Ekstrakt drveta pitomog kestena je smjesa taninskih i netaninskih komponenti. Od taninskih komponenti najzastupljeniji glikozidi su kastalagin i veskalagin, koji su i najvažniji, jer imaju terapijsko djelovanje. Tijekom provedenih in vitro i in vivo ispitivanja ustvrđeno je da tanini ekstrakta drveta pitomog kestena imaju antidiuretsko, adstringentno, antivirusno, antimikrobno, antiprotozoalno i antihelmintičko djelovanje. Isto tako djeluju i kao antikancerogene tvari. Tanini učestvuju u interakciji s membranskim strukturama nekih mikroorganizama pa na taj način izazivaju smanjenje permeabiliteta stanične membrane. Ovo antimikrobno djelovanje je u prednosti u odnosu na djelovanje antibiotika, jer tanini izazivaju samo inhibiciju rasta mikroflore, ali ne i njenu destrukciju. Tanini unešeni p.o. u terapijskim koncentracijama (2-5%) se ne resorbiraju, tako da ne mogu izazvati farmakodinamičke učinke na drugim sustavima. U crijevima se hidrolizom potpuno biotransformiraju do polifenola (galne, digalne i elagne kiseline) i glukoze, kao osnovnih komponenti. U mokraći se mogu ustvrditi samo razgradni produkti tanina u obliku glukuronida. U terapijskim koncentracijama tanini vrlo slabo djeluju na kožu, dok na sluznice djeluju adstringentno. U većim koncentracijama mogu prouzročiti propadanje površnih pa i dubljih slojeva sluznica i granulacionog tkiva. Imajući u vidu činjenicu da ne pokazuju teratogene, kancerogene, niti mutagene učinke, može se zaključiti da su tanini sasvim sigurni prirodni lijekovi. Ako se ovom dodaju i njihova brojna korisna farmakodinamična djelovanja, onda se može zaključiti da bi se tanini trebali češće i obimnije upotrebljavati u veterinarskoj medicini.

Extract of chestnut is a mixture of tannic and non-tannic components. The most common tannic components are the glycosides castalagin and vescalagin, which have a therapeutic effect. In conducted studies in vitro and in vivo, it was found that the tannin extract of chestnut has anti-diarrhoeal, astringent, antiviral, antimicrobial, antiprotozoal and anthelmintic properties. At the same time, it was found that the tannin extract of chestnut has anti-carcinogenic properties. Tannin interacts with the membrane structures of certain microorganisms, and thus decreases the permeability of the cell membrane. This antimicrobial activity is advantageous in terms of the action of antibiotics, because tannins only cause the inhibition of microflora growth but not its destruction. Ingested tannins at therapeutic concentrations (2- 5%) cannot be absorbed and so cannot cause pharmacodynamic effects on the other organic systems. In the intestines, by means of hydrolysis, they are completely biotransformed into polyphenols (gallic, digallic and elastic acids) and glucose. In the urine, only the degradation products of tannin in the form of glucuronide can be identified. In therapeutic concentrations, tannins have an insignificant effect on the skin, while on mucous membranes they act astringently. At higher concentrations, tannins may lead to degradation of superficial, and even deeper layers of mucous membranes and granulation tissue. Given that they do not show teratogenic, mutagenic or carcinogenic effects, everything indicates that tannins should be more often and more extensively used as safe veterinary drugs.