Comparative Antidiabetic Activity of Neomarica Gracilis and Codiaeum Variegatum Leaf Extracts in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus is a chronic metabolic disorder in which persistent hyperglycaemia is accompanied by disturbances in lipid and protein metabolism. Oxidative stress and progressive tissue injury contribute to the complications associated with prolonged metabolic dysregulation. The supplied thesis identifies herbal preparations as a research area of interest and emphasizes simultaneous assessment of efficacy, safety and formulation quality. [1,2] N. gracilis and C. variegatum were selected for comparative investigation. Preliminary screening in the thesis detected alkaloids, glycosides, carbohydrates, proteins/amino acids, flavonoids and phenolic compounds in both extracts; saponins, triterpenoids and steroids were additionally detected in C. variegatum. [3,4] The study therefore moved from extract preparation and phytochemical characterization to pharmaceutical suspension development and evaluation, acute oral toxicity, streptozotocin-induced diabetes, 21-day treatment and pancreatic histopathology. The stated objective was to compare the two individual formulations and their combined preparation against a standard antidiabetic drug. [3,5]

2. MATERIALS AND METHODS

2.1 Ethical approval, animals and housing

Animal experiments were reported as approved by the Institutional Animal Ethics Committee (CCSEA approval PBRI/IAEC/21042026/008). Male Wistar albino rats aged 2–3 months were maintained under standard conditions with a 12-h light/dark cycle, standard chow and water, after acclimatization.

2.2 Extraction and phytochemical analysis

Leaves were dried, powdered and extracted separately in a Soxhlet apparatus using 70% ethanol (ethanol:water 70:30) for approximately 6–8 h or until the siphoning solvent became colourless. Filtrates were concentrated under reduced pressure below 50°C, dried and stored at 4–8°C. Yield was calculated as extract weight divided by starting plant-material weight ×100. [5] Qualitative screening covered alkaloids, glycosides, carbohydrates, proteins/amino acids, flavonoids, tannins/phenolics, saponins, triterpenoids and steroids using standard colour/precipitation reactions. [6] TPC was determined by the Folin–Ciocalteu method using gallic acid standards (10–100 µg/mL), 10% Folin–Ciocalteu reagent and 7.5% sodium carbonate; absorbance was measured at 765 nm and expressed as mg GAE/g extract. TFC used rutin standards (10–100 µg/mL), 2% aluminium chloride and absorbance at 415 nm, expressed as mg RE/g. [6,7]

2.3 Suspension formulation and evaluation

Extract	TPC (mg GAE/g)	TFC (mg RE/g)
N. gracilis	26.52	25.25
C. variegatum	44.92	44.25

Figure 1. Total phenolic and flavonoid contents.

Figure 2. Effect of Formulation I (Neomarica Gracilis) Formulation II (Codiaeum Variegatum) And Formulation III (Polyherbal Combination) On Body Weight of The Rats

Blood Glucose Level (gms)
Groups	Treatments	1 day	3 days	7 days	14 days	21 days
Group 1	Normal control	87.09 ± 0.194	86.47 ± 0.210	88.99 ± 0.336	87.99 ± 0.196	89.78 ± 0.271
Group II	Diabetic control (Streptozocin) 50 mg/kg	156.89 ± 0.181	179.89 ± 0.262	199.78 ± 0.240	239.67 ± 0.308	258.91 ± 0.230
Group III	Glibenclamide (10 mg/kg)	94.07 ± 0.228	93.78 ± 0.106	95.89 ± 0.498	92.91 ± 0.289	95.80 ± 0.095
Group IV	Formulation I (Neomarica gracilis)	105.69 ± 0.097	103.91 ± 0.603	108.99 ± 0.203	112.91 ± 0.237	109.47 ± 0.210
Group V	Formulation II (Codiaeum variegatum)	110.99 ± 0.371	112.79 ± 0.275	109.45 ± 0.222	118.23 ± 0.258	116.79 ± 0.360
Group VI	Formulation III (Polyherbal suspension)	99.85 ± 0.220	98.10 ± 0.200	99.05 ± 0.180	98.20 ± 0.250	102.05 ± 0.210

