Introduction

Traditional healers across the globe utilise a diverse array of botanical species in their Indigenous practices to promote and sustain the health of their respective communities. In recent times, there has been a resurgence of pharmacological interest in phytotherapeutic agents derived from various botanical components or extracts utilized by indigenous ethnic groups. About 40% or more of the therapeutic agents currently used in Western Ghats by the locals are derived or at least partially derived from natural resources, particularly from medicinal plants. Further, the majority of pharmacologically potent compounds obtained from plants have been identified, discovered and purified through follow-up research to substantiate the authenticity of folklore data and ethnomedicinal applications. Consequently, there exists a substantial rationale to elucidate the types of botanical specimens utilised by individuals, the methodologies of their application, and the specific contexts in which these plants demonstrate their effectiveness against various diseases. Furthermore, ayurveda, unani, and sidda, the aboriginal system of native medicines, describe numerous plant species in detail.¹

Ethnopharmacology refers to the roles and influences of traditional plants and trees in pharmacological research and drug development. In general, traditional therapeutic usage of plants and trees is referred to as ethnomedicines. Medicinal preparations play a very significant role in pharmacological ailments in humans and animals because of the existence of phytochemical elements. Bioactive phytochemicals are found in all parts, including leaves, fruits, vegetables, and roots, and they offer resistance to a broad spectrum of diseases owing to the implication of essential components and secondary metabolites. Such indispensable secondary components include flavonoids, terpenoids, alkaloids, and phenolics. So far, a wide variety of medicinal plants have been studied, including the production of secondary metabolites from plant tissue culture approaches; some examples include Catharanthus roseus alkaloids, which have effective anti-cancer activity, Caralluma adscendens, which is a potent appetite suppressant, and so on.^2-3

The plant Diospyros buxifolia (Blume) Heirn., (Ebenaceae family) has a pantropical distribution and includes the genera Diospyros, which have around 500 to 600 species. The species of the genus Diospyros have long been extensively employed in traditional medicine to treat various illnesses. So far, the active main chemicals from Diospyros species have been naphthoquinones, triterpenoids, and tannins.^4-6

Diospyros spp. are often tree shrubs or subshrubs with whole alternating leaves, single blooms, and meaty fruits (berries) containing two or more seeds. In particular, D. buxifolia is a dioecious tree that can reach a height of 30 m and yields berry-like fruits.⁷

Based on the various descriptions in the literature the multiple parts of the genera Diospyros have been used to treat several infectious diseases such as antibacterial, antifungal, anthelminthic, and antiviral; urogenital (anti-hemorrhagic); skin diseases that include dermatitis, fresh wounds, bedsores, and rashes; and for treatment of musculoskeletal disorders related to body pain, bruises, painful fractures, and rheumatism. However, the literature review indicates the extensive use of Diospyros extracts for treating diseases related to oral cavity health (oral wounds, bad breath, and toothaches) and gastrointestinal disorders (diarrhoea, emetic, flatulence, etc.). Further, the bark, fruit, and root are the most commonly employed Diospyros plant components in traditional medicine.^8–10

D. buxifolia is also notable for its ecological and economic significance. This species is primarily found in tropical regions and is documented for its valuable timber and edible fruit. Due to habitat loss, the conservation status of D. buxifolia is critical, necessitating efforts for its preservation. Because of the dangers posed by deforestation and habitat degradation, D. buxifolia requires continuous conservation efforts, according to the International Union for Conservation of Nature’s (IUCN) red list. Ex situ conservation strategies, such as those implemented in botanical gardens, are crucial for preserving genetic diversity and ensuring the species’ survival.^11-12

The distribution is particularly prevalent in regions like Sulawesi, Indonesia, and the Western Ghats of India where conservation efforts are focused. The wood of D. buxifolia is highly valued for its quality, frequently used in furniture and crafts, similar to other Diospyros species known for ebony timber. Additionally, the species produces edible fruits, contributing to local diets and economies.¹³

The present study’s rationale is to help researchers and academics comprehend the ethnomedicine values of D. buxifolia so that they can pursue further investigations with the same and potentially impact the ethnopharmacological insinuations of D. buxifolia.

