In vitro growth-Inhibitory effect of medicinal plants used in Philippine folk medicine for treatment of diarrhoea against intestinal bacteria associated with colorectal cancer

Mikuláš Středa

Bachelor's thesis

Abstract:

The occurrence of colorectal cancer (CRC) has shown significant increase in the last century and is the third most common cancer and the fourth most the fourth most common cause of cancer-related death. Healthy microbiota environment in intestine is key factor for preventing CRC. In the last years the connection with specific bacteria can be seen in the colorectal tumour microenvironment. Although currently use treatment such as surgery or chemotherapy is quite successful, many patients want to go back to traditional medicine which can have less side effects. It has previously been reported that many plant species are used in traditional Philippine medicine for treatment of health complaints related to CRC such as diarrhoea.. Since many of them already showed antibacterial properties, we decided to evaluate the in vitro effects of these plants against selected representatives of bacteria associated with CRC. In this thesis, 10 representatives of medicinal plants, namely Acalypha grandis (inflorescence), Artocarpus blancoi (leaves), Artocarpus camansi (fruit), Artocarpus elasticus (leaves), Artocarpus lakoocha (bark, leaves, fruit), Citrus microcarpa (leaves, fruit), Crescentia cujete (leaves, bark, fruit), Dysoxylum blancoi (bark), Euphorbia thymifolia (aerial part), Merremia peltata (leaves), were tested against 6 CRC associated bacteria Eischerichia coli, Streptococcus bovis, Clostridium septicum, Fusobacterium necrophorum, Fusobacterium nucleatum, and Peptostreptococcus anaerobius by broth microdilution method. Among all samples tested, A lakoocha and A. elasticus were only active plant species producing growth-inhibitory effect against E. coli (MIC = 256 μg/mL) and S. bovis (MIC = 512 μg/mL), respectively. The results of further experiments also showed the time dependent growth-inhibitory effects of three extracts, namely A. blancoi, A. elasticus and D. blancoi, against S. bovis. Other tested bacteria, namely Clostridium septicum, Fusobacterium necrophorum, Fusobacterium nucleatum and Peptostreptococcus anaerobius, did not inhibit growth of CRC bacteria. These results represent experimental background for future studies focused on the effects of Philippine medicinal plants on growth of bacteria associated with CRC.

Keywords

Plant extract, Antimicrobial activity, Colorectal cancer

Language used: English

Date on which the thesis was submitted / produced: 20. 4. 2024

Thesis defence

• Date of defence: 29. 5. 2024
• Supervisor: prof. Ing. Ladislav Kokoška, Ph.D.
• Reader: Tomáš Kudera, Ing.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Bachelor programme:
Tropical Agriculture