Fig 3: Effect of Formulations on Blood Glucose Level of the rats

Treatment Groups	TG (g/L)	TC (g/L)	HDL (g/L)	LDL (g/L)
Normal control	58.90 ± 1.18	80.45 ± 0.92	46.10 ± 0.30	22.90 ± 0.78
Diabetic control (Streptozocin) 50 mg/kg	172.80 ± 2.10	183.90 ± 2.65	19.85 ± 0.58	118.40 ± 1.70
Glibenclamide (10 mg/kg)	63.20 ± 1.50	84.10 ± 1.45	41.10 ± 0.35	27.40 ± 0.92
Formulation I (Neomarica gracilis)	79.40 ± 1.88	99.20 ± 2.02	22.20 ± 0.44	46.10 ± 1.20
Formulation II (Codiaeum variegatum)	74.60 ± 1.92	96.10 ± 2.08	27.80 ± 0.50	39.10 ± 1.22
Formulation III (Polyherbal suspension)	68.80 ± 1.55	91.20 ± 1.48	34.90 ± 0.40	36.20 ± 1.05

Fig4: Graphical representation of effect of Formulations on Biochemical Parameters of the rats

Figure 5: Histopathological Examination of Pancreas

Pancreatic microscopy showed preserved islets in the normal group, marked degeneration in the diabetic control, substantial restoration after glibenclamide, moderate improvement with F-I, better preservation with F-II and the most prominent herbal architectural recovery with F-III.

G-1 (Normal): Normal pancreatic architecture with well-defined and intact islets of Langerhans and normal cellular arrangement.

G-2 (Inducer): Marked degeneration and disorganization of the islets of Langerhans with noticeable pancreatic tissue alterations.

G-3 (Standard): Considerable restoration of pancreatic architecture with improved organization of the islets and reduced degenerative changes.

G-4 (Formulation I): Moderate improvement in islet structure with reduced cellular degeneration compared with the inducer group.

G-5 (Formulation II): Improved pancreatic architecture with better preservation and organization of the islets.

G-6 (Polyherbal suspension): Greater preservation of pancreatic architecture and islet organization, showing the most prominent improvement among the herbal treatment groups.

Overall, the histological findings indicate that the treatments, particularly the polyherbal suspension, provided protective effects against diabetes-induced pancreatic damage

DISCUSSION

The findings form a consistent comparative pattern. C. variegatum had both a slightly higher extraction yield and substantially greater measured phenolic/flavonoid content. This does not by itself establish causality, but it provides a plausible compositional distinction between the two extracts. The broader qualitative profile of C. variegatum, including saponins and triterpenoid/steroidal reactions, further differentiates it from N. gracilis. [3,4,6,7] Formulation performance was satisfactory across all preparations. The polyherbal suspension did not show evidence of impaired physical stability and had the highest reported sedimentation volume and viscosity. The combination therefore retained acceptable pharmaceutical characteristics while allowing the pharmacological effects of the two extracts to be evaluated together. [8,9] The in-vivo data provide the strongest evidence for the comparative advantage of F-III. The diabetic-control glucose value increased from 156.89 to 258.91 across the study, while F-III remained close to 100–102 in the reported numerical scale. F-I and F-II also showed clear improvement but were less consistent with the standard group. The lipid findings followed the same direction, with F-III showing the best herbal HDL value and lower TG, TC and LDL than the individual preparations. [11,12,13] The pancreatic findings provide structural support for the biochemical pattern. Greater preservation of islet organization in F-III suggests that the combined preparation was associated with less apparent STZ-related pancreatic damage than the individual herbal formulations. The thesis attributes the stronger combined effect to complementary or synergistic phytoconstituent actions; this remains a hypothesis because the present work did not directly measure molecular mechanisms, insulin secretion or individual active constituents. [12,13] The findings demonstrate that all tested formulations possessed antidiabetic potential, with Formulation III (polyherbal suspension) showing superior overall activity. Its better performance in controlling body weight, reducing hyperglycemia, and improving lipid abnormalities suggests a possible synergistic or complementary effect of Neomarica gracilis and Codiaeum variegatum. These findings support the potential use of the combined formulation for further investigation as a herbal antidiabetic preparation.

CONCLUSION

N. gracilis and C. variegatum hydroalcoholic leaf extracts were successfully formulated as individual and combined suspensions. C. variegatum showed higher phenolic and flavonoid contents, while all formulations demonstrated acceptable short-term physical stability and no mortality during acute toxicity testing up to 2000 mg/kg. In streptozotocin-induced diabetic rats, all herbal preparations improved glucose and lipid outcomes, with the 1:1 polyherbal suspension showing the strongest overall response and the most favourable pancreatic histological appearance. Overall, the study supports the potential of the Neomarica gracilis–Codiaeum variegatum polyherbal formulation as a promising herbal antidiabetic preparation. However, further studies involving detailed mechanistic investigations, long-term toxicity assessment, dose optimization, and clinical evaluation are required to establish its therapeutic efficacy and safety.

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