Phytochemical and Economic Importance of Mimusops Caffra (Coastal Red-Milkwood): A Review

1. INTRODUCTION

Mimusops caffra E.Mey. ex A.DC, also known as coastal red-milkwood, is a perennial fruit-producing tree belonging to the Sapotaceae family. The Sapotaceae family comprises an estimated 1250 species and 53 genera of tropical trees, shrubs, and branching vines.^[1] Researchers have dedicated considerable attention to this family on account of its phytochemical diversity, ecological significance, and economic importance.^[2,3] Mimusops species contain an assortment of bioactive compounds, including phenolic compounds triterpenoids and saponins, according to phytochemical studies.^[4] Several studies have primarily examined the economic significance of different Mimusops species, specifically in relation to their contributions to the production of edible fruits, timber, and traditional remedies.^[1,5-7] M. caffra is a small-to-medium-sized evergreen fruit tree reaching a maximum height of 25 m at full maturity.^[8] This species is characterised by milky latex, and a well-branched, spreading, the bark is a dark grey in colour with a longitudinally fissure pattern and shown in Figure 1a. The leaves are firmly coriaceous and arranged in a spiral pattern, lacking stipules, with a petiole length ranging from 0.5–1.0 cm long. The upper leaf surface is glossy, with yellowish-brown to ferruginous hairs when young, soon glabrous; while the lower surface has pale green, midrib prominent below and flush above on both surfaces. The lateral veins are arranged in 5-8 pairs.^[9] The fruits are ovoid-shaped berries with an orange-to-red colouration when ripe, and they are available between September and December and shown in Figure 1b. The ripe fruits are palatable and delightfully sweet.^[1] The taxonomical classification of M. caffra is shown in Table 1. The geographic distribution of this species extends across South Tropical Africa, including KwaZulu-Natal, and the Former Transkei Region, it forms up to 75% of the Coastal and Dune Forest in Mozambique.^[10] In Egypt, M. caffra is cultivated in the Agricultural Research Center in Giza. In South Africa, M. caffra is spread alongside the coastal belt in the KwaZulu Natal and the Eastern Cape region.^[11] Evidence shows that M. caffra typically accommodate climatic variability in KwaZulu-Natal.^[12] Furthermore, pharmacological studies, in vitro studies, field trials, and ethnobotanical surveys reporting on the traditional use of M. caffra in Africa are shown in Table 2. The distribution of publications on M. caffra indicates a significant increase in research interest from 2015 to 2025, being the most prolific years, contributing 11 studies Table 2. This surge suggests growing recognition of the species’ potential in nutrition, medicine, and agriculture, reflecting heightened global interest in indigenous plants, sustainability, and natural health products. Notably, there were only three publications between 2002 to 2014, indicating that M. caffra was under-researched during this period, possibly due to limited awareness or funding. However, starting in 2015, a steady flow of research output emerged, highlighting a focus on exploring sustainable use and integration of indigenous plants to address local challenges in sub-Saharan Africa. The concentration of recent studies suggests steadily increased awareness of M. caffra as a valuable species with potential applications, which could benefit local communities economically through sustainable harvesting and cultivation practices.

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Figure 1:

Photographs of Mimusops caffra (a) bark and (b) fruits.

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Despite the ecological, cultural, and nutritional significance of M. caffra in Africa, comprehensive information about this species remains fragmented. The lack of synthesized knowledge on its distribution, traditional uses, phytochemical composition and potential applications impedes its conservation and sustainable exploitation. Moreover, increasing threats to its natural populations, coupled with limited scientific research, pose challenges to developing evidence-based management strategies. This study aims to consolidate existing knowledge, identify research gaps, and provide a comprehensive overview of M. caffra to guide future research efforts and inform conservation strategies.