Materials and Methods

A comprehensive search of electronic databases was conducted to identify studies on D. buxifolia focusing on investigations on phytochemical analysis using leaf, root, stem, and fruit extracts with various solvent systems to enlist the secondary metabolites present. The search was further widened to identify studies about in vitro and in vivo utilisation of D. buxifolia extracts to determine the ethnopharmacological relevance and therapeutic properties. Two independent reviewers evaluated the titles and abstracts of potential studies, followed by a full-text review of eligible publications. Data extracted included phytochemical analysis using GC-MS, antibacterial activities, anti-diabetic activities, antioxidant activity, and inhibition studies of pharmacologically relevant enzymes and results. The collected data were synthesized to provide insights into the phytochemical and ethnopharmacological importance of D. buxifolia.

Results

Ethnopharmacology of D. buxifolia

Ethnopharmacology refers to the roles and influences of traditional plants and trees in pharmacological research and drug development. D. buxifolia, part of the Diospyros genus, is rich in bioactive phytochemicals that exhibit a range of therapeutic applications. The primary compounds identified include flavonoids, terpenoids, naphthoquinones, tannins, saponins, and reducing sugars, which contribute to their pharmacological properties.

Numerous health advantages, such as antioxidant, anti-inflammatory, antibacterial, antifungal, and anticancer abilities, have been associated with these phytochemical ingredients which are constantly present as secondary metabolites.

Key bioactive phytochemicals in D. buxifolia extracts

The medicinal potential of every plant extract originates mostly from the presence of a specific collection of chemical ingredients. Such components have been identified employing basic preliminary assays. In general, the chemical contents of D. buxifolia extracts are categorized into the following classes, based on prior investigations.

Flavonoids

Flavonoids are well known for their antioxidant properties; they help reduce oxidative stress and inflammation in tissues.⁴

Naphthoquinones

Particularly noted for their cytotoxic effects against cancer cells, they play a crucial role in anticancer therapies.⁵

Saponins

Several investigations have revealed that saponins have useful effects on maintaining the cholesterol levels of blood, bone health, blood glucose levels, and cancer risk. A saponin-rich diet has been found to prevent dental cavities, suppress platelet aggregation, treat hypercalciuria, and serve as an antidote to heavy metal toxicity.⁹

Terpenoids

These compounds exhibit significant antimicrobial and anti-inflammatory effects, making them valuable in treating infections and inflammatory conditions.¹⁰

Tannins

These compounds have demonstrated antiviral and antibacterial properties, contributing to the plant’s traditional medicinal uses.¹⁰

Constituent bioactive phytochemicals reported from various parts of D. buxifolia

Leaf extracts

Leaves of D. buxifolia have been used as a traditional remedy against various ailments including oral hygiene, healing of oral wounds, toothaches, gastrointestinal disorders such as diarrhoea, emetic, flatulence, etc. Analysis of the leaf of D. buxifolia showed the presence of several bioactive phytochemical compounds. The structures of these identified bioactive components from leaf extracts using methanol, water, n-hexane, and dichloromethane have been published and registered in Table 1. Studies on leaf extract of D. buxifolia have shown to possess several vital biological potentials such as antioxidant, antimicrobial, antifungal, anti-inflammatory, antidermatitic, antiseptic, anticancer, candidicide, antimalarial, antileishmanial, antitrypanosomal and antidiuretic activity.^14-15

Stem bark extracts

The stem and stem bark are the most commonly employed Diospyros plant components in traditional medicine. The extracts have been used to treat several infectious diseases (antibacterial, antifungal, anthelminthic, and antiviral); urogenital (anti-hemorrhagic); skin diseases (dermatitis, fresh wounds, bedsores, and rashes); and musculoskeletal (body pain, bruises, painful fractures, and rheumatism). Phytochemical analysis of bark methanol and water extracts of D. buxifolia using GC-MS (Gas Chromatography-Mass spectroscopy) disclosed the presence of various therapeutically active phytocomponents (Table 1). These compounds exhibit several pharmacological properties such as anticancer, antimicrobial, antidiabetic, anti-inflammatory, antileishmanial, antiviral, antiseptic, and antidermatitic.^14-15

Table 1: Summary of phytochemicals identified and reported in leaf and stem extracts of buxifolia using GC-MS analysis.

Pharmacologically important biological activities using D. buxifolia extracts:

D. buxifolia extracts have a variety of medicinal benefits. Tables 1 and 2 include details on different phytochemicals and their subsequent potential medicinal uses. Below are some of the main biological activities on which researchers have previously worked with D. buxifolia extracts.

