A review on benefits, potential and conservation of Baccaurea lanceolata

Malaysia has introduced the Plant Genetic Resources for food and agriculture (PGR) policy to further research and profile its wild crops to conserve and protect its rich biological diversity. There is an urge for relevant research to be conducted since it may also serve as an identifying accession of desirable traits for crop improvement. One such underutilised plant, Baccaurea lanceolata or locally known as “liposu” by the Dusun people has long played a traditional and cultural role for the local Bornean people. Unfortunately, although in recent years it has gained traction as a traditional food delicacy among the locals, it has remained underutilised and not commercially cultivated due to limited research and exposure. Despite that, limited studies on plants of Baccaurea species have been shown to contain various beneficial properties. The underutilised fruit of Baccaurea lanceolata has a high probability of containing a health beneficial, noteworthy amount of unique, uncovered phytochemicals. Research on this underutilised plant may also provide a path to road of commercialisation as well as preserving this tree from the danger of forest clearing. This review paper has therefore compiled information from available secondary literature on Baccaurea lanceolata in terms of its traditional knowledge, cultural usage as well as studies on its scientifically proven health benefits.


Introduction
Malaysia is one of the world's megadiverse countries, ranking at 12 th in the world for its biodiversity richness, which takes into account on the estimates of country richness, endemism in vascular plants and four terrestrial vertebrate classes [1]. According to Mohd Shukor et al. [2], Malaysia harbours some 185,000 species of fauna and more than 15,000 species of flowering plants. The study by Abdul Shukor et al. [3] under MARDI agency further reported that among them, there are over 2,500 tree species, 3,000 species of orchids, 500 species of ferns, and 60 species of grasses and bamboos. The same study consequently stated that Malaysia houses more than 500 species of cultivated, underutilised and rare fruit species. Unfortunately, only a small percentage of this species have been utilised for food production and that only about 300 fruit species native to Malaysia had been exploited and utilised [3]. The remainder is still growing wild or semi-wild, and their economic potential has not been investigated thoroughly. In a global scale, FAO in its infographic report also stated that biodiversity, and in particular genetic diversity, is being lost at an alarming rate [4].
Forest is home to almost 80% of terrestrial biodiversity. They account for over 80,000 tree species. Nevertheless, less than 1% have been studied in any depth for their present and future potential. FAO further stated that plants account for over 80% of the human diet. While 30,000 terrestrial plants are

Literature Review
The genus Baccaurea was first described in 1790 [6]. In 1866, 31 species were included in the genus [7]. There were no changes in the classification of Baccaurea genus in subsequent publications in 1963 [8], 1973 [9], 1978 [10], 1979 [11], 1980 and 1981 [7,8]. Following the year 2000, a study by [14] introduces a total of 43 species into the genus Baccaurea. Based on the previous classification system, the genus Baccaurea was included in the Euphorbiaceae family, but based on the APG II classification system, when taking into account on molecular evidence and morphology, the ovules were included in the Phyllanthaceae family [15].
Baccaurea lanceolata is one of the plants belonging to the genus Baccaurea. The information tabulated in Table 1 summarises the general information regarding Baccaurea lanceolata, from its scientific name to its natural habitat and ecology. Usual sighting is in the primary and secondary tropical rain forest, growing on slopes and in the riverine forest, from sea level to 1,300m in its native range. It is, however, more common in the lowlands. The flowering period ranges from March to December while bearing fruit all throughout the year.
Source: Adapted from [14,16] Shown below in Table 2 are the tabulated botanical description of Baccaurea lanceolata, a dioecious, perennial tree.
• Green when fresh, gradually turning brown-green to grey when dry.
• Raised glands are usually present.
• The stipules are glabrous outside and inside, usually (3-)5-16 by 2-6 mm in length. It is caducous (to late caducous), where its midrib is often densely hairy above. Its margin is not ciliated and is usually hyaline. • The papery lamina is ovate to elliptic in shape, 9.2-45 by 3.7-26.5 cm, length to width (l/w) ratio of 1.7-3.4, attenuate to rounded base and acute to cuspidate apex, (0-)3-20 mm in length. • The upper surface of the leaf is glabrous, with the presence of raised glands, sometimes granulate, glossy dark green when fresh, and (grey to brown) to green when dry. • The lower surface is also glabrous, sometimes sparsely hairy at the midrib, raised glands present, discoid glands absent, (dull pale) green when fresh, (grey to brown) to green when dry with paler nervation. • Secondary veins 6-13 per side, closed at the margin to almost so, with reticulate nervation.
• Develops 1-4-seeded berries, 24-54 by 16.5-41 by 16.5-41 mm when dry, 38 by 60 mm when fresh. • Raised glands are present, ruminate when dry, glabrous outside and inside. • Purple or green when young, green to yellow to whitish to greyish to brownish when mature. • Translucent arillode is white to grey.

