Antibacterial efficacy of ethanolic extract of Camellia sinensis and Azadirachta indica leaves on methicillin-resistant Staphylococcus aureus and shiga-toxigenic Escherichia coli.
Zihadi MAH, Rahman M, Talukder S, Hasan MM, Nahar S, Sikder MH.
J Adv Vet Anim Res. 2019 May 18;6(2):247-252. doi: 10.5455/javar.2019.f340.

Antiacne and antiblotch activities of a formulated combination of Aloe barbadensis leaf powder, Garcinia mangostana peel extract, and Camellia sinensis leaf extract.
Waranuch N, Phimnuan P, Yakaew S, Nakyai W, Grandmottet F, Onlom C, Srivilai J, Viyoch J.
Clin Cosmet Investig Dermatol. 2019 May 30;12:383-391. doi: 10.2147/CCID.S200564.

Antimicrobial potential of aqueous extract of Camellia sinensis against representative microbes.
Khan I, Abbas T, Anjum K, Abbas SQ, Shagufta BI, Shah SAA, Akhter N, Hassan SS.
Pak J Pharm Sci. 2019 Mar;32(2):631-636.

Terpenoid Esters Are the Major Constituents From Leaf Lipid Droplets of Camellia sinensis.
Zhou X, Chen X, Du Z, Zhang Y, Zhang W, Kong X, Thelen JJ, Chen C, Chen M.
Front Plant Sci. 2019 Feb 26;10:179. doi: 10.3389/fpls.2019.00179.

Nephroprotective and antioxidant effect of green tea (Camellia sinensis) against nicotine-induced nephrotoxicity in rats and characterization of its bioactive compounds by HPLC-DAD.
Ben Saad A, Ncib S, Rjeibi I, Saidi I, Zouari N.
Appl Physiol Nutr Metab. 2019 Feb 25. doi: 10.1139/apnm-2017-0834.

Anti-fibrotic effect of black tea (Camellia sinensis) extract in experimental pulmonary fibrosis.
Chakraborty K, Dey A, Bhattacharyya A, Dasgupta SC.
Tissue Cell. 2019 Feb;56:14-22. doi: 10.1016/j.tice.2018.11.006.

Catechin in Human Health and Disease.
Isemura M.
Molecules. 2019 Feb 1;24(3). pii: E528. doi: 10.3390/molecules24030528.

Efficacy of Camellia sinensis extract against Candida species in patients with denture stomatitis.
Ghorbani A, Sadrzadeh A, Habibi E, Dadgar K, Akbari J, Moosazadeh M, Hossein B, Ahangarkani F, Vaezi A.
Curr Med Mycol. 2018 Sep;4(3):15-18. doi: 10.18502/cmm.4.3.174.

Differences in Chemical Composition among Commercially Important Cultivars of Genus Camellia.
Wang Y, Kan Z, Wang D, Zhang L, Wan X, McGinley JN, Thompson HJ.
J Agric Food Chem. 2019 May 15;67(19):5457-5464. doi: 10.1021/acs.jafc.8b06164.

Effect of Camellia sinensis plant on decreasing the level of halitosis: A systematic review.
Tahani B, Sabzian R.
Dent Res J (Isfahan). 2018 Nov-Dec;15(6):379-384

Antiproliferative activity of Camellia sinensis mediated silver nanoparticles on three different human cancer cell lines.
Yadav A, Mendhulkar VD.
J Cancer Res Ther. 2018 Oct-Dec;14(6):1316-1324. doi: 10.4103/jcrt.JCRT_575_16.

Assessment of antimicrobial, antioxidant and cytotoxicity properties of Camellia sinensis L.
Shah SB, Parveen Z, Bilal M, Sartaj L, Bibi S, Nasir A, Mahmood A.
Pak J Pharm Sci. 2018 Jul;31(4):1285-1291.

Tea (Camellia sinensis) is a plant widely used for ethnopharmacological use due mainly to the presence of polyphenols such as catechin and its derivatives, anthocyanins, flavonoids.

The color varieties are mainly due to differences in treatment, climate, but basically the variations between plants are few.

It is grown in:

• India
• Cina
• Sri Lanka
• Kenya
• Indonesia

The most common are:

• black
• green
• oolong
• red

The characteristic scent of tea seems to be influenced by the jasmonic acid present in the leaves (1).

When tea is taken to prevent or combat disease, attention should be paid to doses and, as with almost all herbs, ingestion of large amounts may be toxic. When the tea is taken for therapeutic purposes for cardiovascular diseases, diabetes and more, the best results are obtained in people who consume 3-4 cups of tea (600-900 mg of catechins) per day (2).

This study believes  that green tea and red tea have special antioxidant properties with neuroprotective potential and can prevent memory deficits. However, only green tea has better neuroprotection (3).

Black tea contains important flavonoids which, according to this in vitro study, exerting an inhibitory effect on colon cancer cells could be better studied to become possible medicines (4).

Oral administration of green tea extract exercised cardioprotective activity and prevented  doxorubicin induced cardiotoxicity by accelerating heart antioxidant defense mechanisms and down regulating the lipid peroxidation levels to the normal levels (5).

A study from 2004 to 2014 on elderly people found that frequent consumption of tea can reduce the risk of depressive symptoms (6).

Tea studies

References____________________________________

(1) Influence of Chloroplast Defects on Formation of Jasmonic Acid and Characteristic Aroma Compounds in Tea (Camellia sinensis) Leaves Exposed to Postharvest Stresses.  Li J, Zeng L, Liao Y, Gu D, Tang J, Yang Z.  Int J Mol Sci. 2019 Feb 27;20(5). pii: E1044. doi: 10.3390/ijms20051044.

(2) Studies on the Prevention of Cancer and Cardiometabolic Diseases by Tea: Issues on Mechanisms, Effective Doses, and Toxicities.  Yang CS, Zhang J. J Agric Food Chem. 2019 May 15;67(19):5446-5456. doi: 10.1021/acs.jafc.8b05242.

(3) Supplementation with different teas from Camellia sinensis prevents memory deficits and hippocampus oxidative stress in ischemia-reperfusion.  Martins A, Schimidt HL, Garcia A, Colletta Altermann CD, Santos FW, Carpes FP, da Silva WC, Mello-Carpes PB.  Neurochem Int. 2017 Sep;108:287-295. doi: 10.1016/j.neuint.2017.04.019.

(4) Inhibitory effect of black tea (Camellia sinensis) theaflavins and thearubigins against HCT 116 colon cancer cells and HT 460 lung cancer cells.  Imran A, Butt MS, Xiao H, Imran M, Rauf A, Mubarak MS, Ramadan MF.  J Food Biochem. 2019 May;43(5):e12822. doi: 10.1111/jfbc.12822.

(5) Cardioprotective effect of green tea extract on doxorubicin-induced cardiotoxicity in rats.  Khan G, Haque SE, Anwer T, Ahsan MN, Safhi MM, Alam MF.  Acta Pol Pharm. 2014 Sep-Oct;71(5):861-8.

(6) Association between tea consumption and depressive symptom among Chinese older adults.  Shen K, Zhang B, Feng Q.  BMC Geriatr. 2019 Sep 4;19(1):246. doi: 10.1186/s12877-019-1259-z.