Phytopharmacology of Holy basil (Ocimum tenuiflorum, Ocimum sanctum) Part 2
Phytopharmacology
of Holy basil
(Ocimum
tenuiflorum, Ocimum sanctum) Part 2
Morphology
of holy basil
(Ocimum tenuiflorum, Ocimum
sanctum)
Macroscopic
characteristics
Synonyms
Geniosporum tenuiflorum (L.) Merr.
Lumnitzera
tenuiflorum (L.) Spreng.
Moschosma
tenuiflorum (L.) Heynnh.
Ocimum
anisodorum F. Muell.
Ocimum
caryophyllinum F. Muell.
Ocimum
hirsutum. Benth.
Ocimum
inodorum Burm. f
Ocimum
monachorum. L.
Ocimum
sanctum. L.
Ocimum scutellariodes Wild. Ex Benth
Ocimum
subserratum B. Heyne ex Hook f.
Ocimum
tomentosum Lam.
Ocimum
villosum Roxb. nom.illeg.
Plectranthus
monachorum (L.) Spreng [30]
Plant
Holy basil (Ocimum tenuiflorum, Ocimum sanctum)
Tulsi, Holy basil (Ocimum
tenuiflorum, Ocimum sanctum) is an aromatic perennial plant native to India
and wide spread as a cultivated plant throughout the Southeast Asian tropics.
It is an erect, softly hairy, herbaceous (the plant that does not have much
wood), much branched plant attaining 30 to 90 cm height. Three main morphotypes
cultivated in India and Nepal are Raam Tulsi, Krishna Tulsi and Vana Tul (wild
variety) [31]
Roots
Tap root
with multiple fibers Dry roots
As Tulsi, Holy basil (Ocimum tenuiflorum, Ocimum sanctum) is a dicot plant its root
system is tap root. There is however a lot of confusion on internet, whether it
is tap root or fibrous root. According to experts, Tulsi (Ocimum tenuiflorum) being a dicot plant its root for sure is ‘tap
root’. [32]
Root is wiry, branched, hairy, soft, blackish-brown
externally and pale violet internally [33]
Stem
Stem of green Tulsi Stem of urple Tulsi
Its stem is erect, herbaceous, woody, square, hairy,
much branched, 30 to 60 cm tall and depending on variety light green to purple
in color outside and cream colored internally; lower parts sub-serrate, higher
parts slightly furrowed and more densely pubescent. [34], [35]
Leaves
Green Tulsi Purple Tulsi
Leaves green or dark purple in color; the variety with
green leaves is called Shri Tulsi and with reddish leaves is called Krishna
Tulsi. Leaves are simple, opposite, elliptic to elliptic-oblong blades, 3 to 6
cm long, 1 to 2.5 cm wide, cuneate (wedge shaped) at base, obtuse to acute at
apex, entire, serrated margins, pubescent (hairy) on both surfaces; petiole
thin, cylindrical, green with purplish tinge, thinly pubescent (hairy) and
dotted with narrow inconspicuous adaxial (facing towards stem) groove, 1 to 3
cm long; venation reticulate (veins are irregularly distributed) [36], [37]
Flowers
Green Tulsi: Fresh flowers Green Tulsi: Mature flowers
Purple
flowers of Tulsi
Flowers are terminal, slender racemes or panicles, 4 to 12 cm long, 1
to 1.5 cm wide; bracteoles 2 to 3 mm long, ovate, acuminate, ciliate; flowers
in verticils, on pedicels 2 to 4.5 mm long; calyx 2.5 cm long at anthesis (the
flowering period of a plant, from the opening of the flower bud), in fruit up
to 5 mm long, glabrous within, the upper lip suborbicular (nearly circular),
reflexed (bent or curved backward or downward), short-apiculate (ending
abruptly in a small distinct point), the
lower lip longer than upper lip, the teeth 4, lanceolate; corolla pale pink,
white or pale lavender, to 4 mm long; filaments of stamens exserted
(protruded), slender, the upper of each with a small, bearded basal appendage. [38]
The purplish flowers ease placed in close whorls on elongate racemes,
bracts about 3 mm longer than calyx, slender, pubescent; calyx ovoid or
campanulate (bell shaped) 3 to 4 mm, having two lips, upper lip obovate (oval
with narrower end at the base), shortly apiculate (ending abruptly in a small distinct
point), lower lip longer than upper lip having 4 mucronate (ending abruptly in
a short sharp point) teeth, central two large lateral two short; corolla about
4 mm long, pubescent [39]
Fruits
Tulsi fruit
Fruit, a group of 4 nullets,
each with one seed, enclosed in an enlarged, membranous veined calyx; nutlets
broadly elliptic, 0.8 to 1.2 mm long, slightly compressed or nearly smooth to
minutely pitted, purple-green to brown in color marking at the place of attachment
of thalamus [40], [41]
Seeds
Tulsi seeds
Seeds round to oval, small, many, yellow to reddish or black in color,
0.1 cm long, slightly notched at the base, having tough coat which pops around the
seed on wetting [42], [43]
Microscopic characteristics
Root
Transverse section shows single layered
epidermis followed by cortex, consisting of seven or more layers of
