Three rasas aggravate one dosha while the other three pacify it. For example, pungent, bitter and astringent (rasa) aggravate vata while sweet, sour and saline pacify it. Likewise, pungent, sour and saline rasas aggravate pitta while sweet, bitter and astringent ones pacify it. Sweet, sour and saline rasa aggravate kapha while pungent, bitter and astringent pacify it.
रसदोषसन्निपाते तु ये रसा यैर्दोषैः समानगुणाः समानगुणभूयिष्ठा वा भवन्ति ते तानभिवर्धयन्ति, विपरीतगुणा विपरीतगुणभूयिष्ठा वा शमयन्त्यभ्यस्यमाना इति| एतद्व्यवस्थाहेतोः षट्त्वमुपदिश्यते रसानां परस्परेणासंसृष्टानां, त्रित्वं च दोषाणाम् ||७||
In case of the conjunction of rasa and dosha, rasas aggravate those dosha sharing similar properties and pacify those that have opposing or antagonistic properties. This explains six rasas for the three dosha.
rasadoSasannipAte tu ye rasA yairdoSaiH samAnaguNAH samAnaguNabhUyiSThA vA bhavanti te tAnabhivardhayanti, viparItaguNA viparItaguNabhUyiSThA vA zamayantyabhyasyamAnA iti| etadvyavasthAhetoH SaTtvamupadizyate rasAnAM paraspareNAsaMsRSTAnAM, tritvaM ca doSANAm ||7||
Whether it is an agent (generically termed dravya in Sanskrit) with multiple rasas or a disorder having afflictions of various dosha, one should first critically analyze the role of each rasa or dosha individually and then determine the effect of the dravya and the disorder.
tatra khalvanekaraseSu dravyeSvanekadoSAtmakeSu ca vikAreSu rasadoSaprabhAvamekaikazyenAbhisamIkSya tato dravyavikArayoH prabhAvatattvaM vyavasyet ||9||
न त्वेवं खलु सर्वत्र| न हि विकृतिविषमसमवेतानां नानात्मकानां परस्परेण चोपहतानामन्यैश्च विकल्पनैर्विकल्पितानामवयवप्रभावानुमानेनैव समुदायप्रभावतत्त्वमध्यवसातुं शक्यम् ||१०||
But this rule is not applicable universally because in case of complex disorders (and dravya) where the effect is not exactly in accordance with the cause due to multiple causative factors operating, with differing (often conflicting) modes of operation, it is not possible to determine the effect of the dravya or the disease on the basis of the effect of individual rasa or dosha.
na tvevaM khalu sarvatra| na hi vikRtiviSamasamavetAnAM nAnAtmakAnAM paraspareNa copahatAnAmanyaizca vikalpanairvikalpitAnAmavayavaprabhAvAnumAnenaiva samudAyaprabhAvatattvamadhyavasAtuM zakyam ||10||