Antihyperglycemic, Hypolipidemic and Antioxidant Enzymes Effect of Strobilanthes crispus Juice in Normal and Streptozotocin-Induced Diabetic Male and Female Rats

Anticancer Properties of Strobilanthes crispus: A Review

Cancer is a major cause of death worldwide, as exemplified by millions of cancer diagnoses every year. The use of chemotherapy in treating cancer has many disadvantages which include recurrence of cancer, associated with drug resistance, and severe side effects that are harmful to the patients. A better source of anticancer drugs can come from nature. Strobilanthes crispus (S. crispus) is a herbal medicinal plant that is indigenous in Madagascar and the Malay Archipelago. The plant possesses high vitamin and mineral content as well as phytochemicals—like phenols, catechins, tannins, and flavonoids—that are known to have therapeutic effects. Numerous preclinical studies have reported very versatile pharmacological effects of this plant, such as anticancer, antimicrobial, antioxidant, anti-angiogenesis, anti-diabetes, anti-ulcerogenic, and wound healing. Herein, this paper reviews the anticancer properties of S. crispus, providing information for future research and further exploration.

Phytochemical constituents and biological activities of different extracts of Strobilanthes crispus (L.) Bremek leaves grown in different locations of Malaysia

Background

Strobilanthes crispus is a well-known herb in Malaysia with various pharmaceutical properties. S. crispus is known to contain several biologically active chemical constituents which are responsible for its pharmaceutical quality.

Methods

Strobilanthes crispus leaves grown in three different locations in Malaysia [Kelantan (North-east), Selangor (Central), and Penang (North)], were investigated for differences in the content of secondary metabolites [total phenolics content (TPC), total flavonoids content (TFC), and total saponins content (TSC)] as well as for their antioxidant and anticancer properties. Phenolic acids and flavonoids were identified using ultra-high performance liquid chromatography (UHPLC). Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to evaluate the antioxidant activities. The anticancer activity of extracts against HeLa cancer cell line was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.

Results

Samples from the three different locations when extracted with two solvents (aqueous and ethanol extracts) yielded significantly different results for TPC, TFC, and TSC as well as for antioxidant activity. Aqueous extract of S. crispus leaves collected from Kelantan exhibited the highest values: TPC [12.62 mg gallic acid equivalents (GAE)/g dry matter (DM)], TFC (7.44 mg quercetin equivalents (QE)/g DM), TSC (44.7 mg diosgenin equivalents (DE)/g DM), DPPH (73.8 %), and FRAP (267.5 μM of Fe (II)/g) activity with a half-maximal inhibitory concentration (IC₅₀) of 44.1 μg/mL compared to the extracts of leaves collected from the other two locations. The most important secondary metabolites identified in this study, based on concentration, were phenolics classified as followed: caffeic acid>ferulic acid>gallic acid>chlorogenic acid>trans-cinnamic acid; flavonoids: quercetin>rutin>catechin>apigenin>naringenin>kaempferol. Extracts of leaves collected from Kelantan exhibited better anticancer activity against HeLa cancer cell line with an IC₅₀ of 182.5 μg/mL compared to the extracts of leaves from Selangor (IC₅₀ = 266.4 μg/mL) and Penang (IC₅₀ = 331.5 μg/mL) and to tamoxifen (IC₅₀ = 63.4 μg/mL). S. crispus leaves with the highest content of secondary metabolites exhibited the most potent antioxidant and anticancer activity.

Conclusions

Therefore, based on the potent antioxidant and anticancer activity of leaves extracts, it appears that S. crispus grown in the North-east of Malaysia (Kelantan) is a potential source of anticarcinogenic therapeutic compounds.

Subacute oral toxicity study of ethanolic leaves extracts of Strobilanthes crispus in rats

OBJECTIVE

To examine the oral toxicity of repeated dosing of Strobilanthes crispus (S. crispus) ethanol leaves extract on the liver and kidney functions in Sprague Dawley rats.

METHODS

Young female rats aged between 8 and 12 week-old were randomly assigned into four groups with five animals each group (n=5). The first group served as control, while the second, third and fourth groups were orally treated with a single dose daily with 150 mg/kg, 300 mg/kg, and 600 mg/kg of S. crispus ethanol leaves extract for 14 d consecutively. Cage-side observation was conducted for first 4 h after each dosing. The body weight changes, food consumptions and water intake were also recorded. Serum biochemical parameters, i.e., aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine and urea were determined at Day 15. All results were expressed as mean±SD and analysed using Dunnett's test.

RESULTS

It was obtained that 14-day oral administration of S. crispus ethanol leaves extract did not cause any adverse effects or lethality to the female Sprague Dawley rats. No significant changes in serum biochemical parameters, relative organs weights, body weights, food intake and water consumptions were observed between the treatment groups and control.

CONCLUSIONS

In conclusion, 14-day oral administration of S. crispus ethanol leaves extract was safe to be consumed in female rats without affecting the liver and kidney functions.

Antioxidant, total phenolic content and cytotoxicity evaluation of selected Malaysian plants

Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus, Andrographis paniculata, Curcuma xanthorrhiza, Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed that ethanol extracts contain high antioxidant activities compared to aqueous extracts. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, all the plant extracts showed non-toxic effects against a normal human lung fibroblast cell line (Hs888Lu). Although traditionally aqueous extracts are used, we determined that ethanol extracts usually achieved better activity in the assays.