Diallyl tetrasulfide is an organosulfur compound that has been found in A. sativum and has diverse biological activities, including antimicrobial, antioxidant, and anticancer properties.[1],[2],[3],[4] It is active against the bacteria S. aureus and methicillin-resistant S. aureus (MRSA; MICs = 0.5 and 2 mg/L, respectively), as well as the fungi C. albicans, C. krusei, C. glabrata, A. niger, A. flavus, and A. fumigatus (MICs = 0.5, 4, 2, 1, 2, and 4 mg/L, respectively).[1] It reduces cadmium-induced increases in hepatic levels of thiobarbituric acid reactive substances (TBARS) and increases cadmium-induced decreases in the hepatic activity of superoxide dismutase (SOD1), catalase, GST, and glucose-6-phosphate dehydrogenase (G6PDH) in rats when administered at a dose of 40 mg/kg.[2] Diallyl tetrasulfide is cytotoxic to MCF-7 breast cancer cells (IC50 = 92 μM) and reduces tumor growth in a BGC-823 mouse xenograft model when administered at doses of 20, 30, and 40 mg/kg for 32 days.[3],[4]

Reference:
[1]. Tsao, S.-M., and Yin, M.-C. In-vitro antimicrobial activity of four diallyl sulphides occurring naturally in garlic and Chinese leek oils. J. Med. Microbiol. 50(7), 646-649 (2001).
[2]. Murugavel, P., and Pari, L. Effects of diallyl tetrasulfide on cadmium-induced oxidative damage in the liver of rats. Hum. Exp. Toxicol. 26(6), 527-534 (2007).
[3]. Viry, E., Anwar, A., Kirsch, G., et al. Antiproliferative effect of natural tetrasulfides in human breast cancer cells is mediated through the inhibition of the cell division cycle 25 phosphatases. Int. J. Oncol. 38(4), 1103-1111 (2011).
[4]. Jiang, X.-Y., Zhu, X.-S., Xu, H.-Y., et al. Diallyl trisulfide suppresses tumor growth through the attenuation of Nrf2/Akt and activation of p38/JNK and potentiates cisplatin efficacy in gastric cancer treatment. Acta Pharmacol. Sin. 38(7), 1048-1058 (2017).