2. MIMUSOPS CAFFRA AS A SOURCE OF NUTRIENTS

Wild fruits are natural stockrooms of essential macro and micronutrients.^[24] M. caffra is a beneficial fruit-producing tree with a grouping of rich nutrients essential to the human body. According to,^[17] The dietary benefits of the fruits derived from this tree are remarkable, mostly attributed to their higher levels of carbohydrates (sucrose, glucose, and fructose), these serve as a good energy source and would aid in the active functioning of school children and rural people who might otherwise dearth an alternative source of energy. The fruits of M. caffra were reported to have a low protein (5.65%) content. Mngadi et al., (2017)^[8] has reported that about 10 g of fruit would provide more than 85% towards the recommended dietary allowance for Si and Fe for most adults. Studies have shown a correlation between improvements in Alzheimer’s disease, atherosclerosis, and diabetes mellitus with ingestion of fruits and vegetables with high Si content.^[25] Lipids have a physiological importance in relation to the plant growth, and they have a close association with human metabolism, among other functions.^[26] Another study^[17] reported 6.76% lipid yield from the fruits of M. caffra and 37.08% saturated fatty acids (SFAs), 48.10% monounsaturated fatty acids (MUFAs) and 14.34% polyunsaturated fatty acids (PUFAs) from the seed oil. M. caffra seeds contain high levels of proteins, organic matters, amino acids and minerals indicating its potential for effective use as a dietary energy supplement and oil source, it is reported that the highest levels of oleic acid, measuring 46.37% from the seed meal of M. caffra. The seeds of M. caffra exhibit higher levels of dry matter organic matter, organic matter, and neutral detergent fibre content, precisely measuring at 89.65%, 84.90%, and 27.15%, respectively, as reported.^[17] Another research that examined the fruits of M. caffra in the KwaZulu-Natal east coast discovered trace amounts of lead (Pb) arsenic (As) and cadmium (Cd).^[8] All these constituents were found to fall within limits thus confirming the plants’ suitability, for medical and dietary purposes for vulnerable communities that need food security and also determined the composition of M. caffra fruits which included iron (Fe) at 34.3%, zinc (Zn) at 20.6%, manganese (Mn) at 20.0%, copper (Cu) at 2.16% and calcium (Ca) at 0.36%. Despite research examining individual nutrients in M. caffra, there is still a scarcity of a comprehensive analysis of the plant’s complete nutrient profile, which includes seeds, fruits, leaves, and other components such as bark and roots. This could offer a more comprehensive understanding of the plant’s nutritional worth and its uses. There is, therefore, a demand to utilise modern analytical techniques to perform a comprehensive and standardised nutrient analysis of every part of the M. caffra plant, encompassing macro and micronutrients, phytochemicals, and bioactive substances. Although the nutrient composition of M. caffra has been identified, information is insufficient regarding the bioavailability and bio-accessibility of these nutrients. This knowledge is essential for comprehending the possible health advantages and efficient utilisation of these nutrients by the human body.

3. ECOLOGICAL THREATS AND ECOSYSTEM SERVICES PROVIDED BY MIMUSOPS CAFFRA

Wild fruit trees are essential for maintaining a balanced and functional ecosystem. Ecologically, Chivandi et al., (2016)^[17] reported the M. caffra tree is important as a dune stabiliser and is regarded as a key-stone species in coastal dune forests. Its extinction is likely to result in primary dune collapse. The tree has several uses; its wood is used for construction of fish traps and boats and as fuel wood. Several wild fruits especially those from the Sapotaceae family including M. caffra are host to several endophytes.^[27] Some of them exudates and leachates of the tree without causing harm and others cause death.^[28] Jami et al, (2018)^[22] has reported that M. caffra has a mutualistic relationship with Neofusicoccum variabile species and Pseudofusicoccum africanum sp. These endophytes live inside M. caffra branches and produce significantly longer lesions which leading to be the cause of the die-back disease. This relationship serves as an integral component of forest dynamics and influences greatly the survival and regeneration of wild fruit trees.^[29] In addition to being a host for endophytes, M. caffra serves also as a key food source, habitat provider, and soil stabiliser.^[8] Its fruits are an important food source for many animals.^[1] Although the tree offers these services, there is a scarcity of information regarding its extensive interaction with other biotic elements of the environment, including birds, insects, and other animal species. A potential approach is to conduct extensive ecological research and biodiversity surveys to gain insight into the complex network of relationships that exist between M. caffra and different animal species, such as herbivores, pollinators, and seed dispersers. This may shed light on the tree’s function in preserving ecosystem balance and encouraging biodiversity. However, the tree’s role in competition and succession within its ecosystem is not well understood. Conducting extensive ecological studies and field observations to gain insights into the competitive dynamics of M. caffra with other plant species, as well as its contribution to successional processes within the ecosystem. This might involve maintaining close monitoring of any changes to the composition of the vegetation, researching the use of resources, and assessing M. caffra’s effects on other species. Beyond some of the potential ecosystem services provided by the plant species in the ecosystem, M. caffra offers a range of ecosystem services that are crucial for rural people, like fuelwood, fodder, and medicinal plants.

