The scale of the antimicrobial resistance crisis provides the urgent context for this work. According to figures cited in the review, 1.27 million deaths were attributed to drug-resistant infections in 2019 alone, and projections suggest that deaths associated with AMR could reach 8.22 million annually by 2050. The extensive use of antimicrobial drugs in poultry production, for growth promotion, disease prevention and treatment, has driven the emergence of resistant avian pathogens and multidrug-resistant bacterial strains that threaten both animal health and food safety. Drug residues in poultry meat and eggs compound the problem, while manure containing up to 90 percent of consumed drug doses acts as a conduit for resistance genes into soil and water systems, where they can persist unaltered for many years.

The review frames medicine’s history in three phases: a pre-antibiotic era before 1935, the antibiotic era beginning in 1935, and the post-antibiotic era initiated around 2010. While a few decades of antibiotic use represented a golden age for treating once-fatal infections, the pipeline for new synthetic antimicrobials has essentially run dry. At the same time, resistance mechanisms transfer both vertically and horizontally between microbial populations, and governance strategies for AMR vary considerably between countries. Against this backdrop, the authors argue that the bioactive compounds found in medicinal plants, refined by millennia of traditional use, represent the most viable pathway forward for maintaining poultry productivity without perpetuating the resistance crisis.

Technically, the therapeutic power of medicinal plants rests on an extraordinary chemical arsenal. The review notes that over 300,000 plant species exist, with a recently compiled database cataloguing 9,225 phytochemicals from medicinal plants. Common bioactive constituents include tannins, saponins, flavonoids and alkaloids, which confer antiviral, antimicrobial, antioxidant, antifungal and anti-inflammatory activities. These compounds operate through diverse mechanisms: some disintegrate viral capsids, others disrupt bacterial outer membranes, stimulate macrophage production, activate T-cell-mediated immune responses, or modulate inflammatory pathways. The World Health Organization reports that 80 percent of the global population already relies on traditional medicine for primary healthcare, and the market value of medicinal plant products has surpassed $100 billion annually.

For bacterial diseases, the review identifies the most economically significant poultry pathogens as Salmonella species, Mycoplasma gallisepticum and avian pathogenic Escherichia coli, all of which have developed worrying levels of antibiotic resistance. Several plant-based interventions show genuine promise. Guava (Psidium guajava) extract at 5 percent concentration inhibits the growth of both Salmonella typhimurium and E. coli O157:H7. Phyllanthus niruri at 62.5 percent concentration is bactericidal against M. gallisepticum in vitro, while quercetin from Ephedra Houttuynia powder performs comparably to the antibiotic tiamulin in treating mycoplasmosis. Against E. coli, combinations of essential oils show synergistic effects: thymol and carvacrol disintegrate the bacterial outer membrane, allowing eugenol to penetrate the cytoplasm and inhibit growth. Rosemary, garlic, onion and mint extracts similarly reduce intestinal E. coli populations.

Viral diseases represent perhaps the greatest unmet need in poultry medicine, since no effective drugs exist for treating avian influenza, infectious bronchitis, Newcastle disease or infectious bursal disease. The review documents several botanical approaches with measurable antiviral activity. Green tea (Camellia sinensis) extract at 50 micrograms per milliliter strongly inhibits avian influenza virus replication in vitro, while Forsythia suspensa and Scutellaria baicalensis extracts act synergistically against infectious bronchitis virus, reducing viral copies and increasing antiviral G3BP1 protein levels in tracheas. St. John’s Wort (Hypericum perforatum) extract at 120 milligrams per kilogram of body weight demonstrates antiviral activity against infectious bronchitis both in vitro and in vivo. Combination formulas containing Withania somnifera, Tinospora cordifolia and Ocimum sanctum have proven effective against H9N2 avian influenza and IBDV co-infections.