Cultural usages and ecological values
Baccaurea lanceolata as study object is more social-economically determined. While it is less commonly cultivated, a survey study conducted by Khadijah et al. [22] in 2018 determined that there are fifteen Baccaurea lanceolata trees planted in home gardens or orchards in Malaysia; fourteen trees in Sabah and one tree in Sarawak. The previous study conducted in 2014 [23] also confirmed the cultivation status of Baccaurea lanceolata with medium economic status. Baccaurea lanceolata tree is harvested for its timber [24] and is known to be rather hard and durable [14]. Hence, the timber is also used for house construction [16]. Other than that, the Iban uses the fruit of Baccaurea lanceolata as protection against charms and first consumed before paying house visits during Gawai, the harvest festival [16]. Culturally, when hunting, the Dayak depend on a few types of fruit as an indicator for the presence of pig or duk (Macaca nemestrina). Baccaurea lanceolata fruit is one of them. Where the fruits are found abundantly, in time the Dayak realised that the pig and duk are always around. The duk will eat the fruits on top of the trees while the pig will eat the leftover thrown by the duk [25].
The fruits are also consumed by many bird species, deer, monkeys, rodents, and also the Orangutan [26]. Therefore, even though Baccaurea lanceolata contributes only marginally to the local economics, their ecological values are more apparent.

Food
In most Baccaurea species, only the arillode is eaten. However, the pericarp of Baccaurea lanceolata is edible as well [14]. The fruits are very sour; thus, it is usually eaten by dipping it into sugar or salt [14]. The local Sabahan, especially the Dusun, also enjoy the fruit juice and are known to sun-dry the fruit slices, which are used in the cooking process. Figure 11 shows the image of Baccaurea lanceolata juice, while Figure 12 illustrates the sun-drying process of the fruit slices.
While it is true that Baccaurea lanceolata is rarely cultivated, a survey in Sabah by Kodoh et al. [27] found out that its fruit is traded locally in tamu (open market). Ten most common tamu was covered in that particular survey, as well as major ethnic groups in Sabah, mainly Kadazandusun, Rungus and Murut. Baccaurea lanceolata fruit is also occasionally traded at the traditional market in some subdistrict in South Aceh region [28]. The Dayak is also recorded to enjoy the fruit [25].
Consequently, in Sarawak, it is usually served together with chicken rice and is also used during the cooking process [14]. The fruiting season of Baccaurea lanceolata is year-round. Therefore, not only the fruit can constitute a vital nutrient source [14], it provides possible benefits and boosting household incomes [28]. Figure 11. Fresh fruit juice Figure 12. Sun-dried fruit slices

Cosmetic and skincare
In Indonesia, Baccaurea lanceolata fruit is traditionally used as an acne remedy [25]. The skincare products sold are usually in the form of face mask and powder. The fruit is also used as natural sunscreen [25,28] by the tribal hamlets in Kalimantan, where the fruits are processed into powder form and applied to skin prone to sunlight exposure [29].

Traditional medicine
Several parts of Baccaurea lanceolata has been traditionally and culturally used to treat illnesses ranging from body pain, headaches, diarrhoea and reducing drunkenness. Table 3 hence shows the ethnomedicinal properties of different parts of Baccaurea lanceolata.