rectangular, round to oval polygonal, thin-walled parenchymatous cells filled
with brown content, inner layers of cortex devoid of contents; phloem
consisting of sieve elements, thin walled, rectangular parenchyma cells and
scattered groups of fibres, xylem consists of vessels, tracheids, fibres and
parenchyma; vessels pitted; tracheids fibres long, pitted with pointed ends;
fibres thick walled and with pointed ends. [44]
Stem
Transverse section of stem shows a
single layered epidermis with uniserriate (one cell wide), multicellular
covering trichomes having 5-6 cells, occasionally a few cells collapsed; cortex
consists of 10 or more layers of thin walled, rectangular parenchymatous cells;
phloem consists of sieve elements, thin-walled, rectangular parenchyma cells
and fibres; fibres found scattered mostly throughout phloem, in groups; xylem
occupies major portion of stem consisting of vessels, tracheids fibres and
parenchyma; vessels pitted; fibres with pointed ends; centre occupied by pith
consisting of round to oval, thin-walled parenchymatous cells [45]
Leaf
Petiole
Section of petiole shows somewhat
cordate (heart shaped) outline, consisting of single layered epidermis composed
of thin-walled, oval cells having a number of covering and glandular trichomes;
covering trichomes multicellular 1 to 8 celled long, rarely slightly reflexed
at tip; glandular trichomes short, sessile with 1 to 2 celled stalk and 2 to 8
celled balloon shaped head, measuring 22 to 27 μ in diameter; epidermis
followed by 1 or 2 layers and 2 or 3 layers of thin-walled, elongated,
parenchyma cells towards upper and lower surfaces respectively; three vascular
bundles situated centrally, middle one larger than other two; xylem surrounded
by phloem. [46]
Midrib
Transverse
section of the leaf through its midrib shows that upper epidermis consists of a
layer of small, quadrangular transparent cells with thin walls and thin smooth
cuticle. On tangential view, these cells are polygonal with straight or wavy
walls. Lower epidermis consists of a layer of small, quadrangular transparent
cells with thin walls and thin smooth cuticle. Trichomes bent, consisting of 2
to 6 cells; glandular trichomes short, Laminaceae type, consisting of 1 stalk
cell and 2 to 4 cells with rounded heads. Pallisade parenchyma consists of
layer of long cylindrical cells containing chlorophyll; spongy parenchyma
consists of polygonal cells with thin, straight or slightly wavy side walls.
Vascular bundles collateral type with cholenchyma cells. Stoma diacytic (also
called caryophyllaceous or cross-walled type), on upper and lower epidermis
[Note:
Diacytic stoma remains surrounded by a pair of subsidiary cells. The
common wall of the subsidiary cells is at right angles to guard cells) [47]
Lamina
Epidermis
and trichomes similar to those of petiole; both anomoctyic and diacytic type of
stomata present on both surfaces, slightly raised above the level of epidermis;
palisade single layered followed by 4 to 6 layers of closely packed spongy
parenchyma with chloroplast and oleoresin [48]
[Note: Anomocytic means having irregular cells]
Powder
Greenish in color, shows thin-walled, parenchymatous
cells, a few containing reddish brown contents, unicellular and multicelluar
trichomes either entire or in pieces; thin-walled fibers, xylem vessels with
pitted thickenings, fragments of epidermal cells in surface view having
irregular shape, oil globules rounded to oval, simple as well as compound
starch grains having 2 to 5 components, measuring 3 to 17 μ in diameter [49]
Parts used
All parts of the plant are edible. For medicinal purpose leaf
and seeds are used, but sometimes stem is used.
Some Ayurvedic practitioners recommend using all parts of the
plant
References
31. http://www.flowers ofindia.net/catalog/slides/Tulsi.html
32. https://www.industrychannel.com
33.
http://www.ayurveda.hu/api/API-Vol-2.pdf
35.
http://www.ayurveda.hu/api/API-Vol-2.pdf
36. https://www.cabi.org/isc/datasheet/110287
40.
https://www.cabi.org/isc/datasheet/110287
41. http://www.ayurveda.hu/api/API-Vol-2.pdf42.Pavan Malav et al, Morphological
variability in holy basil (Ocimum tenuiflorum L.) from India, Genet resour Corp
Evol
43.
http://www.ayurveda.hu/api/API-Vol-2.pdf
44.
http://www.ayurveda.hu/api/API-Vol-2.pdf
46.http://www.ayurveda.hu/api/API-Vol-2.pdf 47.https://apps.who.int/medicindocs/en/d/Js4927e/21.html#Js4927e.21
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