Dandelion root is used to reduce water retention in high doses, however you would not want to run dandelion root all the time for this because your body will get used to it, and it will stop working as a diuretic.
If you're going to use it in smaller doses it's good for easing inflammation and muscle spasms, removing toxins from the body, treating such varied diseases as those relating to the liver, kidney, gallbladder, and digestive tract.
Not really sure if Vitamin B6 helps with water retention, but it's needed for the processing of amino acids, and helps with the absorbtion of magnesium.
Uva Ursi is used mainly for helping fight a urinary tract infection, and is not recommended to use for longer than 7 to 10 days, or more than 5 cycles per year.
And I haven't a clue what buhu leaf is. lol