Gut Health Benefits of Baobab Fruit: An African Superfood

By Pooja Toshniwal PahariaReviewed by Benedette Cuffari, M.Sc.

Introduction
Bioactive compounds in lychee
Neuroprotective effects
Anti-cancer potential
Safety and dosage considerations
Current research gaps
Conclusions
References

Image Credit: Abdul Momin Photographer / Shutterstock.com

Introduction

Lychee (Litchi chinensis) is a tropical Sapindaceae fruit that is native to China and widely cultivated throughout Asia, Africa, and the Americas. Lychee is rich in numerous bioactive molecules with antioxidant, anti-inflammatory, antimicrobial, and anticancer properties, some of which include epicatechin, procyanidins, and anthocyanins. As a result, lychee-derived compounds have been widely studied for their potential therapeutic applications.

Bioactive compounds in lychee

Lychee concentrates potent phytochemicals in its peel and seeds, the most prevalent of which include epicatechin, quercetin, anthocyanins, rutin, catechin, procyanidin A2, an A-type procyanidin dimer, as well as the B-type procyanidin dimer procyanidin B2. These polyphenols and flavonoids donate electrons or hydrogen atoms and chelate metals, which provides a strong biochemical basis for antioxidant and anti-inflammatory effects.²

Pericarp, which is otherwise known as the lychee peel, is a particularly rich source of these compounds, as demonstrated by liquid chromatography-tandem mass spectrometry (LC–MS/MS). Lychee seeds also contain high levels of phenolic fractions, which suggests that lychee byproducts could function as concentrated nutraceutical ingredients and functional foods.²

Pericarp extracts exhibit dose-dependent free-radical scavenging activity in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. In vivo, these extracts mitigate D-galactose-induced oxidative stress by reducing malondialdehyde (MDA), glutathione (GSH), and protein carbonyl levels while increasing superoxide dismutase (SOD) activity to mitigate reactive oxygen species (ROS) production and lipid peroxidation.²

Neuroprotective effects

In a type II diabetes mellitus (T2DM) rat model with cognitive impairment, lychee seed extract (LSE) improved Morris water-maze performance, reduced β-amyloid (Aβ), advanced glycation end products (AGEs) and Tau in the hippocampus, normalized acetylcholinesterase distribution, as well as reduced cornu ammonis 1 (CA1) neuronal injury-changes consistent with lower oxidative and metabolic stress.

The polyphenol-rich profile of lychee enhances endogenous antioxidant defenses through the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element axis while reducing neuroinflammation by restraining nuclear factor kappa-B (NF-κB)-driven cytokine signaling. Other phytochemicals within lychee have been shown to reduce oxidative stress and inflammation, as well as stimulate neurogenesis.^3,4

Flavonoid-rich foods are associated with better learning/memory and protection of vulnerable neurons, thereby supporting future research on the potential benefits of lychee polyphenols for mitigating cognitive decline. In Parkinson’s disease models, fruit phenolics like catechins and epicatechins protect dopaminergic neurons from 6-hydroxydopamine, a mechanism consistent with Nrf2 activation and NF-κB suppression.^3,4

Image Credit: S_Dedy / Shutterstock.com

Anti-cancer potential

Lychee leaf-extract-mediated silver nanoparticles (AgNPs) have been shown to exhibit anti-cancer activity by suppressing proliferation and inducing apoptosis in various human cancer cell lines. Mechanistically, green plant-derived AgNPs increase ROS, destabilize mitochondrial integrity to cause mitochondrial outer membrane permeabilization (MOMP), release cytochrome c, assemble the apoptosome, as well as activate caspase-9 and caspase-3 within the mitochondria-dependent intrinsic pathway. Lychee leaf-extract AgNPs have been reported to exert cytotoxic effects on human cancer cells, which further supports the mitochondria-caspase axis as a plausible mechanism for lychee’s anti-tumor potential.⁵

Phytochemicals and plant-based nanoparticles contribute to cell-cycle arrest and anti-angiogenic effects by inhibiting cell-cycle proteins, disrupting microtubule assembly, and suppressing angiogenesis. For example, green-synthesized AgNPs induce apoptosis in human breast adenocarcinoma (MCF-7) cells by generating ROS, as well as caspase-3 and caspase-9 activation. Furthermore, green AgNPs induce apoptosis and oxidative stress in normal and cancerous human hepatic cells in vitro, thus indicating selective mitochondrial vulnerability in hepatocellular systems.