Anticancer

D. buxifolia extracts have shown the potential to inhibit tumour growth and induce apoptosis in cancer cells.^4-8

Anti-inflammatory

Its bioactive compounds can mitigate inflammation, providing relief in conditions like arthritis.⁵

Antimicrobial

The plant’s extracts especially the methanolic ones are effective against various pathogens, addressing the growing concern of antibiotic resistance.^10-15

Anti-diabetic

The extracts of the plant have shown promising anti-diabetic action in an in vitro investigation.^16-18

Enzyme inhibitory action

Inhibitors of endogenous carbohydrases α-glucosidase and α-amylase reduce postprandial hyperglycemia and are effective diabetic therapies. Similarly, calorie restriction brought about by pancreatic lipase and carbohydrase suppression helps treat obesity and prevent weight gain. Consequently, assays designed to evaluate enzyme inhibition with a focus on α-glucosidase, α-amylase, and lipase are prevalent within the realm of scientific research; furthermore, the systematic screening of plant extracts and natural compounds for their inhibitory effects on these enzymes constitutes a widely adopted methodology in the quest for the identification of promising pharmacological agents aimed at the management and treatment of metabolic disorders such as diabetes and obesity.^19-23

The diabetes-related enzyme inhibition potential of the D. buxifolia extracts was examined in vitro by determining the α-amylase and amyloglucosidase from 0.125 mg mL^-1 to 1.0 mg mL^-1 at four increasing doses by Rao et al.²³ The results demonstrated that Methanolic extracts of the stems had significant inhibition of amyloglucosidase (62.72±0.15%) followed by methanolic extract of the leaves (58.93±0.08%), aqueous extracts of the stems (36.65±0.05%) and finally aqueous extract of the leaves (20.57±0.03%). 

Discussion

From plants to natural products, enzyme tests are widely used in drug discovery—nearly 50% of all small-molecule medications on the market target enzymes. Enzymes are a desirable target for new drug development initiatives because of their high degree of druggability and target validation provided by their protein structure. An important class of clinical medications, enzyme inhibitors are used to treat conditions like cancer, heart disease, diabetes, neurological problems, and obesity. Natural compounds are secondary metabolites synthesized by biotic entities, including flora and microorganisms. The plant kingdom represents a prolific and readily available reservoir of natural compounds, a significant portion of which has yet to be investigated for potential bioactive metabolites.^3-6

Studies by Hariyanto et al¹⁴ revealed that the semi-polar extracts (n-hexane and Dichloromethane) of D. buxifolia demonstrated potent inhibitory activities against rat intestinal α-glucosidase (IC₅₀ = 33.31±3.23 μg/mL). Further, in the findings, The Ferric Reducing Antioxidant Power studies revealed that leaf extracts using non-polar and semi-polar solvents of the Diospyros species have significant antioxidant potential, with the IC₅₀ range of 6.48±0.38 – 11.35±0.16 μmol of Fe/g. The findings from this evaluation established the therapeutic usefulness of various Diospyros species extracts, further validating the traditional remedial applications. Recent studies by Basivi et al¹⁵ observed that extracts of D. buxifolia displayed good antibacterial activity against Klebsiella pneumoniae and, Staphylococcus aureus. At the same time, Bacillus subtilis, and Escherichia coli showed limited effectiveness against tested strains using the disc diffusion assay.  However, leaf and stem extracts demonstrated the ability to inhibit the growth advancement of Gram-positive and Gram-negative bacterial strains.¹⁵

There are several well-reported antimicrobial action mechanisms of phytochemicals in medicinal plants against bacteria, including disruption and damage of cell walls and cell membranes, leading to the loss of cellular components, interaction with membrane proteins and enzymes leading to membrane structure and function modification, and DNA function alteration. Nonetheless, the report did not elucidate the specific mechanism. The results revealed that the aqueous leaf extract and methanolic stem extracts showed minimum inhibitory concentration values at the highest concentration for B. subtilis and can be considered the most effective plant crude extract, demonstrating stronger antibacterial activity against B. subtilis compared to the other extracts. The results indicate that the methanolic extracts had superior inhibitory effects on the selected microorganisms with stronger antimicrobial activity against K. pneumoniae. Further, this study demonstrates and suggests the potential use of these plant extracts (Table 2) for treating certain bacterial infections.¹⁵

The above study also reported the evaluation of antioxidant activity. The maximum DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity was noted in favour of methanolic leaf extract among all other extracts and this antioxidant activity may be attributed to secondary metabolites present in different parts of D. buxifolia. The methanolic stem extract exhibited a significant reducing ability at 100µg/mL, making it an efficient antioxidant agent.

