A method of improving the appearance of aging skin in a subject in need thereof, the method comprising topically administering a composition comprising a compound of the general Formula I: or a pharmaceutically acceptable salt thereof, wherein: the dashed line denotes a saturated or non-saturated bond; X is selected from the group consisting of CH, C and N, such that when X is C the dashed line denotes a non-saturated bond and when X is CH or N the dashed line denotes a saturated bond; Y is N or CR 4; Z is N or CR 5; and Ra-Rd, and R 1 -R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, aryl, heteroaryl, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, halide, amine, amide, carbonyl, thiocarbonyl, carboxy, thiocarboxy, epoxide, sulfonate, sulfonyl, sulfinyl, sulfonamide, nitro, nitrile, isonitrile, thiirane, aziridine, nitroso, hydrazine, sulfate, azide, phosphonyl, phosphinyl, urea, thiourea, carbamyl and thiocarbamyl, each being substituted or non-substituted, and a carrier suitable for topical administration on skin, being in a form of a water-in-oil emulsion, said emulsion comprising: from 30 to 80 weight percents propylene glycol; from 7.5 to 30 weight percents phosphatidyl choline; from 5 to 20 weight percents lauroyl macrogolglycerides; from 2.5 to 10 weight percents macrogolglycerol stearate; from 0 to 2 weight percents ethanol; from 0 to 2 weight percents caprylocaproyl macrogolglycerides; from 0 to 2 weight percents propylene glycol monolaurate; and from 2 to 20 weight percents water. or a pharmaceutically acceptable salt thereof, wherein: the dashed line denotes a saturated or non-saturated bond; X is selected from the group consisting of CH, C and N, such that when X is C the dashed line denotes a non-saturated bond and when X is CH or N the dashed line denotes a saturated bond; Y is N or CR 4; Z is N or CR 5; and Ra-Rd, and R 1 -R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, aryl, heteroaryl, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, halide, amine, amide, carbonyl, thiocarbonyl, carboxy, thiocarboxy, epoxide, sulfonate, sulfonyl, sulfinyl, sulfonamide, nitro, nitrile, isonitrile, thiirane, aziridine, nitroso, hydrazine, sulfate, azide, phosphonyl, phosphinyl, urea, thiourea, carbamyl and thiocarbamyl, each being substituted or non-substituted, and a carrier suitable for topical administration on skin, being in a form of a water-in-oil emulsion, said emulsion comprising: from 30 to 80 weight percents propylene glycol; from 7.5 to 30 weight percents phosphatidyl choline; from 5 to 20 weight percents lauroyl macrogolglycerides; from 2.5 to 10 weight percents macrogolglycerol stearate; from 0 to 2 weight percents ethanol; from 0 to 2 weight percents caprylocaproyl macrogolglycerides; from 0 to 2 weight percents propylene glycol monolaurate; and from 2 to 20 weight percents water. the dashed line denotes a saturated or non-saturated bond; X is selected from the group consisting of CH, C and N, such that when X is C the dashed line denotes a non-saturated bond and when X is CH or N the dashed line denotes a saturated bond; Y is N or CR 4; Z is N or CR 5; and Ra-Rd, and R 1 -R 5 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, aryl, heteroaryl, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, halide, amine, amide, carbonyl, thiocarbonyl, carboxy, thiocarboxy, epoxide, sulfonate, sulfonyl, sulfinyl, sulfonamide, nitro, nitrile, isonitrile, thiirane, aziridine, nitroso, hydrazine, sulfate, azide, phosphonyl, phosphinyl, urea, thiourea, carbamyl and thiocarbamyl, each being substituted or non-substituted, and a carrier suitable for topical administration on skin, being in a form of a water-in-oil emulsion, said emulsion comprising: from 30 to 80 weight percents propylene glycol; from 7.5 to 30 weight percents phosphatidyl choline; from 5 to 20 weight percents lauroyl macrogolglycerides; from 2.5 to 10 weight percents macrogolglycerol stearate; from 0 to 2 weight percents ethanol; from 0 to 2 weight percents caprylocaproyl macrogolglycerides; from 0 to 2 weight percents propylene glycol monolaurate; and from 2 to 20 weight percents water. from 30 to 80 weight percents propylene glycol; from 7.5 to 30 weight percents phosphatidyl choline; from 5 to 20 weight percents lauroyl macrogolglycerides; from 2.5 to 10 weight percents macrogolglycerol stearate; from 0 to 2 weight percents ethanol; from 0 to 2 weight percents caprylocaproyl macrogolglycerides; from 0 to 2 weight percents propylene glycol monolaurate; and from 2 to 20 weight percents water.