Helichrysum caespititium (DC.) Sond. Ex Harv., (Asteraceae) is a medicinal plant indigenous to South Africa. Its non-polar extracts exhibit significant antimicrobial and, in particular, antigonorrheal activity. This study aimed at isolating and purifying the active antigonorrheal compound from its chloroform extract and validating its inhibition potential on quorum sensing (QS) and biofilm formation of multi-drug resistant (MDR) pathogens. Phytochemical investigation of aerial parts of H. caespititium afforded a diterpene lactone (CF6). The effect of CF6 on violacein production and biofilm formation was studied using in vitro quantitative violacein inhibition (Chromobacterium violaceum) and biofilm formation (Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Neisseria gonorrhoeae, and Pseudomonas aeruginosa). The structure of CF6 was characterized using FTIR, NMR, and UPLC-MS data accordingly, as 10-methyl-8-(propan-17-ylidene)naphthalen-9-yl)-11-vinyl-14-hydroxyfuran-16-one. The susceptibility testing of the pathogens against CF6 revealed Neisseria gonorrhoeae was noticeably susceptible with a MIC value of 60 µg/mL, while Streptococcus pyogenes and Staphylococcus aureus showed MIC of 125 µg/mL. All gram-negative pathogens, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa were inhibited at 250 µg/mL. CF6 also inhibited the production of violacein by 51.88% at 250 µg/mL and prevented cell attachment by 40.76–81.18%, with N. gonorrhoeae being highly prohibited from forming biofilm. In conclusion, 10-methyl-8-(propan-17-ylidene)naphthalen-9-yl)-11-vinyl-14-hydroxyfuran-16-one is the first of its kind to be isolated from the non-polar (chloroform) extract of South African Helichrysum caespititium with antigonorrheal, antimicrobial, antiquorum sensing, and antibiofilm properties. The compound may serve as a drug candidate against MDR pathogens.

Background/Objectives: Medicinal plants are used around the globe to treat and/or manage various medical conditions, including respiratory diseases such as tuberculosis, which affect the lower respiratory tract, with its related symptoms being treated and/or managed using medicinal plants. This review collates the available literature pertaining to the medicinal uses and phytochemistry of Carpobrotus edulis, Drosera capensis, Pelargonium reniforme, and Tulbaghia violacea used for the treatment and management of tuberculosis in South Africa. The abovementioned plants were selected based on their long history of use, anecdotal evidence, and the scientific data available. Methods: Data to compile this review article were sourced and analyzed from Google Scholar, Pubmed, ScienceDirect, and textbooks published from 2000 to 2022. The search terms included the plant and genus names of each species, tuberculosis, and Mycobacterium tuberculosis. Results: The data obtained indicate that the plants do not only have an effect on Mycobacterium tuberculosis, but also on other conditions, including cough, colds, eczema, infections, and asthma, which are differential diagnoses in suspected tuberculosis cases. The literature indicates that extracts from the four plants under review have antimicrobial activity, with MICs ranging between 0.20 and 50.00 mg/mL. The major classes of phytochemicals identified from the four medicinal plants included flavonoids, naphthoquinone, terpenoids, and sulfur-containing compounds. Conclusions: The literature review on the plants reveals that they are also used to treat other lower-respiratory ailments, including cough and fever, which may be signs and symptoms of TB. The literature review reveals that medicinal plants contain valuable phytochemicals which may be strong drug leads to combat the tuberculosis epidemic.