Anti-microbial and Anti-cancer activity of Traditional Chinese Medicine extracts

Abstract

Currently, the treatment of pathogenic microbial infections involves the use of a suitable antibiotic or combination of antibiotics. Unfortunately, the development of drug resistance in microbes is a serious problem. Hence it is necessary to find alternative treatments. Traditional Chinese medicines (TCMs) have been widely used since ancient times in China to treat the diseases caused by microbial infections. This suggests that the TCMs can potentially have anti-microbial activity against selected pathogenic microbes. This study firstly focused on the anti-microbial activity of 24 selected TCM extracts and demonstrated anti-microbial activities of several TCM extractss against three reference microbial strains (P. aeruginosa (Gram negative), S. aureus (Gram positive), and C. albicans (Fungus)). Two TCM extracts were shown to have inhibitory activity against P. aeruginosa, 14 TCM extracts were effective against S. aureus, and 3 TCM extracts were effective against the growth of C. albicans. In addition to the development of antibiotics, TCMs also has been used as additives in health products to overcome health problems caused by microbes and improve human body health. For example, body odour is caused by the overgrowth of C. jeikeium. Thus, the treatment of body odour can be achieved by inhibiting the growth of C. jeikeium. This study tested the anti-bacterial activity of 24 selected TCM extracts against C. jeikeium, 10 of which inhibited this bacteria’s growth. Those 10 TCM extracts can be potentially used as resources from which new deodorant ingredients could be developed. From preliminary data, three TCM extracts were selected for further investigation. Of those selected TCM extracts, TARAXACI HERBA (Pu Gong Ying, TH), which had efficacy against P. aeruginosa, was also tested for its ability to inhibit the growth of P. aeruginosa in shampoo. However, results showed that TARAXACI HERBA did not inhibit the growth of P. aeruginosa in the shampoo tested in this project. Cancer is a disease with severe adverse effects. Multiple myeloma (MM) is an incurable blood cancer that has concerned human society for a long time. Although recent chemotherapy advances have successfully improved the overall survival of MM patients, the development of drug resistance to current treatments makes it necessary to develop a new therapy. All three selected TCMs (COPTIDIS RHIZOMA (CR), TARAXACI HERBA (TH), and LONICERAE JAPONICAE FLOS (LJF)) have previously demonstrated anti-cancer or anti-tumour activity and another TCM, which was available in our lab (Xanthium), also has reported anti-cancer activity. Thus, four TCM extracts were tested for their ability to inhibit the proliferation of myeloma cells. Results showed that all four TCM extracts inhibited the cell proliferation of three different myeloma cell line including a bortezomib (BTZ) resistant RPMI cell line. However, only CR and TH have no toxicity to human fibroblast cells when they are killing cancer cells. A further study was conducted to determine whether the cell proliferation inhibition activity of the four TCM extracts is due to the ability to inhibit thioredoxin reductase (TrxR) activity. Although results indicate that all four TCM extracts can have significant effects on the reactive oxygen species (ROS) level in different myeloma cell lines, only treatment with LJF resulted in the inhibition of TrxR activity in myeloma cell lines. In conclusion, this project confirmed the anti-microbial activity of several TCM extracts among the original 24 selected TCMs. Interestingly, three of the TCM originally selected due to their anti-microbial activity are also able to inhibit cell proliferation of myeloma cells, including a BTZ resistant cell line. However, only one TCM extract (LJF) has the ability to inhibit TrxR activity in myeloma cells.