

14. The method of claim 9 , wherein the at least one isolated Citrus flavonoid comprises naringin and the at least one cationic surface active agent comprises palmitamidopropyltrimonium chloride.

15. The method of claim 9 , wherein the at least one isolated Citrus flavonoid comprises naringenin and the at least one cationic surface active agent comprises palmitamidopropyltrimonium chloride.

16. The method of claim 9 , wherein the at least one isolated Citrus flavonoid comprises hesperetin and the at least one cationic surface active agent comprises behentrimonium chloride.

17. The method of claim 9 , wherein the at least one isolated Citrus flavonoid comprises hesperidin and the at least one cationic surface active agent comprises behentrimonium chloride.