Phytochemical study
To date, only one paper written by Abu Bakar et al. [32] that reported on the phytochemicals contents of Baccaurea lanceolata through several tests-total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC) and total carotenoid content (TCC). The data from the study are tabulated in Table 4, respectively, as shown below: TFC was expressed as mg catechin equivalent (mg CE) in 1 g of dry sample; c TAC was expressed as mg of cyanidin-3-glucoside equivalents (mg c-3-gE) in 100 g of dry sample; d TCC was expressed as mg beta carotene equivalents (mg BCE) in 1 g of dry sample. Source: Adapted from [32] TPC of the fruit extracts ranged from 3.29 to 4.81 mg GAE/g for Baccaurea lanceolata. TAC and TCC content of Baccaurea lanceolata was on the lower side where TAC content ranged from 0.07±0.00 to 0.50±0.13mg c-3-gE whereas TCC was valued from 0.64±0.28 to 0.75±0.00 mg BCE. Low TAC content may be contributed to the fact that high TAC content is usually associated to darkred colour fruit (i.e., cherry) as compared to pale-yellow colour fruit (i.e., plum) [33]. Table 5, on the other hand, summarise the antioxidant activity of different parts of Baccaurea lanceolata (pericarp, flesh and seed), also from the same authors [32].  2.29 ± 0.12 2.81 ± 0.23 1.93 ± 0.17 a DPPH free radical scavenging was expressed as mg ascorbic acid equivalent antioxidant capacity (AEAC) in 1 g of dry sample; b ABTS decolourisation assay was expressed as mg ascorbic acid equivalent antioxidant capacity (AEAC) in 1 g of dry sample; c FRAP was expressed as mM ferric reduction to ferrous in 1 g of dry sample. Source: Adapted from [32] A study by Abu Bakar et al. [32] incorporated three methods to analyse the antioxidant capacity of Baccaurea lanceolata fruit which were DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), ABTS and also FRAP (Ferric Reducing/Antioxidant Power) assays. In DPPH assay, the flesh of Baccaurea lanceolata fruit had the highest scavenging activity. The lowest scavenging assay was observed on the pericarp of Baccaurea lanceolata pericarp while the seed displayed the lowest reducing effects in FRAP assay. The study further reported that there was a strong positive correlation (r2 = 0.999, p < 0.01) between TPC and reducing the power of extracts, which suggested that the powerful reducing agent in Baccaurea might be due to its phenolic compounds. Finally, the same study summarised that highest phytochemical content observed in Baccaurea lanceolata was its edible part (flesh). Generally, consumption of edible parts of the fruit is regarded as safer and suitable for direct human consumption, since damage via oxidation of free radicals and reactive oxygen species that contributes to human chronic diseases are reduced [32].
Another study by Hadi et al. [34] determined the IC50 value in Baccaurea lanceolata through DPPH assay. Table 6 tabulated the data obtained from the study, which was expressed in ppm.

Pharmacological study
Two studies regarding the antimicrobial activity of Baccaurea lanceolata was found. The study by Galappathie et al. [31] tested the leaves and stems of Baccaurea lanceolata, tabulated, as shown in Table 7. Baccaurea lanceolata shows medium to potent inhibition against selected bacterial strains, with the highest inhibition being Moraxella catarrhalis. It, however, does not exhibit any inhibition against fungal strains of Candida albicans.  Source: Adapted from [31] Consequently, another study by Fitriansyah et al. [35] proves that there is an antibacterial activity in other parts of Baccaurea lanceolata (fruit, leaf and bark). It was further reported that out of the three, the ethanol extract of Baccaurea lanceolata fruit shows the most active activity against gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus), gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli) and gram-positive, acne-causing bacteria (Cutibacterium acnes, Staphylococcus epidermidis).

Nutritional value
A study on determining proximate composition (Table 8) and minerals value (Table 9) was conducted in 1999 [36]. The nutritional composition data tabulated were based on 100 g edible portion of Baccaurea lanceolata fruit. The moisture content in Baccaurea lanceolata fruit analysed in the study was high (92.4%) with comparatively low protein and fat, both at 0.2%. Compared to the other food item studied in the same study [36], the overall proximate composition of Baccaurea lanceolata fruit is on the lower side. As tabulated in table 9, highest mineral value in Baccaurea lanceolata fruit is potassium (126 mg per 100 g edible portion) while vitamin C in the fruit is considered low at only 0.6 mg per 100 g edible portion. Except for Kepayang (Pangium edule), a fruit that was also analysed in the study, a low level of vitamin C is detected in all types of indigenous fruit and wild vegetable [36].

Potential Industrial Commercialisation
Lately, Baccaurea lanceolata fruit is gaining traction yet again, especially among the Sabahan local (Dusun local predominantly). The fruit commercially sold are either fresh, pickled or often made into sambal (a type of side dish), where it is cooked together with anchovies or salted fish, Capsicum annum (cili padi) and crushed shallot, garlic and ginger. The seasonings are usually made up of a combination of sugar and salt and other preferred condiments. Other possible commercialisation includes mass-producing the fruit beverages and dried fruit slices. The following Figure 13 shows the sambal of Baccaurea lanceolata fruit.
On the other hand, a 2014 Indonesian study [37] explored the potential of Baccaurea lanceolata as an alternative material for latex coagulant by studying the effect of the fruit extract on dry rubber content. An alternative natural latex thickener is preferred to reduce reliance on chemical, as well as to minimise cost and chemical exposure. Fully matured Baccaurea lanceolata fruit was chosen as it is readily available all year round, free or very cheap to purchase. The identification of the use of fruit extract as a latex thickener includes the duration of freezing, calculation of dry rubber content, and analysis of ash content. The results showed that the Baccaurea lanceolata extract had a density of 0.947g/mL, acetic acid content of 2.79%, and the resulting yield of 48.77%. This study also showed that the time needed for latex freezing was 3 minutes on average with the following conditions-using Baccaurea lanceolata fruit extract as a coagulant, dry rubber content of 30%, and the ash content of 0.86%.

