Chemical Analysis on Two Traditional Decoctions for Diabetes Mellitus

Introduction

Type 2 Diabetes Mellitus (T2DM) is a chronic, progressive, metabolic condition, chiefly characterized by hyperglycemia due to endocrine dysfunction. This is an epidemic, affecting people globally as lifestyle modifications. Most important insulin disturbance affects to the muscles, liver and adipose tissue. Autoimmune processes, virus infections and genetic factors have been discussed as possible causes of diabetes, but the etiology of the disease is so far not settled [1, 2]. Even in properly treated cases, diabetes mellitus (DM) is accompanied by number of complications and the severity increases with the duration of the disease and the degree of metabolic disorders. The clinical symptoms and signs are most often to be found in eyes, kidneys, heart and lower extremities. The chronic metabolic imbalance associated with this disease puts patients at high risk for long-term macro- and microvascular complications, which if not provided with high quality care, lead to frequent hospitalization and complications, including elevated risk for cardiovascular diseases [3]. DM is also associated with symptoms such as polyuria, fatigue, weight loss, delayed wound healing, blurred vision, increment of glucose level in urine, etc [4]. Glucose level fluctuations in the blood also responsible for the occurrence and development of diabetes complications [5]. T2DM is rapidly growing health concern in both developed and developing countries. According to the World Health Organization (WHO), in 2011, approximately 364 million people globally suffer from diabetes (DM), with projections that DM-related deaths will double from 2005 to 2030 [6]. To achieve good metabolic control in diabetes and keep long term, a combination of changes in lifestyle and pharmacological treatment is necessary.

Ayurveda is the major traditional system practiced in Sri Lanka and basically relies on medicinal plants. Many traditional recipes have been using to treat DM in Sri Lanka and most of them are documented in Ayurvedic texts such as “Talpate Piliyam” [7]. In the present study, an attempt was taken to assess the quality and antioxidant potential of two traditional decoctions (Table 1) given to T2DM patients.

Results and Discussion

The demand of the herbal drugs is increasing worldwide generally and particularly in the developed countries but one of the drawbacks in its acceptability is lacking of proper standardization procedure. Purity, safety, potency and efficacy are four main pillars of herbal drug standardization. Many efforts have been taken to standardize herbal medicinal preparations- Vipadikahara Grita Taila [13] and decoctions [14, 15] in Sri Lanka. In the present study two traditional decoctions were evaluated for phytochemicals in terms of qualitative and quantitative analysis and developed TLC fingerprints. Results revealed that phytochemicals- phenols, flavonoids, tannins, alkaloids, saponins, steroids and terpenoids are present in both traditional decoctions. It is well documented that phytochemicals play a major role in the control of DM [16, 17]. Therefore, presence of phenols, flavonoids, tannins, alkaloids, saponins, steroids and terpenoids may responsible in control of DM. TLC is one of the basic, cheap and simple analytical techniques to standardize herbal drugs. Individual compound/mixture of compounds in a TLC fingerprint profile appear as spots and each spot has a retention factor (Rf) which is equal to the distance migrated over the total distance covered by the solvent. In the present study also Rf values were recorded for both decoctions (Table 2).

Antioxidant potential was evaluated for both decoctions using DPPH assay, total polyphenol content and total flavonoid content. An antioxidant capacity of each decoction was expressed in terms of IC50 value and low IC50 value corresponds to a high antioxidant capacity. DPPH is a stable radical which gives a dark purple color at 517 nm. When DPPH radical react with an antioxidant, its purple colour is disappeared and gives pale yellow colour at 517 nm [18]. The total polyphenolic and flavonoid contents in traditional decoction 2 (total phenols: 236.0 ± 1.6 mg gallic acid equivalents/g of extract; total falvonoids: 53.8 ± 0.8 mg quercetin/g of extract respectively) was higher than that of traditional decoction 1(total phenols: 176.5 ± 2.1 mg gallic acid equivalents/g of extract; total falvonoids: 41.2 ± 1.2 mg quercetin/g of extract respectively). In addition, IC50 value is lesser (6.40 ± 0.60 µg/ml) in traditional decoction 2 for DPPH assay, compared to that of traditional decoction 1 (10.52 ± 0.35 µg/ml). High content of phenols and flavonoids present in traditional decoction 2 may contribute for better scavenging ability of DPPH radicals. Four medicinal plants (T. chebula, T. bellerica, P. emblica and C. auriculata) are common to both decoctions and difference in antioxidant activity may be due the other plant/s present in decoction 1 and 2 or synergistic activity.

In conclusion, in the present study, phytochemicals and antioxidant potential was evaluated for two traditional decoctions used for DM. In vitro studies suggest that traditional decoction 2 is the best in terms of antioxidant activity. Further, this can be confirmed by conducting a clinical trial in between two decoctions.