Ruellia tuberosa L. Extract Improves Histopathology and Lowers Malondialdehyde Levels and TNF Alpha Expression in the Kidney of Streptozotocin-Induced Diabetic Rats

Crude extract of Ruellia tuberosa L. flower induces intracellular ROS, promotes DNA damage and apoptosis in triple negative breast cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ruellia tuberosa L. (Acanthaceae) is a weed plant traditionally used in folklore medicine as a diuretic, anti-hypertensive, anti-pyretic, anti-cancerous, anti-diabetic, analgesic, and gastroprotective agent. It has been previously reported that R. tuberosa L. is enriched with various flavonoids, exhibiting significant cytotoxic potential in various cancer models but a detailed study concerning its molecular mechanism is yet to be explored.

AIM OF THE STUDY

Exploring and validating R. tuberosa L. flower methanolic extract (RTME) as an anti-cancerous agent as per traditional usage with special emphasis on multi-drug resistant human triple-negative breast cancer (TNBC) and investigating the possible signaling networks and regulatory pathways involved in it.

MATERIALS AND METHODS

In this study, RTME was prepared using methanol, and phytochemical analysis was performed through GC-MS. Then, the extract was tested for its anti-cancer potential through in-vitro cytotoxicity assay, clonogenic assay, wound healing assay, ROS generation assay, cell cycle arrest, apoptotic nuclear morphology study, cellular apoptosis study, mitochondrial membrane potential (MMP) alteration study, protein, and gene expressions alteration study. In addition, toxicological status was evaluated in female Balb/C mice, and to check the receptor-ligand interactions, in-silico molecular docking was also conducted.

RESULTS

Several phytochemicals were found within RTME through GC-MS, which have been already reported to act as ROS inductive, DNA damaging, cell cycle arresting, and apoptotic agents against cancer cells. Moreover, RTME was found to exhibit significant in-vitro cytotoxicity along with a reduction in colony formation, and inhibition of cell migratory potential. It also induced intracellular ROS, promoted G0/G1 cell cycle arrest, caused mitochondrial membrane potential (MMP) alteration, and promoted cell death. The Western blot and qRT-PCR data revealed that RTME promoted the intrinsic pathway of apoptosis. Furthermore, blood parameters and organ histology on female Balb/C mice disclosed the non-toxic nature of RTME. Finally, an in-silico molecular docking study displayed that the three identified lead phytochemicals in RTME show strong receptor-ligand interactions with the anti-apoptotic Bcl-2 and give a clue to the possible molecular mechanism of the RTME extract.

CONCLUSIONS

RTME is a potential source of several phytochemicals that have promising therapeutic potential against TNBC cells, and thus could further be utilized for anti-cancer drug development.

Microencapsulation of Ruellia tuberosa L. Aqueous Root Extracts Using Chitosan-Sodium Tripolyphosphate and Their In Vitro Biological Activities

The current study aims to perform microencapsulation of R. tuberosa L. extracts using chitosan crosslinked to sodium tripolyphosphate (NaTPP) as wall materials by spray drying and to analyze their in vitro biological activities. The influence of manufacturing conditions, like pH, chitosan concentration, and stirrer time, was assessed. Results showed that microcapsules prepared in pH 4 with a concentration of 0.1% (w/v) chitosan, and 90 min stirring time had 51.80% encapsulation efficiency and high in vitro biological activity. These were shown by high in vitro alpha amylase inhibition and antioxidant activity with IC₅₀ values of 50.65 μg/mL and 123.97 μg/mL, respectively. Releases of the bioactive compounds in microcapsules of R. tuberosa L. were carried out on phosphate buffer medium pH 2.2 and pH 7.4 with times release of 30, 60, 90, and 120 min. The bioactive compounds were released in pH 2.2 in 120 min at 2.48%. At pH 7.4, the active ingredients were more easily released, by 79.90% in 120 min. The microcapsules' morphology showed a rough surface with spherical forms and the average sizes were 53.41 μm. This study supports the essential role of microencapsulation in improving plant extracts with reserved biological activities.

Histopathological Profiles of Rats (Rattus norvegicus) Induced with Streptozotocin and Treated with Aqueous Root Extracts of Ruellia tuberosa L

Diabetes mellitus (DM) is a serious worldwide health threat since the number of people with DM is forecasted to grow annually. Thus, effective and affordable treatment is urgently needed. Our previous studies used n-hexane and hydroethanolic root extracts of Ruellia tuberosa L. which significantly affected diabetic rats. In this study, aqueous R. tuberosa L. root extracts were used as treatments for the diabetic rat model and their effects were evaluated. Diabetes was generated by the administration of streptozotocin (STZ) at 20 mg/kg within 5 sequential days. Male Wistar rats were orally treated with the extracts and standard drug (metformin 200 mg/kg) and vehicle every day for 4 weeks. Hypoglycemic effects were assessed for normal, diabetic control, standard, and extract-treated groups. Histopathology was also carried out for the pancreatic, hepatic, and kidney tissues. The progression of diabetes was considerably diminished after extract treatment. In treated rats, the highest dose of extract induced a decline in blood glucose and serum malondialdehyde (MDA) levels at 25% and 35%, respectively. Furthermore, aqueous extract of R. tuberosa L. treatment decreased MDA levels in the pancreas by 12%. Histologic examination of the organ tissues of diabetic rats showed deteriorating alterations. After treatment, histopathological damages to the tissues and cells were reversed. The results of the experiments recommend that aqueous extract of R. tuberosa L. has antidiabetic effects on STZ-induced diabetic rats; nevertheless, a higher dose of the aqueous extracts is needed to achieve more significant results.