First Report of Pseudopestalotiopsis theae Causing Aloe vera Leaf Spot Disease in Bangladesh

Aloe vera (L.) Burm.f. is one of the important medicinal plants, has been commercially cultivated in the Northern part of Bangladesh. An experiment was conducted to detect A. vera leaf disease collected from Natore district, Bangladesh. Fungal leaf spot disease caused by Pseudopestalotiopsis theae (Sawada) Maharachch., K.D. Hyde & Crous was identified through morphological features and sequencing of internal transcribed spacer region of ribosomal DNA. After submitting nucleotide sequences to NCBI, we received an accession number MH333081.1: Pseudopestalotiopsis theae. The growth pattern of the isolated fungal pathogen was evaluated on different solid culture media, at different temperature and light conditions. The results showed the maximum mycelial growth of the fungus on the Richard Agar medium under the complete dark condition at 25°C. We evaluated fungal antagonists against the isolated pathogenic fungus, in which Trichoderma asperellum showed optimistic results. Synthetic fungicides—Tilt 250EC and Ridomil Gold completely inhibited the studied fungus’s vegetative growth. Pseudopestalotiopsis theae causing A. vera leaf spot disease in Bangladesh is a new record to the best of our knowledge.

Investigation of the Phytoconstituents and Antioxidant Activity of <i>Diospyros malabarica</i>Fruit Extracts

Diospyros malabarica (Deshi Gab) belonging to the family “Ebenaceae” grows well in the humid tropical climate of Bangladesh. In order to investigate the phytoconstituents both qualitatively and quantitatively, the seed and flesh extracts of D. malabarica were prepared using two polar solvents (i.e., water and 70% ethanol) and a nonpolar solvent (i.e., hexane). The maximum yield was obtained for aqueous and ethanolic seed extracts indicating that most of the phytoconstituents present in D. malabarica fruit are polar. The qualitative phytochemical analysis of the extracts revealed the presence of diverse amount of phytoconstituents in the extracts. On the other hand, the quantitative phytochemical analysis for phenols, tannins, flavonoids, alkaloids, saponin, proteins, reducing sugar and vitamin C revealed that the maximum amount of phenols, tannins, flavonoids and reducing sugar were present in aqueous seed extract. However, the maximum amount of total protein and vitamin C was found in ethanolic seed extract. D. malabarica seed powder contained more amount of alkaloids (i.e., 13.6%) than that of flesh (i.e., 3.4%). However, the content of saponin was more in flesh extract (0.74%) when compared to that of seed extract (0.42%). In vitro antioxidant properties of the extracts were also investigated by DPPH free radical scavenging assay, FRAP assay and reducing power assay. The highest antioxidant activity was observed for aqueous seed extract followed by the ethanolic seed, ethanolic flesh, and aqueous flesh extracts. The lowest antioxidant activity was obtained for hexane flesh extract. Furthermore, the lowest (i.e., 44.70 μg/ml) as well as the highest (2359.66 μg/ml) IC50 values were obtained for aqueous seed and hexane flesh extracts, respectively.

Investigation of the Phytochemicals, Antioxidant, and Antimicrobial Activity of the <i>Andrographis paniculata</i>Leaf and Stem Extracts

Andrographis paniculata (Kalmegh) has been considered as a medicinal shrub and used as a medicinal plant in the remote areas of Bangladesh. A. paniculata leaf and stem extracts were prepared using the polar (i.e., water, and 70% ethanol) and nonpolar (i.e., hexane) solvents. The phytochemical contents, total phenol contents (TPC), antioxidant activity, and antibacterial activity of all the extracts of A. paniculata leaf and stem were investigated. Both the gram-positive (i.e., Bacillus subtillis) and gram-negative (i.e., E. coli, and Salmonella typhi) strains of bacteria were used for the antibacterial activity assay of the sample extracts. The ethanolic stem extracts contained the maximum amount of TPC when compared to that of the leaf extracts. However, the aqueous stem extracts had the highest free radical scavenging activity in vitro. The extracts prepared from A. paniculata stem showed better antibacterial activity against all the strains of bacteria (i.e., E. coli, S. typhi, and B. subtillis) when compared to that of the leaf extracts. More specifically, the aqueous stem extract showed superior antibacterial effect against E. coli, and B. subtillis, and the zones of inhibition were 21 mm, and 29 mm in diameter, respectively. On the other hand, the ethanolic stem extract showed the maximum antibacterial activity against S. typhi and the zone of inhibition was 8.15 mm. The minimum inhibitory concentration (MIC) value and IC50 value for all the A. paniculata extracts were ~0.05 μg/μL, and ~1 μg/μL, respectively.

Investigation of the Phytoconstituents and Bioactivity of Various Parts of Wild Type and Cultivated <i>Phyllanthus emblica</i>L.