The diabetes-related enzyme inhibition potential of the D. buxifolia extracts was examined in vitro by determining the α-amylase and amyloglucosidase from 0.125 mg mL^-1 to 1.0 mg mL at four increasing doses by Rao et al.²³  The research concluded that the methanolic stem extract of D. buxifolia exhibited the presence of phytochemicals, as well as significant inhibition of α-amylase and amyloglucosidase, which is indicative of the significant antidiabetic properties of the extracts of D. buxifolia.

The standard reduction power displays variations in the reducing ability of D. buxifolia leaves and stems, which might be due to differing availability. The reducing power of the extracts is proportionate directly to the concentration of the extracted sample and an increase in the reducing ability of plant extract could be attributed to the formation of reductants that can react with free radicals, terminating and stabilizing the radical chain reaction during the process. This research offers a rationale for the antibacterial and antioxidant properties of D. buxifolia extracts in methanol and water and these extracts could be potential sources of antimicrobials inhibiting microorganism growth and antioxidants (Table 2).

Table 2: Summary of pharmacologically important enzyme inhibition studies performed using D. buxifolia extracts.

Conclusion

The phytopharmaceuticals are developed using traditional medicine systems emphasizing the unique demonstration of how historical knowledge informs modern drug discovery. The diversity of phytochemicals within the Diospyros genus suggests a vast potential for drug discovery and development. D. buxifolia holds significant ecological and economic value, it faces challenges from environmental changes and human activities. Continued research and conservation efforts are essential to mitigate these threats and promote sustainable use of this species. D. buxifolia shows promise in various therapeutic areas particularly inhibition of enzymes involved in diabetes, antioxidant, and antimicrobial activity. The plant contains an abundant extent of under-utilized pharmacologically important secondary metabolites, which can be developed into drugs. However, future research investigations are required to fully determine and demonstrate the mechanisms of action to optimize the D. buxifolia extract applications in modern medicine. Thus, the present review provides a better understanding of the ethnomedical benefits of this historically significant medicinal plant and their applications in modern medicine.

Acknowledgment

We would like to thank the Karnataka State Open University for giving us the resources needed to compile this article.

Funding Sources

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Conflict of Interest-

The authors do not have any conflict of interest.

Data Availability Statement

This statement does not apply to this article.

Ethics Statement

This research did not involve human participants, animal subjects, or any material that requires ethical approval.

Informed Consent Statement

This research informed consent was not required.

Clinical Trial Registration

This research does not involve any clinical trials.

Author Contributions

Bhargavi Gangadhar: Concept, Data review, Title choice, Formal analysis, and data interpretation, Writing – original draft.

Sapna Motti: Data review, formal analysis, and Writing.

Suprada Rao Mangalore Suresha: Concept, Data review, formal analysis, and Writing – review & editing.

Chandrashekar Jambhava Samavedamuni: Concept, formal analysis, and Writing – review and editing.

Nataraju Angaswamy: Concept, Data review, Title choice, formal analysis, and Writing – review & editing and final decisions. 

References

1. Coals P.G.R., Williams V.L., Benítez G, Chassagne F, Leonti M. Ethnopharmacology, ethnomedicine, and wildlife conservation. J Ethnopharmacol. 2024;333:118399.
   CrossRef
2. Anmol, Aggarwal G., Sharma M., Singh R., Shivani, Sharma U. Ethnopharmacologically important highly subsidized Indian medicinal plants: Systematic review on their traditional uses, phytochemistry, pharmacology, quality control, conservation status and future prospective. J Ethnopharmacol. 2024;320:117385.
   CrossRef
3. Mallavadhani U.V., Panda A.K., Rao Y.R. Pharmacology and chemotaxonomy of Diospyros. Phytochemistry. 1998;49(4):901-951.
   CrossRef
4. Rauf A., Akram Z., Hafeez N., et al. Anticancer therapeutic potential of genus Diospyros: From phytochemistry to clinical applications-A review. Food Sci Nutr. 2024;12(10):7033-7047.
   CrossRef
5. Maridass M., Ghanthikumar S., Raju G. Preliminary phytochemical analysis of Diospyros species. Ethnobotanical Leaflets. 2008;12:868-872.
6. Kareem O., Ali T., Dar L.A., et al. Positive health benefits of saponins from edible legumes: Phytochemistry and Pharmacology. In: Masoodi MH, Rehman MU, eds. Edible Plants in Health and Diseases. 2022;279-298
   CrossRef
7. Donglan T., Qinglin Z., Liqing X., Dayong G., et al. Number of species and geographical distribution of Diospyros L. (Ebenaceae) in China. Horticultural Plant Journal. 2019;5(2):59-69.
   CrossRef
8. Rauf A., Uddin G., Patel S., et al. Diospyros, an under-utilized, multi-purpose plant genus: A review. Biomed Pharmacother. 2017;91:714-730.
   CrossRef
9. Wallnofer, Bruno. The biology and systematics of Ebenaceae: A review. Annalen des Naturhistorischen Museums in Wien. 2001;103B:485-512.
   
