Antidiarrheal and Antioxidant Activities of Methanol Extract of Bryophyllum pinnatum Leaf Harvested from South-Eastern Nigeria in Mice

Assessment of microwave drying for rapid and convenient analysis of medicinal plants for quality assurance

INTRODUCTION

The safety and quality of many medicinally important herbs are compromised since farmers and small organizations are involved in the cultivation, aggregation, and primary processing of these herbs. Such organizations often lack adequate quality control facilities. To improve the safety and quality of herbal products, simple, rapid, and affordable quality control systems are required.

OBJECTIVES

The aim of this study was to assess the suitability of microwave oven-drying for moisture content (MC) determination and sample preparation of herbs in small organizations.

METHODS

Microwave oven-drying (720 W) and convective oven-drying at 105°C for MC determination were compared. The effects of three different drying methods (microwave oven-drying, low-temperature convective drying, and freeze-drying) on in vitro antioxidant and polyphenol oxidase (PPO) activity were determined, similarity analysis was conducted using HPLC signature spectra, and validation was performed with LC-MS focusing on one herb.

RESULTS

Microwave oven-drying at 720 W significantly reduced the drying time (from hours to minutes), whereas the spatial variation of temperature in convective ovens set at 105°C can cause about 10% underestimation of MC. Microwave oven-drying showed similar macro-properties like freeze-drying and higher extractability (10%-20%) and in vitro antioxidant capacity (33%-66%) and lower PPO activity compared to low-temperature convective drying. HPLC signature spectra revealed strong similarity of soluble components between freeze-dried and microwave oven-dried herbs. LC-MS analysis demonstrated more common compounds between freeze-dried and microwave oven-dried Centella asiatica extracts, whereas convective tray-dried samples had fewer compounds common with samples obtained by freeze-drying or microwave oven-drying.

CONCLUSIONS

Microwave oven-drying is rapid (tens of min) and shows small batch-to-batch variation compared to oven-drying at 105°C. The in vitro antioxidant assays and signature spectra can be used for assessing the source and purity or quality of a specific herb variety.

In Vitro Hypoglycemic and Antioxidant Activities of Dichloromethane Extract of Xerophyta spekei

Diabetes mellitus is a chronic metabolic disorder which has greatly led to an increase in morbidity and mortality globally. Although Xerophyta spekei is widely used for the management of diabetes among the Embu and Mbeere communities in Kenya, it has never been empirically evaluated for its hypoglycemic activity. This study was carried out to verify the hypoglycemic activity of dichloromethane (DCM) extract of Xerophyta spekei as well as its antioxidant activity using various in vitro techniques. Phytochemicals associated with its antioxidant activity were identified through GC-MS. Data were subjected to descriptive statistics and expressed as mean ± standard error of the mean (X̄ ± SEM). Comparison between various variables was performed by using unpaired Student's t-test and one-way analysis of variance (ANOVA), followed by Tukey's post-hoc test. The confidence interval was set at 95%. The obtained results were presented in tables and graphs. Results showed that there was no difference in α-amylase inhibition activity between the plant extract and the standard (IC50 525.9 ± 12.34 and 475.1 ± 9.115, respectively; p  >  0.05). Besides, the glucose adsorption activity of the extract increased with an increase in glucose concentration (from 5.89 to 32.64 mg/dl at 5 mmol and 30 mmol of glucose, respectively; p  <  0.05). The extract also limited the diffusion of glucose more than the negative control (7.49 and 17.63 mg/dl, respectively; p  <  0.05). It also enhanced glucose uptake by yeast cells. In addition, the studied plant extract showed notable antioxidant activities. The therapeutic effects exhibited by this plant in managing diabetes mellitus and other ailments could be due to its antioxidant as well as its hypoglycemic activity. The study recommends the evaluation of X. spekei for in vivo hypoglycemic and antioxidant activities. Besides, the isolation of bioactive phytochemicals from the plant may lead to the development of new hypoglycaemic agents.

Neuropharmacological and Antidiarrheal Potentials of Duabanga grandiflora (DC.) Walp. Stem Bark and Prospective Ligand–Receptor Interactions of Its Bioactive Lead Molecules

Duabanga grandiflora (DC.) Walp. is an ethnomedicinally significant plant used to treat various illnesses, but there is little scientific evidence to support its use. This study explored the pharmacological activities of methanol extract of D. grandiflora stem barks (MEDG) through in vivo approaches in Swiss albino mice and a computer-aided molecular approach. The forced swimming test (FST), tail suspension test (TST), elevated plus maze (EPM), and hole board test (HBT) were used to determine anti-depressant and anxiolytic activity in experimental mice. In addition, anti-diarrheal studies were performed using castor oil-induced diarrhea, castor oil-induced enter pooling, and the charcoal-induced gastrointestinal motility test. MEDG showed substantial depletions in the immobility times in both FST and TST after treatment with the MEDG extract, whereas moderate anxiolytic activity was manifested at a higher dose (400 mg/kg) compared with the control. Correspondingly, MEDG extract revealed a significant reduction in wet feces and decreased the small intestinal transit of charcoal meal in castor oil-induced diarrhea and charcoal-induced gastrointestinal motility test. In the computer-aided molecular approaches, vanillin displayed a promising binding score for both anxiolytic and anti-diarrheal activities, while duabanganal C showed a promising score for the anti-depressant activity. The present experimental findings along with a computer-aided model conclude that MEDG could be a possible Phyto therapeutic agent with potential anti-depressant, anxiolytic and anti-diarrheal activity.