Coccidiosis, caused by Eimeria parasites, remains the most economically important parasitic disease in intensive poultry production, and drug resistance has severely limited conventional treatment options. Here too, plants offer credible alternatives. Green tea supplementation at 0.4 grams per kilogram of feed serves as a possible replacement for ionophore drugs, while a saponin-rich premixture from Yucca schidigera and Trigonella foenum-graecum performs as efficiently as monensin under experimental Eimeria challenge. Artemisia annua, Bidens pilosa and garlic each target different stages of the Eimeria life cycle, inhibiting cell wall formation, sporozoite invasion and oocyst sporulation. Notably, combinations of multiple medicinal plants consistently outperform single-plant interventions.

Beyond direct antimicrobial effects, the review highlights the immunomodulatory potential of plant compounds as perhaps their most strategically valuable property in the post-antibiotic era. Carvacrol from oregano essential oil is described as the gold standard for improving chicken health. Nigella sativa oil enhances both humoral and cellular immune responses when administered alongside avian influenza vaccination, and turmeric supplementation at 250 milligrams per kilogram modulates the acute phase response following Newcastle disease vaccination. Curcumin at 100 to 200 milligrams per kilogram significantly increases production of interleukin-2 and interferon-gamma in broilers, while nanoprotected rosemary essential oil at 200 milligrams per kilogram elevates IgG and IgM levels. These findings suggest that rather than simply killing pathogens directly, medicinal plants can strengthen the bird’s own innate defences, a strategy that may prove more durable against evolving microbes.

The review also emphasizes environmental and production benefits. Poultry already has the lowest carbon footprint of all meat-producing animals, at 23 to 37 grams of CO2 equivalents per gram of protein compared to 194 for beef, yet the industry still accounts for roughly 8 percent of livestock sector greenhouse gas emissions. Yucca schidigera extract, rich in saponins, reduces ammonia emissions when added to feed or drinking water, addressing one of the largest environmental liabilities of poultry farming. Additionally, plant-based vaccine technology is emerging as a transformative frontier: transgenic plants expressing viral proteins can produce subunit and virus-like particle vaccines against Newcastle disease, avian influenza, infectious bronchitis and infectious bursal disease, with oral delivery through feed and heat-stable seed-based formulations offering particularly attractive commercial prospects.

The authors conclude that medicinal plants represent the best available alternative for poultry production in the post-antibiotic era, but they stress that significant work remains before widespread commercialization. They recommend rigorous pharmacokinetic and bioavailability studies in target tissues, elucidation of mechanisms of action and potential herb-drug interactions, dose-response trials to establish MIC50 and MIC90 levels, systematic safety and toxicity evaluations, residue studies with withdrawal time determinations, and long-term monitoring for microbial resistance to herbal compounds themselves. They also call for integrating well-defined herbal products into veterinary education, creating awareness among farmers and healthcare professionals, and implementing regular surveillance of drug residues in poultry products. As the microbes continue their relentless adaptation, the review suggests that humanity’s oldest pharmacy, the plant kingdom, may hold the keys to sustainable food production in the decades ahead.

The study meticulously outlines the extraction procedures employed to obtain essential oils from the leaves and seeds of star apple. Utilizing hydrodistillation, the team sustained a rigorous methodology to ensure the integrity and purity of the essential oils. This technique, well-regarded in phytochemical analysis, allowed for the isolation of the volatile compounds responsible for the plant’s fragrance and potential therapeutic effects. The authors emphasize the significance of employing standardized protocols to maximize yield while minimizing degradation of the sensitive compounds that contribute to the oils’ overall efficacy.

Chemical profiling of the essential oils reveals a rich tapestry of bioactive components. Gas chromatography-mass spectrometry (GC-MS) analyses provided a comprehensive breakdown of the constituents present in both leaf and seed oils. Notable compounds identified in these oils included terpenoids, phenolics, and aldehydes, each contributing unique properties to the overall antimicrobial activity. By comparing the chemical profiles, the researchers underscore the distinct differences that may exist between oils sourced from leaves versus those derived from seeds, providing a robust basis for their subsequent antimicrobial assessments.