Phyllanthus emblica L. belonging to the family Euphorbiaceae is a common medicinal plant in Bangladesh. In order to evaluate the phytoconstituents and bioactivity of various parts of P. emblica, both the wild type (i.e., small) and cultivated (i.e., big) fruits were collected from the local market of Bangladesh and six ethanolic extracts were prepared from various parts of the collected fruits for this current study. A comparative analysis of the phytochemical compositions and various bioactivities especially antibacterial, antifungal, and antioxidant activity of the six ethanolic extracts were accomplished. The qualitative phytochemical analysis of plant extracts revealed the presence of large amounts of proteins, carbohydrates, phenolic compounds, glycosides, alkaloids, coumarins, flavonoids, tannins, saponins and resins etc. The maximum antioxidant activity was observed for wild type P. emblica seed extracts and the minimum activity was observed for cultivated flesh extracts. Moreover, among the samples the wild type P. emblica extracts have excellent amount of total phenol contents and the highest free radical scavenging activity. It is also found that P. emblica samples were active against both gram-positive (i.e., B. subtilis) and gram-negative (i.e., E. coli, and S. typhi) bacteria. The highest antibacterial activity was achieved in the wild type P. emblica seed extracts against both pathogenic (S. typhi) and non-pathogenic bacterial strains (E. coli, and B. subtilis). These samples showed almost no activity against Fusarium sp. fungus.

Investigation of Ovarian Follicular Waves and Major Hormonal Profile in Red Chittagong Cattle

Red Chittagong Cattle (RCC) is one of the renowned varieties of cattle which is indigenous and most potential type of domestic animal genetic resource in Bangladesh with distinct phenotypic characteristics. Reproductive management might be a process for multiplying this cattle variety. Therefore, the goals of this study were to characterize the follicular waves of RCC and to determine the Progesterone (P4), Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) profile during three consecutive estrus cycle. Follicular wave emergence (Day 0) was identified using trans-vaginal ultrasound technique and follicular growth was then monitored from Day 0 to Day 23 during three consecutive estrus cycle and blood samples were collected. After measuring the growth and diameter of the follicles, hormonal assays of collected blood samples were performed using Enzyme Linked Immunosorbent Assay (ELISA). We found that, both RCC cows and heifers showed two waves inter-ovulatory intervals. The length of inter-ovulatory intervals and the diameter of the ovulatory follicle of RCC cows and heifers were slightly different from each other. The identification of the dominant follicle was confirmed from the start of its deviation from other subordinate follicles till it reached to the maximum diameter and identified as dominant follicle which increases linearly for approximately six days (growing phase). This dominant follicle is remained approximately same size for five days (static phase), and then begins to regress (regressing phase) decreasing the antral diameter. The follicular waves are first detectable as 4 - 5 mm follicles approximately at day 0 and day 10 both for RCC cows and heifers which showed two waves inter-ovulatory intervals. The circulating varied concentrations of LH, FSH and P4 were determined using ELISA in case of both cows and heifers and the concentration curves followed the similar pattern of change during the estrus cycle. Hence, the knowledge about ovarian follicular waves will create a base line for reproductive management of RCC as well as to allow reproductive biotechnologies to improve and multiply this cattle variety.

Investigation of the Antimicrobial Activity and <i>in Vivo </i>Cytotoxicity of <i>Diospyros malabarica </i>(Desr.) Kostel. Fruit Extracts

Mankind is facing an unprecedented threat of existence due to the antibiotic resistance developed by bacteria. The unripe fruits of Diospyros malabarica (Desr.) Kostel. (family: Ebenaceae) can be considered as one of the natural sources to tackle this issue. The present study is designed to assess the antimicrobial activity of D. malabarica seed and flesh ex-tracts. Herein, D. malabarica extracts were prepared using polar solvents (i.e., water and 70% ethanol) and their antimicrobial activity as well as in vivo toxicity was investigated. Their antibacterial activity was investigated against gram positive (Bacillus subtilis) and gram negative (Escherichia coli DH5α, and Salmonella typhi) bacteria at different time points. All the extracts showed the highest antibacterial activity after 2 hours of incubation. The aqueous seed extract showed the maximum zone of inhibition (i.e., ~13 mm) against Bacillus subtilis with a minimum inhibitory concentration (MIC) value of 2 μg/μl. The an-tibacterial propensity was also confirmed through trypan blue dye exclusion assay, CellToxTM Green assay, and lipid peroxidation (LPO) assay. On the other hand, the etha-nolic seed extract demonstrated higher antifungal activity through inhibition of mycelial growth. All the extracts showed excellent hemocompatibility against both human and rat red blood cells (RBCs). They also did not show any toxicity to rat liver and kidneys. Taken together, this study demonstrates that the aqueous and ethanolic extracts of D. malabarica seed and flesh could be an effective source of natural antimicrobial agents with no cytotox-ic activity.