Neuroprotective effect of Bryophyllum pinnatum flavonoids against aluminum chloride-induced neurotoxicity in rats

Toxic metals such as aluminum accumulation in the brain have been associated with the pathophysiology of several neurodegenerative disorders. Bryophyllum pinnatum leaves contain a vast array of polyphenols, particularly flavonoids, that may play a role in the prevention of toxic and degenerative effects in the brain. This study assessed the neuro-restorative potential of leaves of B. pinnatum enriched flavonoid fraction (BPFRF) in aluminum-induced neurotoxicity in rats. Neurotoxicity was induced in male Wistar rats by oral administration of 150 mg/kg body weight of aluminum chloride (AlCl₃) for 21 days. Rats were grouped into five (n = 6); Control (untreated), Rivastigmine group, AlCl₃ group and BPFRF group (50 and 100 mg/kg b.wt.) for 21 days. Neuronal changes in the hippocampus and cortex were biochemically and histologically evaluated. Expression patterns of acetylcholinesterase (AChE) mRNA were assessed using semi-quantitative reverse-transcription-polymerase chain reaction protocols. Molecular interactions of BPFRF compounds were investigated in silico. The results revealed that oral administration of BPFRF ameliorated oxidative imbalance by augmenting antioxidant systems and decreasing lipid peroxidation caused by AlCl₃. BPFRF administration also contributed to the down-regulation of AChE mRNA transcripts and improved histological features in the hippocampus and cortex. Molecular docking studies revealed strong molecular interactions between BPFRF compounds, catalase, superoxide dismutase and glutathione peroxidase Overall, these findings suggest the neuroprotective effect of Bryophyllum pinnatum against aluminum-induced neurotoxicity.

Evaluation of the Antidiarrheal and Antioxidant Effects of Some Chewing Sticks Commonly Used for Oral Hygiene in Ghana

Microbial etiology of diarrhea is a significant cause of death, especially in children in developing countries. The presence of microbes that are resistant to current treatment options for diarrhea suggests the need to find newer antimicrobial agents for treatment. Therefore, this study focused on investigating the antimicrobial effect of some Ghanaian chewing sticks commonly used for oral hygiene, Azadirachta indica, Garcinia afzelii, and Garcinia kola, against selected diarrhea-causing organisms. From the stem and bark of each plant, 70% methanolic extract was experimented on Salmonella and Shigella species, namely, Shigella sonnei, Shigella flexeneri, Salmonella typhinirium enterica, Salmonella typhi attenuated, and Klebsiella oxytoca for microbial susceptibility using the agar well diffusion method. Additionally, the antioxidant profile of the methanolic extracts were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic) acid (ABTS) scavenging activities, and ferric-reducing antioxidant potential (FRAP) assays, while the total polyphenolic content was determined using the Folin–Ciocalteau reagent. G. afzelii and A. indica stem demonstrated the highest antimicrobial effect, inhibiting the growth of all test organisms. Additionally, the extracts demonstrated high antioxidant potential and were found to possess significant amounts of phenolic compounds. Therefore, methanolic extracts of G. afzelii and A. indica stem are promising candidates for the identification of safe novel compounds to mitigate diarrheal diseases.

Evaluation of Phytochemical, Antioxidant, and Memory-Enhancing Activity of Garuga pinnata Roxb. Bark and Bryophyllum pinnatum (Lam) Oken. Leaves

Garugapinnata Roxb. (Burseraceae) is a medium-sized tree widely available all over the tropical regions of Asia. Bryophyllum pinnatum (Lam) Oken. (Crassulaceae) is an indigenous and exotic plant grown in tropical regions. Both plants have been used for their anti-inflammatory, antioxidant, anticancer, wound healing, antidiabetic activities, etc. This investigation was designed to explore the result shown by methanolic extract of Garuga pinnata bark and Bryophyllum pinnatum leaves, on cognitive power and retention of the memory in experimental mice along with quantification of phenolic compounds and DPPH radicals neutralizing capacity. The memory-enhancing activity was determined by the elevated plus-maze method in Scopolamine-induced amnesic mice, using Piracetam as allopathic and Shankhpushpi as ayurvedic standard drugs. Two doses (200 and 400 mg/kg p.o.) of both extracts were administered to mice up to 8 consecutive days; transfer latency of individual group was recorded after 45 minutes and memory of the experienced things was examined after 1 day. DPPH assay method and the Folin–Ciocalteu method were employed to determine antioxidant potency and total phenol amount, respectively. 400 mg/kg of the methanolic B. pinnatum bark extract significantly improved memory and learning of mice with transfer latency (TL) of 32.75 s, which is comparable to that of standard Piracetam (21.78 s) and Shankhpushpi (27.83 s). Greater phenolic content was quantified in B. pinnatum bark extract (156.80 ± 0.33 µg GAE/mg dry extract) as well as the antioxidant potency (69.77% of free radical inhibition at the 100 µg/mL concentration). Our study proclaimed the scientific evidence for the memory-boosting effect of both plants.