Green tea is made from the unfermented leaves of Camellia sinensis (L.) Kuntze and is grown in Asia and parts of Africa. This plant is in the form of shrub or tree and has evergreen leaves that reach a height of 2 to 10 meters. Black tea brew is one of the most popular drinks in Iran. The usable part of the green tea plant is its leaves, which are used in traditional medicine for heart disease, jaundice and urinary incontinence (Higashi-Okai et al., 2001) and in modern medicine, it is used to nervous headaches, treat amoebic and bacterial diarrhea and hepatitis, reduce fat and blood sugar due to its antimicrobial, antioxidant, anti-cancer and antiviral properties (Bastianetto et al., 2006). Catechins and theaflavins are two natural groups of polyphenols found in green tea and black tea, respectively (Leung et al., 2001).
Studies found that Black tea crude extract powder had antiviral properties against HSV-1 (Oliveira et al., 2015 and Cantatore et al., 2013) and influenza virus (Zu et al., 2012) which was caused by theaflavins. Black tea crude extract powder has also been shown to have antiviral properties against HIV-1. Factors influencing include a mixture of theaflavin derivatives (TF1, TF2A, TF2B and TF3) (Yang et al., 2012) and Theaflavin derivatives in black tea and catechin derivatives in green tea (Liu et al., 2005).