Micromorphology and Histology of the Secretory Apparatus of Diospyros villosa (L.) de Winter Leaves and Stem Bark

Abstract

Diospyros villosa is a perennial species prominently acknowledged for its local medicinal applications. The native utilisation of this species in traditional medicine may be ascribed to the presence of secretory structures and their exudate (comprised of phytochemicals). However, the morphological nature and optical features of the secretory structures in D. villosa remain largely unclear. This study was directed to ascertain the occurrence and adaptive features of structures found within the leaves and stem bark of D. villosa using light and electron microscopy techniques. The current study notes the existence of trichomes, and other secretory structures were noted. SEM indicated the presence of non-glandular hirsute trichomes with bulky stalk on both leaves and stem surfaces. Transverse stem sections revealed the existence of crystal idioblasts. Moreover, the presence of the main phytochemical groups and their localisation within the foliage and stem bark was elucidated through various histochemical tests. The trichomal length and density were also assessed in leaves at different stages of development. The results indicated that the trichomal density at different stages of development of the D. villosa leaves and stem bark was not significantly different from one another, F(3,39) = 1.183, p = 0.3297. The average length of the non-glandular trichomes in the emergent, young and mature leaves, as well as in the stem, was recorded to be 230 ± 30.6 µm, 246 ± 40.32 μm, 193 ± 27.55 µm and 164 ± 18.62 µm, respectively. The perimeter and circumference of the observed trichomes in the developmental stages of D. villosa leaf and the stem bark were not statistically different, F(3,39) = 1.092, p = 0.3615. The results of histochemical tests showed the existence of phenols alkaloids, which are medicinally important and beneficial for treatment of diseases. The findings of this study, being reported for the first time may be considered in establishing microscopic and pharmacognostic measure for future identification and verification of natural herbal plant. Trichomal micromorphology and histological evaluations could be utilised as a tool for appropriate description for the assessment of this species.

Pharmacognostic Evaluation, Chemical Characterization, and Antibacterial Activity of Bassia indica (Wight) A.J. Scott

“…Anatomical histology and powder microscopy act as excellent tools for the authentication, adulteration, or purity of crude drugs [26]. Anatomical structures observed in the present microscopic study of the leaf, stem, and powder provide necessary information about the morphological characteristics of B. indica, which can aid in the identification and authentication of the plant material [27]. Similar structures have also been reported in other plants of the same genus [28,29].…”

Diospyros villosa Root Monographic Quality Studies

“…These results agree with the possible safe topical administration of this herbal preparation but not with its oral administration [32]. 2022), together with the microscopic characterization of the stem bark of this species [29,30]. Additionally, the determination of the antimicrobial activity and toxicological evaluation of a leaf ethanolic extract of D. villosa dried leaf was already performed in our lab [31].…”

“…Terpenoids, a significant class of constituents referred to in previous phytochemical studies conducted by our team, seem to be minor compounds in our samples [37]. However, alkaloids were not detected in our samples, although this chemical class has recently been described as present in this species' leaf and stem bark [30].…”

“…Additionally, we can observe uniseriate medullary rays, medullar parenchyma, and brachysclereids with a ring of prismatic calcium oxalate crystals. The root hairs were not detected in our samples, although trichomes have been reported to be present in the aerial part of this species [29,30].…”

“…The plant is a diploid species (2n = 2 × 30 chromosomes) [27,28]. The characterization of D. villosa dried leaf through microscopic techniques was performed by Gromek et al (2011), and, recently, his study was complemented by Adu et al (2022), together with the microscopic characterization of the stem bark of this species [29,30]. Additionally, the determination of the antimicrobial activity and toxicological evaluation of a leaf ethanolic extract of D. villosa dried leaf was already performed in our lab [31].…”