Macroscopy

Leaves are alternate, entire to slightly dentate and glabrous, but may be more or less rough when full grown, variable in shape, from elliptic-lanceolate to broad ovate, often with a rounded or cordate base, basal nerves 3, rarely 5, blade 3-6, petioles 2.5-5 cm long.

Flowers are bisexual, complete, short-stalked, actinomorphic, white and glabrous. A fully open flower is 6 mm in average diameter. The inflorescence is terminal or an axillary cyme, which almost resembling to a biparous cyme. It has 14 flowers per cluster. The calyx is cup-shaped. Sepals are about 4mm in length, slightly dentate from top, light green in color and gamoseplous. The corolla has four creamish white color petals which are 6mm in length and polypetlous. The androecium contains two stamens, each having a very small filament and epipetalous. The gynoecium is bifurcated, 4 mm in length and having a globose shaped ovary at the base.[2]

Fruit is drupe, 1.3-2.5 cm long, when ripe yellowish brown, pink or nearly black, shinning but minutely rugose, endocarp rugose, very hard, in a sweetish viscid, almost transparent pulp.[3] Epicarp is thick while mesocarp is mucilaginous and endocarp is hard and stony.[2]

Stone is found in fruit and it is of 8.5 × 7 mm in size, 298 microlitres in volume, 375 mg in weight and each stone contains two seeds, which are separated by a stony septum. The seeds are mildly sweet in taste.

The flowering starts during the last week of April and continues till the end of May. The fruiting season lasts from the beginning of July to the end of August.[2] Figures ​Figures11 and ​and22 are showing Cordia obliqua Willd. tree, bark, leaves and fruits.

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Figure 1

(a) Cordia obliqua Willd. tree (b) Cordia obliqua Willd. tree bark

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Figure 2

(a) Cordia obliqua Willd. branches (b) Cordia obliqua Willd. leaves and fruits

Microscopy

Leaf

The transverse section of leaf shows that mesophyll is differentiated into palisade and spongy parenchyma cells. Epidermis is of single layer, covered externally with prominent cuticle in upper and lower surface. Palisade tissue is consists of one layer of columnar cells, which occupies a little less than half of the width of mesophyll and the spongy mesophyll is covered with cells of irregular size. The midrib is almost circular in out line. Following the epidermis, there is a zone of cortex composed of 1 or 2 layers of collenchyma surrounding the central portion. The vascular bundle is ovoid in shape and circularly arranged, centrally forming pith. Sclerenchyma sheath is found lignified with thick walled cells that cover the vascular bundles and xylem consists of small tracheids and vessels with large lumen[5,6] [Figure 3].

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Figure 3

(a) Cordia obliqua Willd. leaf (b) Leaf T.S. through midrib (c) Leaf T.S. through midrib stained[6]

Table 1 describes different types of stomata number per mm square in lower and upper epidermis and average dimensions of guard cells in micrometer found in Cordia obliqua leaf.[7] A histological study was carried out on three distinct types of galls which are found on the Cordia obliqua leaves. These leaves were collected from various parts of India. It described that Fusiform galls are caused due to Baris cordiae Mshl., found on the petiole and mid rib, green to dark green coloured epiphyllous filzgalls are caused due to Eriophyes mites on the lamina and the third marginal galls are caused due to Aneurothrips sp. The occurrence of these three types of galls on the same leaf and the tissue responses of the leaf to the different insects and mites were also analysed in this study.[8]

Table 1

Study of type and size of various stomata in Cordia obliqua Willd. leaf[7]

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Chemical composition

The fruit contains moisture 75 g, pectin 4.5 g, total sugars 3.55 g, reducing sugars 3.41 g, non-reducing sugars 0.08 g, protein 2.06 g, ash 2.132 g, phosphorus 0.091 g, potassium 1.066 g, magnesium 0.067 g, calcium 0.062 g and iron 0.005 g (all data is per 100 g of the edible portion). The total soluble solids of the fruit pulp constitute 10.2%.[2]

The leaf, stem and root powders with various extracts showed the presence of phenols, alkaloids, tannins and reducing sugar.[5] In a phytochemistry study of Cordia obliqua leaf aqueous extract, a number of chemical tests were performed to find out various chemical constituents and this study confirmed that only steroids are present in leaf aqueous extract and other constituents like saponins, flavonoids, terpenoids, cardiac glycosides and tannins were absent.[9]

Chemical examination of Cordia obliqua seeds, resulted in isolation and characterization of various constituents like alpha-amyrin, betulin, octacosanol, lupeol-3-rhamnoside, beta-sitosterol, beta-sitosterol-3-glucoside, hentricontanol, hentricontane, taxifolin-3,5-dirhamnoside and hesperitin-7-rhamnoside.[10]

Other isolated chemical compounds from various parts of Cordia obliqua plant are Hesperetin-7-rhamnoside from roots,[11] Lupa-20,29-ene-3-o-β-D-maltoside from roots[12] [Figure 4], Lupa-20 (29)-ene-3-O-alpha-L-rhamnopyranoside from roots,[13] natural gums and mucilage from fruits.[14] Constituents like Allantoin-β-sitosterol and some flavonoids were also isolated from stem bark of Cordia obliqua.[15]

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Figure 4

Lupa-20, 29-ene-3-o-β-D-maltoside[1]

Medicinal properties

The fruit is sweet and have effects like slightly cooling, anthelmintic, purgative, diuretic, expectorant, and useful in diseases of the chest, urethra, dry cough, biliousness and chronic fever. It lessens thirst and the scalding of urine, removes pains in the joints, bad humours, burning of the throat and also good in diseases of the spleen (As per Yunani system).

The juice of the bark is given in gripes, along with coconut oil. The bark and unripe fruit are used as a mild tonic.

The kernels are a good remedy in treatment of ringworm. The leaves are useful as an external application to treat ulcers and headache.

The Santals use a powder of the bark for external application in prurigo. The Javanese use the bark in treatment of fevers.[3]

Utilization

A good pickle is prepared from its raw fruits and these are also used as vegetable. The fruit mucilage is used as a gum for pasting cardboard and paper sheets.[2]

Biological activities

Traditionally a number of activities are reported from various parts of this plant. A few of them are scientifically proven. Some of the reported studies are following:

The authors are thankful to Punjab Technical University (PTU), Jallandhar, for providing necessary assistance. Also grateful to staff members and management of ASBASJSM College of Pharmacy, Bela, Ropar.