Safety and dosage considerations

Unripe lychee contains methylenecyclopropyl glycine (MCPG), a hypoglycin-A-related toxin that reduces hepatic glucose levels and inhibits β-oxidation. These effects can worsen acute hypoglycemia and encephalopathy, particularly among undernourished children.

MCPG has been detected in lychee pulp and seeds, with outbreaks often coinciding with pesticide co-exposures. Nevertheless, ripe aril consumption in modest portions is considered safe, with current maximum doses of up to 3.9 kg/day pulp for adults and 1.2 kg/day for children between the ages of one and five permitted.^6,7

Additional studies are needed to verify bioavailability, dissolution, and the pharmacokinetics of standardized and well-characterized extracts. Clinical trials should also prioritize standardized preparations and monitoring patients for sex-specific adverse effects.^6,7

Current research gaps

To date, few large and well-controlled human clinical trials have been performed on lychee extracts. As a result, most evidence is based on in vitro or in vivo data. Absorption, metabolism, distribution, and excretion profiles, active metabolites, and tissue targeting also remain undefined.

Bioactive compound concentrations can also differ by cultivar, growing conditions, ripeness, and extraction or processing methods, which limits dose comparisons and reproducibility. Standardized sourcing, validated assays, and harmonized protocols are required to enable accurate trials and regulatory evaluation.⁸

Conclusions

Lychee consumption has been associated with a wide range of beneficial effects including reduced oxidative stress, modulation of Nrf2 and NF-κB, improved amyloid and Tau pathology, protection of dopaminergic neurons, as well as anti-cancer effects including cell-cycle arrest, mitochondrial apoptosis, and anti-angiogenesis. To translate these promising findings into clinical application, additional research is needed to establish standardized extracts, pharmacokinetic profiles, optimal dosing strategies, and rigorous quality control. Well-designed multicenter randomized clinical trials with safety monitoring, biomarker validation, and defined clinical outcomes will also be essential.

References 

1. Castillo-Olvera, G., Sandoval-Cortes, J., Ascacio-Valdes, J. A., et al. (2025). Litchi chinensis: nutritional, functional, and nutraceutical properties. Food Production, Processing and Nutrition 7(1). DOI:10.1186/s43014-024-00275-z, https://fppn.biomedcentral.com/articles/10.1186/s43014-024-00275-z
2. Yang, Z., Zhang, L., Wu, Y. H., et al. (2022). Evaluation of chemical constituents of litchi pericarp extracts and its antioxidant activity in mice. Foods 11(23). DOI:10.3390/foods11233837, https://www.mdpi.com/2304-8158/11/23/3837
3. Tang, Y., Yu, C., Wu, J., et al.. (2018). Lychee seed extract protects against neuronal injury and improves cognitive function in rats with type II diabetes mellitus with cognitive impairment. International Journal of Molecular Medicine 41(1); 251-263. DOI:10.3892/ijmm.2017.3245, https://www.spandidos-publications.com/10.3892/ijmm.2017.3245
4. Roy, S., Roy, S. C., Zehravi, M., et al. (2025). Exploring the neuroprotective benefits of phytochemicals extracted from indigenous edible fruits in Bangladesh. Animal Models and Experimental Medicine 8(2); 239-265. DOI:10.1002/ame2.12522, https://onlinelibrary.wiley.com/doi/10.1002/ame2.12522
5. Wani, A. K., Akhtar, N., Mir, T., et al. (2023). Targeting apoptotic pathway of cancer cells with phytochemicals and plant-based nanomaterials. Biomolecules 13(2). DOI:10.3390/biom13020194, https://www.mdpi.com/2218-273X/13/2/194
6. Sinha, S. N., Ramakrishna, U. V., Sinha, P. K., & Thakur, C. P. (2020). A recurring disease outbreak following litchi fruit consumption among children in Muzaffarpur, Bihar—A comprehensive investigation on factors of toxicity. PLoS One 15(12). DOI:10.1371/journal.pone.0244798, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244798
7. Floyd, Z. E., Ribnicky, D. M., Raskin, I., et al. (2022). Designing a clinical study with dietary supplements: it's all in the details. Frontiers in Nutrition 8. DOI:10.3389/fnut.2021.779486, https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.779486/full
8. Kanungo, J., Sorkin, B. C., Krzykwa, J., et al. (2024). Screening tools to evaluate the neurotoxic potential of botanicals: building a strategy to assess safety. Expert Opinion on Drug Metabolism & Toxicology 20(7); 629-646. DOI:10.1080/17425255.2024.2378895, https://www.tandfonline.com/doi/full/10.1080/17425255.2024.2378895

Last Updated: Sep 2, 2025