10. Fareed N., El-Kersh D.M., Youssef F.S., Labib R.M. Unveiling major ethnopharmacological aspects of genus Diospyros in context to its chemical diversity: A comprehensive overview. J Food Biochem. 2022;46(12): e14413.
    CrossRef
11. Wanda I.F., Peniwidiyanti, Oksari A.A. Ex situ conservation of Diospyros spp. (Ebenaceae) in the Bogor botanic gardens, Indonesia. IOP Conf Ser: Earth Environ Sci. 2019;308(1):012080.
    CrossRef
12. Balmford A., Bruner A., Cooper P., et al. Economic reasons for conserving wild nature. Science. 2002;297(5583):950-953.
    CrossRef
13. Ribeiro A., Serrano R., da Silva IBM., Gomes ET., Pinto JF., Silva O. The genus Diospyros: A review of novel insights into the biological activity and species of Mozambican Flora. Plants (Basel). 2023;12(15):2833.
    CrossRef
14. Hariyanto N.A., Ramadhan R., Raharjo Y., et al. GC-MS analysis of three Diospyros species and evaluation of its in vitro rat intestinal α-glucosidase and FRAP activity. Biodiversitas. 2024;25(6):2442-2453.
    CrossRef
15. Basivi P.K., Raman J., Tippana A., et al. Unveiling the antibacterial and antioxidant capabilities of Diospyros buxifolia leaf and stem extracts via GC-MS analysis. Nat Prod Res. 2024:1-7.
    CrossRef
16. Ramadhan R., Rosyidah N., Firdaus YFH., et al. Phytochemical analysis in conjunction with in vitro a-glucosidase inhibitory and antioxidant activities of three Diospyros species from East Kalimantan, Indonesia. Biodiversitas. 2023;24(9):4783-4790.
    CrossRef
17. Thirumurugan K., Shihabudeen M.S., Hansi P.D. Antimicrobial and anti-diabetic activity and phytochemical analysis of selected Indian folk medicinal plants. Steroids. 2010; 1(7):430–434.
18. Copeland R.A., Harpel M.R., Tummino P.J. Targeting enzyme inhibitors in drug discovery. Expert Opinion on Therapeutic Targets. 2007;11(7):967-978.
    CrossRef
19. Hopkins A.L., Groom C.R. The druggable genome. Nat Rev Drug Discov. 2002;1(9):727-730.
    CrossRef
20. Luo S., Gill H., Dias D.A., et al. The inhibitory effects of an eight-herb formula (RCM-107) on pancreatic lipase: enzymatic, HPTLC profiling and in silico approaches. Heliyon. 2019;5(9):e02453.
    CrossRef
21. Siegień J., Buchholz T., Popowski D., et al. Pancreatic lipase and α-amylase inhibitory activity of extracts from selected plant materials after gastrointestinal digestion in vitro. Food Chemistry. 2021;355:129414.
    CrossRef
22. Buchholz T., Melzig M.F. Medicinal plants traditionally used for treatment of obesity and diabetes mellitus – screening for pancreatic lipase and α-amylase inhibition: inhibition of digestive enzymes. Phytother Res. 2016;30(2):260-266.
    CrossRef
23. Rao P.V., Krishinasa E., Manohar Re IR., Dhananjaya M., Gan SH. Phytochemical analysis and in vitro evaluation of antidiabetic activity of Diospyros buxifolia. American J of Biochemistry and Molecular Biology. 2016;6(3):95-101.
    CrossRef
24. Sun L., Zhang J., Lu X., et al. Evaluation of the antioxidant activity of total flavonoids extract from persimmon (Diospyros kaki L.) leaves. Food and Chemical Toxicology. 2011; 49(10):2689–2696.
    CrossRef