Harnessing Plant Secondary Metabolites for Vaccine Development in Africa: Current Insights and Future Prospects

Courage Chandipwisa, Harrison Banda, Agness Shimilimo

Plant secondary metabolites are natural compounds with immunomodulatory and adjuvant properties that may complement conventional vaccines and support regionally relevant vaccine strategies in Africa. This structured narrative review analyzed English-language studies published between 2000 and 2025 from PubMed, Google Scholar, Elsevier, and EBSCOhost. Included publications comprised original research, systematic reviews, and clinical trials addressing mechanisms, formulation, safety, and clinical development. Evidence included in vitro studies, animal models, formulation research, and human investigations. Preclinical findings show that selected metabolites enhance antigen presentation, promote dendritic cell maturation, and strengthen humoral and cellular immune responses through modulation of key signaling pathways. Triterpenoid saponins from Quillaja saponaria have progressed into clinical adjuvant platforms, while polysaccharides from Moringa oleifera and flavonoids from Curcuma longa and Artemisia annua demonstrate immunostimulatory effects and improved antigen stability in preclinical models. Nanoencapsulation improves compound stability and delivery but lacks sufficient clinical validation. Clinical translation requires standardized phytochemical characterization, comprehensive safety evaluation, regulatory harmonization, validated manufacturing processes, and adequately powered clinical trials with defined immunological endpoints.

Sciences of Phytochemistry

Indah Woro Utami, Sapri Sapri, Nishia Waya Meray, As'ari As'ari

Utilizing cover crops like Passiflora foetida L. (rambusa) can mitigate significant environmental issues in post-coal mining terrain rehabilitation. Plants thriving in extreme environments are known for producing high levels of secondary metabolites with significant biochemical activity. This study sought to assess the antifungal and antibacterial effects of P. foetida root extracts derived from rehabilitated coal mine soil in East Kalimantan. The roots were macerated with solvents of differing polarity (ethanol, ethyl acetate, and n-hexane) for extracting specific fractions. Utilizing the Kirby-Bauer disc diffusion method, the antifungal efficacy was assessed against Candida albicans, Candida tropicalis, and Candida lipolytica at a 60% concentration. Conversely, the antibacterial efficacy was assessed against Shigella dysenteriae, Streptococcus mutans, and Cutibacterium acnes at a 10% concentration. The findings revealed that the fraction consisting of ethyl acetate demonstrated the most potent and extensive antibacterial efficacy. The ethanol extract and ethyl acetate fraction exhibited significant antifungal activity, particularly against C. tropicalis, with inhibitory zones that were similar to those of the positive control, fluconazole. The treatments exhibited significant differences, as confirmed by statistical analysis (ANOVA and Tukey's HSD test). Studies indicate that that P. foetida roots, particularly those from harsh settings, are a significant source of antimicrobial chemicals, with the semi-polar ethyl acetate fraction being the most promising for further development as a natural antibacterial and antifungal agent.

Sciences of Pharmacy

Steven Victoria Halim, Stefany Marcellia Kumala, Fatichatus Sharifah, Eko Setiawan, Antonius Adji Prayitno Setiadi

Self-medication is a treatment effort often undertaken by students, especially when the burden on healthcare services increases due to the coronavirus disease 2019 (COVID-19) pandemic. Nevertheless, up to five years after the onset of the global pandemic caused by the SARS-CoV-2 virus, no empirical evidence has been found to elucidate the self-medication practice among students in Indonesia. This observational study with a cross-sectional design aimed to identify students' self-medication practices at a university during the second wave of the COVID-19 pandemic. The research data was collected online using a questionnaire (Google Form). The questionnaire used consisted of two parts: student characteristics and student self-medication practices. A total of 1, 019 students were involved in this study. The most used drugs for self-medication by students were vitamins/multivitamins (91.66%) and analgesics (64.57%). Most medicines used by students were obtained from pharmacies (88.71%), while information related to drugs was obtained from recommendations from friends and family members (72.72%). The primary consideration that prompted students to self-medicate during the COVID-19 era was the easy access to medicines (83.81%). Students' self-medication practices during a health service delivery crisis can be irrational. As this study was conducted within a single institution using a specific sampling approach, the findings should be regarded as context-specific rather than broadly generalizable.

Sciences of Pharmacy

Adi Yugatama, Anas Muti'ah Syahrul Azizah, Syaiful Choiri, Ya-lin Huang

Piroxicam (PRX), a non-steroidal anti-inflammatory drug (NSAID), is classified as a biopharmaceutical classification system class II (high permeability and low solubility), which limits its bioavailability. Enhancement of the dissolution rate is a key strategy to enhance the absorption. Solid dispersion systems, particularly when combined with amphiphilic multiple co-block polymers, offer a promising approach to address this challenge. This study aimed to investigate the effect of Poloxamer 188 (P188) and the solid dispersion technique on the solubility and dissolution rate of PRX. Polyethylene glycol (PEG) 4000-based solid dispersions containing PRX were prepared using varying concentrations of Poloxamer 188 surfactant through the fusion method. The solid dispersions were evaluated for saturated solubility in water for 24 hours. Selected formulations were further characterized using thermal analysis and vibrational spectroscopy. The optimized solid dispersion formulation was filled into capsules, and a dissolution assay was carried out to compare its performance with that of pure PRX capsules. The optimized formula, comprising 3% P188 and PEG4000, demonstrated a significant enhancement in saturation solubility parameters (p < 0.05), specifically supersaturation degree, precipitation rate, and supersaturation profile. Additionally, dissolution testing showed a 22.22% increase in the dissolution rate of the PRX solid dispersion capsules compared to pure PRX capsules. In conclusion, P188-based solid dispersion containing PRX enhanced the solubility and dissolution rate, potentially improving therapeutic efficacy.

Sciences of Pharmacy