Researcher Trần Thanh Hùng presenting the doctoral thesis on Litsea cubeba essential oil before the assessment committee.

Researcher Trần Thanh Hùng (cohort 2017) has successfully defended the doctoral thesis at the training institution level in Biotechnology at VNUHCM-University of Science. The thesis, titled “Antibacterial Activity and Biological Effects of Litsea cubeba Fruit Essential Oil and Constituents Against Helicobacter pylori,” was supervised by Dr Trần Trung Hiếu and Dr Lương Thị Mỹ Ngân.

Delivering a comprehensive presentation to the assessment committee, the researcher outlined the study conducted on 25 essential oils extracted from 24 medicinal plants commonly used in traditional Vietnamese medicine. Among these, Litsea cubeba essential oil ( L. cubeba) demonstrated the strongest potential in inhibiting Helicobacter pylori – a bacterial strain widely recognised as a leading cause of peptic ulcers. Both the  L. cubeba and six key constituents (citronellol, citral, citronellal, linalool, 1,8-cineole, and limonene) exhibited strong antibacterial effects against H. pylori strain ATCC 43504 and five antibiotic-resistant clinical strains.

The research clarified several mechanisms of action through which the L. cubeba and these constituents affect H. pylori. These included inhibition of urease – a crucial enzyme enabling bacterial survival in the acidic gastric environment; prevention of biofilm formation; increased membrane permeability; morphological alterations; disruption of outer membrane integrity; and DNA fragmentation. Notably,  L. cubeba completely inhibited the adhesion of H. pylori to gastric mucosa (as tested on mice). These findings highlight promising potential for application in preventing H. pylori infection.

Among the tested constituents, citral displayed effectiveness comparable to the L. cubeba in inhibiting urease activity and biofilm formation, whereas citronellol demonstrated greater capacity to disrupt membrane integrity and damage DNA. Other compounds – including limonene, citronellal, linalool, and 1,8-cineole – also produced notable biological effects, although levels of activity varied depending on the specific mechanism examined.

With these results, the research provides a scientific foundation for applying L. cubeba in the prevention and supportive treatment of gastric ulcers associated with H. pylori. In addition, the findings may guide future investigations seeking natural substances capable of complementing or replacing antibiotics in the management of gastric conditions, particularly in light of growing antibiotic resistance.

_{▪︎ Detailed information on the dissertation has been published on the official doctoral thesis portal of VNUHCM-University of Science.}

PMN_Photo credit: Researcher Trần Thanh Hùng