Phytochemical competence and pharmacological perspectives of an endangered boon—Costus speciosus (Koen.) Sm.: a comprehensive review

Background Costus speciosus (Koen) Sm. popularly known as crepe ginger or spiral ginger and insulin plant is a perennial rhizomatous herb contain variable number of medicinally important bioactive phytochemicals having intensive pharmacological effects due to antioxidant, antimicrobial, insecticidal, anticancerous, and antidiabetic properties. This plant is widely distributed throughout India and has tremendous ethnobotanical uses. This review article is the coalescence of the distribution, morphology, phytochemistry, pharmacology, effect, and mode of action of pharmacologically active principles of Costus speciosus. Main body The therapeutic potential possessed by the plant is mainly the attribution of the bioactive compounds such as phenolics, steroids, alkaloids, flavonoids, saponins, terpenoids, and tannins, which are found to be present in different parts of the plant. Bioactive constituents like diosgenin, gracillin, dioscin, prosapogenins A and B of dioscin, eremanthin, costunolide, β-sitosterol, β-D-glucoside, β-carotene, α-tocopherol quinine, dihydrophytylplastoquinone, 5α-stigmast-9(11) en3β-ol, tetracosanyl octadecanoate, methyl hexadecanoate, methyl octadecanoate, cycloartenol, cycloartanol, and cycloalaudenol are specifically found in C. speciosus. This review also focuses on the possible mechanisms followed by these bioactive compounds while exhibiting various pharmacological properties. Because of the presence of diosgenin, this plant is given the name “insulin plant.” Diosgenin along with an important sesquiterpene, costunolide, performs significantly high antioxidant, anticancer, and antidiabetic activities. Besides these properties, insecticidal, antifungal, antibacterial, and anthelminthic properties have also been discussed. This plant needs to be given more emphasis as it is exploited at the commercial level by the pharmaceutical industries, conservation status is getting poorer, and it is already in a near-threatened state. Therefore, more systematic and intensive research should be done in a sustainable manner. Conclusion Spiral ginger plant shows diverse pharmacological effects due to presence of variety of bioactive phytochemicals, but the compounds like diosgenins, costunolides, eremanthin, and arbusculin are highly specific that exhibit effective antidiabetic, anticancerous, and antioxidative properties through different mechanism. Thus, C. speciosus can be exploited as an economically sustainable source of effective drugs against deadly diseases like diabetes and cancers with less or no side effects, and further research is needed to explore the intricacy of its pharmacological actions with human trials. Graphical Abstract

In Vitro Interactions of Costus speciosus (J. Koenig) Sm., Cymbopogon citratus (Dc. Ex Nees) Stapf. and Tabernaemontana coronaria (L.) Willd. with First-Line Anti-Tuberculosis Drugs Against Mycobacterium tuberculosis H37rv

Global tuberculosis (TB) burden underscores the importance of developing new effective anti-TB drugs. This study was concerned with prospecting for potential anti-TB agents from Malaysian medicinal plants. In our previous study, we have reported that n-hexane fractions of Costus speciosus (C. speciosus) (J. Koening) Sm., Cymbopogon citratus (C. citratus ) (DC.) Stapf. and Tabernaemontana coronaria (T. coronaria) (Jacq.) posses promising anti-TB activity against Mycobacterium tuberculosis (M. tuberculosis) H37Rv with minimum inhibitory concentrations (MICs) of 200–100 µg/mL. This study aimed to investigate the interactions of these active fractions with first-line anti-TB drugs (isoniazid, rifampicin, ethambutol and streptomycin) against M. tuberculosis H37Rv using the microdilution checkerboard method. C. citratus (stem-rhizome) n-hexane fraction exhibited synergism with all drugs except ethambutol which showed additive interaction. Synergistic was also observed when C. speciosus (stem-flower) n-hexane and T. coronaria (leaf) n-hexane fractions in combination with rifampicin. C. speciosus (stem-flower) n-hexane and T. coronaria (leaf) n-hexane exhibited additive interaction with isoniazid, ethambutol and streptomycin. Hence, these active plants are worthy of further investigations for the discovery of anti-TB drug leads.

Traditional Usage of Plants of Costus Species in Assam, India

Customary use of plants in the treatment of ailments in Assam, India is a typical situation. Ethno medicinal study was led in a few topographically unique zones of the state and utilization of plants from Costus species were reported. The extent of study chose for the investigation range across seven organizational regions spread across Assam, India. The regions include Dibrugarh, Golaghat, Tinsukia, Dhemaji, Karbi Anglong, Goalpara and Kokrajhar. Different plants were reported and plants fitting with the said species were chosen for determining the relevance concerning its use in customary medication. The survey divulged that plants associated to three species of the genus Costus namely Costus speciosus, Costus pictus and Costus scaber were espied to be primarily ubiquitous in traditional medicine in the discrete contemplated regions. The species were predominantly utilized as prime ingrediants in hepatoprotactive and anti-diabetic formulations. Costus speciosus was perceived to be chiefly used in the treatment of hepatic disorders and ailments. Costus pictus was observed to be used customarily in the upper Assam region bordering Nagaland for treating diabetes and Costus scaber was being used in the area bordering Arunachal Pradesh for tending people with jaundice, snake bite etc. The research climaxed with the profiling of the costus species as annotated from the ethnomedicinal survey.

Adverse Effect of Rheumatoid Arthritis on Male Wistar Rat’s Fertility: Protective Role of Costus Extract

Rheumatoid arthritis (RA) is an autoimmune systemic complaint. Costus speciosus, an ornamental plant, which traditionally used in urinary diseases, rheumatism, jaundice and dropsy. The purpose of the study is to assess the protective effect of Costus on rheumatoid arthritis induced male rat in fertility. Thirty male adult Wistar rats (190-200 g) were sectioned into 6 groups. They were subdivided into 3 groups; group 1 was control received Distilled water, groups II and III received two various doses of Costus extract (200 and 400 mg/kg, respectively) for 60 days. Another 3 groups were subjected to RA induction via Freund's adjuvant. First group of RA induced rats was given Distilled water. Other two groups were given orally (200 and 400 mg/kg dosage of extract, respectively) from the 2nd day of RA induction for 60 days. Sex organ relative weight, sperm concentration assay, testicular histopathology and immunohistochemistry of androgen receptors, TNF α and Bax protein were determined. Rheumatoid arthritis caused significant decrease in relative weight of sex organs which relatively improved by doses of Costus (200, 400 mg/kg). In addition, RA caused a significant reduction in sperm count which was improved via Costus (200, 400 mg/kg). RA induction caused testicular degeneration with marked depletion of spermatozoa, which markedly improved with costus treatment as shown in histopathological sections. Rheumatoid arthritis caused a reduction in %IHC of androgen receptors and increase of %IHC of both TNF α and Bax protein. Costus (200, 400 mg/kg) significantly improved %IHC of androgen receptors and significantly decreased %IHC of both TNF α and Bax protein, in RA induced groups. We can concluded that Costus speciosus had potentially useful role in improving fertility disorders caused by RA.