4. PHYTOCHEMISTRY AND PHARMACOLOGICAL IMPORTANCE OF MIMUSOPS CAFFRA

Although M. caffra is highly valued as an essential traditional wild fruit tree crucial for its medicinal and miscellaneous uses in rural livelihoods, reports of the plant’s biological activities are insufficient. The first biological activity associated with M. caffra was reported by Simelane, 2014, who reported the antioxidant and anti-plasmodial of extracts and isolated pentacyclic triterpenes.^[14] These results indicate a promising avenue for further research on the pentacyclic triterpenes mechanism of action and potential application. In other study,^[16] M. caffra triterpenes reportedly induced cytotoxic effects on human embryonic cells (HEK293) and human hepatocellular carcinoma cells (HepG2). Pentacyclic triterpenoids (PTs) are one group of compounds of 30 carbon structural compounds with interesting great diversity and biological activities, with more than 100 different chemical skeletons of carbon.^[30] PTs are used in treatment of several human diseases due to its several biological significance including wound healing, hepatoprotective, anti-inflammatory, antibacterial, antitumoral, and antiviral properties, together with their low toxicity.^[31,32] Ursolic acid (UA) is a pentacyclic triterpenoid composed of a C-30 chemical structure built from isoprenoid units with A, B, C, D and E rings which may occur as an aglycone or free acid of saponins.^[33] M. caffra was reported as a source of pentacyclic triterpenoid UA compound.^[14-16] Moreover, studies on phytochemical profiling reported for M. caffra have not been well documented and shown in Table 3. Additional research is required on the in vitro biological activities of different parts of the plant extracts against various human diseases to scientifically support their use in ethnomedicine. These studies may warrant a potential for the incorporation of the plant in the pharmaceutical industry. Research aimed at exploring the phytochemical constituents of the whole plant is also required. This will create a space for the potential development of novel drugs for the treatment of various health conditions and other applications. Additional investigation is required to examine the possible biotechnological uses of M. caffra, in the advancement of functional foods nutrition derived products.

5. CURRENT STATUS AND FUTURE PROSPECTS

This study provides details on the nutritional composition from various studies^[8,17] a comprehensive and standardised analysis across all plant parts is scarce. As highlighted,^[17] the complete nutrient profile and bioactive compounds is essential for exploiting the plant’s potential. Despite the studies primarily focus on the nutritional composition of the plant, limited information on potential therapeutic applications or clinical studies are reported.^[8,17] Conducting clinical studies could provide valuable insights into the therapeutic benefits or potential medicine for the plant or its components. Therefore, there is a demand to execute clinical trials and preclinical studies. Creating and conducting preclinical studies to estimate the potential therapeutic effects of the plant or its extracts on various disease models or health conditions can bridge the existing gap. Based on preclinical findings, conducting clinical trials to evaluate the efficacy, safety, and potential therapeutic applications of the plant or its components in human subjects can contribute significant insights into the planned use and its application. It is also essential to investigate ethnobotanical data and traditional knowledge by collaborating with traditional healers and local communities to convene data on the traditional uses and preparation methods of the plant. This traditional knowledge can be incorporated with scientific research to develop evidence-based treatments or products and identify potential therapeutic applications. Unchecked utilisation may lead to ecological damage. As argue, that sustainable decision-making necessitates integrating multidisciplinary knowledge, including indigenous knowledge systems. We need to promote collaborations between institutions, researchers, stakeholders (including local communities), and traditional knowledge holders to expedite resource distribution, knowledge exchange, and integrated strategies. Multidisciplinary collaborations can effectively address gaps and support feasible utilisation while maintaining traditional practices. While^[34,35] reported on Mimusops genus biological activities, and the study mentions the potential for biotechnological applications and integration in pharmaceuticals, there is a scarcity of specific research in this area for M. caffra. This, therefore, means there is a demand for studies anticipated at the researching of potential biotechnological uses and comprehensive phytochemical analysis of the whole plant, including developing nutraceuticals, functional foods, cosmetics, and novel drug candidates, exploiting on the plant’s unique bioactive compounds and composition. Managing these gaps through future research can provide a comprehensive understanding of M. caffra’s feasible standardised, potential benefits, and conservation approaches while supporting collaborations between traditional knowledge and scientific systems.

6. CONCLUSION

Mimusops caffra protrudes as a various indigenous plant species with significant cultural, ecological, and potential economic value. The expanded ethnomedicinal applications documented in some African countries emphasize its significance in traditional healthcare systems. The various usages of different plant parts for treating a wide range of ailments suggest a rich phytochemical profile worthy of further scientific investigation. The nutritional analysis of M. caffra fruits and seeds reveals a promising source of essential nutrients, particularly minerals and vitamins, which could provide nutrition and food security in rural communities. However, the scarcity of a standardised nutrient profile across all plant parts indicate a critical area for future research. Ecologically, despite its crucial role in its native habitats, the species faces threats from overexploitation, die-back symptoms, habitat loss, and climate change. Preliminary biological studies have revealed promising antiplasmodial, antioxidant and cytotoxic activities in M. caffra parts, opening entrance for significant pharmaceutical applications. However, the lack of clinical studies and comprehensive phytochemical analyses enhances potential research opportunities in exploring the full significant of this valuable indigenous species. This approach would not only enrich and improve our scientific knowledge but also develop reasonable and proper sustainable utilisation and development of this valuable resource across all relevant African nations.