Conservation effort
Malaysia is recognised as a mega biodiversity country which holds different varieties or diversity of genetic resources. Therefore, efforts to conserve and utilise these resources, which are endemic and localised in distribution, are continued to be enhanced. One such effort by the government was to introduce the National Strategies and Actions Plan on Agrobiodiversity Conservation and Sustainable Utilization (2011-2020). In situ and ex situ conservations are one of the critical aspects highlighted in  [38].
In the case of Baccaurea species, due to the very declining area of tropical lowland rain forests, local extinctions of said species occur all the time [14]. Hence, in one of an ex situ conservation (located in MARDI germplasm at Jelebu, Negeri Sembilan), MARDI had taken an effort to collect and conserve the genetic resources of the Baccaurea species, which includes Baccaurea lanceolata species [22]. Example of in situ conservation done in Malaysia is the 50-ha plot in Pasoh Forest Reserve, a lowland Dipterocarp forest, in which a total of 820 species in 294 genera and 78 families of trees measuring more than 1 cm diameter at breast height were enumerated. Generally, the most common fruit tree genera found in the forests comprise of Artocarpus, Baccaurea, Durio, Garcinia, Lansium, Sandoricum, Bouea, Mangifera, Cynometra, Dialium, Parkia, Nephelium and Xerospermum [39].
The policy stated previously are in line with the study of the underutilised plant (in this case, Baccaurea lanceolata). The sustainable effort under sector Plant Genetic Resources for food and agriculture (PGR) contained in NSAP calls for further utilisation, characterisation and evaluation of wild crop relatives and wild plants for food and agriculture. Relevant research will provide insight into these wild, underutilised plant species, and it may also serve as an identifying accession of desirable traits for crop improvement. Therefore, characterisations of Malaysia's biodiversity, primarily through agriculture, is crucial since it plays an essential component in food security since species diversity provides the genetic material for food and crops. The NSAP policies that were integrated into the new National Policy on Biological Diversity 2016-2025 (NBSAP) encompassed every aspect of sustainable development of biodiversity in the country, which subsequently shows Malaysia's commitment in conserving its biological diversity [38].

Future study
An extensive botanical study on Baccaurea lanceolata by Haegens [14] noted that the type specimen of Baccaurea lanceolata is a mixtum, where its leaves share similar characteristics to that of Terminalia sp. The leaves and bark of plants categorised in Terminalia genus are well known for their medicinal potential [40]. Consequently, a 2018 study [41] focusing on determining the antifilarial activities in the leaves of three plants belonging to the Terminalia genus (Terminalia bellerica, Terminalia chebula and Terminalia catappa) were done to explore the potential of the plants as an alternative medicine against filariasis. The study target was Setaria cervi, a bovine filarial parasite. Interestingly, all of the plants show antifilarial potential with Terminalia bellerica exhibiting significant antifilarial potential. Suffice to say; it would be interesting to replicate the same study using a different part of Baccaurea lanceolata (the leaves especially).
Accordingly, although Baccaurea lanceolata fruit has potential as a natural coagulant, more studies on its development should be done until it complies with the national standard set by the government. The same study by Purnomo et al. [37] stated that while rubber treated with Baccaurea lanceolata extract coagulant experienced perfect clotting and has a yellowish-white hue, after the third day, there are drastic changes of colour (brownish to yellow). Finally, on the sixth and seventh day, the rubber was observed to have small bubbles and mottled texture. Its elasticity properties still maintain, however. Going by Standard Nasional Indonesia (SNI) 2000, the quality of rubber will be higher if the surface is uniform, no bubbles, stretches, nor dirt and possess firm texture.
Consequently, the seeds of Baccaurea lanceolata is treated as a waste since it is not consumed. Hence, a study should be done to determine the potential of the seeds in various industrial application such as for cosmetic or bio-stimulant purposes since the study by Abu Bakar et al. [32] shows good antioxidant activity.
The study by Van der Ent et al. [42] through an intensive screening has found out that Baccaurea lanceolata plant (habitat: lowlands, mixed Dipterocarp forest with maximum foliar Ni of 1450µg g -1 ) is a Nickel hyperaccumulator. It was stated in the same study that there was a predisposition for the Phyllanthaceae to accumulate not only Ni but also other trace elements such as Co, Cr, Mn and Zn,