Examining the antimicrobial properties of these essential oils required an extensive testing framework. The researchers employed various microbial strains to comprehensively evaluate the oils’ efficacy. Among them were both gram-positive and gram-negative bacteria, selected for their relevance in clinical settings. The study’s results revealed a surprising potency in the leaf-derived essential oil against several tested pathogens, demonstrating its capacity to inhibit bacterial growth more effectively than its seed counterpart. These promising findings could inform the development of natural antimicrobial agents, as the demand for plant-based alternatives to synthetic chemicals continues to rise.

The intriguing results of this study have broader implications within the fields of natural product research and pharmacognosy. With the world increasingly moving towards embracing green chemistry and sustainable practices, the identification of potent, naturally occurring antimicrobial compounds is critical. Essential oils, such as those derived from star apple, could serve as promising candidates for developing new therapeutic agents, particularly in light of the growing global concerns over antibiotic resistance.

Furthermore, the role of essential oils in enhancing food safety cannot be overstated. As the study suggests, the antimicrobial properties exhibited by star apple essential oils may extend beyond clinical applications, potentially offering solutions for food preservation. Natural preservatives are gaining traction in both consumer preferences and regulatory acceptance, thus underscoring the need for continued exploration of phytonutrients in our quest to ensure food security in a changing world.

Moreover, the investigation of star apple essential oils opens doors to exploring their synergistic effects with other natural compounds. The potential interaction between various phytochemicals may enhance their collective antimicrobial efficacy, presenting novel opportunities for developing multifunctional health products. The study encourages additional research into how these oils can be efficiently combined with other natural agents to maximize therapeutic benefits while minimizing adverse effects.

In the context of traditional medicine, the star apple has been utilized for its supposed health benefits for centuries. While modern scientific investigations are validating many of these traditional uses, there is still much to uncover. The rich history and cultural significance of plants like Chrysophyllum cainito serve as a compelling reminder of the wisdom embedded in indigenous practices, further motivating the scientific community to explore and document these valuable resources.

As the study illustrates, understanding the underlying mechanisms of how essential oils exert their antimicrobial effects remains a pivotal area for further research. Future investigations should delve into the molecular pathways through which these oils inhibit pathogen growth, paving the way for potential therapeutic applications. By bridging the gap between traditional knowledge and contemporary science, researchers can fully unlock the potential of these natural products.

The significance of this research extends not only to academic circles but also holds promise for the broader community, especially for those seeking natural remedies. Consumers are increasingly inclined towards holistic health solutions that promote wellness without the side effects commonly associated with synthetic drugs. This study could inspire entrepreneurs and innovators in the wellness sector to explore star apple-derived products in the marketplace, further popularizing the plant’s benefits.

In conclusion, the work of Babatunde and colleagues provides a vital contribution to the growing body of literature on phytochemicals and their applications. By elucidating the chemical composition and antimicrobial potential of essential oils from the leaves and seeds of star apple, the researchers pave the way for further exploration in both scientific research and practical applications. As interest in natural products continues to surge, studies like this one not only inform but also inspire, encouraging a budding curiosity about what other treasures nature has yet to unveil.

Expanding upon the findings of this study could yield groundbreaking developments in various fields, including pharmaceutical sciences, food technology, and holistic healing practices. The promise held by the essential oils of star apple may be just the tip of the iceberg, beckoning further inquiry into how nature’s bounty can serve the needs of humanity now and in the future.

Subject of Research: The comparative chemical composition and antimicrobial activity of essential oils from leaves and seeds of star apple (Chrysophyllum cainito).

Article Title: Comparative chemical composition and antimicrobial activity of essential oils from leaves and seeds of star apple (Chrysophyllum cainito) L.

Article References:

Babatunde, O., Yeye, E.O., Oladeji, O.S. et al. Comparative chemical composition and antimicrobial activity of essential oils from leaves and seeds of star apple (Chrysophyllum cainito L.). BMC Complement Med Ther 25, 313 (2025). https://doi.org/10.1186/s12906-025-05026-2

Image Credits: AI Generated

DOI: 10.1186/s12906-025-05026-2

Keywords: Essential oils, antimicrobial activity, star apple, Chrysophyllum cainito, phytochemistry, natural products, green chemistry, food preservation.